Les escargots terrestres

[1] - Taylor SL. Molluscan shellfish allergy. Adv Food Nutr Res 2008;54:139-177

Food allergies affect approximately 3.5-4.0% of the worldwide population. Immediate-type food allergies are mediated by the production of IgE antibodies to specific proteins that occur naturally in allergenic foods. Symptoms are individually variable ranging from mild rashes and hives to life-threatening anaphylactic shock. Seafood allergies are among the most common types of food allergies on a worldwide basis. Allergies to fish and crustacean shellfish are very common. Molluscan shellfish allergies are well known but do not appear to occur as frequently. Molluscan shellfish allergies have been documented to all classes of mollusks including gastropods (e.g., limpet, abalone), bivalves (e.g., clams, oysters, mussels), and cephalopods (e.g., squid, octopus). Tropomyosin, a major muscle protein, is the only well-recognized allergen in molluscan shellfish. The allergens in oyster (Cra g 1), abalone (Hal m 1), and squid (Tod p 1) have been identified as tropomyosin. Cross-reactivity to tropomyosin from other molluscan shellfish species has been observed with sera from patients allergic to oysters, suggesting that individuals with allergies to molluscan shellfish should avoid eating all species of molluscan shellfish. Cross-reactions with the related tropomyosin allergens in crustacean shellfish may also occur but this is less clearly defined. Occupational allergies have also been described in workers exposed to molluscan shellfish products by the respiratory and/or cutaneous routes. With food allergies, one man's food may truly be another man's poison. Individuals with food allergies react adversely to the ingestion of foods and food ingredients that most consumers can safely ingest (Taylor and Hefle, 2001). The allergens that provoke adverse reactions in susceptible individuals are naturally occurring proteins in the specific foods (Bush and Hefle, 1996). Molluscan shellfish, like virtually all foods that contain protein, can provoke allergic reactions in some individuals.

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[2] - Pumphrey RS. Fatal anaphylaxis in the UK, 1992-2001. Novartis Found Symp 2004;257:116-128

Each year in the UK, around nine deaths are attributed to anaphylaxis to pharmaceuticals, six to food and four to stings. I have identified 214 deaths associated with anaphylaxis, and have sufficient information for 196 to determine that 88 deaths were due to shock, 96 to asphyxia. Five deaths followed epinephrine overdose, seven were complicated by disseminated intravascular coagulation. There will have been other unrecognized fatal antibiotic and asthmatic food reactions. For foods, peak age was 17-27 with a female and atopic predominance; the first arrest was commonly from asthma 25-35 minutes after the implicated food. For stings, peak age was 45-70 with male and non-atopic predominance; death was commonly from shock 10-15 minutes after the sting. A majority of deaths from pharmaceuticals in hospital took 5 minutes or less from dose to arrest; peak age was 60-75. Maximum time for any cause from trigger to first arrest was 6 hours. The danger of epinephrine overdose and its limitations in reversing anaphylaxis must be recognized. The patient should remain supine with legs raised throughout sting and other shock reactions. Prevention of fatal food reactions will depend on avoidance and optimal daily control of asthma.

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[3] - Wu AY, Williams GA. Clinical Characteristics and Pattern of Skin Test Reactivities in Shellfish Allergy Patients in Hong Kong. Allergy Asthma Proc 2004;25:237-242

Allergens from crustaceans and mollusks exhibit extensive cross-reactivity in vitro. However, the degree and pattern of crossreactivity between different shellfish species in vivo is still unclear. The objective of this study was to determine the clinical characteristics of shellfish allergic patients in Hong Kong and the pattern of skin test reactivities to the different species. This cohort study involves patients attending the allergy clinic of a large teaching hospital for suspected shellfish allergy. Each subject underwent skin-prick tests to eight species of shellfish and house-dust mites. Eighty-four consecutive patients were tested. Twenty-eight patients reported a history of severe anaphylaxis. Fourteen patients had no positive shellfish skin test and were excluded. There were 183 positive shellfish skin tests, with an average of 2.61 positive tests per subject. Ninety percent of subjects also had positive skin tests to house-dust mites. Overall, 65.7% of subjects had more than one positive skin test to shellfish. There were strong statistical associations between species belonging to the same order but also between some mollusks and crustaceans. We found a high degree of skin test cross-reactivity between different species of shellfish and between shellfish and house-dust mites. Therefore, patients with a history of shellfish allergy should be cautious with all types of shellfish.

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[4] - Tomas MR, Faria E, Alendouro P, Tavares B, Pereira C, Lourenço M, et al. Asthma induced by snail. Allergy 1997;52(suppl. 37):117

The allergic reactions to snail aren't frequent. We studied two male patients, 12 and 13 years old, with clinic suspicion of asthma crisis after eating snails. After clinic, laboratorial evaluation and basal respiratory function, the patients performed skin tests with battery of common inhalant and food allergens (prick) and two snail species (prick-prick test). The positive results were observed to house dust mites (Dermatophagoides pteronyssinus and farinae) and snails (Helix aspersa, Helix lactea). Then, the patients performed oral provocation test eating increasing doses of cooked snails under functional respiratory registration and clinic surveillance. In two cases the challenge was positive. After eating 75 gr, they presented asthma agudization with FEV, and MEFSo fall respectively 26,2% and 40% in the fvst case and 47.8% and 61,8% in the second. We studied the cutaneous sensitivity to snail in two control groups of asthmatic patients. One group included 19 allergies to house dust mites and the test was positive in 7 patients. In the second group the skin test to snail were negative in all 11 non allergic patients. The snail sensitization in allergic patients to house dust mites can be due to crossed-reactivity between antigenic structures of these allergens (probably by Dermafophagoides minor epitopes with snail antigenic components). Some authors consider possible the cross-reactivity with mites of the specie Riccardoella, a lung parasite of molluscs.

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[5] - van Ree R. Clinical importance of cross-reactivity in food allergy. Curr Opin Allergy Clin Immunol 2004;4:235-240

PURPOSE OF REVIEW: Review of recent developments in the field of cross-reactivity in food allergy and the clinical relevance of these developments. RECENT FINDINGS: New foods have been added to the list of Bet v 1 and profilin-related food allergies. Clinical relevance of cross-reactions based on recognition of carbohydrate determinants and profilin is limited for the population of pollen-allergic patients as a whole. For selected food allergic patients, however, N-glycans and particularly profilin are potentially of clinical relevance. Lipid transfer proteins have further been established as clinically more severe allergens in several foods. This severity is attributed to their stability to proteolysis and processing. Storage proteins of several nuts and seeds have been identified as important allergens, but cross-reactivity between storage proteins of different foods appears to be limited. Using cross-reactivity as the basis for immunotherapy in food allergy seems promising but needs confirmation by double-blind, placebo-controlled trials. SUMMARY: The continued identification and characterization of cross-reactive allergens facilitates the study of factors determining clinical relevance of cross-reactivity and of possible efficacy of immunotherapy in food allergy.

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[6] - Amoroso S, Cocchiara R, Locorotondo G, Parlato A, Lampiasi N, Albeggiani G, et al. Antigens of Euparipha pisana (snail). I. Identification of allergens by means of in vivo and in vitro analysis. Int Arch Allergy Appl Immunol 1988;85:69-75

The data obtained in this study suggest that eating Euparipha pisana (snail), a common food in Mediterranean countries, could give serious allergic reaction such as asthma. We describe here the identification and partial characterization of allergenic molecules form this new source. An aqueous extract of snail was obtained by homogenization in distilled water, centrifugation, dialysis and defatting with ethyl ether. Skin prick test (SPT) performed with the snail extract on 70 subjects allergic to the more common allergens of the Mediterranean area gave a SPT positivity in 61% of the subjects tested, with a mean value of histamine-equivalent prick (HEP) equal to 0.81 +/- 0.25 (n = 43), while no SPT-snail-positive reactions were obtained by using the same extract on 30 not allergic subjects. To ascertain if such a sensitivity was IgE-mediated, sera from SPT-snail-positive subjects were analyzed by RAST, coupling the snail extract to polystyrene balls and to paper discs. 19% of the sera tested were RAST-positive, mean value of binding 4.8 +/- 2.8% (n = 13), while when using sera from SPT-snail-negative subjects, the RAST mean value was 0.49 +/- 0.18% (n = 27). Histamine release (HR) was also performed. Basophils prepared from SPT-snail-positive subjects were incubated with a snail extract. All of the SPT-snail-positive subjects gave a significant value of HR, mean value 21.8 +/- 7% using 1 micrograms of snail extract (n = 16), while 1.41 +/- 1.1% (n = 10) was the mean value obtained when SPT-snail-negative subjects were analyzed

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[7] - Asturias JA, Eraso E, Arilla C, Gómez-Bayón N, Inácio F, Martínez A. Cloning, Isolation, and IgE-Binding Properties of Helix aspersa (Brown Garden Snail) Tropomyosin. Int Arch Allergy Immunol 2002;128:90-96

Background: Gastropod consumption is quite frequent in the Mediterranean countries and cross-reactivities with crustaceans have been described, but the mechanism of this allergenic cross-reactivity has not been studied in detail. This study aimed to produce recombinant Helix aspersa (brown garden snail) tropomyosin and investigate its implication for cross-reactivity among invertebrates. Methods: A tropomyosin-specific cDNA encoding H. aspersa tropomyosin was synthetized, and recombinant allergen was overexpressed in Escherichia coli as nonfusion protein. IgE-binding reactivity was studied by immunoblotting and immunoblot inhibition experiments with sera from snail-allergic patients. Results: Cloned brown garden snail tropomyosin shares high homology with other edible mollusk tropomyosins (84-69% identity) as well as with those from arthropods (65-62%), and less homology with vertebrate ones (56% identity). Tropomyosin reacted with 18% of the sera from patients with snail allergy. Inhibition experiments, using natural and recombinant tropomyosins, showed different degrees of cross-reactivity between invertebrate tropomyosins. Sera from snail-allergic subjects recognized tropomyosins in both mollusks and crustacean extracts. Conclusions: Tropomyosin represents a minor allergen in snail extracts, but it is clearly involved in invertebrate cross-reactivity

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[8] - Guilloux L, Vuitton DA, Delbourg M, Lagier A, Adessi B, Marchand CR, et al. Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (D. pteronyssinus) - II. In vitro study. Allergy 1998;53:151-158

Epidemiologic and in vitro data have shown that the association of house-dust mite (HDM) allergy and snail allergy in the same patients was due to cross-reactivity between HDM and snail allergenic components. However, the cross-reacting allergen(s) have not yet been identified. In vitro reactivity of seven patients' sera to the various extracts and hemolymph of four different Helix snail species was analyzed by IgE detection and immunodots and Western blots. Cross-reactivity between snails and Dermatophagoides pteronyssinus was assessed by immunodot and ELISA inhibition in two patients. Heterologous inhibition of the snail immunodot and ELISA was observed in one serum. Western blotting showed a specific binding on all four snail species extracts; molecular weights of snail allergens ranged from < 21 to 200 kDa. Marked individual differences were observed in the seven sera under study; most sera demonstrated IgE recognition of multiple bands, illustrating that no single allergen is responsible for cross-reactivity between snail and mite. These results confirm that cross-reactivity exists between snails of the Helix genus and HDM. This cross-reactivity, involving more than a single allergen, may be of clinical significance in atopic patients allergic to D. pteronyssinus. The identity of the cross-reacting allergens remains to be determined. Potential candidates include the thermostable minor allergens of D. pteronyssinus, tropomyosin and hemocyanin.

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[9] - Lourenço Martins LM, Peltre G, Fialho da Costa Faro CJ, Vieira Pires EM, Fernando da Cruz Inacio F. The Helix aspersa (Brown Garden Snail) Allergen Repertoire. Int Arch Allergy Immunol 2005;136:7-15

BACKGROUND: Ingestion of snails can induce strong asthmatic or anaphylactic responses, mainly in house-dust-mite-sensitized patients. The aim of this study was to identify the Helix aspersa (Hel a), Theba pisana (The p) and Otala lactea (Ota l) allergens and the extent of their cross-reactivity with the Dermatophagoides pteronyssinus (Der p) mite. PATIENTS AND METHODS: In 60 atopic patients, skin prick tests (SPT) to snail and D. pteronyssinus, total and specific IgE, specific IgE immunoblots, RAST and immunoblot inhibition assays were performed . RESULTS: Mean total IgE was >1,000 kU/l. Mean specific IgE (class 6 for Der p and class 2 for Hel a) SPT were positive in 44 patients for snail and in 56 for mite. Isoelectric focusing (IEF) and SDS-PAGE followed by immunoblotting of H. aspersa extract enabled the identification of 27 and 20 allergens, respectively. Myosin heavy chains from snails (molecular weight >208 kDa) disclosed two major allergens. Hel a and Der p RAST were strongly inhibited by their homologous extracts, with Hel a RAST being inhibited by the Der p extract to a much greater extent (72.6%) than the inverse (5.6%). A complete inhibition of the immunoblots by their homologous extract was obtained. However, Hel a extract did not inhibit Der p IEF separated recognition. On the other hand, mite extract extensively inhibited snail immunoblots from both IEF and SDS-PAGE separations. Immune detection on chicken, pig, rabbit, cow and horse myosins did not reveal any IgE cross recognition with snail . CONCLUSIONS: In most cases of snail allergy, mite appeared to be the sensitizing agent. Nevertheless, snails may also be able to induce sensitization by themselves. This hypothesis is supported by the finding of specific IgE to Hel a in 2 patients who did not show specific IgE to Der p, and one of them was suffering from asthma after snail ingestion.

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[10] - Guilloux L, Vuitton DA, Delbourg M, Lagier A, Adessi B, Marchand CR, et al. Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (D. pteronyssinus) - II. In vitro study. Allergy 1998;53:151-158

Epidemiologic and in vitro data have shown that the association of house-dust mite (HDM) allergy and snail allergy in the same patients was due to cross-reactivity between HDM and snail allergenic components. However, the cross-reacting allergen(s) have not yet been identified. In vitro reactivity of seven patients' sera to the various extracts and hemolymph of four different Helix snail species was analyzed by IgE detection and immunodots and Western blots. Cross-reactivity between snails and Dermatophagoides pteronyssinus was assessed by immunodot and ELISA inhibition in two patients. Heterologous inhibition of the snail immunodot and ELISA was observed in one serum. Western blotting showed a specific binding on all four snail species extracts; molecular weights of snail allergens ranged from < 21 to 200 kDa. Marked individual differences were observed in the seven sera under study; most sera demonstrated IgE recognition of multiple bands, illustrating that no single allergen is responsible for cross-reactivity between snail and mite. These results confirm that cross-reactivity exists between snails of the Helix genus and HDM. This cross-reactivity, involving more than a single allergen, may be of clinical significance in atopic patients allergic to D. pteronyssinus. The identity of the cross-reacting allergens remains to be determined. Potential candidates include the thermostable minor allergens of D. pteronyssinus, tropomyosin and hemocyanin.

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[11] - Asturias JA, Eraso E, Arilla C, Gómez-Bayón N, Inácio F, Martínez A. Cloning, Isolation, and IgE-Binding Properties of Helix aspersa (Brown Garden Snail) Tropomyosin. Int Arch Allergy Immunol 2002;128:90-96

Background: Gastropod consumption is quite frequent in the Mediterranean countries and cross-reactivities with crustaceans have been described, but the mechanism of this allergenic cross-reactivity has not been studied in detail. This study aimed to produce recombinant Helix aspersa (brown garden snail) tropomyosin and investigate its implication for cross-reactivity among invertebrates. Methods: A tropomyosin-specific cDNA encoding H. aspersa tropomyosin was synthetized, and recombinant allergen was overexpressed in Escherichia coli as nonfusion protein. IgE-binding reactivity was studied by immunoblotting and immunoblot inhibition experiments with sera from snail-allergic patients. Results: Cloned brown garden snail tropomyosin shares high homology with other edible mollusk tropomyosins (84-69% identity) as well as with those from arthropods (65-62%), and less homology with vertebrate ones (56% identity). Tropomyosin reacted with 18% of the sera from patients with snail allergy. Inhibition experiments, using natural and recombinant tropomyosins, showed different degrees of cross-reactivity between invertebrate tropomyosins. Sera from snail-allergic subjects recognized tropomyosins in both mollusks and crustacean extracts. Conclusions: Tropomyosin represents a minor allergen in snail extracts, but it is clearly involved in invertebrate cross-reactivity

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[12] - Lourenço Martins LM, Peltre G, Fialho da Costa Faro CJ, Vieira Pires EM, Fernando da Cruz Inacio F. The Helix aspersa (Brown Garden Snail) Allergen Repertoire. Int Arch Allergy Immunol 2005;136:7-15

BACKGROUND: Ingestion of snails can induce strong asthmatic or anaphylactic responses, mainly in house-dust-mite-sensitized patients. The aim of this study was to identify the Helix aspersa (Hel a), Theba pisana (The p) and Otala lactea (Ota l) allergens and the extent of their cross-reactivity with the Dermatophagoides pteronyssinus (Der p) mite. PATIENTS AND METHODS: In 60 atopic patients, skin prick tests (SPT) to snail and D. pteronyssinus, total and specific IgE, specific IgE immunoblots, RAST and immunoblot inhibition assays were performed . RESULTS: Mean total IgE was >1,000 kU/l. Mean specific IgE (class 6 for Der p and class 2 for Hel a) SPT were positive in 44 patients for snail and in 56 for mite. Isoelectric focusing (IEF) and SDS-PAGE followed by immunoblotting of H. aspersa extract enabled the identification of 27 and 20 allergens, respectively. Myosin heavy chains from snails (molecular weight >208 kDa) disclosed two major allergens. Hel a and Der p RAST were strongly inhibited by their homologous extracts, with Hel a RAST being inhibited by the Der p extract to a much greater extent (72.6%) than the inverse (5.6%). A complete inhibition of the immunoblots by their homologous extract was obtained. However, Hel a extract did not inhibit Der p IEF separated recognition. On the other hand, mite extract extensively inhibited snail immunoblots from both IEF and SDS-PAGE separations. Immune detection on chicken, pig, rabbit, cow and horse myosins did not reveal any IgE cross recognition with snail . CONCLUSIONS: In most cases of snail allergy, mite appeared to be the sensitizing agent. Nevertheless, snails may also be able to induce sensitization by themselves. This hypothesis is supported by the finding of specific IgE to Hel a in 2 patients who did not show specific IgE to Der p, and one of them was suffering from asthma after snail ingestion.

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[13] - Asturias JA, Eraso E, Arilla C, Gómez-Bayón N, Inácio F, Martínez A. Cloning, Isolation, and IgE-Binding Properties of Helix aspersa (Brown Garden Snail) Tropomyosin. Int Arch Allergy Immunol 2002;128:90-96

Background: Gastropod consumption is quite frequent in the Mediterranean countries and cross-reactivities with crustaceans have been described, but the mechanism of this allergenic cross-reactivity has not been studied in detail. This study aimed to produce recombinant Helix aspersa (brown garden snail) tropomyosin and investigate its implication for cross-reactivity among invertebrates. Methods: A tropomyosin-specific cDNA encoding H. aspersa tropomyosin was synthetized, and recombinant allergen was overexpressed in Escherichia coli as nonfusion protein. IgE-binding reactivity was studied by immunoblotting and immunoblot inhibition experiments with sera from snail-allergic patients. Results: Cloned brown garden snail tropomyosin shares high homology with other edible mollusk tropomyosins (84-69% identity) as well as with those from arthropods (65-62%), and less homology with vertebrate ones (56% identity). Tropomyosin reacted with 18% of the sera from patients with snail allergy. Inhibition experiments, using natural and recombinant tropomyosins, showed different degrees of cross-reactivity between invertebrate tropomyosins. Sera from snail-allergic subjects recognized tropomyosins in both mollusks and crustacean extracts. Conclusions: Tropomyosin represents a minor allergen in snail extracts, but it is clearly involved in invertebrate cross-reactivity

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[14] - Sidenius KE, Hallas TE, Poulsen LK, Mosbech H. Allergen cross-reactivity between house-dust mites and other invertebrates. Allergy 2001;56:723-733

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[15] - van Ree R, Antonicelli L, Akkerdaas JH, Pajno GB, Barberio G, Corbetta L, et al. Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity. Allergy 1996;51:387-393

A group of 28 patients from Italy was studied who had asthma after consumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitization to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-reactive with house-dust mite. In contrast, the mite RAST was not significantly inhibited by snail. This indicates that house-dust mite was the sensitizing agent. Immunoblot analyses revealed multiple bands in snail extract recognized by IgE. In contrast to what has been described for cross-reactivity between shrimp and mite, tropomyosin played only a minor role as a cross-reactive allergen in these patients. The observations in this study indicate that snail consumption can cause severe asthmatic symptoms in house-dust-mite-allergic patients. It might, therefore, be advisable to screen mite-allergic asthma patients for allergy to snail and other invertebrate animal foods.

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[16] - Rame JM, Lavaud F, Staevska M, Dubiez A, Adessi B, Vigan M, et al. Prevalence of the Sensitization to Snails and Shrimps in Patients Allergic to House Dust Mites (HDM) a Prospective European Multicenter Study. AAAAI 58th Annual Meeting, New York, 1-6 March, 2002, Poster n°654

To determine the prevalence of cross-sensitization to snails and shrimps in allergic patients and especially in patients allergic to HDM in different settings with different cultural eating habits, 394 consecutive patients who attended 3 Allergy Units in Besançon (192 patients, mean age 32) and Reims (151 patients, mean age 34), France, and in Sofia (51 patients, mean age 40), Bulgaria, were prospectively prick-tested using the same commercial allergen extracts (Allerbio, France) of D. pteronyssinus and D. farinae, cockroach, Alternaria sp, D. glomerata and P. pratense pollens, latex, cat, dog, shrimp and 2 commercial extracts of H. pomatia snail (Allerbio and Stallergènes), as well as „prick-n-prick‰ tested using boiled land- and sea-snails. Sensitization to snails, observed in 51 patients, was associated with sensitization to HDM (41/51; 80% of all cases; p<0.05; 7/11 in Besançon; 11/14 in Reims; and 23/26 in Sofia), and not with any other sensitization to aeroallergens. Shrimp sensitization was present in 13/51 patients allergic to snails, and snail sensitization was present in 13/25 patients sensitized to shrimp. This association was significant but was dependent on HDM sensitization. Among patients allergic to HDM, 18% were sensitized to snails and 10% were sensitized to shrimps. HDM/snail cross-sensitization was more frequent in multi-sensitized atopic patients: 34/41 patients sensitized to snails had positive prick-tests to 2 or more than 2 allergens including HDM. It was not significantly correlated with either past immunotherapy to HDM or previous consumption of snails: 82% never received HDM immunotherapy (61% in France and 100% in Bulgaria) and 63% had never eaten snails (41% in France and 80% in Bulgaria). The prick-n-prick tests using boiled snails had a higher sensitivity to disclose sensitization to snails than commercial extracts. Both commercial extracts had a similar sensitivity but did not identify the same snail-allergic patients. These results show that 1/5 and 1/10 patients allergic to HDM exhibit a sensitization to mollusks and shrimps respectively. Despite previous suggestive observations, cross-sensitization seems independent of previous HDM immunotherapy but is nevertheless strongly associated with atopic condition. It appears independent of mollusk consumption and this suggests that cross-sensitization is related to primary sensitization by the aero-allergen. The relatively high prevalence of sensitization to edible invertebrates in patients allergic to HDM and the potential risk of severe food allergy in these patients should encourage allergists to systematically test mollusks and crustaceans in these patients, especially when they live in countries where eating snails and sea food is common

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[17] - Didier A, Goyeau E, Panaye JP, Carme S, Cabrera J, Khoury C, et al. Prévalence des test cutanés positifs à l'escargot chez les patients présentant des manifestations allergiques respiratoires. Corrélations avec l'allergie aux acariens et incidence clinique. Rev Fr Allergol Immunol Clin 1996;36:466-469

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[18] - Meglio P, Plantamura M, Arabito E, Falagiani P, Torre A, Rossi P. Does SIT to Der p protect from snail sensitization ? Allergy 2002;57:868-869

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[19] - Vuitton DA, Rancé F, Paquin ML, Adessi B, Vigan M, Gomot A, et al. Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (D. pteronyssinus) - I. In vivo study. Allergy 1998;53:144-150

Clinical reports have suggested an unusual frequency in the number of patients with food allergy to snails who are also allergic to the house-dust mite (HDM). As allergy to HDM is one of the most frequent sensitizations in atopic patients of Western countries, evaluation of the relevance of the concomitant sensitization to Dermatophagoides pteronyssinus and to snails is an important consideration. To evaluate the responsibility of different snail components and of snail mites for inducing in vivo hypersensitivity in patients allergic to HDM, the in vivo reactivity of patients with clinical symptoms after ingestion of snails was assessed by skin prick tests with extracts and hemolymph from four different Helix species snails, and extracts from the snail parasitic mite, Riccardoella limacum. In addition, to obtain epidemiologic data on cosensitization to HDM and snails in allergic patients, the frequency of snail sensitization and its relationship to HDM sensitization were determined in a population of 169 allergic children. All patients allergic to snails had positive skin prick tests to the snail extracts and none to R. limacum extract. The number of positive skin reactions did not significantly differ whatever the species, snail part, or heating procedure used. The strongest reactions were obtained with Helix pomatia (Burgundy snail). Among the 169 prospectively tested children, 38 had a positive prick test to snail extracts; 79% of the snail-sensitized children had sensitization to HDM; and 31% of the children allergic to HDM were found to be sensitized to snails. These results show that snail components, and not the mite R. limacum, were responsible for the in vivo hypersensitivity. These snail components reacting in vivo are present in different parts of snails, including the hemolymph. One-third of the children allergic to HDM were sensitized to snails without any previous ingestion of snails: this observation suggests that HDM was the sensitizing agent and that the cross-reaction could be clinically relevant in countries where eating snails is common.

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[20] - Rame JM, Lavaud F, Staevska M, Dubiez A, Adessi B, Vigan M, et al. Prevalence of the Sensitization to Snails and Shrimps in Patients Allergic to House Dust Mites (HDM) a Prospective European Multicenter Study. AAAAI 58th Annual Meeting, New York, 1-6 March, 2002, Poster n°654

To determine the prevalence of cross-sensitization to snails and shrimps in allergic patients and especially in patients allergic to HDM in different settings with different cultural eating habits, 394 consecutive patients who attended 3 Allergy Units in Besançon (192 patients, mean age 32) and Reims (151 patients, mean age 34), France, and in Sofia (51 patients, mean age 40), Bulgaria, were prospectively prick-tested using the same commercial allergen extracts (Allerbio, France) of D. pteronyssinus and D. farinae, cockroach, Alternaria sp, D. glomerata and P. pratense pollens, latex, cat, dog, shrimp and 2 commercial extracts of H. pomatia snail (Allerbio and Stallergènes), as well as „prick-n-prick‰ tested using boiled land- and sea-snails. Sensitization to snails, observed in 51 patients, was associated with sensitization to HDM (41/51; 80% of all cases; p<0.05; 7/11 in Besançon; 11/14 in Reims; and 23/26 in Sofia), and not with any other sensitization to aeroallergens. Shrimp sensitization was present in 13/51 patients allergic to snails, and snail sensitization was present in 13/25 patients sensitized to shrimp. This association was significant but was dependent on HDM sensitization. Among patients allergic to HDM, 18% were sensitized to snails and 10% were sensitized to shrimps. HDM/snail cross-sensitization was more frequent in multi-sensitized atopic patients: 34/41 patients sensitized to snails had positive prick-tests to 2 or more than 2 allergens including HDM. It was not significantly correlated with either past immunotherapy to HDM or previous consumption of snails: 82% never received HDM immunotherapy (61% in France and 100% in Bulgaria) and 63% had never eaten snails (41% in France and 80% in Bulgaria). The prick-n-prick tests using boiled snails had a higher sensitivity to disclose sensitization to snails than commercial extracts. Both commercial extracts had a similar sensitivity but did not identify the same snail-allergic patients. These results show that 1/5 and 1/10 patients allergic to HDM exhibit a sensitization to mollusks and shrimps respectively. Despite previous suggestive observations, cross-sensitization seems independent of previous HDM immunotherapy but is nevertheless strongly associated with atopic condition. It appears independent of mollusk consumption and this suggests that cross-sensitization is related to primary sensitization by the aero-allergen. The relatively high prevalence of sensitization to edible invertebrates in patients allergic to HDM and the potential risk of severe food allergy in these patients should encourage allergists to systematically test mollusks and crustaceans in these patients, especially when they live in countries where eating snails and sea food is common

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[21] - van Ree R, Antonicelli L, Akkerdaas JH, Garritani MS, Aalberse RC, Bonifazi F. Possible induction of food allergy during mite immunotherapy. Allergy 1996;51:108-113

Sera of 17 patients receiving immunotherapy for house-dust mite allergy were tested for IgE antibodies against snail and shrimp. Serum samples were taken at the start of immunotherapy and 14-20 months later. While the average IgE response to mite, Der p 1, and Der p 2 did not alter significantly, the average response to snail showed a significant increase. This included two conversions from negative to strongly positive. These novel IgE antibodies against snail were shown to be cross-reactive with mite. Three patients had a positive RAST for shrimp. For one of them, a strong increase of IgE against shrimp (and snail) was observed. In 2/3 snail/shrimp-positive sera, IgE antibodies against the cross-reactive allergen tropomyosin from mite, snail, and shrimp were demonstrated. A clear IgE response to snail (> 10% binding in a snail RAST) was confirmed by a positive skin prick test (SPT) for 6/10 patients. The two patients with antitropomyosin IgE also had a positive SPT for shrimp, and demonstrated the oral allergy syndrome (OAS) after eating shrimp. The observations in this study indicate that house-dust mite immunotherapy is accompanied by the induction of IgE against foods, including tropomyosin-reactive IgE. Food allergy (OAS) was observed in patients that had IgE antibodies against this cross-reactive allergen. In conclusion, induction of IgE during mite immunotherapy might occasionally cause allergy to foods of invertebrate animal origin.

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[22] - Tomaz E, Pires A, Inácio F, Quaresma R. Tropomyosin`s clinical importance in house dust mite allergic patients. EAACI 25th Congress, Vienna, 10-14 June, 2006, Poster n°991

Background: Tropomyosin is a protein largely distributed through several animal species. In invertebrates, such as house dust mite, crustaceans, silverfish and mollusks, it has been described as an allergic component, sometimes responsible for cross-reactivity. Methods: The purpose of this study was to determine the prevalence of sensitisation to tropomyosin in a house dust mite sensitized population, before and after immunotherapy, and its relationship to sensitisation and/or food allergy to snail, shrimp and Blatella germanica. 169 patients were reviewed (male=89; female=80), mean age 22 years old, allergic to house dust mite, who had performed Tropomyosin specific IgE analyses, before and, at least, after 12 months of immunotherapy. Specific IgE to snail, Blatella germanica and shrimp were analyzed in patients with positive Tropomyosin specific IgE (> 0,35 KuA/L). Patients were asked about allergic symptoms to food, specially crustaceans and mollusks. Results: Tropomyiosin sensitisation prevalence in this population was 3,5% (3 male, 3 female, mean age 19 years old; 50% were already sensitized before immunotherapy, 50% sensitized during immunotherapy). The sensitisation to Tropomyosin is closely associated to the sensitisation to snail, Blatella germanica and shrimp. The prevalence of food allergy is 33% (n=2) among tropomyosin sensitized patients and 2% (n=4) among non sensitized patients. Conclusion: The prevalence of sensitisation to Tropomyosin among this house dust mites allergic population is low (3,5%) and similar to data published by other authors that pointed Tropomyosin as a minor allergen of mites. The patients sensitized to Tropomyosin are also sensitized to species with homologues Tropomyosines, such as snail, Blatella germanica and shrimp. There is a high prevalence of food allergic symptoms to mollusks and crustacean among Tropomyosin sensitized patients. Those aspects come to reinforce the involvement of Tropomyosin on cross-reactivity between invertebrate species.

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[23] - Kütting B, Brehler R. Reflections on clinical relevance of cross-reactivity between house dust mite, molluscs and crustacean. Allergologie 2002;25:321-325

Introduction: Cross-reactivity between house dust mite and molluscs or crustacean has been reported in the past, mainly French and Italian publications are related to this subject. In our region this house-dust mite associated food allergy seems to play a less important role. Patients: 33 patients consulting our outpatients department because of a clinically relevant type-I-sensitization to house dust mite were included in the study. The relevance of a possible house dust mite related food allergy due to cross-reactive IgE antibodies was studied by a questionnaire, skin prick tests and in vitro assays, as well. Results: 29 patients consumed shrimps, but only 2 patients reported on adverse reactions after consumption. Snails were rarely eaten, only one person regularly eats snails, 10 persons sporadically, but 22 persons never eat snails. No adverse effects were reported after consumption of snails. The two persons with clinical symptoms after consumption of shrimps had positive skin prick test results in the prick to prick test, but specific IgE was detected in one case. Conclusion: In our opinion patients suffering from a sensitization to house dust mite should be informed about possible related food allergies to molluscs and crustacean in spite of the fact that such adverse reactions are quite rare. Therefore this related food allergy can not be compared to the mugwort/celery syndrome. Patients with a food allergy after consumption of invertebrates should be examined if they are sensitized to house dust mite because in adults food allergy is mainly due to cross-reactivity between inhalative and food allergens.

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[24] - Tomaz E, Pires A, Inácio F, Quaresma R. Tropomyosin`s clinical importance in house dust mite allergic patients. EAACI 25th Congress, Vienna, 10-14 June, 2006, Poster n°991

Background: Tropomyosin is a protein largely distributed through several animal species. In invertebrates, such as house dust mite, crustaceans, silverfish and mollusks, it has been described as an allergic component, sometimes responsible for cross-reactivity. Methods: The purpose of this study was to determine the prevalence of sensitisation to tropomyosin in a house dust mite sensitized population, before and after immunotherapy, and its relationship to sensitisation and/or food allergy to snail, shrimp and Blatella germanica. 169 patients were reviewed (male=89; female=80), mean age 22 years old, allergic to house dust mite, who had performed Tropomyosin specific IgE analyses, before and, at least, after 12 months of immunotherapy. Specific IgE to snail, Blatella germanica and shrimp were analyzed in patients with positive Tropomyosin specific IgE (> 0,35 KuA/L). Patients were asked about allergic symptoms to food, specially crustaceans and mollusks. Results: Tropomyiosin sensitisation prevalence in this population was 3,5% (3 male, 3 female, mean age 19 years old; 50% were already sensitized before immunotherapy, 50% sensitized during immunotherapy). The sensitisation to Tropomyosin is closely associated to the sensitisation to snail, Blatella germanica and shrimp. The prevalence of food allergy is 33% (n=2) among tropomyosin sensitized patients and 2% (n=4) among non sensitized patients. Conclusion: The prevalence of sensitisation to Tropomyosin among this house dust mites allergic population is low (3,5%) and similar to data published by other authors that pointed Tropomyosin as a minor allergen of mites. The patients sensitized to Tropomyosin are also sensitized to species with homologues Tropomyosines, such as snail, Blatella germanica and shrimp. There is a high prevalence of food allergic symptoms to mollusks and crustacean among Tropomyosin sensitized patients. Those aspects come to reinforce the involvement of Tropomyosin on cross-reactivity between invertebrate species.

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[25] - Didier A, Goyeau E, Panaye JP, Carme S, Cabrera J, Khoury C, et al. Prévalence des test cutanés positifs à l'escargot chez les patients présentant des manifestations allergiques respiratoires. Corrélations avec l'allergie aux acariens et incidence clinique. Rev Fr Allergol Immunol Clin 1996;36:466-469

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[26] - Lourenço Martins LM, Peltre G, Fialho da Costa Faro CJ, Vieira Pires EM, Fernando da Cruz Inacio F. The Helix aspersa (Brown Garden Snail) Allergen Repertoire. Int Arch Allergy Immunol 2005;136:7-15

BACKGROUND: Ingestion of snails can induce strong asthmatic or anaphylactic responses, mainly in house-dust-mite-sensitized patients. The aim of this study was to identify the Helix aspersa (Hel a), Theba pisana (The p) and Otala lactea (Ota l) allergens and the extent of their cross-reactivity with the Dermatophagoides pteronyssinus (Der p) mite. PATIENTS AND METHODS: In 60 atopic patients, skin prick tests (SPT) to snail and D. pteronyssinus, total and specific IgE, specific IgE immunoblots, RAST and immunoblot inhibition assays were performed . RESULTS: Mean total IgE was >1,000 kU/l. Mean specific IgE (class 6 for Der p and class 2 for Hel a) SPT were positive in 44 patients for snail and in 56 for mite. Isoelectric focusing (IEF) and SDS-PAGE followed by immunoblotting of H. aspersa extract enabled the identification of 27 and 20 allergens, respectively. Myosin heavy chains from snails (molecular weight >208 kDa) disclosed two major allergens. Hel a and Der p RAST were strongly inhibited by their homologous extracts, with Hel a RAST being inhibited by the Der p extract to a much greater extent (72.6%) than the inverse (5.6%). A complete inhibition of the immunoblots by their homologous extract was obtained. However, Hel a extract did not inhibit Der p IEF separated recognition. On the other hand, mite extract extensively inhibited snail immunoblots from both IEF and SDS-PAGE separations. Immune detection on chicken, pig, rabbit, cow and horse myosins did not reveal any IgE cross recognition with snail . CONCLUSIONS: In most cases of snail allergy, mite appeared to be the sensitizing agent. Nevertheless, snails may also be able to induce sensitization by themselves. This hypothesis is supported by the finding of specific IgE to Hel a in 2 patients who did not show specific IgE to Der p, and one of them was suffering from asthma after snail ingestion.

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[27] - Rame JM, Lavaud F, Staevska M, Dubiez A, Adessi B, Vigan M, et al. Prevalence of the Sensitization to Snails and Shrimps in Patients Allergic to House Dust Mites (HDM) a Prospective European Multicenter Study. AAAAI 58th Annual Meeting, New York, 1-6 March, 2002, Poster n°654

To determine the prevalence of cross-sensitization to snails and shrimps in allergic patients and especially in patients allergic to HDM in different settings with different cultural eating habits, 394 consecutive patients who attended 3 Allergy Units in Besançon (192 patients, mean age 32) and Reims (151 patients, mean age 34), France, and in Sofia (51 patients, mean age 40), Bulgaria, were prospectively prick-tested using the same commercial allergen extracts (Allerbio, France) of D. pteronyssinus and D. farinae, cockroach, Alternaria sp, D. glomerata and P. pratense pollens, latex, cat, dog, shrimp and 2 commercial extracts of H. pomatia snail (Allerbio and Stallergènes), as well as „prick-n-prick‰ tested using boiled land- and sea-snails. Sensitization to snails, observed in 51 patients, was associated with sensitization to HDM (41/51; 80% of all cases; p<0.05; 7/11 in Besançon; 11/14 in Reims; and 23/26 in Sofia), and not with any other sensitization to aeroallergens. Shrimp sensitization was present in 13/51 patients allergic to snails, and snail sensitization was present in 13/25 patients sensitized to shrimp. This association was significant but was dependent on HDM sensitization. Among patients allergic to HDM, 18% were sensitized to snails and 10% were sensitized to shrimps. HDM/snail cross-sensitization was more frequent in multi-sensitized atopic patients: 34/41 patients sensitized to snails had positive prick-tests to 2 or more than 2 allergens including HDM. It was not significantly correlated with either past immunotherapy to HDM or previous consumption of snails: 82% never received HDM immunotherapy (61% in France and 100% in Bulgaria) and 63% had never eaten snails (41% in France and 80% in Bulgaria). The prick-n-prick tests using boiled snails had a higher sensitivity to disclose sensitization to snails than commercial extracts. Both commercial extracts had a similar sensitivity but did not identify the same snail-allergic patients. These results show that 1/5 and 1/10 patients allergic to HDM exhibit a sensitization to mollusks and shrimps respectively. Despite previous suggestive observations, cross-sensitization seems independent of previous HDM immunotherapy but is nevertheless strongly associated with atopic condition. It appears independent of mollusk consumption and this suggests that cross-sensitization is related to primary sensitization by the aero-allergen. The relatively high prevalence of sensitization to edible invertebrates in patients allergic to HDM and the potential risk of severe food allergy in these patients should encourage allergists to systematically test mollusks and crustaceans in these patients, especially when they live in countries where eating snails and sea food is common

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[28] - Vuitton DA, Rancé F, Paquin ML, Adessi B, Vigan M, Gomot A, et al. Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (D. pteronyssinus) - I. In vivo study. Allergy 1998;53:144-150

Clinical reports have suggested an unusual frequency in the number of patients with food allergy to snails who are also allergic to the house-dust mite (HDM). As allergy to HDM is one of the most frequent sensitizations in atopic patients of Western countries, evaluation of the relevance of the concomitant sensitization to Dermatophagoides pteronyssinus and to snails is an important consideration. To evaluate the responsibility of different snail components and of snail mites for inducing in vivo hypersensitivity in patients allergic to HDM, the in vivo reactivity of patients with clinical symptoms after ingestion of snails was assessed by skin prick tests with extracts and hemolymph from four different Helix species snails, and extracts from the snail parasitic mite, Riccardoella limacum. In addition, to obtain epidemiologic data on cosensitization to HDM and snails in allergic patients, the frequency of snail sensitization and its relationship to HDM sensitization were determined in a population of 169 allergic children. All patients allergic to snails had positive skin prick tests to the snail extracts and none to R. limacum extract. The number of positive skin reactions did not significantly differ whatever the species, snail part, or heating procedure used. The strongest reactions were obtained with Helix pomatia (Burgundy snail). Among the 169 prospectively tested children, 38 had a positive prick test to snail extracts; 79% of the snail-sensitized children had sensitization to HDM; and 31% of the children allergic to HDM were found to be sensitized to snails. These results show that snail components, and not the mite R. limacum, were responsible for the in vivo hypersensitivity. These snail components reacting in vivo are present in different parts of snails, including the hemolymph. One-third of the children allergic to HDM were sensitized to snails without any previous ingestion of snails: this observation suggests that HDM was the sensitizing agent and that the cross-reaction could be clinically relevant in countries where eating snails is common.

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[29] - de la Cuesta CG, Garcia BE, Cordoba H, Dieguez I, Oehling A. Food allergy to Helix terrestre (snail). Allergol Immunopathol (Madr) 1989;17:337-339

Among the rare foods capable of producing food allergies is the snail (Helix terrestre). The snail is a delicacy eaten in Spain, France and Portugal. This study presents the findings of an allergic study of 10 patients with this infrequent food allergy during the past 10 years. The shock organ in the majority (80%) of these patients was the bronchial tree. Six of them did not have any digestive or skin symptoms which are usually seen in cases of food allergy. All patients manifested the symptomatology after ingestion of Helix terrestre. Two also had reactions after eating Patella vulgata (limpet). The snail and the limpet are within the phylogenetic line of molluscs, i.e. of gastropods. All patients tolerated the ingestion of cephalopods and bivalves which belong to two other phylogenetic lines. Skin tests to seafoods (squids, prawns, lobsters and clams) were negative for all patients. This suggests that the sensitizing antigen is probably a protein found only in gastropod molluscs. Skin tests along with the histamine release test were valid diagnostic methods for this food allergy. The limited bibliography on this subject is probably due to the fact that the consumption of snails as well as limpets is limited to specific geographical areas.

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[30] - van Ree R, Antonicelli L, Akkerdaas JH, Pajno GB, Barberio G, Corbetta L, et al. Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity. Allergy 1996;51:387-393

A group of 28 patients from Italy was studied who had asthma after consumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitization to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-reactive with house-dust mite. In contrast, the mite RAST was not significantly inhibited by snail. This indicates that house-dust mite was the sensitizing agent. Immunoblot analyses revealed multiple bands in snail extract recognized by IgE. In contrast to what has been described for cross-reactivity between shrimp and mite, tropomyosin played only a minor role as a cross-reactive allergen in these patients. The observations in this study indicate that snail consumption can cause severe asthmatic symptoms in house-dust-mite-allergic patients. It might, therefore, be advisable to screen mite-allergic asthma patients for allergy to snail and other invertebrate animal foods.

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[31] - Pétrus M, Cougnaud V, Rhabbour M, Causse E, Netter JC. Allergie à l'escargot et aux acariens chez l'enfant. Arch Pediatr 1997;4:767-769

BACKGROUND: Anaphylactic reactions after consumption of snails by patients sensitized to house-dust mites have been reported several times. CASE REPORT: Two 8- and 10-year old children sensitized to house-dust mites developed Quincke's oedema after eating snails. Immunoallergologic investigations including pricks-test, labial test, IgE Rast confirmed associated allergy between snails and house dust mites. CONCLUSION: Considering the potential severity of anaphylactic reactions, it is necessary to warn children allergic to house dust mites and their parents about the high risk of associated allergy with snails.

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[32] - Grembiale RD, Naty S, Pelaia G, Tranfa CM, Marsico SA. Snail ingestion and asthma. Allergy 1996;51:361

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[33] - Longo G, Barbi E, Puppin F. Exercise-induced anaphylaxis to snails. Allergy 2000;55:513-514

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[34] - Caiado J, Lundberg M, Öman H, Pedro E, Pereira-Santos MC, Pereira Barbosa MA. Isolated snail allergy without house dust mites sensitization: case-report. Allergy 2007;62(suppl. 83):218-219

Background: Snail consumption is frequent in the Mediterranean area. It has been recognized as a food allergy with a significant association with known respiratory house dust mite (HDM) sensitization. This fact is usually due to cross-sensitization to the major allergen, tropomyiosin, present in HDM, seafood, snail and cockroach. Snail allergy can have some different clinic presentations namely asthma, urticaria, angioedema, anaphylaxis or even death. There have been very few case-reports of isolated snail allergy, in the absence of HDM sensitization. Case report: The authors report a 49-year-old man, who was admitted to the Immunoallergology Department in 2006 with bilateral eyelid oedema, itchy lip and throat and dysphonia, thirty minutes after snail ingestion, denying either urticaria or dyspnoea. He had no history of previous respiratory symptoms related to HDM allergy. The patient was submitted to skin prick tests (SPT) with HDM and other aeroallergens, namely cockroach, which were negative. SPT with snail extract (Helix aspersa- Bial Aristegui˙) and prick-to-prick with cooked and raw snail were positive and negative to all other food allergens, namely seafood. Specific IgE (Unicap-Phadia˙) to HDM and tropomyosin were negative (< 0.35 kUA/l) and positive to snail- Helix aspersa (0.89 kUA/l ˆ class II). Total IgE: 66.0 kU/l. Immunoblotting of serum sample of the patient was performed in Sweden (manufactured by MIAB- Phadia˙) and it was identified one, and probably two new bands, 55 and 95 kDa, respectively, which were not paralleled by similar bands on control sample, i.e. they were specific for the patient. The absence of HDM sensitization was confirmed in Sweden with determination of native protein of Dermatophagoides pteronyssinus (n Der p1) and tropomyosin which were negative. Discussion: The peculiarity of this case-report is based on the fact that snail allergy without cross-sensitization with HDM is very uncommon. Some authors have described some bands of this species of snail (Helix aspersa), but in this patient there was identified one (55 kDa) and probably two (95 KDa) new bands, not referred in the literature until now. They are, probably, minor allergens possibly responsible for snail allergy in this patient.

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[35] - Brouwer J. Cross-reactivity between Aspergillus fumigatus and Penicillium. Int Arch Allergy Immunol 1996;110:166-173

Rabbit anti-Aspergillus fumigatus, rabbit anti-Penicillium and sera from patients with precipitating antibodies against A. fumigatus or Penicillium were analyzed by means of inhibition experiments in ELISA (IgG) and (or) immunoblot analysis (IgG). Sera from healthy donors were also analyzed in ELISA inhibition and sera from patients with allergic bronchopulmonary aspergillosis (ABPA) in RAST (IgE) inhibition. Most sera from patients with precipitins against Penicillium gave anti-A. fumigatus ELISA titers in the same range as sera from patients with aspergillosis. Anti-Penicillium IgG reacted with several A. fumigatus antigens with molecular weights between 28 and 130 kD. This reaction could be inhibited by the carbohydrate fraction of A. fumigatus and by extracts of related fungi. The binding to Penicillium of IgE antibodies in sera from patients with ABPA could be inhibited by A. fumigatus almost as effectively as by Penicillium. The binding of these antibodies to A. fumigatus was only slightly affected by Penicillium antigens. The presence of IgG antibodies that cross-react with A. fumigatus may strongly affect the immunoblot patterns and ELISA results obtained with sera from patients with aspergillosis. Penicillium spp. probably belong to the major stimuli which induce the synthesis of so-called naturally occurring antibodies to A. fumigatus.

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[36] - de la Cuesta CG, Garcia BE, Cordoba H, Dieguez I, Oehling A. Food allergy to Helix terrestre (snail). Allergol Immunopathol (Madr) 1989;17:337-339

Among the rare foods capable of producing food allergies is the snail (Helix terrestre). The snail is a delicacy eaten in Spain, France and Portugal. This study presents the findings of an allergic study of 10 patients with this infrequent food allergy during the past 10 years. The shock organ in the majority (80%) of these patients was the bronchial tree. Six of them did not have any digestive or skin symptoms which are usually seen in cases of food allergy. All patients manifested the symptomatology after ingestion of Helix terrestre. Two also had reactions after eating Patella vulgata (limpet). The snail and the limpet are within the phylogenetic line of molluscs, i.e. of gastropods. All patients tolerated the ingestion of cephalopods and bivalves which belong to two other phylogenetic lines. Skin tests to seafoods (squids, prawns, lobsters and clams) were negative for all patients. This suggests that the sensitizing antigen is probably a protein found only in gastropod molluscs. Skin tests along with the histamine release test were valid diagnostic methods for this food allergy. The limited bibliography on this subject is probably due to the fact that the consumption of snails as well as limpets is limited to specific geographical areas.

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[37] - Amoroso S, Cocchiara R, Locorotondo G, Parlato A, Lampiasi N, Albeggiani G, et al. Antigens of Euparipha pisana (snail). I. Identification of allergens by means of in vivo and in vitro analysis. Int Arch Allergy Appl Immunol 1988;85:69-75

The data obtained in this study suggest that eating Euparipha pisana (snail), a common food in Mediterranean countries, could give serious allergic reaction such as asthma. We describe here the identification and partial characterization of allergenic molecules form this new source. An aqueous extract of snail was obtained by homogenization in distilled water, centrifugation, dialysis and defatting with ethyl ether. Skin prick test (SPT) performed with the snail extract on 70 subjects allergic to the more common allergens of the Mediterranean area gave a SPT positivity in 61% of the subjects tested, with a mean value of histamine-equivalent prick (HEP) equal to 0.81 +/- 0.25 (n = 43), while no SPT-snail-positive reactions were obtained by using the same extract on 30 not allergic subjects. To ascertain if such a sensitivity was IgE-mediated, sera from SPT-snail-positive subjects were analyzed by RAST, coupling the snail extract to polystyrene balls and to paper discs. 19% of the sera tested were RAST-positive, mean value of binding 4.8 +/- 2.8% (n = 13), while when using sera from SPT-snail-negative subjects, the RAST mean value was 0.49 +/- 0.18% (n = 27). Histamine release (HR) was also performed. Basophils prepared from SPT-snail-positive subjects were incubated with a snail extract. All of the SPT-snail-positive subjects gave a significant value of HR, mean value 21.8 +/- 7% using 1 micrograms of snail extract (n = 16), while 1.41 +/- 1.1% (n = 10) was the mean value obtained when SPT-snail-negative subjects were analyzed

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[38] - Rame JM, Lavaud F, Staevska M, Dubiez A, Adessi B, Vigan M, et al. Prevalence of the Sensitization to Snails and Shrimps in Patients Allergic to House Dust Mites (HDM) a Prospective European Multicenter Study. AAAAI 58th Annual Meeting, New York, 1-6 March, 2002, Poster n°654

To determine the prevalence of cross-sensitization to snails and shrimps in allergic patients and especially in patients allergic to HDM in different settings with different cultural eating habits, 394 consecutive patients who attended 3 Allergy Units in Besançon (192 patients, mean age 32) and Reims (151 patients, mean age 34), France, and in Sofia (51 patients, mean age 40), Bulgaria, were prospectively prick-tested using the same commercial allergen extracts (Allerbio, France) of D. pteronyssinus and D. farinae, cockroach, Alternaria sp, D. glomerata and P. pratense pollens, latex, cat, dog, shrimp and 2 commercial extracts of H. pomatia snail (Allerbio and Stallergènes), as well as „prick-n-prick‰ tested using boiled land- and sea-snails. Sensitization to snails, observed in 51 patients, was associated with sensitization to HDM (41/51; 80% of all cases; p<0.05; 7/11 in Besançon; 11/14 in Reims; and 23/26 in Sofia), and not with any other sensitization to aeroallergens. Shrimp sensitization was present in 13/51 patients allergic to snails, and snail sensitization was present in 13/25 patients sensitized to shrimp. This association was significant but was dependent on HDM sensitization. Among patients allergic to HDM, 18% were sensitized to snails and 10% were sensitized to shrimps. HDM/snail cross-sensitization was more frequent in multi-sensitized atopic patients: 34/41 patients sensitized to snails had positive prick-tests to 2 or more than 2 allergens including HDM. It was not significantly correlated with either past immunotherapy to HDM or previous consumption of snails: 82% never received HDM immunotherapy (61% in France and 100% in Bulgaria) and 63% had never eaten snails (41% in France and 80% in Bulgaria). The prick-n-prick tests using boiled snails had a higher sensitivity to disclose sensitization to snails than commercial extracts. Both commercial extracts had a similar sensitivity but did not identify the same snail-allergic patients. These results show that 1/5 and 1/10 patients allergic to HDM exhibit a sensitization to mollusks and shrimps respectively. Despite previous suggestive observations, cross-sensitization seems independent of previous HDM immunotherapy but is nevertheless strongly associated with atopic condition. It appears independent of mollusk consumption and this suggests that cross-sensitization is related to primary sensitization by the aero-allergen. The relatively high prevalence of sensitization to edible invertebrates in patients allergic to HDM and the potential risk of severe food allergy in these patients should encourage allergists to systematically test mollusks and crustaceans in these patients, especially when they live in countries where eating snails and sea food is common

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[39] - Meglio P, Plantamura M, Arabito E, Falagiani P, Torre A, Rossi P. Does SIT to Der p protect from snail sensitization ? Allergy 2002;57:868-869

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[40] - van Ree R, Antonicelli L, Akkerdaas JH, Pajno GB, Barberio G, Corbetta L, et al. Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity. Allergy 1996;51:387-393

A group of 28 patients from Italy was studied who had asthma after consumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitization to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-reactive with house-dust mite. In contrast, the mite RAST was not significantly inhibited by snail. This indicates that house-dust mite was the sensitizing agent. Immunoblot analyses revealed multiple bands in snail extract recognized by IgE. In contrast to what has been described for cross-reactivity between shrimp and mite, tropomyosin played only a minor role as a cross-reactive allergen in these patients. The observations in this study indicate that snail consumption can cause severe asthmatic symptoms in house-dust-mite-allergic patients. It might, therefore, be advisable to screen mite-allergic asthma patients for allergy to snail and other invertebrate animal foods.

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[41] - Sidenius KE, Hallas TE, Poulsen LK, Mosbech H. Allergen cross-reactivity between house-dust mites and other invertebrates. Allergy 2001;56:723-733

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[42] - Lourenço Martins LM, Peltre G, Fialho da Costa Faro CJ, Vieira Pires EM, Fernando da Cruz Inacio F. The Helix aspersa (Brown Garden Snail) Allergen Repertoire. Int Arch Allergy Immunol 2005;136:7-15

BACKGROUND: Ingestion of snails can induce strong asthmatic or anaphylactic responses, mainly in house-dust-mite-sensitized patients. The aim of this study was to identify the Helix aspersa (Hel a), Theba pisana (The p) and Otala lactea (Ota l) allergens and the extent of their cross-reactivity with the Dermatophagoides pteronyssinus (Der p) mite. PATIENTS AND METHODS: In 60 atopic patients, skin prick tests (SPT) to snail and D. pteronyssinus, total and specific IgE, specific IgE immunoblots, RAST and immunoblot inhibition assays were performed . RESULTS: Mean total IgE was >1,000 kU/l. Mean specific IgE (class 6 for Der p and class 2 for Hel a) SPT were positive in 44 patients for snail and in 56 for mite. Isoelectric focusing (IEF) and SDS-PAGE followed by immunoblotting of H. aspersa extract enabled the identification of 27 and 20 allergens, respectively. Myosin heavy chains from snails (molecular weight >208 kDa) disclosed two major allergens. Hel a and Der p RAST were strongly inhibited by their homologous extracts, with Hel a RAST being inhibited by the Der p extract to a much greater extent (72.6%) than the inverse (5.6%). A complete inhibition of the immunoblots by their homologous extract was obtained. However, Hel a extract did not inhibit Der p IEF separated recognition. On the other hand, mite extract extensively inhibited snail immunoblots from both IEF and SDS-PAGE separations. Immune detection on chicken, pig, rabbit, cow and horse myosins did not reveal any IgE cross recognition with snail . CONCLUSIONS: In most cases of snail allergy, mite appeared to be the sensitizing agent. Nevertheless, snails may also be able to induce sensitization by themselves. This hypothesis is supported by the finding of specific IgE to Hel a in 2 patients who did not show specific IgE to Der p, and one of them was suffering from asthma after snail ingestion.

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[43] - Sidenius KE, Hallas TE, Poulsen LK, Mosbech H. Allergen cross-reactivity between house-dust mites and other invertebrates. Allergy 2001;56:723-733

↩

[44] - Pajno GB, La Grutta S, Barberio G, Canonica GW, Passalacqua G. Harmful effect of immunotherapy in children with combined snail and mite allergy. J Allergy Clin Immunol 2002;109:627-629

Background: With respect to allergy, the possibility of cross-reactivity between snail and mite is well recognized, and anecdotal reports suggesting that allergen immunotherapy with mite extract can worsen snail-induced allergy exist. Objective: We describe the effect of immunotherapy in 4 children with snail-mite allergy. Methods: Four children (1 boy and 3 girls; 9-13 years of age) had consistent clinical histories (mild immediate respiratory symptoms after ingestion) and positive skin reactions for allergy to snail. They also had mite-induced asthma and were therefore prescribed subcutaneous specific immunotherapy and subsequently followed. Results: Several months (8-25) after starting immunotherapy, all children experienced life-threatening reactions, anaphylaxis, and respiratory failure after inadvertent ingestion of snail. Skin reactivity to the fresh food increased in all patients. Conclusions: This observation confirms that in patients with combined mite-snail allergy, immunotherapy should be avoided.

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[45] - van Ree R, Antonicelli L, Akkerdaas JH, Pajno GB, Barberio G, Corbetta L, et al. Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity. Allergy 1996;51:387-393

A group of 28 patients from Italy was studied who had asthma after consumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitization to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-reactive with house-dust mite. In contrast, the mite RAST was not significantly inhibited by snail. This indicates that house-dust mite was the sensitizing agent. Immunoblot analyses revealed multiple bands in snail extract recognized by IgE. In contrast to what has been described for cross-reactivity between shrimp and mite, tropomyosin played only a minor role as a cross-reactive allergen in these patients. The observations in this study indicate that snail consumption can cause severe asthmatic symptoms in house-dust-mite-allergic patients. It might, therefore, be advisable to screen mite-allergic asthma patients for allergy to snail and other invertebrate animal foods.

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[46] - Banzet ML, Adessi B, Vuitton DA, et l'AMEFORCAL Manifestations allergiques après ingestion d'escargots chez 12 malades allergiques aux acariens: une nouvelle allergie croisée ? Rev Fr Allergol Immunol Clin 1992;32:198-202

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[47] - Vuitton DA, Rancé F, Paquin ML, Adessi B, Vigan M, Gomot A, et al. Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (D. pteronyssinus) - I. In vivo study. Allergy 1998;53:144-150

Clinical reports have suggested an unusual frequency in the number of patients with food allergy to snails who are also allergic to the house-dust mite (HDM). As allergy to HDM is one of the most frequent sensitizations in atopic patients of Western countries, evaluation of the relevance of the concomitant sensitization to Dermatophagoides pteronyssinus and to snails is an important consideration. To evaluate the responsibility of different snail components and of snail mites for inducing in vivo hypersensitivity in patients allergic to HDM, the in vivo reactivity of patients with clinical symptoms after ingestion of snails was assessed by skin prick tests with extracts and hemolymph from four different Helix species snails, and extracts from the snail parasitic mite, Riccardoella limacum. In addition, to obtain epidemiologic data on cosensitization to HDM and snails in allergic patients, the frequency of snail sensitization and its relationship to HDM sensitization were determined in a population of 169 allergic children. All patients allergic to snails had positive skin prick tests to the snail extracts and none to R. limacum extract. The number of positive skin reactions did not significantly differ whatever the species, snail part, or heating procedure used. The strongest reactions were obtained with Helix pomatia (Burgundy snail). Among the 169 prospectively tested children, 38 had a positive prick test to snail extracts; 79% of the snail-sensitized children had sensitization to HDM; and 31% of the children allergic to HDM were found to be sensitized to snails. These results show that snail components, and not the mite R. limacum, were responsible for the in vivo hypersensitivity. These snail components reacting in vivo are present in different parts of snails, including the hemolymph. One-third of the children allergic to HDM were sensitized to snails without any previous ingestion of snails: this observation suggests that HDM was the sensitizing agent and that the cross-reaction could be clinically relevant in countries where eating snails is common.

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[48] - Reese G, Lehrer SB. Food allergen cross-reactivity and clinical significance. Ann Allergy Asthma Immunol 2000;85:431-433

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[49] - Meglio P, Plantamura M, Arabito E, Falagiani P, Torre A, Rossi P. Does SIT to Der p protect from snail sensitization ? Allergy 2002;57:868-869

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[50] - Rame JM, Lavaud F, Staevska M, Dubiez A, Adessi B, Vigan M, et al. Prevalence of the Sensitization to Snails and Shrimps in Patients Allergic to House Dust Mites (HDM) a Prospective European Multicenter Study. AAAAI 58th Annual Meeting, New York, 1-6 March, 2002, Poster n°654

To determine the prevalence of cross-sensitization to snails and shrimps in allergic patients and especially in patients allergic to HDM in different settings with different cultural eating habits, 394 consecutive patients who attended 3 Allergy Units in Besançon (192 patients, mean age 32) and Reims (151 patients, mean age 34), France, and in Sofia (51 patients, mean age 40), Bulgaria, were prospectively prick-tested using the same commercial allergen extracts (Allerbio, France) of D. pteronyssinus and D. farinae, cockroach, Alternaria sp, D. glomerata and P. pratense pollens, latex, cat, dog, shrimp and 2 commercial extracts of H. pomatia snail (Allerbio and Stallergènes), as well as „prick-n-prick‰ tested using boiled land- and sea-snails. Sensitization to snails, observed in 51 patients, was associated with sensitization to HDM (41/51; 80% of all cases; p<0.05; 7/11 in Besançon; 11/14 in Reims; and 23/26 in Sofia), and not with any other sensitization to aeroallergens. Shrimp sensitization was present in 13/51 patients allergic to snails, and snail sensitization was present in 13/25 patients sensitized to shrimp. This association was significant but was dependent on HDM sensitization. Among patients allergic to HDM, 18% were sensitized to snails and 10% were sensitized to shrimps. HDM/snail cross-sensitization was more frequent in multi-sensitized atopic patients: 34/41 patients sensitized to snails had positive prick-tests to 2 or more than 2 allergens including HDM. It was not significantly correlated with either past immunotherapy to HDM or previous consumption of snails: 82% never received HDM immunotherapy (61% in France and 100% in Bulgaria) and 63% had never eaten snails (41% in France and 80% in Bulgaria). The prick-n-prick tests using boiled snails had a higher sensitivity to disclose sensitization to snails than commercial extracts. Both commercial extracts had a similar sensitivity but did not identify the same snail-allergic patients. These results show that 1/5 and 1/10 patients allergic to HDM exhibit a sensitization to mollusks and shrimps respectively. Despite previous suggestive observations, cross-sensitization seems independent of previous HDM immunotherapy but is nevertheless strongly associated with atopic condition. It appears independent of mollusk consumption and this suggests that cross-sensitization is related to primary sensitization by the aero-allergen. The relatively high prevalence of sensitization to edible invertebrates in patients allergic to HDM and the potential risk of severe food allergy in these patients should encourage allergists to systematically test mollusks and crustaceans in these patients, especially when they live in countries where eating snails and sea food is common

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[51] - Banzet ML, Adessi B, Vuitton DA, et l'AMEFORCAL Manifestations allergiques après ingestion d'escargots chez 12 malades allergiques aux acariens: une nouvelle allergie croisée ? Rev Fr Allergol Immunol Clin 1992;32:198-202

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[52] - van Ree R, Antonicelli L, Akkerdaas JH, Pajno GB, Barberio G, Corbetta L, et al. Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity. Allergy 1996;51:387-393

A group of 28 patients from Italy was studied who had asthma after consumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitization to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-reactive with house-dust mite. In contrast, the mite RAST was not significantly inhibited by snail. This indicates that house-dust mite was the sensitizing agent. Immunoblot analyses revealed multiple bands in snail extract recognized by IgE. In contrast to what has been described for cross-reactivity between shrimp and mite, tropomyosin played only a minor role as a cross-reactive allergen in these patients. The observations in this study indicate that snail consumption can cause severe asthmatic symptoms in house-dust-mite-allergic patients. It might, therefore, be advisable to screen mite-allergic asthma patients for allergy to snail and other invertebrate animal foods.

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[53] - Guilloux L, Vuitton DA, Delbourg M, Lagier A, Adessi B, Marchand CR, et al. Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (D. pteronyssinus) - II. In vitro study. Allergy 1998;53:151-158

Epidemiologic and in vitro data have shown that the association of house-dust mite (HDM) allergy and snail allergy in the same patients was due to cross-reactivity between HDM and snail allergenic components. However, the cross-reacting allergen(s) have not yet been identified. In vitro reactivity of seven patients' sera to the various extracts and hemolymph of four different Helix snail species was analyzed by IgE detection and immunodots and Western blots. Cross-reactivity between snails and Dermatophagoides pteronyssinus was assessed by immunodot and ELISA inhibition in two patients. Heterologous inhibition of the snail immunodot and ELISA was observed in one serum. Western blotting showed a specific binding on all four snail species extracts; molecular weights of snail allergens ranged from < 21 to 200 kDa. Marked individual differences were observed in the seven sera under study; most sera demonstrated IgE recognition of multiple bands, illustrating that no single allergen is responsible for cross-reactivity between snail and mite. These results confirm that cross-reactivity exists between snails of the Helix genus and HDM. This cross-reactivity, involving more than a single allergen, may be of clinical significance in atopic patients allergic to D. pteronyssinus. The identity of the cross-reacting allergens remains to be determined. Potential candidates include the thermostable minor allergens of D. pteronyssinus, tropomyosin and hemocyanin.

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[54] - van Ree R. Clinical importance of cross-reactivity in food allergy. Curr Opin Allergy Clin Immunol 2004;4:235-240

PURPOSE OF REVIEW: Review of recent developments in the field of cross-reactivity in food allergy and the clinical relevance of these developments. RECENT FINDINGS: New foods have been added to the list of Bet v 1 and profilin-related food allergies. Clinical relevance of cross-reactions based on recognition of carbohydrate determinants and profilin is limited for the population of pollen-allergic patients as a whole. For selected food allergic patients, however, N-glycans and particularly profilin are potentially of clinical relevance. Lipid transfer proteins have further been established as clinically more severe allergens in several foods. This severity is attributed to their stability to proteolysis and processing. Storage proteins of several nuts and seeds have been identified as important allergens, but cross-reactivity between storage proteins of different foods appears to be limited. Using cross-reactivity as the basis for immunotherapy in food allergy seems promising but needs confirmation by double-blind, placebo-controlled trials. SUMMARY: The continued identification and characterization of cross-reactive allergens facilitates the study of factors determining clinical relevance of cross-reactivity and of possible efficacy of immunotherapy in food allergy.

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[55] - van Ree R, Antonicelli L, Akkerdaas JH, Garritani MS, Aalberse RC, Bonifazi F. Possible induction of food allergy during mite immunotherapy. Allergy 1996;51:108-113

Sera of 17 patients receiving immunotherapy for house-dust mite allergy were tested for IgE antibodies against snail and shrimp. Serum samples were taken at the start of immunotherapy and 14-20 months later. While the average IgE response to mite, Der p 1, and Der p 2 did not alter significantly, the average response to snail showed a significant increase. This included two conversions from negative to strongly positive. These novel IgE antibodies against snail were shown to be cross-reactive with mite. Three patients had a positive RAST for shrimp. For one of them, a strong increase of IgE against shrimp (and snail) was observed. In 2/3 snail/shrimp-positive sera, IgE antibodies against the cross-reactive allergen tropomyosin from mite, snail, and shrimp were demonstrated. A clear IgE response to snail (> 10% binding in a snail RAST) was confirmed by a positive skin prick test (SPT) for 6/10 patients. The two patients with antitropomyosin IgE also had a positive SPT for shrimp, and demonstrated the oral allergy syndrome (OAS) after eating shrimp. The observations in this study indicate that house-dust mite immunotherapy is accompanied by the induction of IgE against foods, including tropomyosin-reactive IgE. Food allergy (OAS) was observed in patients that had IgE antibodies against this cross-reactive allergen. In conclusion, induction of IgE during mite immunotherapy might occasionally cause allergy to foods of invertebrate animal origin.

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[56] - Tomaz E, Pires A, Inácio F, Quaresma R. Tropomyosin`s clinical importance in house dust mite allergic patients. EAACI 25th Congress, Vienna, 10-14 June, 2006, Poster n°991

Background: Tropomyosin is a protein largely distributed through several animal species. In invertebrates, such as house dust mite, crustaceans, silverfish and mollusks, it has been described as an allergic component, sometimes responsible for cross-reactivity. Methods: The purpose of this study was to determine the prevalence of sensitisation to tropomyosin in a house dust mite sensitized population, before and after immunotherapy, and its relationship to sensitisation and/or food allergy to snail, shrimp and Blatella germanica. 169 patients were reviewed (male=89; female=80), mean age 22 years old, allergic to house dust mite, who had performed Tropomyosin specific IgE analyses, before and, at least, after 12 months of immunotherapy. Specific IgE to snail, Blatella germanica and shrimp were analyzed in patients with positive Tropomyosin specific IgE (> 0,35 KuA/L). Patients were asked about allergic symptoms to food, specially crustaceans and mollusks. Results: Tropomyiosin sensitisation prevalence in this population was 3,5% (3 male, 3 female, mean age 19 years old; 50% were already sensitized before immunotherapy, 50% sensitized during immunotherapy). The sensitisation to Tropomyosin is closely associated to the sensitisation to snail, Blatella germanica and shrimp. The prevalence of food allergy is 33% (n=2) among tropomyosin sensitized patients and 2% (n=4) among non sensitized patients. Conclusion: The prevalence of sensitisation to Tropomyosin among this house dust mites allergic population is low (3,5%) and similar to data published by other authors that pointed Tropomyosin as a minor allergen of mites. The patients sensitized to Tropomyosin are also sensitized to species with homologues Tropomyosines, such as snail, Blatella germanica and shrimp. There is a high prevalence of food allergic symptoms to mollusks and crustacean among Tropomyosin sensitized patients. Those aspects come to reinforce the involvement of Tropomyosin on cross-reactivity between invertebrate species.

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[57] - Pereira dos Reis R, Pires AP, Tomaz E, Inacio F. Tropomyosin sensitisation in house dust mite-allergic patients. Rev Port Imunoalergol 2007;15:251-258

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[58] - Pajno GB, La Grutta S, Barberio G, Canonica GW, Passalacqua G. Harmful effect of immunotherapy in children with combined snail and mite allergy. J Allergy Clin Immunol 2002;109:627-629

Background: With respect to allergy, the possibility of cross-reactivity between snail and mite is well recognized, and anecdotal reports suggesting that allergen immunotherapy with mite extract can worsen snail-induced allergy exist. Objective: We describe the effect of immunotherapy in 4 children with snail-mite allergy. Methods: Four children (1 boy and 3 girls; 9-13 years of age) had consistent clinical histories (mild immediate respiratory symptoms after ingestion) and positive skin reactions for allergy to snail. They also had mite-induced asthma and were therefore prescribed subcutaneous specific immunotherapy and subsequently followed. Results: Several months (8-25) after starting immunotherapy, all children experienced life-threatening reactions, anaphylaxis, and respiratory failure after inadvertent ingestion of snail. Skin reactivity to the fresh food increased in all patients. Conclusions: This observation confirms that in patients with combined mite-snail allergy, immunotherapy should be avoided.

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[59] - Morisset M. L'allergie aux fruits de mer. Alim'Inter 2008;13:201-205

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[60] - Moneret-Vautrin DA. Allergie alimentaire aux mollusques. Alim'Inter 2007;12:174-177

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[61] - Jeong KY, Hong CS, Yong TS. Allergenic tropomyosins and their cross-reactivities. Protein Pept Lett 2006;13:835-845

The ingestion or inhalation of some proteins may lead to adverse immune reactions. Allergens may trigger allergic reactions in genetically predisposed individuals when they are absorbed through the skin or make contact with mucous membranes. An allergic disease often deteriorates the quality of life and may sometimes be life-threatening due to anaphylactic shock. A number of allergens have been characterized from various multicellular organisms to date. It is thought to be reasonable to pay a special attention to the substance which is highly cross-reactive and which causes adverse responses in the molecules that are not sensitized but similar to the sensitized allergen. Tropomyosin has been described as an important food allergen in shrimp, lobster, crab, oysters, squid, and other invertebrates. Allergic reactions to shellfish and mollusks are often cross-reactive, which may be explained by the highly conserved amino acid sequences of tropomyosins among invertebrates, but vertebrate tropomyosins are not known to be allergenic. Several tropomyosins from domestic arthropods have been reported to be allergenic. Recently, it was suggested that an infection of helminthic parasites might lead to sensitization to tropomyosin and elicit allergic reactions to other invertebrates. Much effort has been made to characterize these allergenic tropomyosins from various sources. We will discuss the physicochemical characteristics and the potential application of tropomyosin for the diagnosis and therapeutics of allergic disorders.

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[62] - van Ree R, Antonicelli L, Akkerdaas JH, Pajno GB, Barberio G, Corbetta L, et al. Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity. Allergy 1996;51:387-393

A group of 28 patients from Italy was studied who had asthma after consumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitization to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-reactive with house-dust mite. In contrast, the mite RAST was not significantly inhibited by snail. This indicates that house-dust mite was the sensitizing agent. Immunoblot analyses revealed multiple bands in snail extract recognized by IgE. In contrast to what has been described for cross-reactivity between shrimp and mite, tropomyosin played only a minor role as a cross-reactive allergen in these patients. The observations in this study indicate that snail consumption can cause severe asthmatic symptoms in house-dust-mite-allergic patients. It might, therefore, be advisable to screen mite-allergic asthma patients for allergy to snail and other invertebrate animal foods.

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[63] - Guilloux L, Vuitton DA, Delbourg M, Lagier A, Adessi B, Marchand CR, et al. Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (D. pteronyssinus) - II. In vitro study. Allergy 1998;53:151-158

Epidemiologic and in vitro data have shown that the association of house-dust mite (HDM) allergy and snail allergy in the same patients was due to cross-reactivity between HDM and snail allergenic components. However, the cross-reacting allergen(s) have not yet been identified. In vitro reactivity of seven patients' sera to the various extracts and hemolymph of four different Helix snail species was analyzed by IgE detection and immunodots and Western blots. Cross-reactivity between snails and Dermatophagoides pteronyssinus was assessed by immunodot and ELISA inhibition in two patients. Heterologous inhibition of the snail immunodot and ELISA was observed in one serum. Western blotting showed a specific binding on all four snail species extracts; molecular weights of snail allergens ranged from < 21 to 200 kDa. Marked individual differences were observed in the seven sera under study; most sera demonstrated IgE recognition of multiple bands, illustrating that no single allergen is responsible for cross-reactivity between snail and mite. These results confirm that cross-reactivity exists between snails of the Helix genus and HDM. This cross-reactivity, involving more than a single allergen, may be of clinical significance in atopic patients allergic to D. pteronyssinus. The identity of the cross-reacting allergens remains to be determined. Potential candidates include the thermostable minor allergens of D. pteronyssinus, tropomyosin and hemocyanin.

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[64] - Asturias JA, Eraso E, Arilla C, Gómez-Bayón N, Inácio F, Martínez A. Cloning, Isolation, and IgE-Binding Properties of Helix aspersa (Brown Garden Snail) Tropomyosin. Int Arch Allergy Immunol 2002;128:90-96

Background: Gastropod consumption is quite frequent in the Mediterranean countries and cross-reactivities with crustaceans have been described, but the mechanism of this allergenic cross-reactivity has not been studied in detail. This study aimed to produce recombinant Helix aspersa (brown garden snail) tropomyosin and investigate its implication for cross-reactivity among invertebrates. Methods: A tropomyosin-specific cDNA encoding H. aspersa tropomyosin was synthetized, and recombinant allergen was overexpressed in Escherichia coli as nonfusion protein. IgE-binding reactivity was studied by immunoblotting and immunoblot inhibition experiments with sera from snail-allergic patients. Results: Cloned brown garden snail tropomyosin shares high homology with other edible mollusk tropomyosins (84-69% identity) as well as with those from arthropods (65-62%), and less homology with vertebrate ones (56% identity). Tropomyosin reacted with 18% of the sera from patients with snail allergy. Inhibition experiments, using natural and recombinant tropomyosins, showed different degrees of cross-reactivity between invertebrate tropomyosins. Sera from snail-allergic subjects recognized tropomyosins in both mollusks and crustacean extracts. Conclusions: Tropomyosin represents a minor allergen in snail extracts, but it is clearly involved in invertebrate cross-reactivity

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[65] - Guilloux L, Vuitton DA, Delbourg M, Lagier A, Adessi B, Marchand CR, et al. Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (D. pteronyssinus) - II. In vitro study. Allergy 1998;53:151-158

Epidemiologic and in vitro data have shown that the association of house-dust mite (HDM) allergy and snail allergy in the same patients was due to cross-reactivity between HDM and snail allergenic components. However, the cross-reacting allergen(s) have not yet been identified. In vitro reactivity of seven patients' sera to the various extracts and hemolymph of four different Helix snail species was analyzed by IgE detection and immunodots and Western blots. Cross-reactivity between snails and Dermatophagoides pteronyssinus was assessed by immunodot and ELISA inhibition in two patients. Heterologous inhibition of the snail immunodot and ELISA was observed in one serum. Western blotting showed a specific binding on all four snail species extracts; molecular weights of snail allergens ranged from < 21 to 200 kDa. Marked individual differences were observed in the seven sera under study; most sera demonstrated IgE recognition of multiple bands, illustrating that no single allergen is responsible for cross-reactivity between snail and mite. These results confirm that cross-reactivity exists between snails of the Helix genus and HDM. This cross-reactivity, involving more than a single allergen, may be of clinical significance in atopic patients allergic to D. pteronyssinus. The identity of the cross-reacting allergens remains to be determined. Potential candidates include the thermostable minor allergens of D. pteronyssinus, tropomyosin and hemocyanin.

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[66] - Vuitton DA, Rancé F, Paquin ML, Adessi B, Vigan M, Gomot A, et al. Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (D. pteronyssinus) - I. In vivo study. Allergy 1998;53:144-150

Clinical reports have suggested an unusual frequency in the number of patients with food allergy to snails who are also allergic to the house-dust mite (HDM). As allergy to HDM is one of the most frequent sensitizations in atopic patients of Western countries, evaluation of the relevance of the concomitant sensitization to Dermatophagoides pteronyssinus and to snails is an important consideration. To evaluate the responsibility of different snail components and of snail mites for inducing in vivo hypersensitivity in patients allergic to HDM, the in vivo reactivity of patients with clinical symptoms after ingestion of snails was assessed by skin prick tests with extracts and hemolymph from four different Helix species snails, and extracts from the snail parasitic mite, Riccardoella limacum. In addition, to obtain epidemiologic data on cosensitization to HDM and snails in allergic patients, the frequency of snail sensitization and its relationship to HDM sensitization were determined in a population of 169 allergic children. All patients allergic to snails had positive skin prick tests to the snail extracts and none to R. limacum extract. The number of positive skin reactions did not significantly differ whatever the species, snail part, or heating procedure used. The strongest reactions were obtained with Helix pomatia (Burgundy snail). Among the 169 prospectively tested children, 38 had a positive prick test to snail extracts; 79% of the snail-sensitized children had sensitization to HDM; and 31% of the children allergic to HDM were found to be sensitized to snails. These results show that snail components, and not the mite R. limacum, were responsible for the in vivo hypersensitivity. These snail components reacting in vivo are present in different parts of snails, including the hemolymph. One-third of the children allergic to HDM were sensitized to snails without any previous ingestion of snails: this observation suggests that HDM was the sensitizing agent and that the cross-reaction could be clinically relevant in countries where eating snails is common.

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[67] - van Ree R, Antonicelli L, Akkerdaas JH, Pajno GB, Barberio G, Corbetta L, et al. Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity. Allergy 1996;51:387-393

A group of 28 patients from Italy was studied who had asthma after consumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitization to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-reactive with house-dust mite. In contrast, the mite RAST was not significantly inhibited by snail. This indicates that house-dust mite was the sensitizing agent. Immunoblot analyses revealed multiple bands in snail extract recognized by IgE. In contrast to what has been described for cross-reactivity between shrimp and mite, tropomyosin played only a minor role as a cross-reactive allergen in these patients. The observations in this study indicate that snail consumption can cause severe asthmatic symptoms in house-dust-mite-allergic patients. It might, therefore, be advisable to screen mite-allergic asthma patients for allergy to snail and other invertebrate animal foods.

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[68] - Sidenius KE, Hallas TE, Poulsen LK, Mosbech H. Allergen cross-reactivity between house-dust mites and other invertebrates. Allergy 2001;56:723-733

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[69] - de la Cuesta CG, Garcia BE, Cordoba H, Dieguez I, Oehling A. Food allergy to Helix terrestre (snail). Allergol Immunopathol (Madr) 1989;17:337-339

Among the rare foods capable of producing food allergies is the snail (Helix terrestre). The snail is a delicacy eaten in Spain, France and Portugal. This study presents the findings of an allergic study of 10 patients with this infrequent food allergy during the past 10 years. The shock organ in the majority (80%) of these patients was the bronchial tree. Six of them did not have any digestive or skin symptoms which are usually seen in cases of food allergy. All patients manifested the symptomatology after ingestion of Helix terrestre. Two also had reactions after eating Patella vulgata (limpet). The snail and the limpet are within the phylogenetic line of molluscs, i.e. of gastropods. All patients tolerated the ingestion of cephalopods and bivalves which belong to two other phylogenetic lines. Skin tests to seafoods (squids, prawns, lobsters and clams) were negative for all patients. This suggests that the sensitizing antigen is probably a protein found only in gastropod molluscs. Skin tests along with the histamine release test were valid diagnostic methods for this food allergy. The limited bibliography on this subject is probably due to the fact that the consumption of snails as well as limpets is limited to specific geographical areas.

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[70] - Vuitton DA, Rancé F, Paquin ML, Adessi B, Vigan M, Gomot A, et al. Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (D. pteronyssinus) - I. In vivo study. Allergy 1998;53:144-150

Clinical reports have suggested an unusual frequency in the number of patients with food allergy to snails who are also allergic to the house-dust mite (HDM). As allergy to HDM is one of the most frequent sensitizations in atopic patients of Western countries, evaluation of the relevance of the concomitant sensitization to Dermatophagoides pteronyssinus and to snails is an important consideration. To evaluate the responsibility of different snail components and of snail mites for inducing in vivo hypersensitivity in patients allergic to HDM, the in vivo reactivity of patients with clinical symptoms after ingestion of snails was assessed by skin prick tests with extracts and hemolymph from four different Helix species snails, and extracts from the snail parasitic mite, Riccardoella limacum. In addition, to obtain epidemiologic data on cosensitization to HDM and snails in allergic patients, the frequency of snail sensitization and its relationship to HDM sensitization were determined in a population of 169 allergic children. All patients allergic to snails had positive skin prick tests to the snail extracts and none to R. limacum extract. The number of positive skin reactions did not significantly differ whatever the species, snail part, or heating procedure used. The strongest reactions were obtained with Helix pomatia (Burgundy snail). Among the 169 prospectively tested children, 38 had a positive prick test to snail extracts; 79% of the snail-sensitized children had sensitization to HDM; and 31% of the children allergic to HDM were found to be sensitized to snails. These results show that snail components, and not the mite R. limacum, were responsible for the in vivo hypersensitivity. These snail components reacting in vivo are present in different parts of snails, including the hemolymph. One-third of the children allergic to HDM were sensitized to snails without any previous ingestion of snails: this observation suggests that HDM was the sensitizing agent and that the cross-reaction could be clinically relevant in countries where eating snails is common.

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[71] - van Ree R, Antonicelli L, Akkerdaas JH, Pajno GB, Barberio G, Corbetta L, et al. Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity. Allergy 1996;51:387-393

A group of 28 patients from Italy was studied who had asthma after consumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitization to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-reactive with house-dust mite. In contrast, the mite RAST was not significantly inhibited by snail. This indicates that house-dust mite was the sensitizing agent. Immunoblot analyses revealed multiple bands in snail extract recognized by IgE. In contrast to what has been described for cross-reactivity between shrimp and mite, tropomyosin played only a minor role as a cross-reactive allergen in these patients. The observations in this study indicate that snail consumption can cause severe asthmatic symptoms in house-dust-mite-allergic patients. It might, therefore, be advisable to screen mite-allergic asthma patients for allergy to snail and other invertebrate animal foods.

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[72] - Didier A, Goyeau E, Panaye JP, Carme S, Cabrera J, Khoury C, et al. Prévalence des test cutanés positifs à l'escargot chez les patients présentant des manifestations allergiques respiratoires. Corrélations avec l'allergie aux acariens et incidence clinique. Rev Fr Allergol Immunol Clin 1996;36:466-469

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[73] - Lopata AL, Zinn C, Potter PC. Characteristics of hypersensitivity reactions and identification of a unique 49 kd IgE-binding protein (Hal m1) in abalone (Haliotis midae). J Allergy Clin Immunol 1997;100:642-648

There is a paucity of published data on the clinical presentation and the nature of the allergens involved in hypersensitivity to mollusks. This study reports the clinical and immunologic findings in 38 patients with reported immediate and delayed adverse reactions to abalone (Haliotis midae, Class Gastropoda). METHODS: Patients were recruited as part of a South African seafood allergy survey. Allergic symptoms were assessed by a self-administered questionnaire. A total of 38 patients with abalone sensitivity were recruited. Specific IgE responses to abalone and other mollusks were studied by using RAST and inhibition ELISAs. Skin prick tests and lymphocyte proliferation assays were also performed on several of the subjects. Allergenic components of Haliotis midae were identified with Western blotting. RESULTS: Twenty five of the 38 patients in the study were first seen with immediate symptoms, and 13 had delayed reactions. Seventeen of the sera tested were RAST positive. Skin prick tests responses with abalone extract were positive in all subjects with positive RAST responses (n = 8) and in 6 of 13 subjects with negative RAST responses. Five of the subjects with positive RAST responses had positive results on Western blotting and demonstrated binding to two major allergens with molecular weights of 38 and 49 kd. The 49 kd IgE-binding protein has been designated as Hal-m-1. CONCLUSIONS: Abalone allergens are heat-stable proteins with molecular weights of 38 and 49 kd, later designated as Hal-m-1 according to International Union of Immunological Societies allergen nomenclature regulation. Our studies indicate a clear clinical and immunologic heterogeneity in patients reactive to abalone.

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[74] - de la Cuesta CG, Garcia BE, Cordoba H, Dieguez I, Oehling A. Food allergy to Helix terrestre (snail). Allergol Immunopathol (Madr) 1989;17:337-339

Among the rare foods capable of producing food allergies is the snail (Helix terrestre). The snail is a delicacy eaten in Spain, France and Portugal. This study presents the findings of an allergic study of 10 patients with this infrequent food allergy during the past 10 years. The shock organ in the majority (80%) of these patients was the bronchial tree. Six of them did not have any digestive or skin symptoms which are usually seen in cases of food allergy. All patients manifested the symptomatology after ingestion of Helix terrestre. Two also had reactions after eating Patella vulgata (limpet). The snail and the limpet are within the phylogenetic line of molluscs, i.e. of gastropods. All patients tolerated the ingestion of cephalopods and bivalves which belong to two other phylogenetic lines. Skin tests to seafoods (squids, prawns, lobsters and clams) were negative for all patients. This suggests that the sensitizing antigen is probably a protein found only in gastropod molluscs. Skin tests along with the histamine release test were valid diagnostic methods for this food allergy. The limited bibliography on this subject is probably due to the fact that the consumption of snails as well as limpets is limited to specific geographical areas.

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[75] - Rame JM, Lavaud F, Staevska M, Dubiez A, Adessi B, Vigan M, et al. Prevalence of the Sensitization to Snails and Shrimps in Patients Allergic to House Dust Mites (HDM) a Prospective European Multicenter Study. AAAAI 58th Annual Meeting, New York, 1-6 March, 2002, Poster n°654

To determine the prevalence of cross-sensitization to snails and shrimps in allergic patients and especially in patients allergic to HDM in different settings with different cultural eating habits, 394 consecutive patients who attended 3 Allergy Units in Besançon (192 patients, mean age 32) and Reims (151 patients, mean age 34), France, and in Sofia (51 patients, mean age 40), Bulgaria, were prospectively prick-tested using the same commercial allergen extracts (Allerbio, France) of D. pteronyssinus and D. farinae, cockroach, Alternaria sp, D. glomerata and P. pratense pollens, latex, cat, dog, shrimp and 2 commercial extracts of H. pomatia snail (Allerbio and Stallergènes), as well as „prick-n-prick‰ tested using boiled land- and sea-snails. Sensitization to snails, observed in 51 patients, was associated with sensitization to HDM (41/51; 80% of all cases; p<0.05; 7/11 in Besançon; 11/14 in Reims; and 23/26 in Sofia), and not with any other sensitization to aeroallergens. Shrimp sensitization was present in 13/51 patients allergic to snails, and snail sensitization was present in 13/25 patients sensitized to shrimp. This association was significant but was dependent on HDM sensitization. Among patients allergic to HDM, 18% were sensitized to snails and 10% were sensitized to shrimps. HDM/snail cross-sensitization was more frequent in multi-sensitized atopic patients: 34/41 patients sensitized to snails had positive prick-tests to 2 or more than 2 allergens including HDM. It was not significantly correlated with either past immunotherapy to HDM or previous consumption of snails: 82% never received HDM immunotherapy (61% in France and 100% in Bulgaria) and 63% had never eaten snails (41% in France and 80% in Bulgaria). The prick-n-prick tests using boiled snails had a higher sensitivity to disclose sensitization to snails than commercial extracts. Both commercial extracts had a similar sensitivity but did not identify the same snail-allergic patients. These results show that 1/5 and 1/10 patients allergic to HDM exhibit a sensitization to mollusks and shrimps respectively. Despite previous suggestive observations, cross-sensitization seems independent of previous HDM immunotherapy but is nevertheless strongly associated with atopic condition. It appears independent of mollusk consumption and this suggests that cross-sensitization is related to primary sensitization by the aero-allergen. The relatively high prevalence of sensitization to edible invertebrates in patients allergic to HDM and the potential risk of severe food allergy in these patients should encourage allergists to systematically test mollusks and crustaceans in these patients, especially when they live in countries where eating snails and sea food is common

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[76] - van Ree R, Antonicelli L, Akkerdaas JH, Pajno GB, Barberio G, Corbetta L, et al. Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity. Allergy 1996;51:387-393

A group of 28 patients from Italy was studied who had asthma after consumption of snail. All patients also had asthma and/or rhinitis caused by house-dust mite. RAST analyses confirmed the combined sensitization to snail and mite. In a few sera, IgE antibodies reactive with other foods of invertebrate origin (mussel and shrimp) were detected. RAST inhibition showed that most IgE antibodies against snail were cross-reactive with house-dust mite. In contrast, the mite RAST was not significantly inhibited by snail. This indicates that house-dust mite was the sensitizing agent. Immunoblot analyses revealed multiple bands in snail extract recognized by IgE. In contrast to what has been described for cross-reactivity between shrimp and mite, tropomyosin played only a minor role as a cross-reactive allergen in these patients. The observations in this study indicate that snail consumption can cause severe asthmatic symptoms in house-dust-mite-allergic patients. It might, therefore, be advisable to screen mite-allergic asthma patients for allergy to snail and other invertebrate animal foods.

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[77] - Tomaz E, Pires A, Inácio F, Quaresma R. Tropomyosin`s clinical importance in house dust mite allergic patients. EAACI 25th Congress, Vienna, 10-14 June, 2006, Poster n°991

Background: Tropomyosin is a protein largely distributed through several animal species. In invertebrates, such as house dust mite, crustaceans, silverfish and mollusks, it has been described as an allergic component, sometimes responsible for cross-reactivity. Methods: The purpose of this study was to determine the prevalence of sensitisation to tropomyosin in a house dust mite sensitized population, before and after immunotherapy, and its relationship to sensitisation and/or food allergy to snail, shrimp and Blatella germanica. 169 patients were reviewed (male=89; female=80), mean age 22 years old, allergic to house dust mite, who had performed Tropomyosin specific IgE analyses, before and, at least, after 12 months of immunotherapy. Specific IgE to snail, Blatella germanica and shrimp were analyzed in patients with positive Tropomyosin specific IgE (> 0,35 KuA/L). Patients were asked about allergic symptoms to food, specially crustaceans and mollusks. Results: Tropomyiosin sensitisation prevalence in this population was 3,5% (3 male, 3 female, mean age 19 years old; 50% were already sensitized before immunotherapy, 50% sensitized during immunotherapy). The sensitisation to Tropomyosin is closely associated to the sensitisation to snail, Blatella germanica and shrimp. The prevalence of food allergy is 33% (n=2) among tropomyosin sensitized patients and 2% (n=4) among non sensitized patients. Conclusion: The prevalence of sensitisation to Tropomyosin among this house dust mites allergic population is low (3,5%) and similar to data published by other authors that pointed Tropomyosin as a minor allergen of mites. The patients sensitized to Tropomyosin are also sensitized to species with homologues Tropomyosines, such as snail, Blatella germanica and shrimp. There is a high prevalence of food allergic symptoms to mollusks and crustacean among Tropomyosin sensitized patients. Those aspects come to reinforce the involvement of Tropomyosin on cross-reactivity between invertebrate species.

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[78] - Poulos LM, O'Meara TJ, Hamilton RG, Tovey ER. Inhaled latex allergen (Hev b 1). J Allergy Clin Immunol 2002;109:701-706

Background: IgE-mediated responses to natural rubber latex allergens have become a major health problem among recognized risk groups. Objective: The purpose of this investigation was to measure the amounts of Hevea brasiliensis latex allergen (Hev b 1) inhaled and deposited on surfaces when latex or vinyl gloves were worn and compare the results with the conventional measures (breathing zone samplers) of occupational exposure. Methods: Hev b 1 exposure was measured by nasal sampling and breathing zone sampling. Latex allergen exposure was generated by having each subject don a pair of powdered latex examination gloves and continuing his or her normal daily activity for 30 minutes. By means of adhesive tape, surface dust samples were collected from the surfaces of gloves, the subject's hands, and work areas. Sampling was performed with subjects wearing no gloves, subjects wearing powdered vinyl gloves, subjects wearing powdered latex gloves, and nearby colleagues wearing latex gloves. All samples were assayed through use of the HALOgen assay (Inhalix, Sydney, Australia) with a Hev b 1ˆspecific mAb. Particles transporting latex allergen were identified by a surrounding immunostain halo, and these were quantified and reported as total numbers of particles inhaled, airborne, or found on surface areas evaluated. Results: Study subjects inhaled 26 times more allergen when powdered latex gloves were worn than under the „no glove‰ and powdered vinyl glove conditions. During the same period, Hev b 1 particle levels measured in the ambient air through use of the breathing zone sampler increased by 24-fold. The median numbers of particles carrying Hev b 1 allergen per square centimeter on the surface of the hands after the wearing of latex and vinyl gloves were 1964 and 5, respectively. Latex allergen was physically associated both with cornstarch granules and with larger dust particles having a darker, more irregular appearance. Conclusion: In a laboratory where gloves are worn for protection, the use of latex gloves resulted in a 26-fold increase in inhaled latex allergen over background levels measured while vinyl gloves were worn as controls. Low levels of latex exposure also occurred when vinyl gloves or no gloves were worn; the reasons for this are under investigation.

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[79] - Wu AY, Williams GA. Clinical Characteristics and Pattern of Skin Test Reactivities in Shellfish Allergy Patients in Hong Kong. Allergy Asthma Proc 2004;25:237-242

Allergens from crustaceans and mollusks exhibit extensive cross-reactivity in vitro. However, the degree and pattern of crossreactivity between different shellfish species in vivo is still unclear. The objective of this study was to determine the clinical characteristics of shellfish allergic patients in Hong Kong and the pattern of skin test reactivities to the different species. This cohort study involves patients attending the allergy clinic of a large teaching hospital for suspected shellfish allergy. Each subject underwent skin-prick tests to eight species of shellfish and house-dust mites. Eighty-four consecutive patients were tested. Twenty-eight patients reported a history of severe anaphylaxis. Fourteen patients had no positive shellfish skin test and were excluded. There were 183 positive shellfish skin tests, with an average of 2.61 positive tests per subject. Ninety percent of subjects also had positive skin tests to house-dust mites. Overall, 65.7% of subjects had more than one positive skin test to shellfish. There were strong statistical associations between species belonging to the same order but also between some mollusks and crustaceans. We found a high degree of skin test cross-reactivity between different species of shellfish and between shellfish and house-dust mites. Therefore, patients with a history of shellfish allergy should be cautious with all types of shellfish.

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[80] - Lommerse JP, Thomas-Oates JE, Gielens C, Preaux G, Kamerling JP, Vliegenthart JF. Primary structure of 21 novel monoantennary and diantennary N-linked carbohydrate chains from alphaD-hemocyanin of Helix pomatia. Eur J Biochem 1997;249:195-222

The primary structures of 21 novel monoantennary and diantennary N-glycans of the glycoprotein alphaD-hemocyanin (alphaD-Hc) of Helix pomatia have been determined. Outer oligosaccharide fragments (antennae) were released from the glycoprotein by Smith degradation of an alphaD-Hc pronase digest. The major antenna, obtained following HPLC fractionation on Lichrosorb-NH2, was characterized using 1H-NMR spectroscopy, fast-atom-bombardment mass spectrometry, and linkage analysis, and corresponds to a pentasaccharide fragment. The intact carbohydrate chains of alphaD-Hc were released with peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase-F digestion, separated from the protein on Bio-Gel P-100, and subfractionated on Bio-Gel P-4. A portion of subfractions was reduced with sodium borodeuteride, and the non-reduced and reduced samples were further fractionated on CarboPac PA-1, Lichrosorb-NH2/Lichrosphere-NH2, and/or Lichrosphere-C18. Purified oligosaccharides and oligosaccharide-alditols were analyzed using 500/600-MHz 1H-NMR spectroscopy. In total, four novel types of antenna were identified, namely, [structures: see text] which are all attached to O-2 of alphaMan residues of the trimannosyl-N,N'-diacetylchitobiose core element, which is generally beta-1,2-xylosylated and alpha-1,6-fucosylated, Man(alpha1-6)[Man(alpha1-3)][+/-Xyl(beta1-2)]Man(beta1-4)GlcNAc(beta1-4) [+/-Fuc(alpha1-6)]GlcNAc.

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[81] - van Kuik JA, van Halbeek H, Kamerling JP, Vliegenthart JF. Primary structure of the low-molecular-weight carbohydrate chains of Helix pomatia alpha-hemocyanin. Xylose as a constituent of N-linked oligosaccharides in an animal glycoprotein. J Biol Chem 1985;260:13984-13988

alpha-Hemocyanin of Helix pomatia is a copper-containing glycoprotein which serves as an oxygen carrier in the hemolymph. Its carbohydrate moiety has as constituents fucose, xylose, 3-O-methylgalactose, mannose, galactose, N-acetylgalactosamine, and N-acetyl-glucosamine residues. Alkaline borhydride did not split off any carbohydrate material, suggesting the absence of O-glycosidic chains. The N-glycosidic carbohydrate chains of this glycoprotein were liberated by hydrazinolysis of a Pronase digest then fractionated as alditols on Bio-Gel P-4. The fractions containing the low-molecular-weight glycans were investigated by 500-MHz 1H NMR spectroscopy in conjunction with sugar and methylation analysis. The largest, and most abundant, compound was established to be: (Formula: see text). Another compound was characterized as the afuco analogue of this structure. H. pomatia alpha-hemocyanin is the first example of an animal glycoprotein having xylose as a constituent of N-glycosidic carbohydrate chains.

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[82] - Faye L, Chrispeels MJ. Common antigenic determinants in the glycoproteins of plants, molluscs and insects. Glycoconj J 1988;5:245-256

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[83] - Gutternigg M, Bürgmayr S, Pöltl G, Rudolf J, Staudacher E. Neutral N-glycan patterns of the gastropods Limax maximus, Cepaea hortensis, Planorbarius corneus, Arianta arbustorum and Achatina fulica. Glycoconj J 2007;24:475-489

The N-glycosylation potentials of Limax maximus, Cepaea hortensis, Planorbarius corneus, Arianta arbustorum and Achatina fulica were analysed by investigation of the N-glycan structures of the skin and viscera glycoproteins by a combination of HPLC and mass-spectrometry methods. It is one of the first steps to enlarge the knowledge on the glycosylation abilities of gastropods, which may help to establish new cell culture systems, to uncover new means for pest control for some species, and to identify carbohydrate-epitopes which may be relevant for immune response. All snails analysed contained mainly oligomannosidic and small paucimannosidic structures, often terminated with 3-O-methylated mannoses. The truncated structures carried modifications by beta1-2-linked xylose to the beta-mannose residue, and/or an alpha-fucosylation, mainly alpha1,6-linked to the innermost N-acetylglucosaminyl residue of the core. Many of these structures were missing the terminal N-acetylglucosamine, which has been shown to be a prerequisite for processing to complex N-glycans in the Golgi. In some species (Planorbarius corneus and Achatina fulica) traces of large structures, terminated by 3-O-methylated galactoses and carrying xylose and/or fucose residues, were also detected. In Planorbarius viscera low amounts of terminal alpha1-2-fucosylation were determined. Combining these results, gastropods seem to be capable to produce all kinds of structures ranging from those typical in mammals through to structures similar to those found in plants, insects or nematodes. The detailed knowledge of this very complex glycosylation system of the gastropods will be a valuable tool to understand the principle rules of glycosylation in all organisms.

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