Les Liliacées

Spices are the most attractive ingredients to confer an authentic taste to food. As they are derived from plants, they harbour allergenic potency and can induce symptoms ranging from mild local to severe systemic reactions. Due to the content of pharmacologically active substances of spices, the diagnosis of allergy and the differentiation from intolerance reactions may be difficult. Association with inhalative allergies via IgE cross-reactivity, but also direct gastrointestinal sensitization plays a role. This article is a botanical and allergological overview of the most important spices and molecules responsible for eliciting IgE-mediated reactions or cross-reactions. As no curative treatments are known at present, strict avoidance is recommended and, therefore, accurate labelling of pre-packed food is necessary.

BACKGROUND: Garlic is well known to cause contact dermatitis and asthma. However, it is a very rare cause of food allergy. We present the case of a 23-year-old woman with previous history of allergy to pollen and dried fruit, and food-dependent, exercise-induced anaphylaxis for which no specific food could be identified as responsible, who experienced an anaphylactic reaction after eating young garlic. METHODS: Skin prick tests and specific IgE immunoassay with several pollens and foods were performed, as well as the prick-prick test with young garlic and SDS-PAGE followed by immunoblotting IgE to young garlic and other Liliaceae species, mustard, sesame, parsley, celery, hazelnut, almond, and pollen of birch and mugwort. RESULTS: Skin prick tests and specific IgE were mainly positive for grass, plane tree, and mugwort pollen; peanut; hazelnut; walnut; almond; and mustard. Prick-prick tests with young garlic and garlic were positive. Total IgE was 113 U/ml. SDS-PAGE immunoblotting showed IgE-binding bands at 12 kDa to young garlic, garlic, onion, and leek extracts. Similar bands could also be detected with mugwort pollen and hazelnut extract. CONCLUSIONS: We describe IgE-mediated reaction to young garlic in a patient sensitized to pollen and dried fruit.

The IgE mediated systemic response caused after ingestion of foods such as seafood, nuts, legumes, eggs, and milk has been well documented. Of interest is garlic and onion, two members of the Liliacaea family, which also includes leek, asparagus chive and numerous flowers and grasses. Garlic has been shown to induce contact dermatitis and urticaria, and inhalation of the dried form has even precipitated asthma exacerbations. In contrast, garlic and onion have seldom been reported causes of anaphylaxis. We report a case of a five year old boy with a history of perennial allergic rhinitis, atopic dermatitis, mild intermittent asthma, and allergy to both peanut and eggs who underwent a life threatening reaction after ingestion of a marinaded steak. He was being treated with cetirizine prn, albuterol via nebulizer prn, Epi Pen Jr.prn, inhalent immunotherapy and food avoidance with good control of his symptoms. The patient ate a steak that was seasoned with „Kraft Greek Vinaigrette Dressing‰ and had an anaphylactic reaction requiring an emergency department visit, intravenous fluids, antihistamines, and corticosteroids. The patient was allergy skin prick tested to the dressing and its major components. He was also rechallenged to peanuts and eggs for which he previously demonstrated a 3+ reaction in 1999. His response showed a 4+ reaction to peanuts and Kraft Greek Vinaigrette Dressing, 3+ response to whole egg, garlic, and histamine, and no response to cantaloupe (which cross reacts with cucumber), lemon, karaya gum and tragacanth gum. Further evaluation consisted of RAST to garlic, onion, cucumber, lemon, and black olives. Since a food challenge would be inappropriate, it cannot be demonstrated conclusively that both items were responsible for his reaction. However, because both garlic and onion are members of the same family and are known to cross-react, and as the patient demonstrated a high positive RAST to both, it can be reasonably concluded that the two ingredients in combination were mediators of his systemic response.

Repeated exposure to garlic dust induced severe asthma in an atopic patient. Subsequently, the patient also developed marked adverse responses after ingestion of garlic. Immunologic investigations carried out in an asymptomatic period revealed significant skin reactivity and bronchospasm after challenge with both garlic dust and extract. The results of a controlled oral challenge test to garlic dust were also positive. The patient's serum contained unusually high quantities of garlic-specific IgE. Cross allergenicity between garlic and other members of the Liliaceae family were documented by the RAST inhibition technique.

The current increase in the prevalence of food allergies appears to have several causes including better screening, improved diagnosis and changes in both the techniques used by food manufacturers and eating habits. Labial food challenge (LFC)is simple, rapid to perform and is associated with only low risks of systemic reaction. It is thus an appealing alternative to the oral food challenge (OFC) for pediatric use. We report a series of 202 LFC performed over two years in 142 children with food allergy suspected from the case history, positive skin prick tests and specific serum IgE assays: 156 LFC were positive; and 46 negative, followed by positive single-blind, placebo-controlled food challenges (SBPCFC). The foods provoking reactions were egg white (75 cases), peanut (60 cases), mustard (23 cases), cow's milk (13 cases), cod (8 cases), kiwi fruit, shrimp (4 cases each), chicken, peanut oil (3 cases each), hazel nuts (2 cases), and snails, apple, fennel, garlic, chilli peppers, pepper, and duck (1 case each). LFC positivity was mostly (89.7% of cases) manifested as a labial edema with contiguous urticaria. There were systemic reactions in 4.5% of cases: generalized urticaria, hoarseness and rapid-onset and generalized eczema. The 46 infants with negative LFC results had positive SBPCFC. The reactions were in 34 cases generalized urticaria, 10 cases asthma attacks, 2 cases early and generalized eczema, and in one case general anaphylactic shock. The sensitivity of the LFC was 77%. The LFC was easy to perform with children. Positive results indicate the presence of food allergy, but negative results require further investigations preferably double-blind, placebo-controlled food challenge (DBPCFC).

BACKGROUND: Garlic (Allium sativum) is one of the most common relishes used in cooking worldwide. Very few garlic allergens have been reported, and garlic allergy has been rarely studied . OBJECTIVE: The aim of the study was to identify allergenic proteins in garlic and to investigate their importance in allergies to other Allium species (leek, shallot, and onion) . METHODS: A crude extract of garlic proteins was separated by SDS-PAGE and 2-dimensional electrophoresis; immunoblotting was then performed with the use of individual and pooled sera from patients with garlic allergy, and the major IgE-binding proteins were analyzed by amino acid sequencing and mass spectrometry. The putative allergens were further purified by chromatography; the antigenicity, allergenicity, and IgE-binding cross-reactivity of the purified protein were then studied by immunoblotting, periodate oxidation, skin tests, and IgE-binding inhibition assays . RESULTS: A major allergen, alliin lyase, was identified by mass spectrometry and Edman sequencing and purified to homogeneity through the use of a simple 2-step chromatographic method. Skin tests showed that the purified protein elicited IgE-mediated hypersensitive responses in patients with garlic allergy. Periodate oxidation showed that carbohydrate groups were involved in the antigenicity, allergenicity, and cross-reactivity. Garlic alliin lyase showed strong cross-reactivity with alliin lyases from other Allium species, namely leek, shallot, and onion . CONCLUSIONS: Alliin lyase was found to be a major garlic allergen in a garlic-allergic group of patients in Taiwan. The wide distribution of alliin lyase in Allium suggests it may be a new cross-reactive allergen.

Introduction: Onion allergy has been very rarely described in the medical literature. We report one of the first cases of true food allergy caused by onions. Case Report: A 45 years old man experienced five episodes of urticaria immediately after eating raw onions. He tolerated cooked onions, and could eat all other fruits and vegetables without any problem. However, he had not been eating peaches since he was young because of oral allergy syndrome and gastric pain. SPT with a large series of seasonal and perennial airborne allergens were negative, whereas the man showed a moderate (3+) to strong (4+) skin reactivity to a large series of plant-derived foods including Rosaceae (Peach peel, plum, almond), legumes (pea, soybean, bean, peanut), nuts (hazelnut, walnut), tomato, orange, garlic, onion, celery, and cereals (maize and rice). We already showed that that both the plum and the peach peel extract do not contain Bet v 1-like allergens nor profilin, and that positive patients have a high probability to react against lipid transfer proteins (1,2). Methods: Serum reactivity to both onion extract and LTP purified from peach peel by chromatographic means (2) was assessed both by ELISA (positive if > 300 OD) and immunoblot. Possible cross-reactivity between onion allergen(s) recognised by patient's serum and peach LTP was assessed by cross-inhibition experiments (2). Pooled sera from strong LTP reactors and from normal subjects were used as positive and negative controls, respectively. Results: The patient strongly reacted against both peach LTP and onion extract (1913 and 1745 OD, respectively). IgE levels in positive and negative control sera were 2402/735 OD and 168/253 OD, respectively. In cross-inhibition studies, peach LTP caused a marked but incomplete inhibition of patient's reactivity against onion (that dropped to 347 OD), and onion extract partially inhibited serum reactivity to peach LTP (that was reduced to 1208 OD). On immunoblot, patient's serum reacted both to a single band at about 15 kDa, and a double band at about 43 kDa in onion extracts. Pre-absorption of serum with peach peel LTP caused the total loss of the 15 kDa reactivity, whereas no change at 43 kDa was noted. Conclusion: This LTP-hypersensitive patient showed IgE reactivity to a double protein band at 43 kDa in onion extract as well. Although it is not possible to demonstrate beyond any doubt which allergenic protein was responsible for the clinical allergy, the fact that none of our > 50 LTP reactors reported onion allergy suggests that the 43 kDa doublet might be the relevant allergen. [aussi: 8th International Symposium on Problems of Food Allergy, Venice 2001, March 11-13]

A case of severe systemic reactions (intense itching, urticaria, confusion, blurred vision, transient loss of consciousness, sweating, tachycardia) after ingestion of raw or lightly-cooked onion is described. The patient, a 44-year-old woman, had no troubles with well-cooked onions. Differently from the cases of sensitivity to onion described in literature, this patient was monosensitized, being skin tests negative to pollens, inhalants and other foods. The patient had 3.7 kU/L of onion-specific segum IgE, as determined by REAST. The density of onion-specific IgE (calculated as percent ratio to total IgE) was 30.8%. The reactivity of patient's serum IgE towards thermolabile and thermostable components has been tested with unheated and heated (30' at 100 degrees C) onion extracts bound to polystyrene beads and tested in the RAST system. Unheated extract resulted positive in class 2, heated extract negative, demonstrating that this patients, differently from similar clinical cases described in literature, had IgE antibodies recognizing just thermolabile onion fraction. This is the first case described in literature of a monosensitization to the thermolabile component of onion, negative also to related foods (Liliacee) and characterized by severe systemic reactions. The importance of specific-IgE density (%) rather their absolute amount (kU/L) as parameter predictive for the clinical severity of allergic reactions is discussed.

BACKGROUND: Asparagus (Asparagus officinalis) is an extensively grown and consumed vegetable. To a lesser extent than other Liliaceae vegetables, allergic contact dermatitis (ACD) due to asparagus has been reported. However, only a few case reports of asparagus IgE-mediated allergy have been published. In a previous study, we demonstrated that two lipid transfer proteins (LTPs) (Aspa o 1.01 and Aspa o 1.02) were relevant allergens of asparagus . OBJECTIVE: We retrospectively analysed the 27 patients diagnosed with asparagus allergy during the last 5 years. All of them reported adverse symptoms after either asparagus ingestion or handling. We describe their clinical features and evaluate whether they were associated to immunological findings (immunoblot pattern and skin reactivity to LTPs) . METHODS: Patients underwent skin prick and patch tests with standard panels of vegetables and aeroallergens. Besides crude asparagus extract, two purified LTPs were prick and patch tested. Total and specific IgE measurements and asparagus extract IgE immunoblotting were performed. Patients reporting asthma symptoms underwent specific inhalation challenge to asparagus . RESULTS: Of the 27 subjects, eight had ACD, 17 had IgE-mediated allergy and two had both ACD- and IgE-mediated allergy. Positive patch tests with the crude asparagus extract but not with LTPs were observed in subjects with ACD (n=10). Of 19 patients with IgE-mediated disease, 10 had contact urticaria after asparagus handling. Of them, five subjects and five others without skin allergy showed respiratory symptoms; of them, eight were diagnosed with occupational asthma confirmed by positive asparagus inhalation challenge, whereas the remaining two had isolated rhinitis. Four patients suffered from immediate allergic reactions related to asparagus ingestion (food allergy); three of them reported anaphylaxis whereas the other had oral allergic syndrome. Positive IgE immunoblotting (bands of 15 and 45-70 kDa) was observed in 10 subjects. Of 10 subjects with positive prick test to LTPs, six showed bands at 15 kDa. Either IgE-binding bands or positive prick tests to LTPs were observed in asthma (62%) and anaphylaxis (67%) . CONCLUSION: Asparagus is a relevant source of occupational allergy inducing ACD and also IgE-mediated reactions. Severe disease (anaphylaxis or asthma) is common and LTPs seem to play a major role. The clinical relevance of LTP sensitization among patients with mild disease or symptom-free subjects should be addressed in prospective studies.

BACKGROUND: Food allergy is quite common in children, but it usually trends to improve with ageing. When an individual has specific IgE to a large variety of foods (multifood allergy) the clinical picture may be of remarkable severity and the avoidance of the offending foods may lead to severe dietary impairment.We describe a case of a child with ascertained multifood allergy. METHODS: The prick-by-prick testing with fresh foods and serum IgE tests were used to evaluate the patient's sensitivity to food allergens. The clinical effect of sensitizations were evaluated by DBPCFC which was carried out for egg, fish, peanuts, walnut, fig, asparagus, orange, chicory, medlar, peach, strawberry and cherry. Each challenge was performed on a separate day. Medical assistance and resuscitation facilities were available during the whole challenge procedures. RESULTS: SPT with fresh food gave a 4 mm wheal for fig, asparagus, cherry and walnut; a 5 mm wheal for medlar and orange; a 6 mm wheal for chicory and strawberry; a 7 mm wheal for fish and peanuts; an 8 mm wheal for peach and a 9 mm wheal for egg. The RAST assay confirmed the presence of specific IgE to egg, fish, peanuts, walnut, fig, orange, strawberry, peach, and cherry. The total serum IgE was 730,6 kU/l.The DBPCFC was positive, at various degrees, for all foods tested according to skin sensitizations. CONCLUSIONS: The case herein described is a true multifood allergy, as confirmed by the DBPCFC. Multifood allergy is not common, but when present it can lead to severe dietary limitation.

The current increase in the prevalence of food allergies appears to have several causes including better screening, improved diagnosis and changes in both the techniques used by food manufacturers and eating habits. Labial food challenge (LFC)is simple, rapid to perform and is associated with only low risks of systemic reaction. It is thus an appealing alternative to the oral food challenge (OFC) for pediatric use. We report a series of 202 LFC performed over two years in 142 children with food allergy suspected from the case history, positive skin prick tests and specific serum IgE assays: 156 LFC were positive; and 46 negative, followed by positive single-blind, placebo-controlled food challenges (SBPCFC). The foods provoking reactions were egg white (75 cases), peanut (60 cases), mustard (23 cases), cow's milk (13 cases), cod (8 cases), kiwi fruit, shrimp (4 cases each), chicken, peanut oil (3 cases each), hazel nuts (2 cases), and snails, apple, fennel, garlic, chilli peppers, pepper, and duck (1 case each). LFC positivity was mostly (89.7% of cases) manifested as a labial edema with contiguous urticaria. There were systemic reactions in 4.5% of cases: generalized urticaria, hoarseness and rapid-onset and generalized eczema. The 46 infants with negative LFC results had positive SBPCFC. The reactions were in 34 cases generalized urticaria, 10 cases asthma attacks, 2 cases early and generalized eczema, and in one case general anaphylactic shock. The sensitivity of the LFC was 77%. The LFC was easy to perform with children. Positive results indicate the presence of food allergy, but negative results require further investigations preferably double-blind, placebo-controlled food challenge (DBPCFC).

BACKGROUND: Garlic dust has not been a frequently encountered cause of IgE-mediated disease . OBJECTIVE: We report on 12 patients (all of them garlic workers) with the clinical criteria for occupational asthma . METHODS: Skin prick tests and serum-specific IgE determinations were performed with common inhalants, garlic, and other members of the Liliaceae family (onion, leek, and asparagus). Bronchial challenge test with garlic powder was performed in all patients. Garlic and onion extract proteins were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Immunoblot and IgE immunoblot inhibition analyses were performed with patients' sera on extracts of garlic, onion, and pollens of Phleum pratense and Chenopodium album . RESULTS: Garlic sensitization was demonstrated by bronchial challenge test in seven patients (group 1) and ruled out in the remaining five (group 2). Clinical data were similar in both groups. The patients with garlic allergy had a mean age of 27 years, and all of them had pollen allergy; sensitization to other members of the Liliaceae family was also common. Electrophoresis of garlic extract revealed two major protein bands at approximately 12 and 54 kd. During IgE immunoblotting, the pool of sera reacted with garlic proteins mainly at 54 kd. Preincubation with onion, Phleum, and Chenopodium partially abolished the IgE binding to several allergens of garlic . CONCLUSION: We report on seven patients in whom an occupational garlic allergy was demonstrated. Garlic allergy is relatively rare but seems to affect young subjects with pollen allergy, and sensitization to other members of the Liliaceae family is common. The results of this study confirm the presence of some structurally similar allergens in garlic, onion, and certain pollens.

Repeated exposure to garlic dust induced severe asthma in an atopic patient. Subsequently, the patient also developed marked adverse responses after ingestion of garlic. Immunologic investigations carried out in an asymptomatic period revealed significant skin reactivity and bronchospasm after challenge with both garlic dust and extract. The results of a controlled oral challenge test to garlic dust were also positive. The patient's serum contained unusually high quantities of garlic-specific IgE. Cross allergenicity between garlic and other members of the Liliaceae family were documented by the RAST inhibition technique.

BACKGROUND: Garlic (Allium sativum) is one of the most common relishes used in cooking worldwide. Very few garlic allergens have been reported, and garlic allergy has been rarely studied . OBJECTIVE: The aim of the study was to identify allergenic proteins in garlic and to investigate their importance in allergies to other Allium species (leek, shallot, and onion) . METHODS: A crude extract of garlic proteins was separated by SDS-PAGE and 2-dimensional electrophoresis; immunoblotting was then performed with the use of individual and pooled sera from patients with garlic allergy, and the major IgE-binding proteins were analyzed by amino acid sequencing and mass spectrometry. The putative allergens were further purified by chromatography; the antigenicity, allergenicity, and IgE-binding cross-reactivity of the purified protein were then studied by immunoblotting, periodate oxidation, skin tests, and IgE-binding inhibition assays . RESULTS: A major allergen, alliin lyase, was identified by mass spectrometry and Edman sequencing and purified to homogeneity through the use of a simple 2-step chromatographic method. Skin tests showed that the purified protein elicited IgE-mediated hypersensitive responses in patients with garlic allergy. Periodate oxidation showed that carbohydrate groups were involved in the antigenicity, allergenicity, and cross-reactivity. Garlic alliin lyase showed strong cross-reactivity with alliin lyases from other Allium species, namely leek, shallot, and onion . CONCLUSIONS: Alliin lyase was found to be a major garlic allergen in a garlic-allergic group of patients in Taiwan. The wide distribution of alliin lyase in Allium suggests it may be a new cross-reactive allergen.

BACKGROUND: Vegetables of the Liliaceae family, such as garlic or onion, have been reported to cause occupational asthma. However, there are few data on adverse reactions to asparagus. We evaluated the role of asparagus as a cause of asthma in a patient with respiratory symptoms occurring at work (horticulture) and studied relevant allergens. METHODS: A 28-year-old man complained of rhinoconjunctivitis and asthma when harvesting asparagus at work. Eating cooked asparagus did not provoke symptoms. A positive skin test reaction was observed with raw asparagus, Alternaria alternata, and grass-pollen extracts. The methacholine test demonstrated mild bronchial hyperresponsiveness. The patient had an immediate asthmatic response after challenge with raw asparagus extract. Bronchial provocation tests with boiled asparagus, A. alternata, and control extracts were negative. Two unexposed subjects with seasonal allergic asthma did not react to the raw asparagus extract. RESULTS: The double-blind, placebo-controlled food challenge with raw asparagus was negative. Serum asparagus-specific IgE was 13.9 kU(A)/l. By SDS-PAGE immunoblot, at least six IgE-binding components, ranging from 22 to 73 kDa, were detected only in raw asparagus. CONCLUSIONS: We report a case of occupational asthma caused by asparagus inhalation, confirmed by specific bronchoprovocation. Immunoblot analysis showed that asparagus allergens are very labile and quite sensitive to heat denaturation

BACKGROUND: Garlic dust has not been a frequently encountered cause of IgE-mediated disease . OBJECTIVE: We report on 12 patients (all of them garlic workers) with the clinical criteria for occupational asthma . METHODS: Skin prick tests and serum-specific IgE determinations were performed with common inhalants, garlic, and other members of the Liliaceae family (onion, leek, and asparagus). Bronchial challenge test with garlic powder was performed in all patients. Garlic and onion extract proteins were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Immunoblot and IgE immunoblot inhibition analyses were performed with patients' sera on extracts of garlic, onion, and pollens of Phleum pratense and Chenopodium album . RESULTS: Garlic sensitization was demonstrated by bronchial challenge test in seven patients (group 1) and ruled out in the remaining five (group 2). Clinical data were similar in both groups. The patients with garlic allergy had a mean age of 27 years, and all of them had pollen allergy; sensitization to other members of the Liliaceae family was also common. Electrophoresis of garlic extract revealed two major protein bands at approximately 12 and 54 kd. During IgE immunoblotting, the pool of sera reacted with garlic proteins mainly at 54 kd. Preincubation with onion, Phleum, and Chenopodium partially abolished the IgE binding to several allergens of garlic . CONCLUSION: We report on seven patients in whom an occupational garlic allergy was demonstrated. Garlic allergy is relatively rare but seems to affect young subjects with pollen allergy, and sensitization to other members of the Liliaceae family is common. The results of this study confirm the presence of some structurally similar allergens in garlic, onion, and certain pollens.

Introduction: Onion allergy has been very rarely described in the medical literature. We report one of the first cases of true food allergy caused by onions. Case Report: A 45 years old man experienced five episodes of urticaria immediately after eating raw onions. He tolerated cooked onions, and could eat all other fruits and vegetables without any problem. However, he had not been eating peaches since he was young because of oral allergy syndrome and gastric pain. SPT with a large series of seasonal and perennial airborne allergens were negative, whereas the man showed a moderate (3+) to strong (4+) skin reactivity to a large series of plant-derived foods including Rosaceae (Peach peel, plum, almond), legumes (pea, soybean, bean, peanut), nuts (hazelnut, walnut), tomato, orange, garlic, onion, celery, and cereals (maize and rice). We already showed that that both the plum and the peach peel extract do not contain Bet v 1-like allergens nor profilin, and that positive patients have a high probability to react against lipid transfer proteins (1,2). Methods: Serum reactivity to both onion extract and LTP purified from peach peel by chromatographic means (2) was assessed both by ELISA (positive if > 300 OD) and immunoblot. Possible cross-reactivity between onion allergen(s) recognised by patient's serum and peach LTP was assessed by cross-inhibition experiments (2). Pooled sera from strong LTP reactors and from normal subjects were used as positive and negative controls, respectively. Results: The patient strongly reacted against both peach LTP and onion extract (1913 and 1745 OD, respectively). IgE levels in positive and negative control sera were 2402/735 OD and 168/253 OD, respectively. In cross-inhibition studies, peach LTP caused a marked but incomplete inhibition of patient's reactivity against onion (that dropped to 347 OD), and onion extract partially inhibited serum reactivity to peach LTP (that was reduced to 1208 OD). On immunoblot, patient's serum reacted both to a single band at about 15 kDa, and a double band at about 43 kDa in onion extracts. Pre-absorption of serum with peach peel LTP caused the total loss of the 15 kDa reactivity, whereas no change at 43 kDa was noted. Conclusion: This LTP-hypersensitive patient showed IgE reactivity to a double protein band at 43 kDa in onion extract as well. Although it is not possible to demonstrate beyond any doubt which allergenic protein was responsible for the clinical allergy, the fact that none of our > 50 LTP reactors reported onion allergy suggests that the 43 kDa doublet might be the relevant allergen. [aussi: 8th International Symposium on Problems of Food Allergy, Venice 2001, March 11-13]

A case of severe systemic reactions (intense itching, urticaria, confusion, blurred vision, transient loss of consciousness, sweating, tachycardia) after ingestion of raw or lightly-cooked onion is described. The patient, a 44-year-old woman, had no troubles with well-cooked onions. Differently from the cases of sensitivity to onion described in literature, this patient was monosensitized, being skin tests negative to pollens, inhalants and other foods. The patient had 3.7 kU/L of onion-specific segum IgE, as determined by REAST. The density of onion-specific IgE (calculated as percent ratio to total IgE) was 30.8%. The reactivity of patient's serum IgE towards thermolabile and thermostable components has been tested with unheated and heated (30' at 100 degrees C) onion extracts bound to polystyrene beads and tested in the RAST system. Unheated extract resulted positive in class 2, heated extract negative, demonstrating that this patients, differently from similar clinical cases described in literature, had IgE antibodies recognizing just thermolabile onion fraction. This is the first case described in literature of a monosensitization to the thermolabile component of onion, negative also to related foods (Liliacee) and characterized by severe systemic reactions. The importance of specific-IgE density (%) rather their absolute amount (kU/L) as parameter predictive for the clinical severity of allergic reactions is discussed.

Two patients experienced itching conjunctivitis, running nose, tightness of the throat and coughing during preparation of fresh asparagus. Eating asparagus after cooking did not provoke any allergic symptoms. Both patients were atopic, sensitized additionally to pollens of grasses and trees as well as to onion. OBJECTIVE: To assess the hypersensitivity reactions to fresh and heated asparagus and to investigate any crossreactivities among the allergens. METHODS: Skin-prick tests were performed with commercial allergens and native asparagus and the patients were tested with Pharmacia CAP system for specific IgE antibodies against asparagus, onion, garlic, birch pollen, mugwort pollen and two recombinant birch pollen allergens, Bet v I and profilin. Inhibition of IgE antibody binding to solid phase homologous and unrelated allergens by increasing doses of liquid allergens (inhibitors) was studied. RESULTS: Skin-prick tests with native green and white asparagus were strongly positive, but negative with cooked asparagus. Both patients had measurable levels of IgE antibodies against asparagus (3.0 and 6.2 kU/L respectively) and several other allergens. One patient was highly sensitive to birch and Bet v I. Both were positive to profilin, mugwort and onion. In all cases the antibody uptake could be extensively and specifically inhibited by homologous allergen. The asparagus-specific IgE antibodies of the two patients could only be inhibited by asparagus. No inhibition was obtained after heating of the asparagus extract to 100 degrees C. CONCLUSIONS: The patients were specifically sensitized by asparagus. No immunological crossreactions could be observed. The measurements of IgE antibodies to other allergens were also specific, representing parallel multiple sensitivity. Profilin inhibited profilin-specific IgE binding but did not react with the asparagus-specific IgE antibodies of these patients. The asparagus allergen recognized by the specific IgE antibodies of these patients was thermolabile.

BACKGROUND: Vegetables of the Liliaceae family, such as garlic or onion, have been reported to cause occupational asthma. However, there are few data on adverse reactions to asparagus. We evaluated the role of asparagus as a cause of asthma in a patient with respiratory symptoms occurring at work (horticulture) and studied relevant allergens. METHODS: A 28-year-old man complained of rhinoconjunctivitis and asthma when harvesting asparagus at work. Eating cooked asparagus did not provoke symptoms. A positive skin test reaction was observed with raw asparagus, Alternaria alternata, and grass-pollen extracts. The methacholine test demonstrated mild bronchial hyperresponsiveness. The patient had an immediate asthmatic response after challenge with raw asparagus extract. Bronchial provocation tests with boiled asparagus, A. alternata, and control extracts were negative. Two unexposed subjects with seasonal allergic asthma did not react to the raw asparagus extract. RESULTS: The double-blind, placebo-controlled food challenge with raw asparagus was negative. Serum asparagus-specific IgE was 13.9 kU(A)/l. By SDS-PAGE immunoblot, at least six IgE-binding components, ranging from 22 to 73 kDa, were detected only in raw asparagus. CONCLUSIONS: We report a case of occupational asthma caused by asparagus inhalation, confirmed by specific bronchoprovocation. Immunoblot analysis showed that asparagus allergens are very labile and quite sensitive to heat denaturation

BACKGROUND: Asparagus (Asparagus officinalis) is an extensively grown and consumed vegetable. To a lesser extent than other Liliaceae vegetables, allergic contact dermatitis (ACD) due to asparagus has been reported. However, only a few case reports of asparagus IgE-mediated allergy have been published. In a previous study, we demonstrated that two lipid transfer proteins (LTPs) (Aspa o 1.01 and Aspa o 1.02) were relevant allergens of asparagus . OBJECTIVE: We retrospectively analysed the 27 patients diagnosed with asparagus allergy during the last 5 years. All of them reported adverse symptoms after either asparagus ingestion or handling. We describe their clinical features and evaluate whether they were associated to immunological findings (immunoblot pattern and skin reactivity to LTPs) . METHODS: Patients underwent skin prick and patch tests with standard panels of vegetables and aeroallergens. Besides crude asparagus extract, two purified LTPs were prick and patch tested. Total and specific IgE measurements and asparagus extract IgE immunoblotting were performed. Patients reporting asthma symptoms underwent specific inhalation challenge to asparagus . RESULTS: Of the 27 subjects, eight had ACD, 17 had IgE-mediated allergy and two had both ACD- and IgE-mediated allergy. Positive patch tests with the crude asparagus extract but not with LTPs were observed in subjects with ACD (n=10). Of 19 patients with IgE-mediated disease, 10 had contact urticaria after asparagus handling. Of them, five subjects and five others without skin allergy showed respiratory symptoms; of them, eight were diagnosed with occupational asthma confirmed by positive asparagus inhalation challenge, whereas the remaining two had isolated rhinitis. Four patients suffered from immediate allergic reactions related to asparagus ingestion (food allergy); three of them reported anaphylaxis whereas the other had oral allergic syndrome. Positive IgE immunoblotting (bands of 15 and 45-70 kDa) was observed in 10 subjects. Of 10 subjects with positive prick test to LTPs, six showed bands at 15 kDa. Either IgE-binding bands or positive prick tests to LTPs were observed in asthma (62%) and anaphylaxis (67%) . CONCLUSION: Asparagus is a relevant source of occupational allergy inducing ACD and also IgE-mediated reactions. Severe disease (anaphylaxis or asthma) is common and LTPs seem to play a major role. The clinical relevance of LTP sensitization among patients with mild disease or symptom-free subjects should be addressed in prospective studies.

BACKGROUND: Garlic dust has not been a frequently encountered cause of IgE-mediated disease . OBJECTIVE: We report on 12 patients (all of them garlic workers) with the clinical criteria for occupational asthma . METHODS: Skin prick tests and serum-specific IgE determinations were performed with common inhalants, garlic, and other members of the Liliaceae family (onion, leek, and asparagus). Bronchial challenge test with garlic powder was performed in all patients. Garlic and onion extract proteins were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Immunoblot and IgE immunoblot inhibition analyses were performed with patients' sera on extracts of garlic, onion, and pollens of Phleum pratense and Chenopodium album . RESULTS: Garlic sensitization was demonstrated by bronchial challenge test in seven patients (group 1) and ruled out in the remaining five (group 2). Clinical data were similar in both groups. The patients with garlic allergy had a mean age of 27 years, and all of them had pollen allergy; sensitization to other members of the Liliaceae family was also common. Electrophoresis of garlic extract revealed two major protein bands at approximately 12 and 54 kd. During IgE immunoblotting, the pool of sera reacted with garlic proteins mainly at 54 kd. Preincubation with onion, Phleum, and Chenopodium partially abolished the IgE binding to several allergens of garlic . CONCLUSION: We report on seven patients in whom an occupational garlic allergy was demonstrated. Garlic allergy is relatively rare but seems to affect young subjects with pollen allergy, and sensitization to other members of the Liliaceae family is common. The results of this study confirm the presence of some structurally similar allergens in garlic, onion, and certain pollens.

Introduction: Onion allergy has been very rarely described in the medical literature. We report one of the first cases of true food allergy caused by onions. Case Report: A 45 years old man experienced five episodes of urticaria immediately after eating raw onions. He tolerated cooked onions, and could eat all other fruits and vegetables without any problem. However, he had not been eating peaches since he was young because of oral allergy syndrome and gastric pain. SPT with a large series of seasonal and perennial airborne allergens were negative, whereas the man showed a moderate (3+) to strong (4+) skin reactivity to a large series of plant-derived foods including Rosaceae (Peach peel, plum, almond), legumes (pea, soybean, bean, peanut), nuts (hazelnut, walnut), tomato, orange, garlic, onion, celery, and cereals (maize and rice). We already showed that that both the plum and the peach peel extract do not contain Bet v 1-like allergens nor profilin, and that positive patients have a high probability to react against lipid transfer proteins (1,2). Methods: Serum reactivity to both onion extract and LTP purified from peach peel by chromatographic means (2) was assessed both by ELISA (positive if > 300 OD) and immunoblot. Possible cross-reactivity between onion allergen(s) recognised by patient's serum and peach LTP was assessed by cross-inhibition experiments (2). Pooled sera from strong LTP reactors and from normal subjects were used as positive and negative controls, respectively. Results: The patient strongly reacted against both peach LTP and onion extract (1913 and 1745 OD, respectively). IgE levels in positive and negative control sera were 2402/735 OD and 168/253 OD, respectively. In cross-inhibition studies, peach LTP caused a marked but incomplete inhibition of patient's reactivity against onion (that dropped to 347 OD), and onion extract partially inhibited serum reactivity to peach LTP (that was reduced to 1208 OD). On immunoblot, patient's serum reacted both to a single band at about 15 kDa, and a double band at about 43 kDa in onion extracts. Pre-absorption of serum with peach peel LTP caused the total loss of the 15 kDa reactivity, whereas no change at 43 kDa was noted. Conclusion: This LTP-hypersensitive patient showed IgE reactivity to a double protein band at 43 kDa in onion extract as well. Although it is not possible to demonstrate beyond any doubt which allergenic protein was responsible for the clinical allergy, the fact that none of our > 50 LTP reactors reported onion allergy suggests that the 43 kDa doublet might be the relevant allergen. [aussi: 8th International Symposium on Problems of Food Allergy, Venice 2001, March 11-13]

A case of severe systemic reactions (intense itching, urticaria, confusion, blurred vision, transient loss of consciousness, sweating, tachycardia) after ingestion of raw or lightly-cooked onion is described. The patient, a 44-year-old woman, had no troubles with well-cooked onions. Differently from the cases of sensitivity to onion described in literature, this patient was monosensitized, being skin tests negative to pollens, inhalants and other foods. The patient had 3.7 kU/L of onion-specific segum IgE, as determined by REAST. The density of onion-specific IgE (calculated as percent ratio to total IgE) was 30.8%. The reactivity of patient's serum IgE towards thermolabile and thermostable components has been tested with unheated and heated (30' at 100 degrees C) onion extracts bound to polystyrene beads and tested in the RAST system. Unheated extract resulted positive in class 2, heated extract negative, demonstrating that this patients, differently from similar clinical cases described in literature, had IgE antibodies recognizing just thermolabile onion fraction. This is the first case described in literature of a monosensitization to the thermolabile component of onion, negative also to related foods (Liliacee) and characterized by severe systemic reactions. The importance of specific-IgE density (%) rather their absolute amount (kU/L) as parameter predictive for the clinical severity of allergic reactions is discussed.