Allergy to lentils in Mediterranean pediatric patients.

BACKGROUND: Peanuts and soybeans are the major legumes involved in human food allergy; however, scarce data exist on adverse reactions to other temperate legumes, such as lentils. OBJECTIVE: The purpose of this study was to identify patients who are allergic to lentils, to assess clinical features and other associated food allergies, and to characterize allergens in lentil extract. METHODS: Twenty-two children each with a history of adverse reactions to lentils were enrolled in the study. The diagnosis of lentil allergy was based on food challenges or a convincing history of anaphylaxis, with positive skin tests and/or specific serum IgE to lentils. Lentil components were characterized by SDS-PAGE immunoblotting. RESULTS: Twenty of 22 subjects had symptomatic allergy to lentils at the diagnostic time. The most frequent symptoms were oropharyngeal symptoms (40%) and acute urticaria (30%); 3 patients also reported symptoms when they were exposed to steam from cooked lentils. In 18 patients, symptoms after lentil ingestion started under 4 years of age (median, 2.7 years). Nine patients had allergic reactions to other legumes: chick peas (6 patients), peas (2 patients), and green beans (1 patient). Immunoblotting patterns obtained with patients' sera showed IgE-binding bands ranging from 14 to 84 kd. Five sera recognized 9 or more IgE-binding bands, and more than 50% of patients who were tested have specific IgE antibodies to 7 components in lentil extract. CONCLUSION: Allergic reactions to lentils started early in life, usually below 4 years of age; oropharyngeal symptoms and acute urticaria were the most common symptoms through ingestion, and symptomatic reactivity to chick peas is frequently associated.

Cross-reactivity of IgE-binding components between boiled Atlantic shrimp and German cockroach.

IgE-antibody reactivity to boiled Atlantic shrimp (Pandalus borealis) and German cockroach (Blattella germanica) of sera from 89 patients, sensitive to one or the other, was investigated with an enzymatic immunoassay for specific IgE detection (CAP-FEIA System, Pharmacia, Sweden). IgE serum levels to both antishrimp and anticockroach allergens were found to be positive in 76 of the 89 (85.4%) tested sera. A positive anticockroach IgE was very rare in the absence of detectable antishrimp IgE (five of 89 sera). Linear regression analysis on antishrimp and anti-German cockroach IgE levels-log plot revealed a correlation coefficient (r) of 0.73. Inhibition experiments showed that boiled Atlantic shrimp extract inhibited CAP with German cockroach, and vice versa. Immunoblotting showed the strongest IgE binding for both allergenic extracts between 30 and 43 kDa. By blot inhibition, the binding capacity of German cockroach was totally abolished by Atlantic shrimp extract, while German cockroach extract only partially IgE binding to Atlantic shrimp. Cross-reactivity exists between shrimp, an important food allergen, and German cockroach, which has an increasing role in allergic asthma. It could be important to determine the clinical significance of cross-allergy to both allergens, in which exposures occur in different ways.

[Relationship between the degree of specific IgE sensitization to food allergens and the appearance of clinical manifestations]. / Relación entre el grado de sensibilización IgE específica a alérgenos alimentarios y la aparición de manifestaciones clínicas.

AIMS: To assess distribution and correlation between serum concentrations of specific IgE for food allergens and clinical symptoms after exposure. PATIENTS AND METHODS: Four hundred and thirty seven allergic children with 1097 sensitizations to food allergens, confirmed by prick-test and/or Phadezym RAST, were evaluated. From these sensitizations, 558 were associated to clinical symptoms after food intake (SFS), demonstrated by clinical history and/or open oral provocation, and 539 were asymptomatic food sensitizations (AFS). RESULTS: In these patients, the most frequent values of serum specific IgE (44%) were found in the 0.7 and 3.5 PRU/ml range, although in 18% of the cases no specific IgE was detected. Some differences in this distribution exist for different groups of food allergen, with predominance of negative results for food of the rosaceae group. On the contrary, specific IgE values higher than 17.5 PRU/ml are predominant for fish allergens. There is a statistically significant correlation (chi 2 p < 0.001) between anti-food allergen specific IgE concentrations and the clinical symptoms occurred after intake, so the serum specific IgE values between 0.35 and 3.5 PRU/ml are present with higher frequency in the AFS, while values higher than 17.5 PRU/ml are found with a statistically significant higher frequency in the SFS. When different food groups are evaluated separately, some mild differences exist. CONCLUSIONS: A statistically significant correlation between anti-food allergen specific IgE concentrations and the clinical symptoms ocurred after intake. Therefore, specific IgE quantitative assessment and its relationship to clinical symptoms may be of great interest in the management of food allergy.