RESUMO
BACKGROUND: The aims of this study were to evaluate the allergenicity of boiled and crude lentil extracts and to compare specific IgE binding in tolerant and nontolerant lentil-allergic children. METHODS: Thirty-eight children were studied and divided into three groups. Group I comprised 24 children with a positive open oral challenge, or a convincing history of anaphylaxis after the ingestion of lentils; group II comprised nine children with a history of allergic reactions in the past, but currently tolerant of lentils; and group III comprised five children allergic to other legumes, but always tolerant of the ingestion of lentils. Specific IgE determinations and ELISA inhibitions were performed with the crude and boiled lentil extracts. The allergenic profile of both extracts was evaluated by SDS-PAGE and immunoblot. RESULTS: Mean specific IgE levels in group I were significantly higher than in groups II and III. The heating process caused a significant decrease in specific IgE binding. However, IgE-inhibition studies showed that the boiled lentil extract had a greater inhibitory capacity than the crude extract. Immunoblots revealed no important differences in IgE-binding patterns between the two extracts. Multiple allergens were detected in a wide range of molecular masses. CONCLUSIONS: Boiled lentil extracts maintain strong allergenicity. Patients who have developed tolerance of lentil ingestion have lower specific IgE levels than symptomatic patients.