Anafilaxia à lapa: um caso clínico raro / Limpet anaphylaxis: a rare case

A lapa (Patella vulgata) é um molusco frequentemente encontrado em regiões costeiras com clima quente. A alergia alimentar à lapa é muito rara, com poucos casos descritos na literatura. Os autores descrevem um caso de anafilaxia à lapa, com evidência de reação de hipersensibilidade do tipo I, através de IgE específica positiva à lapa, tanto com métodos in vivo, como in vitro.

Limpet (Patella vulgata) is a mollusk mainly found in warm coastal regions. Limpet allergy is considered rare, and few cases can be found in the literature. We describe a clinical case of limpet anaphylaxis, including in vitro and in vivo evidence of IgE mechanism involvement.

Guia prático de urticária aguda / Practical guide to acute urticaria

A urticária aguda é uma causa frequente de consulta com alergistas, caracterizada por urticas e/ou angioedema. Embora autolimitada e benigna, pode causar desconforto significativo e raramente representar uma doença sistêmica grave ou reação alérgica com risco de vida. Nesta revisão, elaborada pelo Departamento Científico de Urticária da Associação Brasileira de Alergia e Imunologia, foram abordadas as principais questões referentes ao tema para auxiliar o médico especialista e generalista.

Acute urticaria is a frequent cause of consultations with allergists, being characterized by wheals and/or angioedema. Although self-limited and benign, it may cause significant discomfort and uncommonly represent a serious systemic disease or life-threatening allergic reaction. In this review prepared by the Urticaria Scientific Department of the Brazilian Association of Allergy and Immunology, the main questions about this topic are addressed to help specialists and general practitioners.

Correlação entre o autodiagnóstico de alergia alimentar e a presença de IgE específica / Correlation between self-diagnosis of food allergy and presence of specific IgE

Introdução: Nos últimos anos a prevalência de alergia alimentar tem aumentado, contudo, o número de autodiagnósticos errados, também. Essa superestimação dos diagnósticos, frequentemente, culmina em dietas restritivas desnecessárias que podem, muitas vezes, ocasionar mais danos do que benefícios para a saúde. Objetivo: Avaliar a relação entre o autodiagnóstico de alergia alimentar e a presença de IgE específica para o referido alimento. Método: Trata-se de um estudo transversal e observacional que avaliou 100 pacientes que aceitaram participar da pesquisa, com idade entre 18 e 75 anos, por meio de um questionário próprio para investigação do autodiagnóstico de doenças alérgicas e um teste cutâneo de leitura imediata ou prick test para detecção de IgE específica para alimentos que podem induzir a uma reação alérgica. Resultados: Foram aplicados e analisados 100 questionários em voluntários na faixa etária de 18 a 75 anos. Destes, 35 pacientes afirmaram ter alergia alimentar durante a aplicação do questionário. Apenas 10 tiveram resultado positivo ao prick test. A maioria dos resultados positivos no prick test estavam associados ao camarão, ao amendoim e ao caranguejo. Conclusão: O presente estudo evidenciou uma importante superestimação do número de autodiagnósticos de alergias alimentares, sendo o número de pacientes que se autodeclararam alérgicos a alimentos consideravelmente maior do que os resultados positivos no prick test. Constata-se que é necessário mais estudos que possuam em sua metodologia informações pré e pós-testes diagnósticos de alergia alimentar, para uma correta avaliação da proporção de casos.

Introduction: In recent years, the prevalence of food allergy has increased, as well as the number of incorrect self-diagnoses. This overestimation of diagnoses often culminates in unnecessary restrictive diets that may cause more harm than benefits to health. Objective: To evaluate the relationship between self-diagnosis of food allergy and the presence of specific IgE for that food. Method: This is a cross-sectional and observational study that evaluated 100 patients who agreed to participate in the research, aged between 18 and 75 years. A questionnaire was used to investigate the self-diagnosis of allergic diseases, and a skin prick test was used to detect food-specific IgE that may induce an allergic reaction. Results: One hundred questionnaires were administered and analyzed in volunteers aged from 18 to 75 years. Of these, 35 patients claimed to have food allergy during the administration of the questionnaire. Only 10 tested positive on the prick test. Most positive prick test results were associated with shrimp, peanut, and crab. Conclusion: The present study showed an important overestimation of the number of self-diagnosed food allergies, as the number of patients who self-reported being allergic to food was considerably greater than that of positive prick test results. More studies that have in their methods pre- and post-diagnostic information from food allergy tests are needed for a correct assessment of the proportion of cases.

Detecting Allergens From Black Tiger Shrimp Penaeus monodon That Can Bind and Cross-link IgE by ELISA, Western Blot, and a Humanized Rat Basophilic Leukemia Reporter Cell Line RS-ATL8

BACKGROUND: Black tiger shrimp Penaeus monodon is one of the common causes of shellfish allergy that is increasing worldwide. One of the important problems in the management of shellfish allergy is the lack of accurate diagnostic assay because the biological and immunological properties of allergens in black tiger shrimp have not been well characterized. This study aims to detect proteins with the ability to bind and cross-link immunoglobulin E (IgE) from black tiger shrimp by enzyme-linked immunosorbent assay (ELISA), Western blot, and a humanized rat basophilic leukemia reporter cell line RS-ATL8. METHODS: Sera from shrimp allergic subjects were subjected to ELISA and Western blots using raw or cooked shrimp extract as antigens. Pooled sera were used to sensitize the RS-ATL8 reporter cell line and cells were activated by shrimp extract. Eluted protein extracts separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were tested on the RS-ATL8 cell line and subjected to mass spectrometry to identify potential candidate allergens. RESULTS: Allergic sera reacted stronger to raw shrimp extract than cooked shrimp extract (P=0.009). Western blot demonstrated that major IgE reactivity protein bands were at 32–39 kDa and 91–230 kDa in both raw and cooked shrimp extracts. The eluted protein bands at the molecular weight of 38 and 115 kDa from raw shrimp extract induced IgE cross-linking as assayed by the RS-ATL8 cell line. These protein bands were subjected to mass spectrometry for analysis. Ubiquitin-activating enzyme and crustacyanin were identified as potential candidate novel shrimp allergens. CONCLUSIONS: The RS-ATL8 reporter cell line can be used to identify potential new shrimp allergens that can functionally cross-link IgE and induce mast cell degranulation.