43 research outputs found
Laboratorial approach in the diagnosis of food allergy
OBJCTIVE: Review the available laboratory tests used to assist in the diagnosis of IgE-mediated and non-IgE-mediated food allergy. DATA SOURCES: Papers in English and Portuguese published in PubMed and Embase, in the last ten years. Terms searched were food allergy, diagnose and laboratory, isolated and/or associated. DATA SYNTHESIS: The diagnostic approach to food allergy reactions includes a good medical history, laboratory studies, elimination diets and blinded food challenges. More recently, the use of a quantitative measurement of food-specific IgE antibodies has been shown to be more predictive of symptomatic IgE-mediated food allergy. Food-specific IgE serum levels exceeding the diagnostic values indicate that the patient is greater than 95% likely to experience an allergic reaction if he/she ingests the specific food. Such decision point values have been defined just for some foods and inconsistent results were obtained when allergy to the same food was studied in different centers. Food challenges, in particular the double-blind placebo-controlled food challenge (DBPCFC), represent the most reliable way to establish or rule out food hypersensitivity. CONCLUSIONS: A number of recent developments are improving the predictive value of some laboratory tests for the diagnosis of food allergies. However, to date, no in-vitro or in-vivo test shows full correlation with clinical food allergy and the DBPCFC remains the gold standard for the definitive diagnosis of specific food allergies. There is an urgent need for new and fundamentally improved diagnostic approaches, which must be validated in patients with food allergy confirmed by a positive DBPCFC.OBJETIVO: Revisar os exames laboratoriais disponĂveis utilizados no diagnĂłstico da alergia alimentar mediada ou nĂŁo por IgE. FONTES DE DADOS: Artigos publicados em base de dados PubMed e Embase (lĂngua inglesa e portuguesa) nos Ăşltimos dez anos. As palavras-chave utilizadas como fonte de busca foram alergia alimentar, diagnĂłstico e laboratĂłrio, isolados e/ou associados. SĂŤNTESE DOS DADOS: A abordagem diagnĂłstica das reações alĂ©rgicas a alimentos inclui histĂłria clĂnica completa, estudos laboratoriais, dietas de eliminação e desencadeamentos cegos com alimentos. Recentemente, a medida quantitativa de anticorpos IgE especĂficos a alimentos tem mostrado ser mais preditiva de alergia alimentar sintomática mediada por IgE. NĂveis sĂ©ricos de IgE especĂfica a alimento que excedam os valores diagnĂłsticos indicam que o paciente tem chance maior que 95% de apresentar uma reação alĂ©rgica se ingerir o alimento em questĂŁo. Estes valores de decisĂŁo foram definidos para alguns alimentos e resultados inconsistentes sĂŁo obtidos ao se estudar diferentes populações. Os desencadeamentos com alimento, especialmente o duplo-cego controlado por placebo (DADCCP), representa a maneira mais confiável de estabelecer ou descartar o diagnĂłstico de hipersensibilidade alimentar. CONCLUSĂ•ES: NĂşmero crescente de aquisições tem melhorado o valor preditivo de alguns testes laboratoriais empregados no diagnĂłstico de alergias alimentares. Entretanto, atĂ© hoje, nĂŁo há teste in vitro ou in vivo que mostre correlação completa com a clĂnica da alergia alimentar. O DADCCP continua sendo o padrĂŁo-ouro no diagnĂłstico definitivo de alergia alimentar especĂfica. SĂŁo necessárias, urgentemente, novas abordagens diagnĂłsticas válidadas em pacientes com alergia alimentar confirmada por DADCCP positivo.Universidade Federal de SĂŁo Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PediatriaUNIFESP-EPM Departamento de PediatriaUniversidade de SĂŁo Paulo Faculdade de Medicina Departamento de PediatriaUniversidade Federal da Bahia Departamento de PediatriaUNIFESP-EPMUniversidade Federal do Paraná Departamento de PediatriaUNIFESP, EPM, Depto. de PediatriaUNIFESP, EPM Depto. de PediatriaUNIFESP, EPMSciEL
Serum eosinophil cationic protein in children with atopic dermatitis
BACKGROUND: Eosinophil cationic protein (ECP) is a cytotoxic agent secreted by activated eosinophils during allergic and inflammatory processes. The aim of the study was to determine the ECP level, absolute and relative eosinophil count and IgE antibodies in children with atopic dermatitis (AD) compared with those of nonatopic children, and to assess the correlation of these laboratory parameters with the clinical severity of AD. ----- METHODS: This prospective study comprised 70 children. There were 49 children with AD aged 3-36 months, and the control group comprised 21 children with a negative personal and family history for atopic diseases. Detailed history, serum ECP levels (UniCAP FEIA), relative and absolute eosinophil counts and total serum IgE antibodies were determined in both groups. In the children with AD, skin involvement was measured by the SCORAD index. ----- RESULTS: The calculated SCORAD index was between 16 and 83. IgE antibodies, relative and absolute eosinophil counts showed a significantly wider range of values and a statistically higher median (P 0.05). The same was found for the correlation of serum ECP and intensity of skin changes (r = -0.095) and serum ECP and subjective symptoms (r = -0.045). The correlation was positive, but weak and statistically not significant for the serum ECP and extent of the skin lesions (r = 0.079, P > 0.05). ----- CONCLUSION: Elevated levels of ECP, relative and absolute eosinophil counts, as well as IgE antibodies were determined in the patients with AD. As these laboratory findings did not correlate with the severity of AD, they can be considered only as additional methods in the evaluation of patients with AD