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 disponíveis utilizados no diagnóstico da alergia alimentar mediada ou não por IgE. FONTES DE DADOS: Artigos publicados em base de dados PubMed e Embase (língua inglesa e portuguesa) nos últimos dez anos. As palavras-chave utilizadas como fonte de busca foram alergia alimentar, diagnóstico e laboratório, isolados e/ou associados. SÍNTESE DOS DADOS: A abordagem diagnóstica das reações alérgicas a alimentos inclui história clínica completa, estudos laboratoriais, dietas de eliminação e desencadeamentos cegos com alimentos. Recentemente, a medida quantitativa de anticorpos IgE específicos a alimentos tem mostrado ser mais preditiva de alergia alimentar sintomática mediada por IgE. Níveis séricos de IgE específica a alimento que excedam os valores diagnósticos indicam que o paciente tem chance maior que 95% de apresentar uma reação alérgica se ingerir o alimento em questão. Estes valores de decisão foram definidos para alguns alimentos e resultados inconsistentes são 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 diagnóstico de hipersensibilidade alimentar. CONCLUSÕES: Número crescente de aquisições tem melhorado o valor preditivo de alguns testes laboratoriais empregados no diagnóstico de alergias alimentares. Entretanto, até hoje, não há teste in vitro ou in vivo que mostre correlação completa com a clínica da alergia alimentar. O DADCCP continua sendo o padrão-ouro no diagnóstico definitivo de alergia alimentar específica. São necessárias, urgentemente, novas abordagens diagnósticas válidadas em pacientes com alergia alimentar confirmada por DADCCP positivo.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PediatriaUNIFESP-EPM Departamento de PediatriaUniversidade de São 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

Rapid Analysis of Listeria monocytogenes Cell Wall Teichoic Acid Carbohydrates by ESI-MS/MS

We report the application of electrospray ionization (ESI) mass spectrometry for compositional characterization of wall teichoic acids (WTA), a major component of Gram-positive bacterial cell walls. Tandem mass spectrometry (ESI-MS/MS) of purified and chemically hydrolyzed monomeric WTA components provided sufficient information to identify WTA monomers and their specific carbohydrate constituents. A lithium matrix was used for ionization of uncharged WTA monomers, and successfully applied to analyze the WTA molecules of four Listeria strains differing in carbohydrate substitution on a conserved polyribitol-phosphate backbone structure. Carbohydrate residues such as N-acetylglucosamine or rhamnose linked to the WTA could directly be identified by ESI-MS/MS, circumventing the need for quantitative analysis by gas chromatography. The presence of a terminal N-acetylglucosamine residue tethered to the ribitol was confirmed using fluorescently labeled wheat-germ agglutinin. In conclusion, the mass spectrometry method described here will greatly facilitate compositional analysis and characterization of teichoic acids and similar macromolecules from diverse bacterial species, and represents a significant advance in the identification of serovar-specific carbohydrates and sugar molecules on bacteria

Contribution of scaling up nutrition Academic Platforms to nutrition capacity strengthening in Africa: local efforts, continental prospects and challenges

Addressing contemporary nutrition problems often require application of knowledge from multiple disciplines. The scaling up nutrition (SUN) movement harnesses multiple sectors for effective global and in-country planning and implementation. Although the role of knowl- edge networks (academia and research institutions) is recognised, the how of engaging knowl- edge networks in the current SUN architecture is only now becoming apparent. For relevant sectors to play their roles effectively, observed capacity gaps, particularly in developing coun- try settings, need to be addressed. The present paper presents the work being undertaken by the Ghana SUN Academic Platform, a local knowledge network, towards strengthening nutrition capacity in Ghana. The Platform presently provides technical support, evidence and capacity towards scaling up effective nutrition interventions in Ghana and beyond. The data presented draws heavily on the observations and collective experiences of the authors in practice, com- plemented by a review of relevant literature. The ultimate goal of the AP is to build capacity of professionals from nutrition and cognate sectors (including planning, agriculture, health, economics, research and academia). This is an essential ingredient for effective and durable SUN efforts. The paper recognises that both disciplinary and interdisciplinary capacity is required for effective SUN efforts in Africa, and offers an approach that utilises cross-sector/inter-professional, peer-learning and experiential learning initiatives

Report / Workshop on Home and Village Prepared Supplementary Food Practices in Asia

Meeting: Asian Congress of Nutrition, 4th, 1-4 Nov. 1983, Bangkok, T

Proceedings of Workshop on Home and Village Prepared Supplementary Food Practices in Asia

Meeting: Workshop on Home and Village Prepared Supplementary Food Practices in Asia, 28-30 Oct. 1983, Bangkok, T

Proceedings of the First Asiafoods Conference

Meeting: Asiafoods Conference, 1st, 17-21 Sept. 1984, Bangkok, T