Protocol for a systematic review of the diagnostic test accuracy of tests for IgE-mediated food allergy

Background: The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of updating the guidelines on the diagnosis and management of food allergy. The existing guidelines are based on a systematic review of the literature until 30 September 2012. Therefore, a new systematic review must be undertaken to inform the new guidelines. This systematic review aims to assess the accuracy of index tests to support the diagnosis of IgE-mediated food allergy. Methods: The databases Cochrane CENTRAL (Trials), MEDLINE (OVID) and Embase (OVID) will be searched for diagnostic test accuracy studies from 1 October 2012 to 30 June 2021. Inclusion and exclusion criteria will be used to select appropriate studies. Data from these studies will be extracted and tabulated, and then reviewed for risk of bias and applicability using the QUADAS-2 tool. All evaluations will be done in duplicate. Studies with a high risk of bias and low applicability will be excluded. Meta-analysis will be performed if there are three or more studies of the same index test and food. Results: A protocol for the systematic review and meta-analyses is presented and was registered using Prospero prior to commencing the literature search. Discussion: Oral food challenges are the reference standard for diagnosis but involve considerable risks and resources. This protocol for systematic review aims to assess the accuracy of various tests to diagnose food allergy, which can be useful in both clinical and research settings

Sensibilização Alérgica Em Brasileiros Com Dermatite Atópica: Comparação Entre Os Perfis De Sensibilização A Componentes Alergênicos Em Diferentes Fenótipos

Background: atopic dermatites (AD), the most common cutaneous inflammatory disease and prime manifestation of atopic march, it is mostly IgE-mediated. It is estimated that, in one third of moderate to severe cases, food allergens are involved. In the latest years, the development of molecular allergy has brought a better understanding of the sensitization process and favored the establishment of more precise diagnosis and prognosis. Until now molecular studies with AD patients are scarces. Objectives: (1) analyze the sensitization profile (focusing on food allergens) of different severity of AD by the measurement of specific IgE towards allergens (ImmunoCAP®) and its components on a microarrayed-based platform (ImmunoCAP-ISAC®); (2) compare ImmunoCAP® and ImmunoCAP-ISAC® results; (3) identify cross-reactive components for the studied population. Methods: a cross-sectional study on a tertiary allergy service in São Paulo, Brazil. Patients with non-severe AD (SCORAD5000 vs 791 vs 939,5 kU/l, severe AD, non-severe AD and suspected food allergics, respectively) and sensitization to a broader number of ImmunoCAP® allergens. Molecular analysis revealed association between severe AD and nPen m1 sensitization (46,7% vs 13,8% of non-severe AD). Moderate positive correlation (0,523 to 0,684) were observed to dog’s epithelium ImmunoCAP® and rCan f 1, Blomia tropicalis ImmunoCAP® and rBlo t 5, CAPfx2 and nPen m 1, alpha-lactalbumin ImmunoCAP® and nBos d 4, beta-lactoglobulin ImmunoCAP® and nBos d 5 and casein ImmunoCAP® and n Bos d 8. Correlations between cat’s epithelium ImmunoCAP® and rFel d 1, Dermatophagoides pteronyssinus (Dp) and nDer p 1 and Dp and rDer p 2 were stronger (0,701 to 0,741). Shrimp and house-dust mite tropomyosin and cat serum albumin were the cross-reactive componentes with higher sensitization rates (30% and 13,7%, respectively). Conclusions: in general, severe AD patients were sensitized more often to food allergens compared to non-severe AD patients. There were no difference between the two groups for ImmunoCAP® inhalant allergens. However, molecular analysis showed significantly higher sensitization rates to Blo t 5 and nPen m 1. ImmunoCAP® and ImmunoCAP-ISAC® do not have comparable results. At the present studied population cross-reactive components with higher sensitization rates were tropomyosins and serum albumins.Introdução: A dermatite atópica (DA), doença inflamatória da pele mais comum e manifestação inicial da marcha atópica, cursa com sensibilização alérgica na maioria dos casos. Estima-se que, em um terço dos casos moderados a graves, alérgenos alimentares estejam envolvidos. O desenvolvimento da alergologia molecular permitiu nos últimos anos compreender melhor o processo de sensibilização tornando mais acurado o diagnóstico e inclusive permitindo inferências prognósticas. Ainda são os escassos os estudos envolvendo pacientes com DA. Objetivos: (1) Estudar o padrão de sensibilização alérgica de pacientes com diferentes intensidades de DA, pela mensuração de IgE sérica específica para alérgenos fonte e componentes, usando-se a técnica habitual (ImmunoCAP®) e uma plataforma multiplex (ImmunoCAP-ISAC®); (2) Comparar os resultados das duas técnicas empregadas; (3) Identificar componentes de reatividade cruzada relevantes para a população estudada. Métodos: Estudo transversal realizado em serviço especializado em alergia no município de São Paulo, Brasil. Pacientes com DA não grave (SCORAD 5.000 vs 791 vs 939,5 kU/l, para DA grave, DA não grave e suspeita de AA isolada, respectivamente) e maior número de sensibilizações para alérgenos alimentares e inalantes empregando-se o ImmunoCAP®. O estudo molecular revelou associação entre DA grave e sensibilização para nPen m 1, a tropomiosina do camarão (46,7% vs 13,8% no grupo DA não grave). Quanto à comparação dos resultados pelos dois métodos, foram observadas correlações positivas moderadas (0,523 a 0,684) entre ImmunoCAP® para cão e rCan f 1, ImmunoCAP® para Blomia tropicalis e rBlo t 5, CAP/ fx2 e nPen m 1, ImmunoCAP® para alfa-lactoalbumina e nBos d4, ImmunoCAP® para beta-lactoglobulina e nBos d 5 e entre ImmunoCAP® para caseína e nBos d 8. Já, as correlações entre ImmunoCAP® para gato e rFel d 1, entre Dermatophagoides pteronyssinus (Dp) e nDer p1 e entre Dp e rDer p 2, foram mais fortes (0,701 a 0,741). Os componentes de reatividade cruzada com maiores taxas de sensibilização foram a tropomiosina do camarão e do ácaro (30%) e albumina sérica felina (13,7%). Conclusões: em geral os pacientes com DA grave foram mais sensibilizados a alérgenos alimentares quando comparados àqueles com menor intensidade da doença. Não houve diferença de sensibilização para aeroalérgenos nos dois grupos empregando-se o ImmunoCAP®. Porém, na investigação molecular, aqueles com DA grave tiveram níveis de sensibilização significantemente maiores para o componente rBlo t 5 e nPen m1. Os resultados obtidos pelos métodos ImmunoCAP® e ImmunoCAP-ISAC® mostraram resultados distintos e nos fazem concluir que não são comparáveis. Na população estudada, os componentes de reação cruzada com maior prevalência de sensibilização foram as tropomiosinas e as albuminas séricas.Dados abertos - Sucupira - Teses e dissertações (2017

Elimination diet in food allergy: friend or foe?

Objectives: To review and discuss the role of an elimination diet in food-allergic children, emphasizing nutritional aspects for a better practical approach. Sources: Non-systematic review of the literature. Findings: Under an elimination diet, food-allergic patients may suffer from growth impairment or obesity and compromised quality of life. Disease phenotype, age, type, number of foods excluded, comorbidities, eating difficulties, economic status, and food availability must be considered for an appropriate diet prescription. Diet quality encompasses diversity and degree of food processing, which may alter immune regulation. Conclusions: A friendly food elimination diet prescription depends on a multidisciplinary approach beyond macro and micronutrients

EAACI guidelines on the diagnosis of IgE-mediated food allergy

This European Academy of Allergy and Clinical Immunology guideline provides recommendations for diagnosing IgE-mediated food allergy and was developed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Food allergy diagnosis starts with an allergy-focused clinical history followed by tests to determine IgE sensitization, such as serum allergen-specific IgE (sIgE) and skin prick test (SPT), and the basophil activation test (BAT), if available. Evidence for IgE sensitization should be sought for any suspected foods. The diagnosis of allergy to some foods, such as peanut and cashew nut, is well supported by SPT and serum sIgE, whereas there are less data and the performance of these tests is poorer for other foods, such as wheat and soya. The measurement of sIgE to allergen components such as Ara h 2 from peanut, Cor a 14 from hazelnut and Ana o 3 from cashew can be useful to further support the diagnosis, especially in pollen-sensitized individuals. BAT to peanut and sesame can be used additionally. The reference standard for food allergy diagnosis is the oral food challenge (OFC). OFC should be performed in equivocal cases. For practical reasons, open challenges are suitable in most cases. Reassessment of food allergic children with allergy tests and/or OFCs periodically over time will enable reintroduction of food into the diet in the case of spontaneous acquisition of oral tolerance.</p