Specific IgE and IgG measured by the MeDALL allergen-chip depend on allergen and route of exposure: The EGEA study

Background: The nature of allergens and route and dose of exposure may affect the natural development of IgE and IgG responses. Objective: We sought to investigate the natural IgE and IgG responses toward a large panel of respiratory and food allergens in subjects exposed to different respiratory allergen loads. Methods: A cross-sectional analysis was conducted in 340 adults of the EGEA (Epidemiological study of the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy) (170 with and 170 without asthma) cohort. IgE and IgG responses to 47 inhalant and food allergen components were analyzed in sera using allergen microarray and compared between 5 French regions according to the route of allergen exposure (inhaled vs food allergens). Results: Overall 48.8% of the population had allergen-specific IgE levels of 0.3 ISAC standardized units (ISU) or more to at least 1 of the 47 allergens with no significant differences across the regions. For ubiquitous respiratory allergens (ie, grass, olive/ash pollen, house dust mites), specific IgE did not show marked differences between regions and specific IgG (≥0.5 ISU) was present in most subjects everywhere. For regionally occurring pollen allergens (ragweed, birch, cypress), IgE sensitization was significantly associated with regional pollen exposure. For airborne allergens cross-reacting with food allergens, frequent IgG recognition was observed even in regions with low allergen prevalence (Bet v 1) or for allergens less frequently recognized by IgE (profilins). Conclusions: The variability in allergen-specific IgE and IgG frequencies depends on exposure, route of exposure, and overall immunogenicity of the allergen. Allergen contact by the oral route might preferentially induce IgG responses.The study was supported in part by Inserm Aviesan Itmo santé publique, the Scientific committee “AGIR for chronic diseases,” grant F4605 of the Austrian Science Fund (FWF [Fonds zur Förderung der wissenschaftlichen Forschung]) to R.V. and by the European Commission's Seventh Framework 29 Program MeDALL under grant agreement no. 261357

Mechanisms of the Development of Allergy (MeDALL): Introducing novel concepts in allergy phenotypes

Asthma, rhinitis, and eczema are complex diseases with multiple genetic and environmental factors interlinked through IgE-associated and non-IgE-associated mechanisms. Mechanisms of the Development of ALLergy (MeDALL; EU FP7-CP-IP; project no: 261357; 2010-2015) studied the complex links of allergic diseases at the clinical and mechanistic levels by linking epidemiologic, clinical, and mechanistic research, including in vivo and in vitro models. MeDALL integrated 14 European birth cohorts, including 44,010 participants and 160 cohort follow-ups between pregnancy and age 20 years. Thirteen thousand children were prospectively followed after puberty by using a newly standardized MeDALL Core Questionnaire. A microarray developed for allergen molecules with increased IgE sensitivity was obtained for 3,292 children. Estimates of air pollution exposure from previous studies were available for 10,000 children. Omics data included those from historical genome-wide association studies (23,000 children) and DNA methylation (2,173), targeted multiplex biomarker (1,427), and transcriptomic (723) studies. Using classical epidemiology and machine-learning methods in 16,147 children aged 4 years and 11,080 children aged 8 years, MeDALL showed the multimorbidity of eczema, rhinitis, and asthma and estimated that only 38% of multimorbidity was attributable to IgE sensitization. MeDALL has proposed a new vision of multimorbidity independent of IgE sensitization, and has shown that monosensitization and polysensitization represent 2 distinct phenotypes. The translational component of MeDALL is shown by the identification of a novel allergic phenotype characterized by polysensitization and multimorbidity, which is associated with the frequency, persistence, and severity of allergic symptoms. The results of MeDALL will help integrate personalized, predictive, preventative, and participatory approaches in allergic diseases

MACVIA Clinical Decision Algorithm in Allergic Rhinitis in adolescents and adults

International audienceThe selection of pharmacotherapy for patients with allergic rhinitis depends on several factors, including age, prominent symptoms, symptom severity, control of allergic rhinitis, patient preferences and cost. Allergen exposure and resulting symptoms vary and treatment adjustment is required. Clinical decision support systems (CDSS) may be beneficial for the assessment of disease control. Clinical decision support systems should be based on the best evidence and algorithms to aid patients and health care professionals to jointly determine the treatment and its step-up or step-down strategy depending on AR control. MACVIA-LR (Fighting chronic diseases for active and healthy ageing) one of the reference sites of the European Innovation Partnership on Active and Healthy Ageing, has initiated an allergy sentinel network (MASK: MACVIA-ARIA Sentinel networK). A clinical decision support system is currently being developed to optimize allergic rhinitis control. An algorithm developed by consensus is presented in this paper. This algorithm should be confirmed by appropriate trials