Asthma and allergies in farming environments – The PASTURE/FORALLVENT/EFRAIM-Project

Background: Cross-sectional studies in farming and rural environments (ALEX, PARSIFAL) revealed new hints about protective effects of contact to farm animals and the consumption of farm milk on asthma, atopy, and hay fever. Therefore, the prospective birth cohort study PASTURE among farming and non-farming populations was started in 2002 funded by the European Commission. The aim was to assess the role of indoor exposure to microbes and to investigate immunological and genetic mechanisms. The cohort was followed up by FORALLVENT (2006–2008) and EFRAIM (2008–2012). Material and Methods: In total, 1133 children (46.8% from farming families) were recruited in 5 European counties (Austria, Finland, France, Germany, and Switzerland). Yearly detailed questionnaire data and diary data (first year of living) were obtained asking about respiratory diseases, activities on farms, and life style. In blood samples from cord blood and at the age 1, 4.5, and 6 years the T-cell and B-cell response was assessed; genetic markers and mRNA were measured. Furthermore, breast milk, cow's milk, faeces, and diverse dust samples (mattress, indoor floor, cow's shed) were available in the biobank for different time points. Skin examinations and lung function measurement were performed. Questionnaire data and blood samples of siblings were additionally collected. Results from first cord blood analyses Exposure to farming environment and working activities on farms of mothers during pregnancy affected the cytokine- and IgE-expression. Specific IgE to allergens was associated with reduced IFN-gamma and with maternal immunity to Toxoplasma gondii and rubella virus. Maternal vitamin D intake during pregnancy increased gene expression of ILT3 and ILT4. Discussion: In future, the interdisciplinary project team expects a better understanding of the mechanisms of developing allergic immune response. New insights into the observed strong protective effects will allow to identify necessary steps for further development of preventive strategies for asthma and allergies in childhood.