The EFRAIM project was the continuation of the assessment of the PASTURE birth cohort. In addition the EFRAIM project comprised further analysis of blood and environmental samples collected from the cohorts between birth and age six years, as well as more data analysis.
PASTURE is a birth cohort of children born to farm and non-farm women from rural areas across Europe. Five study centres in Austria, Germany, Finland, France and Switzerland enrolled over 1,000 children. The presence of asthma and allergic illnesses was assessed in the parents before their child’s birth and in the children at birth, at age 2 and 12 months. Particular attention was given to environmental microbial and dietary exposure as well as to the child’s maturing immune response early in life. In addition genetic factors were taken into account.
In part supported by the FORALLVENT EU-project, and in part by the 5 field centres own funding, the contact to the cohorts was maintained by follow up questionnaire assessments at age 1.5, two, three, four and five years. Furthermore, environmental samples for microbial and dietary determinants were collected. Maturation of the immune system was again investigated in blood samples collected at age 4.5 years.
EFRAIM was the continuation of follow up of the PASTURE birth cohort until age 6. The assessment included a comprehensive questionnaire on health and environ-mental exposures. A clinical examination comprised the assessment of the prevalence of atopic dermatitis. Comparable to a routine clinical assessment, a lung function test determined respiratory parameters. Concentrations of exhaled nitric oxide were measured to identify inflammatory airway responses in the cohort children. Atopic sensitization was determined as the presence of specific serum IgE antibodies against common inhalant and food allergens. Investigations on the development of the innate and adaptive immune response continued in blood samples of the 6 year olds. These measures included the assessment of gene expression of receptors for the recognition of microbial molecules, the investigation of the differentiation and function of immunologically active blood cells and the assessment of molecules stimulating and modulating the adaptive immune response. Moreover, environmental samples were collected again for the follow up of microbial and dietary exposures in the cohort.
Many PASTURE samples which had been collected before age 6 not yet had been analysed. The EFRAIM project provided financial resources for the continuation of this work. Early life factors were particularly addressed such as putatively protective factors in breast milk and serum markers of the antioxidant vitamins E and D. Serum levels of ω3- and ω6- polyunsaturated fatty acids and their ratio were determined and were related to allergic outcomes. Mucosal barrier function was measured by different direct and indirect markers. Relevant qualitative and quantitative microbial exposure was assessed by fingerprinting of faecal, cow’s milk and house dust samples collected in the first years of life. Epigenetic phenomena were analysed in blood samples taken at different time points.
The availability of large numbers of consecutive samples covering immune responses on different levels (receptors, RNA, signalling and modulating proteins, regulating cytokines, immunologically active cells) and genetic information in the five rural birth cohorts allowed dissecting the maturation of the immune system under well defined environmental conditions in utero up to school age as shown schematically in the figure below.
To meet the challenge of this large study, a consortium of experts of several European countries accumulated and shared expertise in the fields of immunology, genetics, microbiology, epidemiology, paediatrics, dust analysis, statistics, milk sciences and vaccine development. The consortium provided laboratory facilities of high standards and up to date methodology.