Cohort Profile: The Bern Infant Lung Development Cohort

Childhood asthma resembles a complex syndrome rather than a single disease. Clinical manifestations include cough, shortness of breath and wheeze. Because of its high prevalence, it is of major public health relevance. Presentation and disease course of childhood wheezing disorders vary, and its phenotypes are difficult to distinguish in early childhood despite the demand for diverse therapeutic strategies. Current treatments have no sustained effect on development of lung function and cannot prevent tracking of reduced lung function. Risk factors for childhood wheeze and subsequent asthma include genes, environmental factors and their interaction: all these affect lung development directly or indirectly (Figure 1). Data on the association between lung development and respiratory symptoms in early childhood are mostly derived from small hospital-based studies. Larger epidemiological studies have been based on questionnaires and most studies have been conducted in older children, in high-risk populations or retrospectively. There is a lack of prospectively assessed lung function studies in unselected healthy infants that take into account genetic and environmental factors. However, in order to disentangle the complex interaction of these predisposing factors on lung development and childhood wheeze, relatively large groups of infants need to be studied, with repeated lung function measurements, assessment of environmental and hereditary factors and clinical outcomes. The ‘Bern Infant Lung Development’ (BILD) cohort aims to contribute towards closing this gap. It was set up in 1999 to study physiological properties of the respiratory system and environmental and genetic risk factors affecting lung development in healthy individuals from infancy through childhood in relation to wheeze. How is it funded?