Respiratory Syncytial Virus Bronchiolitis and Asthma - Insights from Recent Studies and Implications for Therapy

Infection with respiratory syncytial virus (RSV) is a leading cause of upper and lower respiratory tract infection in infants. It is accompanied by a considerably disease burden and a hospitalisation rate of up to 3% in infected infants. Besides, it is still a matter of intensive discussion whether severe RSV infection in early infancy causes the development of asthma later in live or whether RSV bronchiolitis just chronologically precedes asthma in children who are susceptible to asthma. The latter could be due to a common genetic background of both diseases predisposing to an exaggerated inflammatory response of the lungs to allergens and pathogens. Genetic studies might help to elucidate the mechanisms leading to both diseases and to highlight common as well as diverse pathways. The results of such investigations will influence the current understanding of the diseases and might even change our therapeutical approaches to both disorders. This review summarizes current findings in the genetics of bronchial asthma and severe RSV bronchiolitis. The question whether a relationship exists between severe RSV bronchiolitis in infancy and childhood asthma will also be discussed by taking recent epidemiological studies in account. A special focus is laid on the implications of these findings for a targeted drug therapy of both diseases.