Rhinovirus-associated wheeze during infancy and asthma development

Abstract

Rhinovirus is commonly associated with bronchiolitis - only second to RSV during the first year life. The prevalence of HRV-bronchiolitis may be very high in predisposed infants. HRV diagnosis is almost exclusively based on PCR, which detects respiratory infections with or without symptoms. Two immunologic factors, interferon responses and atopy, have been associated with susceptibility to HRV-bronchiolitis in multiple studies. The current data supports the hypothesis that susceptibility to HRV-bronchiolitis is likely to be an early manifestation of biased immune responses, which are linked to both decreased viral defence and atopic airway inflammation. Prospective studies have consistently shown that early wheezing associated with HRV infection is closely associated with recurrent wheezing and the development of asthma in children. Collectively, these studies suggest that HRV infection in wheezing children could serve as a clinically useful marker for early identification of asthma prone children. The findings to date provide the rationale for future studies to incorporate rhinovirus illnesses into asthma risk indices.

Figure 1

Early life influences on the development of asthma. Development of the lungs and immune system are initially influenced by genetics and prenatal factors, and later by a number of environmental and lifestyle factors in the first few years of life. Exposure to farm environments, furred animals, and day care in early life can reduce the risk of asthma. In contrast, low interferon responses, wheezing with respiratory viruses, and the development of atopy indicate an increased risk for subsequent childhood asthma.