LOWER AIRWAYS INFLAMMATORY RESPONSE DURING RHINOVIRUS COLDS

Human rhinovirus (HRV) causes the majority of common colds and possibl y also asthma exacerbations. Mechanisms linking viruses to changes in airway reactivity are not defined and we hypothesized that changes in endobronchial cell populations may be implicated. Bronchial mucosal bi opsies taken before, during and after experimental infections with HRV serotype 16 were examined and histamine reactivity was measured in 17 adult volunteers (6 atopic asthmatics). Biopsies were examined for ma st cells, eosinophils, lymphocytes and neutrophils by immunohistochemi cal techniques. Increases in histamine responsiveness (PC20) were foun d (p = 0.048), accompanied by an increase in submucosal lymphocytes (p = 0.05). There was a significant increase in epithelial eosinophils w ith the cold (p = 0.042), and in asthmatics this appeared to persist i nto convalescence. Rhinoviral common colds are associated with a bronc hial mucosal lymphocytic and eosinophilic infiltrate that may be relat ed to changes in airway responsiveness and asthma exacerbations.