RHINOVIRUS INFECTION INDUCES MUCUS HYPERSECRETION

Rhinorrhea is a prominent symptom of the common cold. Although increas es in vascular permeability and serous cell secretion have been demons trated in human nasal mucus during active rhinovirus infections, chang es in mucin constituents have not been quantified. Nonallergic (n = 48 ) and asymptomatic allergic rhinitis (n = 32) subjects were inoculated with rhinovirus type hanks before the spring allergy season. Nasal la vages were performed before inoculation (day 0), then daily for 5 days afterward. The subjects were divided into infected and noninfected gr oups on the basis of evidence of successful rhinovirus infection (nasa l shedding of virus or fourfold increases in specific serum antibodies ). Concentrations of interleukin (IL)-8, markers of vascular leak (IgG ), seromucous cells (lysozyme), and mucoglycoprotein exocytosis [7F10- immunoreactive mucin (7F10-irm) and Alcian blue staining of acidic muc oglycoproteins] were measured in lavage fluids. The infected subgroup had maximal increases in nasal lavage fluid concentrations of IL-8 (se venfold), IgG (fourfold), total protein (twofold), and gel-phase 7F10- irm (twofold) on day 3. There were no differences between infected all ergic and nonallergic subjects. IL-8 and gel-phase 7F10-irm were signi ficantly higher in infected than in noninfected subjects. In addition to promoting plasma exudation, rhinovirus hanks infection increases IL -8 and gel-phase mucin secretion. These processes may contribute to a progression from watery rhinorrhea to mucoid discharge, with mild neut rophilic infiltration during the common cold.