Experimental rhinovirus 16 infection. Effects on cell differentials and soluble markers in sputum in asthmatic subjects.

Asthma exacerbations are often associated with respiratory virus infections, particularly with rhinovirus. In the present study we investigated the effect of experimental rhinovirus 16 (RV16) infection on airway inflammation as assessed by analysis of hypertonic saline-induced sputum. Twenty-seven nonsmoking atopic, mildly asthmatic subjects participated in a placebo-controlled parallel study. RV16 (n   =  19) or its diluent (n = 8) was nasally administered. Sputum inductions were performed at entry and on Days 2 and 9 after inoculation, and airway responsiveness to histamine (PC20) was measured on Days 4 and 11. Cell differentials and levels of albumin, eosinophil cationic protein (ECP), IL-8, and IL-6 were determined. The cellular origin of IL-8 was investigated by intracellular staining. RV infection was confirmed by culture and/or by antibody titer rise in each of the RV16-treated subjects. There were no significant changes in the sputum differentials of nonsquamous cells (MANOVA, p ⩾ 0.40). In the RV...