Histopathologic examination and enumeration of polymorphonuclear leukocytes in the nasal mucosa during experimental rhinovirus colds.

The histology of the nasal mucosa was examined by serial scrape and punch biopsies in 20 rhinovirus infected volunteers and 10 sham inoculated controls. No morphologic changes could be detected in the epithelial or subepithelial portions in the mucosa of specimens from infected volunteers. There was a significant increase in the number of polymorphonuclear leukocytes (PMNs) in the nasal epithelium of the infected subjects early in the course of the cold compared to their pre-infection baseline. However, trauma to the nasal mucosa from repeated sampling led to an outpouring of PMNs into nasal mucus, making evaluation of the results difficult. The number of mast cells seen in the mucosal specimens of the infected subjects did not differ from that seen in controls.