Early mucosal changes in experimental sinusitis.

Normal mucociliary flow is a significant defense mechanism in the prevention of acute sinusitis. We have undertaken a study to examine the early sinus mucosal and mucociliary changes that occur in response to acute infection. Twenty rabbits were evaluated for 5 days after an obstructed maxillary sinus was inoculated with either Streptococcus pneumoniae, Hemophilus influenzae, Pseudomonas aeruginosa, or a sterile saline solution. Data collected included measurements of sinus mucosal ciliary beat frequency, quantitation of ciliated cell losses, and electron microscopic observations. Results demonstrate statistically significant (p < 0.05) changes in mucosal ciliary beat frequency that were either excitatory or inhibitory, depending both on the length of the infection and the specific organism. No changes in ciliary beat frequency were observed in the control animals (p > 0.55). Control animals likewise demonstrated no loss of ciliated cells from mucosal epithelium; however, dramatic losses of ciliated cells from the sinus mucosa of the experimental groups were observed. These losses occurred at different rates, depending on the infecting organism, but all infected groups demonstrated a > 86% decrease in the number of viable ciliated cells from the sinus mucosa after sinusitis of 5 days duration. We conclude that a significant loss of ciliated cells from sinus mucosa and a corresponding disruption of normal mucociliary flow occurs early after exposure to pathogenic organisms and is a significant predisposing factor in the development of acute sinusitis.