Reduction of ciliary beat frequency in vitro by sputum from patients with bronchiectasis: a serine proteinase effect.

We have examined the effect of adding elastase positive sputum from six patients with purulent bronchiectasis on the ciliary beat frequency of nasal epithelium from normal subjects. Control studies of cilia suspended in tissue culture medium showed little change in ciliary beat frequency over six hours. Cilia incubated in elastase positive secretions, however, showed a considerable decrease in ciliary beat frequency over the period, falling from a mean of 13 X 40 beats/second to 6 X 78 beats/second (p less than 0.001). Inhibition of the elastase activity with pure human alpha 1 antitrypsin abolished this effect (mean at start 13 X 75 beats/second, mean at six hours 11 X 64 beats/second). The patients were then treated with amoxycillin for two weeks and sputum was collected at the end of the course. These secretions showed no detectable elastase activity and also had little effect on ciliary beat frequency. The results suggest that serine proteinase activity associated with elastase can decrease mucociliary function in vitro and that antibiotic treatment even in the apparently stable state may have a beneficial effect.