Neutrophil elastase and its complex with alpha 1-antitrypsin in the pathogenesis of chronic suppurative otitis media.

Neutrophil elastase (NE) and its complex with alpha 1-antitrypsin were quantified in ear discharges from 15 patients with chronic suppurative otitis media (CSOM), and their levels were compared to those in middle ear effusions from 10 pediatric patients with chronic otitis media with effusion (OME). The localization of immunoreactive NE was also examined by immunocytologic study. The mean value of total NE was 161.8 +/- 29.5 micrograms/mL in CSOM, which was significantly higher than that in OME (16.5 +/- 6.7 micrograms/mL). The mean value of NE-alpha 1-antitrypsin complex was 13.7 +/- 8.8 micrograms/mL in CSOM and 7.8 +/- 4.0 micrograms/mL in OME. There was no significant difference between culture-positive and culture-negative samples in CSOM. Immunoreactive NE could be observed in the neutrophils of ear discharges, and extracellular release of NE was also observed. Ear discharges in CSOM contain a considerable amount of uncomplexed NE, of which the level does not depend on active bacterial infections. Uncomplexed NE seems to play a role in the chronicity of CSOM.