Objective: To investigate the role of fibrinolysis in pathogenesis of middle ears adhesions.
Methods: The amount of Tissue-type Plasminogen Activator (tPA) of 28 sections from 6 ears with adhesive otitis media (AOM) and of 22 sections from 6 normal ears was examined by Super Sensitive Biotin-Streptavidin (SSBSA) method. Amount of Fibrin of 11 sections from 3 ears with significant adhesions was compared with that of 12 sections from 3 normal ears. Qualitative analysis of light microscopy with computer-assisted image system was employed.
Results: In adhesive ears, tPA stains were negative in 11 of 28 sections and faint positive were 10 of 28 sections, while Fibrin stains were positive in 6 of 11 sections and strong positive were in 3 of 11 sections. In normal ears, tPA stains positive were in 8 of 22 sections and strong positive were 10 of 22 sections, meanwhile, fibrin stains were negative in 8 of 12 sections and faint positive were in 3 of 12 sections. Quantitative analysis showed that the amount of tPA was 16.70 +/- 5.11 and 39.84 +/- 6.26 in ears with AOM and normal ones respectively (P < 0.05).
Conclusion: In adhesive ears the amount of tPA was less than that in the normal ears, whereas, the amount of Fibrin was greater in ears with AOM than that in normal ears. It indicates that fibrinolysis involved in the process of adhesion formation of AOM, which may acts as a key factor.