Abstract
Complement components in middle ear effusion (MEE) were assayed to determine whether the complement system was activated or not in the middle ear of the patients with otitis media with effusion. Complement activities were assayed in 53 specimens from MEEs and 43 from patients' sera. Complenent activities of patients' sera were not differred from normal human serum (NHS). CH 50 and C3 activity of MEE were slightly lower than the sera. Cl activity of MEE was remarkably lower than the sera. C4 activity of MEE was slightly lower in mucous MEE in child patients, but in other MEEs it was almost the same as their sera. It was found that Cl activity of MEE was low because of the reduced amounts of Clr and Cls in MEE and because of the Cl inhibitory substances in MEE. Immunoelectrophoresis revealed the conversion of factor B and splitting of C3 in MEE with 0.01 M EDTA. C5a in MEE (0.01 M EDTA) was found higher than inpatients' plasma and mucous MEE contained more C5a than serous ones. These findings suggest that the activation of complement system in MEE actually occurred, and might not be mainly through the classicl pathway but in a large part through the alternative pathway.
