Immune complexes in middle ear fluid in chronic secretory otitis media.

Data on 87 patients (113 ears) with chronic secretory otitis media (SOM) are reported. The bacteriological analysis of the middle ear fluid (MEF) revealed Streptococcus pneumoniae in 7% of ears, Hemophilus influenzae in 9%, opportunistic bacteria in 20%, while 64% of the samples showed no growth. Free capsular polysaccharide pneumococcal antigens were found in 5% of the MEF samples using counterimmunoelectrophoresis (CIEP) with Omniserum containing 83 different pneumococcal polysaccharide types. Heating of the samples to disrupt the immune complexes increased the frequency of positive samples to 27%. These findings, together with the frequent occurrence of S pneumoniae and H influenzae in the nasopharynx, strongly support the opinion that chronic SOM in a considerable number of cases is an immune complex disease.