Immune complexes in the middle ear fluid and adenoid tissue in chronic secretory otitis media.

Specimens of middle ear effusion and adenoid tissue were studied for bacteria and pneumococcal capsular antigen in 107 patients with secretory otitis media. 120 of 163 middle ear effusion samples (73.6%) were negative on bacterial culture. Hemophilus influenzae was present in 9.2% and Streptococcus pneumoniae in 1.8%. Hemophilus influenzae was cultured from 44.8% and Streptococcus pneumoniae from 35.5% of 107 adenoid tissue specimens. Free pneumococcal capsular antigen was demonstrated in 10.4% of the middle ear fluids and this figure rose to 23% when antigen was liberated from the immune complexes by heating. The corresponding figures for adenoid tissue suspension were 27.1% and 39%. The adenoid tissue or the lymphoid tissue of the entire oropharynx could act as the source of antigen which could maintain immune complex disease in some patients suffering from secretory otitis media.