Pneumococcal immune complexes and clinical course of secretory otitis media.

One-hundred-and-six children (182 ears) with secretory otitis media (SOM) were included in a follow-up study to determine whether presence of immune complexes to pneumococcal capsular polysaccharides in the middle ear fluid or adenoid suspension was related to the clinical course of SOM. The patients with immune complexes did not differ significantly from those without demonstrable immune complexes as to length of healing period or chronicity. The presence of immune complexes must be seen as evidence of the infectious etiology of SOM (pneumococcal in at least 25%), the immune complexes forming part of the immunological defense system. Poor immune response to serotype 6 can explain why this serotype plays a dominant role in the pneumococcal immune complexes in SOM fluid and adenoid suspension.