Pneumococcal antibodies in families with recurrent otitis media.

In a recent study it was found that children with recurrent acute otitis media (rAOM), in contrast to healthy children, frequently lack detectable antipneumococcal IgG antibodies against capsular types 6A and 19F. In children with rAOM, the concentrations of antibodies against type 6A polysaccharide remained low even after the period of rAOM had ceased. Antibody levels against various pneumococcal capsular polysaccharides were determined in otitis-prone and healthy members of 19 families. 25 children with a history of rAOM (mean age 7.2 years) and their parents, one of whom in each family had had rAOM during childhood, were investigated. Compared to the parents, the rAOM children had lower concentrations of IgG antibodies against the pneumococcal types 6A, 14, 19F and 23F and of IgA antibodies against type 23F. Compared to their parents, the rAOM children had higher concentrations of IgM antibodies against types 3 and 23F. 'Healthy parents' did not differ from 'rAOM parents' in IgG antibody levels against any of the pneumococcal capsular polysaccharides investigated. The findings indicate that rAOM occurs in individuals with a delayed rather than with a persisting inability to mount an adequate antibody response against the offending pneumococci.