ANTI-PNEUMOCOCCAL ANTIBODY-ACTIVITY IN NASOPHARYNGEAL SECRETIONS IN HEALTHY-ADULTS AND CHILDREN

The local antibody activity to Streptococcus pneumoniae serotype 6B wa s measured in nasopharyngeal secretions from 20 healthy adults and 43 children, 1-3 years of age, 14 of whom were healthy and 29 were at ris k for developing recurrent episodes of acute otitis media (RAOM) accor ding to the criteria described below. In children, anti pneumococcal I gA and IgG antibody activity was of the same magnitude in both groups. Adults showed significantly higher specific IgA activity. Antibody ac tivity of the IgG isotype was also higher in adults, possibly reflecti ng the higher serum antibody levels. The children at risk of developin g RAOM had significantly higher levels of secretory component (SC) in their nasopharyngeal secretions. Our data suggest that local immunity in the nasopharynx is not fully developed in young children, which mig ht contribute to bacterial survival and colonization in the region.