C1 subcomponents in acute pneumococcal otitis media in children.

Twenty children with acute pneumococcal otitis media were studied. In 6 children the infection ran a normal course and healed after the first episode and in 14 it relapsed. The serum levels of the immunoglobulins IgG, IgA and IgM were normal in all 20 children. Specific antibodies to pneumococcal polysaccharide were found in all cases, with no differences in the titers between the relapsed cases and those that healed. The complement components were quantitated with electroimmuno assay. G1q proved depressed in 60 per cent of the relapsed cases and in 16 per cent of the healed cases. C1r and C1s were disproportionally high compared with the C1q levels. Furthermore, crossed immunoelectrophoresis revealed abnormal complexes composed of C1r and C1s, and complexes composed of C1r, C1s and C1 IA. These complexes were more pronounced in sera from the children with relapsing otitis media.