The immunological role of the outer membrane proteins of non-typable Hemophilus influenzae in otitis media with effusion in children.

Specific IgG and IgA antibodies against the outer membrane proteins of non-typable Hemophilus influenzae were investigated in otitis media with effusion in children. Amounts of these antibodies were determined in middle ear effusions (MEEs) and in sera by enzyme-linked immunosorbent assay. At the same time the amounts of total IgG and IgA antibodies in MEEs in comparison with those in sera were analyzed by laser nephelometry. The amounts of specific and total IgG and IgA in the MEEs were higher than those in the sera. The MEEs/sera ratios of IgG and IgA antibodies in the children with mucoid effusions were higher than those in the children with serous effusions. The exception involved IgG determined by laser nephelometry. These data support the hypothesis that bacterial infections and the subsequent immune response contribute to the prolongation of otitis media with effusion in children, especially when effusions become mucoid.