Quantitation of antibodies to Haemophilus influenzae type b in humans by enzyme-linked immunosorbent assay

Publisher Website
Google Scholar
Abstract
The enzyme-linked immunosorbent assay was adapted to detect serum IgG, IgM, IgA and secretory IgA antibodies to H. influenzae type b capsular polysaccharide in humans. Serum samples were studied from 92 healthy children of various ages, 50 healthy adults, 24 patients with various H. influenzae type b infections and 16 patients with clinical signs of epiglottitis and cellulitis suspected to be caused by H. influenzae type b. The mean antibody titers of the sera from healthy children increased with age and reached adult levels in children > 6 yr old. A significant antibody response to capsular polysaccharide was observed in serum samples from the majority of patients with infections due to H. influenzae type b and in 4 of 16 patients with clinical signs of epiglottitis and cellulitis. In addition to the enzyme-linked immunosorbent assay, the antibody responses of patients were tested by a bactericidal assay. When the 2 methods were compared, there was no evident correlation (r, about 0.22). The enzyme-linked immunosorbent assay was further adapted to test secretory IgA antibodies specific to capsular polysaccharide in nasopharynx secretions and in milk samples from lactating women. Antibodies were detected in 12 of 24 secretions and 9 of 11 milk samples.