Immunological response to outer membrane vesicles of Haemophilus influenzae in patients with acute sinusitis

The immunological response of 30 patients with acute sinusitis was examined by using an enzyme-linked immunosorbent assay (ELISA) designed to detect antibodies against outer membrane vesicles of Haemophilus influenzae. Using this ELISA, we found that 15 patients had slight increases in specific antibody in their convalescent serum. Maxillary sinus secretions from 15 patients had specific antibodies. IgG and IgA antibodies were detected with equal frequency, but IgA antibody was often found in maxillary sinus secretions while it was absent from serum. Thus it appears that patients with acute sinusitis respond systemically and locally with the specific antibody to H. influenzae.