Immune response to nontypeable Hemophilus influenzae in the general population and among children with otitis media with effusion

The Division of Infectious Diseases at the Children's Hospital of Buffalo is engaged in a longitudinal study of otitis media in children who range in age from birth to 5 years (National Institute of Child Health and Human Development grant no. 196-79-02). Children are examined four times each year during well visits and at each episode of ear infection. Blood and middle ear fluid are collected in order to identify the cause of infection and to determine the specific antibody response to the inciting agent. The project has gotten underway only recently, and the results presented here represent a very early assessment of the data. The major thrust of this presentation will be on the antibody response to nontypeable Hemophilus influenzae (NTHI) in the serum and middle ear fluids of children with otitis media with effusion (OME). Very little is known about the immune response to NTHI. Antibody to NTHI has been identified previously in the middle ear fluids of children with OME. Bactericidal antibodies to NTHI are generally absent in serum at the start of OME, but appear during convalescence. This antibody, which appears to be directed against the outer membrane protein component of the organism, is clearly protective in an animal model. The present report confirms the presence of specific antibody to NTHI in the serum and middle ear fluid of children with OME. Furthermore, it suggests that recurrent middle ear disease is associated with higher levels of antibody in the middle ear.