To Clarify the contribution of regional lymph nodes to the middle ear local immune response, horseradish peroxidase (HRP) -specific antibody (Ab) bearing cells were identified in middle ear, eustachian tube and neck lymph nodes after middle ear sensitization with HRP. Animals were killed 1, 3, 5, 7, 14, 21, 28 days after middle ear inoculation. Anti-HRP Abtiter in bulla washings/effusions were monitored with an enzyme-linked immunosorbent assay. The number of the HRP-specific Ab bearing cells in the middle ear, eustadhian tube and regional lymph nodes increased 7 days after local challenge. These results suggest that local Ab production in the middle ear may occur 7 days after local sensitization.
