Effect of a middle ear immune response on inner ear antibody levels.

The effect of a middle ear immune response upon antibody levels in the perilymphatic compartment of the inner ear was investigated in the guinea pig. Animals were systemically sensitized with keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA) until high circulating levels were achieved. The middle ear cavity was then challenged with KLH, resulting in a vigorous immune response with effusion and mucosal inflammation. Antibody levels against KLH and BSA were then compared in serum, middle ear effusions, and perilymph. Anti-KLH levels in perilymph were found to increase substantially during middle ear response to challenge, while the anti-BSA levels did not, indicating a local origin for the anti-KLH antibody. The most likely explanations for these findings are inner ear antibody originated in the middle ear and diffused across the round window membrane, or antigen diffused across the round window membrane and evoked local production of antibody within the inner ear.