Elevation of inner ear antibody levels following direct antigen challenge of the endolymphatic sac.

The effect of direct antigen challenge of the endolymphatic sac (e.sac) on inner ear antibody levels was investigated in guinea pigs. Two weeks following e.sac antigen inoculation, perilymph antibody levels to keyhole limpet hemocyanin (KLH) were found to be significantly elevated in the challenged ear of those animals compared to the unchallenged, opposite ear. Moreover, when the endolymphatic duct (e.duct) in a group of animals were obstructed prior to antigen challenge of their e.sac then the rise in perilymph antibody was prevented. The local accumulation of plasma cells and lymphocytes in the perisaccular space and e.sac lumen was seen following these antigen injections. These experiments suggest that inner ear antibody emanates from the e.sac and reaches the perilymphatic compartment along the route of the e.duct. Furthermore, these findings emphasize the central role of the e.sac in inner ear immunity.