EXPERIMENTAL MODEL FOR OTITIS MEDIA WITH EFFUSION INDUCED BY TYPE III HYPERSENSITIVITY REACTION

Experimentally induced type III hypersensitivity reaction in the middle ear was studied histo chemically using models of otitis media with effusion (OME). Intratympanic inoculation of horseradish peroxidase (HRP) to the presensitized 50 guinea pigs resulted in serous middle ear effusions. The deposition of immune complex in the basement membrane of mucous membrane and the submucosal vascular walls was the characteristic feature of the initial experiments. These immune complexes were, however, clearly removed from the middle ear mucosa as well as middle ear effusion within 7 days. The following characteristic features were the hypersecretion of middle ear mucosa and the mucosubstance filling the whole lumen of the eustachian tube. Immune complex formation was supposed to relate with initiation of OME. The tubal dysfunction caused by the type III hypersensitivity and local immunity of middle ear mucosa seemed to be responsible for the chronicity and relapsing of OME.