Middle Ear Effusion in Experimental Hypersensitivity

Monkeys which were transfused with human serum containing a specific antibody developed a clear, middle ear effusion when the appropriate antigen (ragweed) was insufflated into their middle ear space via the Eustachian tube. The typical histological changes expected to occur in an immediate type 1 immune response were present. Intracellular edema, capillary dilation, and an initial exudative reaction were all seen. Serum IgE levels were found to be significantly raised in the animal following passive sensitization. IgE was also present in the effusion, and IgE specific fluorescent mast and plasma cells were noted in the middle ear mucosa of the sensitized animals.