Immunofluorescent studies in experimental middle ear effusions.

Immunological phenomena occurring in the mucosa of the middle ear and Eustachian tube were investigated following tubal obstruction in squirrel monkeys which produced middle ear effusions. Although there are many variations among specimens, in general all classes of immunoglobulin producing plasma cells have shown an increase in number and/or an increase in intensity of fluorescence. IgG and IgA-producing plasma cells were more prominent than those producing other immunoglobulins. These findings support the concept that the middle ear and Eustachian tube in monkeys as in humans is protected by an immunodefense system.