Experimental middle ear effusions: An immunofluorescent study

Immunological phenomena occurring in the mucosa of the middle ear and Eustachian tube were investigated following experimental tubal obstruction which produced middle ear effusions in squirrel monkeys. 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. Presence of IgA in the secretory epithelial cells of the Eustachian tube of normal monkeys further supports the concept that the middle ear and Eustachian tube in the monkey as in human are protected by an immunodefense system.