The pathogenic role of anti-type II collagen a as analysed in a variety of
hearing losses, in age-matched controls and in different autoimmune disease
s. The immune reactivity of peripheral blood lymphocytes to type II collage
n was studied by the degree of proliferation measured as the incorporation
of bromodeoxyuridine in cultured lymphocytes. The anti-type II collagen ant
ibodies showed a very low incidence in the hearing loss group. Lymphocytes
of otosclerosis, Menieres disease and other sensorineural deafness patients
proliferated in response to concanavalin A and to type II collagen to a lo
wer extent than peripheral blood lymphocytes from healthy controls. Nonethe
less, these differences were not statistically significant. The immune hype
rreactivity to type II collagen cannot explain the autoimmune mechanism of
hearing losses. Humoral and cellular hyperreactivities to inner ear protein
s different from type II collagen, could explain the autoimmune mechanism o
f deafness.