[Lymphocytes of patients with auto-immune deafness present type II collagen hyporeactivity in the presence of the pineal hormone melatonin].

A study was made of the behavior of peripheral blood lymphocytes in healthy controls and patients with various types of hearing loss. Hearing loss of auto-immune origin was studied in the presence and absence of melatonin, activated or not by concanavalin A. In patients with auto-immune hearing loss, lymphocytes showed hyporeactivity to type II collagen in terms of proliferative activity in the presence of concavalin A. Hyporeactivity was especially relevant in melatonin-incubated cells. In different nosologic entities, lymphocyte hyporeactivity to type II collagen was similar in bilateral sensorineural hearing loss, Ménière's disease and otosclerosis. We conclude that the lymphocytes of patients with autoimmune hearing loss showed hyporeactivity to type II collagen when compared to lymphocytes from control subjects. This hyporeactivity was revealed when lymphocytes were activated in the presence of melatonin.