Correlation between antibodies to type II collagen and treatment outcome in bilateral progressive sensorineural hearing loss

Our aim was to assess whether "idiopathic" bilateral progressive sensorineural hearing loss (BPSHL) has an immunological cause in some patients; antibodies to native type II collagen were sought by an ELISA in eighteen patients with BPSHL, before and after corticosteroid treatment, and in twelve patients with Menière's disease, fifteen with otosclerosis, eighteen with rheumatoid arthritis, nine with fibrositis, and nine healthy controls. A positive result was defined as a mean dilution titre of 2 or more. Eight of eighteen BPSHL patients had positive titres-significantly (p<0·005) more than in any other group (one Menière's disease, two otosclerosis, and no others). The mean antibody titre was higher in the BPSHL group than in any other group (2·02 [SEM 0·62] vs 0·17 [0·17]) Menière's disease, 0·44 [0·32] otosclerosis, 0 all others; p<0·005). The nine BPSHL patients who showed a clinical response to corticosteroids (improvement in at least one tone by audiogram or 25 db in speech discrimination score) had the highest mean antibody titre (3·46 [0·88] vs 0·59 [0·59] for the nine non-responsive patients; p<0·04). We suggest that in some patients with BPSHL, immunity to type II collagen, a major constituent of the inner ear, may be important in the pathogenesis of the disorder.