STEROID 21-HYDROXYLASE AUTOANTIBODIES IN INSULIN-DEPENDENT DIABETES-MELLITUS

We have studied the sera from 304 patients with insulin-dependent diab etes mellitus (IDDM) for steroid 21-hydroxylase (P450c21) autoantibodi es by an in vitro translation and immunoprecipitation assay. Autoantib odies to P450c21 were found in 7 patients with IDDM (2.3%). When the I DDM patients with P450c21 antibodies were analyzed for their HLA,6 of them (86%) belonged to the HLA DQB10201-positive group. A strong corr elation (r = 0.91, P < 0.001) of immunoprecipitation results was obser ved with adrenocortical autoantibodies detected by indirect immunofluo rescence, indicating that the adrenal autoantibodies in patients with IDDM were anti-P450c21 autoantibodies. The levels of P450c21 autoantib odies were significantly higher (P < 0.05) in patients with IDDM than in 13 (9 P450c21 autoantibody positive) patients with Addison's diseas e. Although the occurrence of P450c21 antibodies in IDDM was relativel y low, antibody-positive patients had high antibody levels and may hav e an ongoing subclinical process of adrenal autoimmunity. (C) 1997 Aca demic Press, Inc.