A STUDY OF THE EPITOPES ON STEROID 21-HYDROXYLASE RECOGNIZED BY AUTOANTIBODIES IN PATIENTS WITH OR WITHOUT ADDISONS-DISEASE

Steroid 21-hydroxylase (21-OH) autoantibodies are found in patients wi th autoimmune Addison's disease (AAD), either isolated or associated w ith autoimmune polyglandular syndrome (APS) type I and II and in adren al-cortex autoantibody (ACA)-positive patients without AAD. In order t o assess any differences in the 21-OH autoantibodies in these differen t patient groups, we have studied their reactivity with different epit opes on 21-OH using full length and modified S-35-labelled 21-OH prote ins produced in an in vitro transcription/translation system. There we re no major differences in the pattern of autoantibody reactivity with the different mollified 21-OH proteins in patients with isolated AAD or with APS types I and II, and in 21-OH autoantibody-positive patient s with clinical AAD, subclinical. AAD and those maintaining a normal a drenal function. Our studies also indicate that the main epitopes for 21-OH autoantibodies in patients with different forms of autoimmune ad renal disease are located in the C-terminal end and in a central regio n of 21-OH.