21-hydroxylase autoantibodies are more prevalent in Turner syndrome but without an association to the autoimmune polyendocrine syndrome type I

Turner syndrome (TS) is associated with an increased frequency of autoimmunity. Frequently observed autoimmune diseases in TS are also seen in the autoimmune polyendocrine syndrome type I (APS I), of which Addison disease is a key component. An overlapping antibody profile between TS and APS I could be considered. The aim of this work was to study women with TS regarding 21-hydroxylase (21-OH) antibodies and interferon omega (IFN-omega) antibodies, a highly specific marker for APS I, to determine if there are immunological overlaps between TS and APS I. Blood samples from 141 TS were assayed for 21-OH antibodies and IFN-omega antibodies using in-vitro-transcribed and translated autoantigen. Indices with a cut-off point of 57 and 200 for 21-OH antibody and IFN-omega antibody were used as reference. The median age of TS was 31 center dot 6 years (range = 11 center dot 2-62 center dot 2). Positive indices of 21-OH antibodies were present in six TS (4%), with a mean of 144 center dot 8 (range = 60-535). None had apparent adrenal insufficiency. There was no age difference comparing 21-OH antibody-positive TS (median age = 33 center dot 9 years, range = 17 center dot 7-44 center dot 7) and 21-OH antibody-negative TS (median age = 31 center dot 6 years, range = 11 center dot 2-62 center dot 2) (P = 0 center dot 8). No TS was positive for IFN-omega antibodies (mean = 42 center dot 4, range = -435-191). No overlapping autoimmune profile between TS and APS I was found. Autoimmunity against 21-OH among TS patients was more prevalent than previously identified, suggesting an increased risk of adrenal failure in TS. However, whether adrenal impairment will develop remains unknown.