Endocrine Abstracts

JOINT213921

Background: Autoimmunity plays a fundamental role in the development of Addison’s disease (AD), and the presence of 21-hydroxylase autoantibodies (21OH-Abs) has been widely used as a highly specific diagnostic marker for proper diagnosis, considering that up to 90% of AD patients remain positive for 21OH-Abs up to 30 years post-diagnosis of AD (1). Moreover, 21OH-Abs could predict autoimmune adrenalitis in patients with premature ovarian failure (POI) making their measurement a recommended diagnostic tool (2). Therefore, the present study aims to establish the prevalence of 21OH-Abs positivity in Bulgarian patients with AD and POI.

Methods: A total of 43 AD (35 women and eight men [18-75 years]), 15 female non-genetic POI patients [18-39 years], and a control group of 31 healthy individuals (23 women and eight men [25-73 years]) were included in the study. 21OH-Abs were measured by ELISA (ElisaRSR™ 21-OH Ab) in all participants.

Results: 21OH-Abs were positive in 72.1% [31] of AD patients (50% [4] of AD men and 77.1% [27] of AD women, P = 0.227), while no one of the POI patients or healthy controls showed positive results. Six (17.1%) of the AD women had also POI with four of them (66.7%) being 21OH-Abs positive. Negative for 21OH-Abs AD patients were slightly older than positive AD patients (55.5 vs. 50 years, P = 0.063), However, no significant association between 21OH-Abs positivity and the disease duration was observed.

Conclusions: 21OH-Abs were highly positive in AD patients, proving the autoimmune etiology of the disease. Nevertheless, nearly 30 percent of patients were antibody-negative, suggesting decreased antibody production associated with aging or different underlying AD causes that need to be explored. In Bulgarian POI patients, 21OH-Abs positivity appears to be uncommon.References1. Wolff AB, Breivik L, Hufthammer KO, et al. The natural history of 21-hydroxylase autoantibodies in autoimmune Addison’s disease. Eur J Endocrinol. 2021;184(4):607-615.2. ESHRE, ASRM, CREWHIRL and IMS Guideline Group on POI; Panay et al. Evidence-based guideline: premature ovarian insufficiency. Climacteric. 2024;27(6):510-520.