Prolactin, estradiol and anticardiolipin antibodies in premenopausal women with systemic lupus erythematosus: a pilot study.

INTRODUCTION Systemic lupus erythematosus (SLE) is an autoimmune disease, with higher prevalence in women. An incidence peak occurs during the reproductive years, suggesting that estradiol may play a role in the clinical presentation of SLE. Anticardiolipin antibodies (ACA) are associated with antiphospholipid antibody syndrome (APLS), but can be found in patients with SLE without APLS, and relate to cardiovascular risk and nephrite. OBJECTIVE This study aimed at assessing whether the presence of ACA is associated with hormonal changes in a sample of women with SLE. METHODS Forty-seven women diagnosed with SLE according to the American College of Rheumatology criteria, aged 30.8 ± 8.12 years, were evaluated. None was on hormonal contraception, and their SLE activity was estimated using the SLE Disease Activity Index (SLEDAI). Patients were stratified, according to the presence or absence of ACA, and estradiol and prolactin levels were measured. RESULTS Nine (19.1%) of 47 patients were positive for ACA. No differences were found between groups concerning age, duration of disease, and SLEDAI. In contrast, the median estradiol level was lower in the ACA-positive group [46.8 (21.0-72.1) pg/mL] than in the ACA-negative group [122.3 (64.8-172.7) pg/mL, P = 0.004]. CONCLUSION These results suggest, for the first time, an inverse association between ACA and estradiol levels in premenopausal SLE patients. Considering that both lower endogenous estradiol levels and ACA positivity are related to atherosclerosis, our finding may be clinically relevant in predicting cardiovascular risk and/or APLS development in SLE.