Influence of prolactin and estrogen on disease activity in patients with systemic lupus erythematosus

Objective The objective of this paper is to evaluate the role of prolactin and estrogen levels on disease activity in patients with systemic lupus erythematosus (SLE). Patients and methods This study included 60 female patients with SLE, with a mean age of 33.5±13.12 years. It was conducted between November 2014 and October 2015. Disease activity was defined according to Systemic Lupus Erythematosus Activity Index; score of at least 6 was considered as an active disease. Prolactin (PRL) and estrogen levels and other serological markers of lupus disease activity, namely, complement 3,4 (C3 and C4), erythrocyte sedimentation rate, C-reactive protein, and anti-double-stranded DNA (anti-dsDNA) titer were calculated. Results Hyperprolactinemia was present in 25.0% of patients, and low estrogen level was present in 33.3% of patients. There was no significant correlation between either of estrogen or prolactin levels and all clinical and laboratory features, except for a significant positive correlation between anti-dsDNA and hyperprolactinemia. Conclusion There was no significant correlation between either of PRL or estrogen levels and Systemic Lupus Erythematosus Activity Index score. Overall, 80.0% of patients with hyperprolactinemia and 80.0% with low estrogen level had SLE activity. There was a significant difference in the frequency of further indicators of disease activity in SLE such as raised erythrocyte sedimentation rate, raised C-reactive protein, or decrease in complement factors with high serum PRL and low estrogen level.