The Effect of Estradiol and Testosterone Levels Alone or in Combination with Their Receptors in Predicting the Severity of Systemic Lupus Erythematosus: A Cohort Study

Background: Developing a practical method to predict active systemic lupus erythematosus (SLE) in patients with inactive/mild status at the onset of the disease could lead to appropriate treatment that ultimately prevents future relapses. The development of SLE is influenced by steroid hormones and probably the receptors of these hormones. Therefore, we aimed to investigate the predictive effect of the levels of estradiol and testosterone hormones and their receptors on the severity of SLE disease. Methods: Serum samples were taken from 59 female patients with inactive SLE in Golestan province in northern Iran. The concentration of estradiol (E2) and testosterone (T) hormones and their receptors, estrogen receptors (ER) and androgen receptors (AR), was measured at the beginning of the study after sampling. After a one-year follow-up (2021 to 2022), the patients were divided into active and inactive SLE groups based on the clinical criteria of the SLE activity index. T test and Mann-Whitney U-test were used to analyze the difference of variables. The correlation was analyzed using Pearson and Spearman tests. Discriminative power was measured, and a cutoff point was suggested. Results: There was a significant difference in the average E2+ER/T+AR ratio between active and inactive SLE groups (P<0.001). It was also found that this ratio has a significant correlation with the severity of the disease (r=0.546, P<0.001). Conclusion: Despite the normal concentration of each steroid hormone and its receptors, the E2+ER/T+AR ratio may be a good indicator of the development of active SLE.