Pathogenetic and clinical significance of endometrial estrogen and progesterone membrane receptors in AUB-O

Abstract

Introduction. Abnormal uterine bleeding (AUB) is one of the most common gynecological conditions in reproductive-age women, with 50–60% of cases associated with ovulatory dysfunction (AUB-O). Non-classical membrane receptors such as GPR30 and PGRMC1/2 are critical regulators of endometrial hormonal sensitivity and receptivity. Aim. To investigate the expression of GPR30 and PGRMC1/2 in the endometrium of women with AUB-O and evaluate their diagnostic and prognostic significance. Methods. A prospective case–control study included 120 women: Group I – 30 early reproductive-age AUB-O patients; Group II – 30 mid-reproductive; Group III – 30 late reproductive; and 30 healthy controls. Endometrial biopsies were analyzed immunohistochemically. Expression was quantified using the H-score system. χ² test, correlation, and ROC curve analysis were applied. Results. Both GPR30 and PGRMC1/2 expression declined progressively across groups (p<0.01). The lowest H-scores were observed in Group III (GPR30 – 94.5 ± 7.8; PGRMC1/2 – 41.6 ± 5.9). A strong positive correlation between receptor expression was found (r=+0.61; p<0.01). ROC analysis demonstrated significant predictive value: AUC for GPR30 – 0.81, for PGRMC1/2 – 0.79, and combined – 0.86. Conclusion. Reduced expression of GPR30 and PGRMC1/2 is associated with impaired hormonal sensitivity of the endometrium in AUB-O. Combined evaluation of these markers may serve as a reliable biomarker for predicting recurrence risk and guiding personalized treatment strategies.