ARID1a expression in the endometrium of women of reproductive age with abnormal uterine bleeding and obesity

Objective. The aim of the study was to evaluate the expression of the proliferative marker ARID1a in endometrial biopsies of patients with abnormal uterine bleeding (AUB) and obesity and its role in the pathogenesis of endometrial dysfunction. Materials and methods. The study included 40 endometrial samples from patients of reproductive age with AUB-E: 20 from patients with AUB-E and obesity (group 1) and 20 from patients with normal body mass index (BMI) and AUB (group 2). 10 endometrial samples were obtained from healthy women of reproductive age, taken on the 2nd-3rd day of the menstrual cycle. All patients underwent histological examination according to the standard procedure. At the second stage, an immunohistochemical study of the ARID1a proliferation marker was performed using polyclonal rabbit antibodies to Anti-ARID1a (clone EPR13501-73) in standard dilution (1:500) according to the protocol of the manufacturer Abcam (Great Britain). The IBM SPSS Statistics v.26 program (IBM Corporation, USA) was used for statistical data analysis. To determine statistically significant differences between quantitative parameters with a normal distribution, one-factor analysis of variance (ANOVA) was used with the calculation of a 95% confidence interval followed by the post-hoc Games-Howell test for multiple comparisons. The differences were considered significant at p<0.05. Results. ARID1a expression was evaluated in the glandular and stromal compartments of the endometrium. In the endometrial glands, the expression of ARID1a was statistically significantly higher in the first group of obese patients compared with the normal and control groups. In the endometrial stroma, the expression of the proliferative marker was higher in the main group compared with the control group. However, when comparing between groups within the main group, statistical significance in the level of expression was not achieved. Conclusion. The results obtained demonstrate the possible pathological effect of obesity on the structural and functional properties of the endometrium, which leads to delayed regeneration of the endometrium due to the glandular component and, consequently, to AUB-E.