P-330 The differential expression of transcription factors OTX2 and SOX15 in follicular fluid and Cumulus cells of patients with endometriosis

Study question What effect does endometriosis have on the expression level of transcription factors OTX2 and SOX15 as oocyte maturation markers in follicular fluid and Cumulus cells? Summary answer Endometriosis reduces the expression level of OTX2 and SOX15 into follicular fluid and Cumulus cells which can negatively affect oocyte maturation and quality. What is known already The relationship between endometriosis and infertility is further complicated by the fact that it’s a chronic disease marked by the development of endometrial-like tissue outside the uterus. It also results in anatomical abnormalities, hormonal imbalances, and inflammatory responses that negatively affect oocyte viability, maturation, and quality as well as reproductive outcomes. Since it is challenging to directly assess oocyte quality, analysis of follicular fluid and Cumulus cells is often used as an alternative approach. The increase in these two genes' expression during oocyte maturation illustrates the importance of choosing these two particular transcription factors, OTX2 and SOX15, for this investigation. Study design, size, duration This study, conducted from October 2023 to February 2025, involved 30 women with stages III or IV endometriosis and 30 control participants. Follicular fluid and Cumulus cell samples were collected after obtaining informed consent. Inclusion criteria included women aged 18-45 years with regular menstrual cycles and undergoing GnRH agonist or antagonist protocols. Exclusion criteria encompassed HPV, HSV-2, PCOS, diminished ovarian reserve, endometrial abnormalities, and history of inflammatory diseases. Participants/materials, setting, methods In this study, RNA was extracted from follicular fluid and Cumulus cell samples from women with and without endometriosis. cDNA synthesis followed, and real-time PCR was performed to assess gene expression. Data were analyzed using GraphPad Prism software, employing the independent t-test for normally distributed data and the Mann-Whitney U test for non-parametric distributed data. Statistical significance was set at a p-value of ≤ 0.05. Main results and the role of chance The main results of this study demonstrate that women diagnosed with stages III or IV endometriosis exhibited significantly decreased (p-value<0.0001) expression levels of transcription factors OTX2 and SOX15 in their follicular fluid and Cumulus cell samples when compared to the control group. This decrease in expression was correlated with clinical observations revealing a significant in both the total number of oocytes (p-value=0.0553) and the number of mature metaphase II (MII) oocytes (p-value=0.0205), as well as a lower history of pregnancy (p-value=0.026) in endometriosis patients. Although other demographics such as age, Body Mass Index (BMI), Luteinizing Hormone (LH), Follicle-Stimulating Hormone (FSH), and Anti-Müllerian Hormone (AMH) levels, duration of ovarian stimulation, and history of abortion did not show any significant differences between the case and control groups. Limitations, reasons for caution Limitations include strict sample collection criteria resulting in a small statistical population, potential damage to Cumulus cells during isolation and counting, and the need for pairing follicular fluid and Cumulus cell samples from the same individuals for more accurate results. Protocol optimization was also necessary. Wider implications of the findings The reduced expression of OTX2 and SOX15 in cumulus cells and follicular fluid, alongside decreased pregnancy history and lower total and MII oocyte counts, suggest impaired oocyte maturation and quality. Assessing OTX2 and SOX15 expression may offer a novel approach to predicting oocyte and embryo quality in women with endometriosis. Trial registration number No