Open Access Maced J Med Sci. 2022 Mar 13; 10(B):797-802. 797 Scientifc Foundation SPIROSKI, Skopje, Republic of Macedonia Open Access Macedonian Journal of Medical Sciences. 2022 Mar 13; 10(B):797-802. https://doi.org/10.3889/oamjms.2022.8733 eISSN: 1857-9655 Category: B - Clinical Sciences Section: Gynecology and Obstetrics Serum Level of Ligand Programmed Death-1 in Endometriosis Lyudmila Akhmaltdinova 1 , Leila Appazova 1 * , Yasminur Turdybekova 2 , Irina Kopobayeva 2 , Zhanna Amirbekova 2 , Igor Marinkin 3 1 Collective Use Laboratory, Research Center, Non-commercial Joint-stock Company “Karaganda Medical University,” Karaganda, Kazakhstan; 2 Department of Obstetrics, Gynecology and Perinatology, Non-commercial Joint-stock Company “Karaganda Medical University,” Karaganda, Kazakhstan; 3 Department of Obstetrics and Gynecology, Novosibirsk State Medical University, Novosibirsk, Russian Federation Abstract AIM: In this study, is to evaluate serum level of ligand programmed death-1 (PDL1) in patients with genital endometriosis. MATERIAL AND METHODS: For PDL-1, cancer antigen 125 (CA 125), interleukin (IL)-6, IL-8, tumor necrosis factor (TNF), and vascular endothelial growth factor (VEGF) determination, venous blood was taken 1 h before surgery and/or treatment. All patients were stratifed by the presence or absence of endometriosis according to the American Society of Reproductive Medicine’s Revised Classifcation of Endometriosis of the American Society of Reproductive Medicine. RESULTS: Twenty-one patients with endometriosis participated in the study. The PDL-1 level an experienced group was 55.32 ng/ml (interquartile range [IQR] 34.53–76.20); in the control group was 19.72 ng/ml (IQR 14.72–24.78), which was a statistically signifcant decrease (p < 0.001). A signifcant increase in CA125 31.87 (IQR 15.43–36.96) was detected (p < 0.001). In the experimental group, all pro-infammatory cytokines were elevated (IL-6, IL-8, and TNF, p < 0.013; <0.001; and <0.001) and almost twice increased VEGF 243.44 (IQR 194.56–328.07), (p = 0.016). A noticeable correlation was found between the following indicators PDL-1-CA125, PDL-1-IL-8, and PDL-1-TNF, and a moderate correlation was found between PDL-1 and VEFF (p = 0.006). CONCLUSIONS: The results of the study showed that the levels of PDL-1, CA 125, IL-6, IL-8, TNF, and VEGF were statistically signifcantly diferent in the experimental and control groups, and a correlation was also revealed between the levels of PDL-1 and CA125, IL-8 and TNF in patients with genital endometriosis. Therefore, further studies with larger numbers of patients are required. Edited by: Ksenija Bogoeva-Kostovska Citation: Akhmaltdinova L, Appazova L, Turdybekova Y, Kopobayeva I, Amirbekova Z, Marinkin I. Serum Level of Ligand Programmed Death-1 in Endometriosis. Open- Access Maced J Med Sci. 2022 Mar 13; 10(B):797-802. https://doi.org/10.3889/oamjms.2022.8733 Keywords: Endometriosis; Ligand programmed death-1; Cancer antigen 125; Interleukin-6; Interleukin-8; Tumor necrosis factor; Vascular endothelial growth factor; Cytokines *Correspondence: Leila Appazova, Collective Use Laboratory of the Research Center of the Non-commercial Joint-stock Company “Karaganda Medical University,” Karaganda, Kazakhstan. E-mail: leyla_saruarovna@mail.ru Received: 23-Jan-2022 Revised: 20-Feb-2022 Accepted: 03-Mar-2022 Copyright: © 2022 Lyudmila Akhmaltdinova, Leila Appazova, Yasminur Turdybekova, Irina Kopobayeva, Zhanna Amirbekova, Igor Marinkin Funding: This research did not receive any fnancial support Competing Interest: The authors have declared that no competing interest exists Open Access: This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial 4.0 International License (CC BY-NC 4.0) Introduction Endometriosis is a chronic disease characterized by endometrial tissues located outside the uterine cavity. This disease afects about 10–15% of women of reproductive age and up to 20–30% of infertile women [1]. Clinically, endometriosis is mainly manifested by pelvic pain, dysmenorrhea, dyspareunia, and infertility. Surgical and/or hormone therapy remains the primary therapy of choice. However, these treatments are associated with side efects and recurrence of endometriosis in 30–50% of women within 3–5 years after surgery [2]. At present, there are many etiological theories why endometriosis occurs, yet none of them explains all the existing cases of this disease. Endometriosis can only be diagnosed by invasive manipulations to confrm its morphology as there are no specifc biomarkers in the blood, saliva, or urine that could be used to diagnose and select proper treatment. Therefore, the study of the pathogenesis of endometriosis is still an urgent problem in the modern world. The study of the immune aspects related to the development of endometriosis is one of the promising areas of recent times, since the study of the relationship between endometriosis and the immune system revealed some changes in the cellular immunity system: Impaired function of T-cells and B-cells, natural killer (NK) cells, changes in interleukin (IL) levels, tumor necrosis factor (TNF)-α, and vascular endothelial growth factor (VEGF) [3]. These data can be used both to study the fundamental mechanisms of development and to try to use them for diagnostic procedures. The programmed death 1 protein (PD-1) is an immune checkpoint receptor that provides immunosuppression. PD-1 prevents autoimmunity, controls damage to healthy tissues during infection. PD-1 is known to be expressed in NK cells, B-cells, dendritic cells, antigen-presenting cells, activated CD4+ and CD8+ T-cells, and monocytes [4], [5]. In its turn, PD-1 binds to one of its ligands, PD-L1 or PD-L2, thereby inhibiting the activation of T-cells [6]. The high expression of PD-1 on the surface of T-cells alters its ability to eliminate cancer and infectious diseases, on the basis