Relationship of the complement system with recurrence of pain syndrome after surgical treatment of ovarian endometrioid cysts

Abstract Aim. To evaluate the levels of complement system components (C3 and C4) in women with endometrioid ovarian cysts and their relationship with pain recurrence within a year after surgical treatment. Design. Prospective cohort comparative study Materials and methods. The study included 60 women referred for surgical treatment of endometrioid ovarian cysts with pain syndrome of varying severity (dysmenorrhea and/or dyspareunia and/or chronic pelvic pain). Before surgical treatment, the levels of C3 and C4 in the blood serum of all patients was determined. One year after the surgery, the presence of pain syndrome in the studied patients was re-evaluated. Women who noted its resumption within a year after the surgery were combined into the main group (group 1, n = 30), patients who reported the absence of pain syndrome in any form at the control visit formed the comparison group (group 2, n = 30). Results. Since half of the women participating in the study (n = 30) experienced recurrence of pain within a year after surgery, we performed a comparative analysis of the initial levels of C3 and C4 in patients with endometrioid ovarian cysts with and without persistent pain after surgery. It was found that in the comparison group, the initial level of C3 was 1.23 (1.13–1.31) g/L, C4 — 0.21 (0.19–0.26) g/L, and in women who noted chronic pelvic pain, dyspareunia and/or dyspareunia one year after surgery, it was 1.32 (1.17–1.52) and 0.23 (0.2–0.28) g/L, respectively. High statistical significance of differences between the groups in the level of C3 was determined: p = 0.037. In women with persistent pain syndrome, the level of C4 was also slightly higher, but the differences were not statistically significant: p = 0.338. Conclusion. Initially, a relatively higher level of C3 is associated with an increased likelihood of pain recurrence one year after surgical treatment. Determination of C3 level in the future can be used to predict the recurrence of pain after surgery and prescribe personalized drug therapy. Key words: endometrioma, endometrioid ovarian cysts, complement system C3, C4.