Changes in the level of anti-inflammatory and pro-inflammatory cytokines in patients with external genital endometriosis (literature review)

External genital endometriosis is characterized by the spread of the endometrium beyond the uterine cavity with damage to the pelvic peritoneum, ovaries, fallopian tubes, and ligaments. This endometriotic tissue undergoes the same cyclic changes as normal endometrium, and symptoms correspond to pathological conditions of the menstrual cycle. The study of biochemical parameters allows us to identify the disease and assess the level of its development. The aim of the work is to study the degree of changes in the level of anti-inflammatory and pro-inflammatory cytokines in serum and peritoneal fluid in patients with external genital endometriosis. The main methods for assessing the level of cytokines include immunoassay methods: ELISA (Enzyme-Linked Immunosorbent Assay) or Luminex analysis. Inflammation is a clear sign of the formation of endometriosis. Studies have shown that increased serum levels of transforming growth factor β1, tumor necrosis factor α, interleukin 1β, high-density lipoprotein, and nitric monoxide (NO) metabolites are observed in women with stage I–II external genital endometriosis. In patients with stages III–IV of disease, an increase in cholesterol, low- and high-density lipoproteins was observed in the peritoneal fluid. A relationship was found between the level of high-density lipoproteins and tumor necrosis factor α (its content increases twofold), indicators of transforming growth factor beta and metabolites of nitrogen compounds. High levels of tumor necrosis factor α can be considered in presents of infection. High levels of transforming growth factor β1 are considered as markers for stage III–IV external genital endometriosis, and in the future the development of fibrosis.