Alterations in Cellular Immunity in Patients With Endometriosis: Systematic Review and Meta-Analysis

Determining the pathogenesis of endometriosis remains a major challenge in contemporary gynecology, and the investigation of alterations in cellular immunity may provide important insights into this issue. A comprehensive search of electronic databases (PubMed, The Cochrane Library, ClinicalTrials.gov, Scopus, Embase, and Google Scholar) identified 24 studies meeting the inclusion criteria for qualitative synthesis. The primary analysis compared the concentration of IL-4 in peripheral blood (MD = 1.32, 95% CI: -15.00 to 17.63, p = 0.87); the secondary compared the concentration of HLA-DR⁺-macrophages (MD = -2.62, 95% CI: -8.98 to 3.73, p = 0.42) and HLA-ABC⁺-macrophages (MD = -6.84, 95% CI: -23.94 to 10.26, p = 0.43) in peritoneal fluid; the third compared the IL-6 concentration in peritoneal fluid (MD = 338.00, 95% CI: 85.02 to 590.98, p = 0.009); the fourth compared the NK-cell level in peritoneal fluid (MD = 6.75, 95% CI: -12.42 to 25.91, p = 0.49); the fifth compared the level of NK-cells in ectopic and eutopic endometrium (MD = -9.12, 95% CI: -24.39 to 6.15, p = 0.24) between endometriosis and control groups. Overall, the included studies suggest that signaling pathways involving T lymphocytes, monocytes, macrophages, and natural killer cells are altered in patients with endometriosis.