Serum Levels of Interleukins in Endometriosis Patients: A Systematic Review and Meta-analysis

Objective: The aims of this systematic review and meta-analysis were to produce a comprehensive survey of the serum levels of interleukins (ILs) in untreated people with endometriosis compared with people without endometriosis. Data Sources: A systematic literature search of English language studies within Cinahl, Medline Complete, PubMed, and Scopus from inception to May 2023 was performed. Methods of Study Selection: We included studies that compared IL serum levels in people with endometriosis to those without endometriosis. Meta-analysis was performed on IL-1RA, IL-1 beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-17A, IL-18, IL-23, and IL-37. Tabulation, Integration, and Results: The systematic search retrieved 651 studies, of which 77 underwent a full-text review. A total of 30 studies met inclusion criteria for the meta-analysis. IL-1Ra, IL-6, and IL-37 serum levels were 2.56 (95% CI 2.20-2.92, p <.001), 1.38 (95% CI 0.58-2.17, p <.001), and 1.77 (95% CI 1.33-2.20, p <.001) standard deviations higher in the patients with endometriosis compared with patients without endometriosis while IL-23 serum levels 0.40 (95% CI -0.73 to -0.07, p = .02) standard deviations lower, respectively. Conclusion: There is mounting evidence that ILs, especially IL-6, may be good candidates for unique noninvasive diagnostic tools and/or treatment pathways for endometriosis.