{"paper_id":"3d0ec75f-284a-4ab1-8886-dd8cb530fd5d","body_text":"Abstract\nMany pro-inflammatory cytokines especially tumor necrotic factor alpha (TNFα), interleukin (IL)-1β, and IL-6 have crucial role in the pathogenesis of endometriosis. In this study, we investigated the immune-modulatory role of humanized anti-IL-6 receptor monoclonal antibodies in the treatment of endometriosis. This is a prospective, randomized, controlled, blinded study in which Sprague Dawley rats were used as animal model of endometriosis. Animals were randomly divided into two groups, a test group which received tocilizumab (Actemra; Roche, Switzerland) and a control group which received saline. Afterwards, a comparison was done between the eutopic and ectopic endometrium that was excised from both groups, histopathologically and immune-histochemically. Histopathologic assessment and immune-histochemical staining were performed using antibodies against IL-6. Tocilizumab significantly suppressed the volume of endometriotic lesions compared with non-treated rats (P = 0.006) and atrophied the ectopic endometrial-like epithelium (in 42.8% of treated rats vs 0% in the control group). Tocilizumab also decreased the anti-IL-6 receptor immune-histochemical staining intensity in ectopic endometrium (from non to +++ in the test group vs ++ or more in the control group), with no apparent difference in the eutopic one reflecting the down-regulation of IL-6-producing cells in ectopic endometriotic lesions. In rats with induced endometriosis, anti-IL-6 receptor monoclonal antibodies could offer a new horizon of usage of this immune-modulatory biologic drug, used in other autoimmune diseases, in treatment of endometriosis.\nSimilar content being viewed by others\nData availability\nAre confirmed.\nReferences\nBulun SE. Endometriosis. N Engl J Med. 2009;360(3):268–79.\nVinatier D, Orazi G, Cosson M, Dufour P. Theories of endometriosis. 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Reprod Sci. 2016;23(5):662–9.\nFunding\nThis project was supported financially by the Mansoura University Fund, Egypt.\nAuthor information\nAuthors and Affiliations\nCorresponding author\nEthics declarations\nConflict of interest\nThe authors declare that they have no conflict of interest.\nEthical approval\nThe study was approved by the Mansoura Faculty of Medicine Institutional Research Board (MFM-IRB).\nAdditional information\nPublisher’s note\nSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.\nRights and permissions\nAbout this article\nCite this article\nEl-Zayadi, A.A., Mohamed, S.A., Arafa, M. et al. Anti-IL-6 receptor monoclonal antibody as a new treatment of endometriosis. Immunol Res 68, 389–397 (2020). https://doi.org/10.1007/s12026-020-09153-5\nReceived:\nAccepted:\nPublished:\nVersion of record:\nIssue date:\nDOI: https://doi.org/10.1007/s12026-020-09153-5","source_license":"CC0","license_restricted":false}