A systematic review of toll-like receptors in endometriosis

Introduction The pathogen-associated molecular patterns and the danger-associated molecular patterns are possibly responsible for the activation of the inflammatory process in endometriosis through the activation of toll-like receptors (TLRs). Objective The aim of this systematic review was to critically analyze the findings of published articles on TLRs in endometriosis. Methods The keywords used were “endometriosis” and “toll-like” and the search was performed in Pubmed, Scielo and Lilacs databases. This study followed the PRISMA guidelines and the risk of bias of articles was conducted by Newcastle–Ottawa scale (NOS). Results Overall, the studies analyzed in this review point toward an increased expression of TLRs two, four and nine in women with endometriosis. Among all TLRs, TLR4 was the most cited receptor. Conclusion Despite the evidence demonstrating elevated TLR levels in endometriosis, the relationship with the disease is still unclear and needs to be clarified in further studies about innate immune response.