Human leukocyte antigen expression by peritoneal macrophages from women with pelvic endometriosis is depressed but coordinated with costimulatory molecule expression

Coordination with costimulatory molecules but relatively low expression of HLA-ABC and HLA-DR indicates a positive but limited immune response (antigen presentation) to events in the peritoneal cavity in women with endometriosis. This may induce immune tolerance to implanted or metaplastic endometrial tissue.