title: Histocompatibility leukocyte antigen-G is not expressed by endometriosis or endometrial tissue.
abstract: OBJECTIVE
  The immunological mechanisms that support persistence and proliferation of ectopic endometrial implants within the peritoneal cavity of women with endometriosis are unknown. Inhibition of natural killer (NK) and cytotoxic T-cell function has been proposed as a mechanism. We tested the hypothesis that expression of a nonclassical major histocompatibility antigen, HLA-G, might explain the local immunosuppression associated with ectopic endometrium.
  
  
  METHODS
  Nested case-control study of women with and without laparoscopic evidence of endometriosis.
  
  
  METHODS
  Reproductive endocrinology clinic at a university hospital.
  
  
  METHODS
  Peritoneal fluid specimens from 10 women with revised AFS stage I-IV endometriosis and from 10 age-matched normal controls without laparoscopic evidence of endometriosis were tested for the presence of HLA-G protein. Endometriosis and normal endometrial biopsies from four patients were used to prepare stromal cell cultures directly evaluated for HLA-G protein.
  
  
  METHODS
  None.
  
  
  METHODS
  The expression of HLA-G in peritoneal fluid, tissue, and cell cultures was determined by immunoblotting with a specific monoclonal antibody.
  
  
  RESULTS
  HLA-G protein was not detectable in peritoneal fluid specimens of endometriosis patients or controls. Moreover, ectopic and normal endometrial tissues and stromal cells did not express HLA-G.
  
  
  CONCLUSIONS
  Immune cell inhibition in endometriosis must be mediated by factors other than HLA-G.
authors: Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, San Francisco, California 94143-0556, USA.
authors: D
authors: D
authors: Hornung
authors: E
authors: E
authors: Fujii
authors: K H
authors: KH
authors: Lim
authors: J L
authors: JL
authors: Vigne
authors: M T
authors: MT
authors: McMaster
authors: R N
authors: RN
authors: Taylor
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D001202:Ascitic Fluid / Q000276:immunology; D015153:Blotting, Western; D016022:Case-Control Studies; D002478:Cells, Cultured; D002822:Choriocarcinoma / Q000276:immunology; D004715:Endometriosis / Q000276:immunology* / Q000473:pathology; D004717:Endometrium / Q000166:cytology / Q000276:immunology* / Q000473:pathology; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D005260:Female; D006680:HLA Antigens / Q000032:analysis*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000032:analysis*; D006801:Humans; D010535:Laparoscopy; D008969:Molecular Sequence Data; D012016:Reference Values; D017154:Stromal Cells / Q000166:cytology / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I