title: Human leukocyte antigen-G, a ligand for the natural killer receptor KIR2DL4, is expressed by eutopic endometrium only in the menstrual phase.
abstract: OBJECTIVE
  To investigate menstrual cycle changes in expression by eutopic endometrium of a nonclassic human leukocyte antigen, HLA-G, which binds to the killer immunoglobulin-like receptor (KIR) 2DL4 (CD158d) on natural killer (NK) cells. Such antigens have been linked to endometriosis.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  We examined 20 Japanese women undergoing hysterectomy for endometriosis and 17 undergoing hysterectomy for myoma.
  
  
  METHODS
  Immunohistochemical HLA-G staining of eutopic endometrium and peritoneal fluid (PF) cells from women with and without endometriosis. Flow cytometric analysis of PF NK cells from women with and without endometriosis.
  
  
  METHODS
  HLA-G staining in eutopic endometrium was quantified by image analysis. The KIR2DL4-expressing NK cells in PF were investigated by flow cytometry.
  
  
  RESULTS
  The HLA-G was expressed by eutopic endometrium only in the menstrual phase and not in the late proliferative or secretory endometrium. Intensity of HLA-G staining did not differ significantly between women with and without endometriosis. The HLA-G- expressing cells were detected in PF during the menstrual period. These cells are morphologically and flow cytometrically different from mesothelial cells and NK cells.
  
  
  CONCLUSIONS
  The HLA-G expression is observed in eutopic endometrium only during the menstrual phase, and no differences were observed between women with and without endometriosis. Epithelial cells bearing HLA-G may enter the peritoneal cavity during retrograde menstruation, allowing the antigen to react locally with KIR2DL4.
authors.affiliation: Department of Obstetrics and Gynecology, Kochi Medical School, Nankoku, Kochi, Japan. km501212km@hotmail.com
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kawashima
authors.forename: Nagamasa
authors.initials: N
authors.lastname: Maeda
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Adachi
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Yorito
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Chiaki
authors.initials: C
authors.lastname: Izumiya
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Hayashi
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Furihata
authors.forename: Keiko
authors.initials: K
authors.lastname: Udaka
authors.forename: Takao
authors.initials: T
authors.lastname: Fukaya
mesh_terms: D000328:Adult; D001202:Ascitic Fluid / Q000276:immunology*; D016022:Case-Control Studies; D004715:Endometriosis / Q000276:immunology* / Q000503:physiopathology / Q000601:surgery; D004717:Endometrium / Q000276:immunology* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005434:Flow Cytometry; D006680:HLA Antigens / Q000032:analysis*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000032:analysis*; D006801:Humans; D007044:Hysterectomy; D007150:Immunohistochemistry; D007564:Japan; D007694:Killer Cells, Natural / Q000276:immunology*; D008597:Menstrual Cycle / Q000276:immunology*; D008875:Middle Aged; D054345:Receptors, KIR2DL4 / Q000032:analysis*
chemical_list: D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; C515079:KIR2DL4 protein, human; D054345:Receptors, KIR2DL4