title: The endometria of patients with endometriosis show higher expression of class I human leukocyte antigen than the endometria of healthy women.
abstract: OBJECTIVE
  To compare the expression of class I human leukocyte antigen (HLA I) in endometrial samples from patients with and without endometriosis.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Acute-care teaching hospital in Barcelona, Spain.
  
  
  METHODS
  The endometriosis group included 32 patients for whom the only diagnosis during an operation was endometriosis. The control group included 20 women who underwent a laparoscopy and in whom no evidence of endometriosis or any other genital disease was seen.
  
  
  METHODS
  Samples of endometrium were obtained by curettage and immediately frozen. A pan-HLA I mouse antihuman IgG2a monoclonal antibody was used for immunohistochemical study.
  
  
  METHODS
  Frequency of positive glandular and stromal cells was evaluated in each section.
  
  
  RESULTS
  A significantly higher expression of HLA I in the endometriosis group than in controls, both in the glandular cells (median 100% vs. 80%) and in the stromal cells (median 60% vs. 20%), was observed.
  
  
  CONCLUSIONS
  Patients with endometriosis had a significantly higher expression of HLA I molecules in endometrial cells than did the controls. This could be a possible explanation for their higher resistance to natural killer cytolysis.
authors.affiliation: Obstetrics and Gynecology Service, Hospital Universitari del Mar, Universitat Autònoma de Barcelona, Barcelona, Spain. mvernet@imas.imim.es
authors.forename: María del Mar
authors.initials: Mdel M
authors.lastname: Vernet-Tomás
authors.forename: Carlos T
authors.initials: CT
authors.lastname: Pérez-Ares
authors.forename: Núria
authors.initials: N
authors.lastname: Verdú
authors.forename: José Luis
authors.initials: JL
authors.lastname: Molinero
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Fernández-Figueras
authors.forename: Ramon
authors.initials: R
authors.lastname: Carreras
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004715:Endometriosis / Q000276:immunology* / Q000378:metabolism; D004717:Endometrium / Q000276:immunology* / Q000378:metabolism; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007694:Killer Cells, Natural / Q000276:immunology; D017154:Stromal Cells / Q000276:immunology / Q000378:metabolism
chemical_list: D015395:Histocompatibility Antigens Class I