title: Pregnancy as a model of controlled invasion might be attributed to the ratio of CD3/CD8 to CD56.
abstract: OBJECTIVE
  Pregnancy can be considered as a model of successfully controlled tissue invasion. Cellular mediated immunity appears to regulate the controlled invasion of fetal trophoblast cells. In endometrium cancer, a dysregulation of invasive malignant cells can be observed. Since immunocompetent cells are known to be involved in recognition and rejection of 'non-self' antigens, we investigated the presence and distribution pattern of CD3, CD8, CD56, and CD68 positive cells in decidua from normal and failing pregnancies, compared with malignant and benign endometrium.
  
  
  METHODS
  Decidual tissue from first trimester normal pregnancies (NP; n = 15) and abortion (AB; n = 12), endometrial samples from premenopausal women (NE; n = 8), and endometrioid adenocarcinoma (EA; n = 8) were examined by immunohistochemistry using monoclonal antibody against large spectrum cytokeratin, and against the receptors CD3, CD8, CD56 and CD68, respectively.
  
  
  RESULTS
  In NP, we observed 32.5% CD3, 44.7% CD56, and 22.9% CD68+ cells. In AB, we found 36.9% CD3, 45.3% CD56, and 17.8% CD68+ cells. The differences in ratio between normal pregnancy and abortion were not statistically significant. In NE, we counted 39.5% CD3, 30.2% CD56 and 30.2% CD68 cells. In EA, we observed 47.9% CD3, 12.4% CD56 and 39.7% CD68+ cells. The decrease of CD56 positive cells in endometrioid adenocarcinoma was statistically significant. Interestingly, we found 4.1% of cells positive for CD8 in NP, 4.9% in AB, 22.7% in NE, and 48.2% in EA.
  
  
  CONCLUSIONS
  The increase of CD8 cells in NE, and particularly in EA, and decrease of CD56 cells, compared with NP or AB, suggests an interaction between CD8 cells and CD56 cells. Studying different pathological situations in the uterus, such as malignancies or ectopic pregnancies, might help us to understand the mechanisms involved in the maintenance of pregnancy.
authors.affiliation: Department of Medicine/Psychosomatics, Charité, Humboldt University Berlin, Germany. petra.arck@charite.de
authors.forename: P C
authors.initials: PC
authors.lastname: Arck
authors.forename: K
authors.initials: K
authors.lastname: Hertwig
authors.forename: E
authors.initials: E
authors.lastname: Hagen
authors.forename: M
authors.initials: M
authors.lastname: Hildebrandt
authors.forename: B F
authors.initials: BF
authors.lastname: Klapp
mesh_terms: D000028:Abortion, Induced; D000022:Abortion, Spontaneous / Q000276:immunology; D000230:Adenocarcinoma / Q000276:immunology; D000328:Adult; D015703:Antigens, CD / Q000032:analysis*; D017252:CD3 Complex / Q000032:analysis; D019002:CD56 Antigen / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D003656:Decidua / Q000166:cytology / Q000276:immunology; D016889:Endometrial Neoplasms / Q000276:immunology; D004717:Endometrium / Q000276:immunology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000276:immunology*; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000276:immunology*; D011247:Pregnancy / Q000276:immunology*; D011261:Pregnancy Trimester, First / Q000276:immunology; D017697:Premenopause / Q000276:immunology
chemical_list: D015703:Antigens, CD; D017252:CD3 Complex; D019002:CD56 Antigen; D016827:CD8 Antigens