title: Increased human leukocyte antigen-G expression at the maternal-fetal interface is associated with preterm birth.
abstract: Abstract Objective: The maternal-fetal interface must modulate immune function to allow tolerance of fetal cells while still reacting to pathogens to suppress infection. Human leukocyte antigen-G (HLA-G) is a class Ib major histocompatibility complex protein involved in maternal-fetal tolerance. We posited that alterations in placental HLA-G expression predispose women to preterm birth. The aim of this study was to compare HLA-G expression in the maternal-fetal interface of term versus preterm human placentas.
  
  
  METHODS
  We performed a cross-sectional study of specimens from the basal plate of the human placenta from women enrolled in a tissue specimen and clinical data consortium. Immunohistochemistry with digital microscopic analysis was used to quantify HLA-G protein expression in the basal plate from preterm and term placentas.
  
  
  RESULTS
  Preterm birth <37 weeks occurred in 29.5% of 149 singleton pregnancies. HLA-G-positive cells occupied one-third of the basal plates, and the HLA-G-positive area was increased by 14% in placentas from preterm births than in those from term births (32.1% in term placentas versus 36.6% in preterm placentas).
  
  
  CONCLUSIONS
  Although HLA-G is required for maternal tolerance of the semi-allogeneic fetus, higher levels of HLA-G expression at the maternal-fetal interface is associated with preterm birth.
authors.affiliation: Department of Obstetrics and Gynecology and.
authors.forename: Molly J
authors.initials: MJ
authors.lastname: Stout
authors.forename: Bin
authors.initials: B
authors.lastname: Cao
authors.forename: Michele
authors.initials: M
authors.lastname: Landeau
authors.forename: Jacob
authors.initials: J
authors.lastname: French
authors.forename: George A
authors.initials: GA
authors.lastname: Macones
authors.forename: Indira U
authors.initials: IU
authors.lastname: Mysorekar
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D059951:HLA-G Antigens / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange; D010920:Placenta / Q000276:immunology / Q000378:metabolism*; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology / Q000276:immunology* / Q000378:metabolism*; D055815:Young Adult
chemical_list: D059951:HLA-G Antigens
keywords: Extravillous trophoblast; infection; maternal–fetal tolerance; placenta