title: A study of human leukocyte antigen G expression in hydatidiform moles.
abstract: OBJECTIVE
  Human leukocyte antigen G (HLA-G) is a nonclassic major histocompatibility gene normally expressed only in extravillous trophoblasts throughout pregnancy. It may be responsible in part for the successful evasion of the hemiallogenic trophoblasts from maternal immune surveillance. We investigated whether HLA-G is expressed in molar pregnancies.
  
  
  METHODS
  We examined 5 complete hydatidiform mole specimens and 5 partial hydatidiform mole specimens to determine whether HLA-G is expressed by immunohistochemistry and by RNA in situ hybridization analysis.
  
  
  RESULTS
  We found that both the protein and RNA of HLA-G is expressed in complete and partial hydatidiform moles.
  
  
  CONCLUSIONS
  HLA-G RNA and protein are expressed in molar pregnancies. HLA-G expression is independent of embryonic development and may therefore be an integral part of placental development. Furthermore, expression of HLA-G in the complete hydatidiform mole, a naturally occurring androgenote, confirms expression of the paternal allele of HLA-G. Imprinting of HLA-G is therefore unlikely to play a role in protecting fetal trophoblasts from maternal immune rejection.
authors.affiliation: Department of Obstetrics and Gynecology, Hadassah University Hospital, Jerusalem, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Goldman-Wohl
authors.forename: I
authors.initials: I
authors.lastname: Ariel
authors.forename: C
authors.initials: C
authors.lastname: Greenfield
authors.forename: D
authors.initials: D
authors.lastname: Hochner-Celnikier
authors.forename: Y
authors.initials: Y
authors.lastname: Lavy
authors.forename: S
authors.initials: S
authors.lastname: Yagel
mesh_terms: D005260:Female; D015870:Gene Expression; D006680:HLA Antigens / Q000032:analysis* / Q000235:genetics*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000032:analysis* / Q000235:genetics*; D006801:Humans; D006828:Hydatidiform Mole / Q000276:immunology*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D010920:Placenta / Q000276:immunology; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis; D014327:Trophoblasts / Q000276:immunology; D014594:Uterine Neoplasms / Q000276:immunology*
chemical_list: D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; D012333:RNA, Messenger