title: Studies on the placental transfer of cell-free human immunodeficiency virus and p24 antigen in an ex vivo human placental model.
abstract: OBJECTIVE
  We studied whether the human placenta has the structural integrity to impede transplacental passage of cell-free human immunodeficiency virus (HIV)-1 or p24 antigen from the maternal to the fetal circulation.
  
  
  METHODS
  Nine term human placentas from uncomplicated vaginal or cesarean section deliveries were studied ex vivo with a placental perfusion apparatus to determine whether cell-free HIV-1 at 200-2000 tissue culture infectious dose (TCID50/mL) would pass to the fetal circulation. Passage of virus or p24 was assessed by infectivity titration and/or p24 antigen capture enzyme immunoassay.
  
  
  RESULTS
  Infectious HIV-1 was not detected in any of the fetal perfusate samples taken periodically during experiments. Low concentrations of HIV-1 p24 antigen, however, were detected in fetal perfusate samples from three placentas.
  
  
  CONCLUSIONS
  The term human placenta effectively impedes passage of cell-free HIV-1 from the maternal to the fetal circulation. However, it may be permeable to passage of p24 antigen.
authors.affiliation: Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas 75235-9032, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Bawdon
authors.forename: M
authors.initials: M
authors.lastname: Gravell
authors.forename: R
authors.initials: R
authors.lastname: Hamilton
authors.forename: J
authors.initials: J
authors.lastname: Sever
authors.forename: R
authors.initials: R
authors.lastname: Miller
authors.forename: C J
authors.initials: CJ
authors.lastname: Gibbs
mesh_terms: D002474:Cell-Free System; D005260:Female; D016655:HIV Core Protein p24 / Q000097:blood*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D008431:Maternal-Fetal Exchange / Q000502:physiology*; D008954:Models, Biological; D010920:Placenta / Q000502:physiology*; D011247:Pregnancy
chemical_list: D016655:HIV Core Protein p24