Studies on the placental transfer of cell-free human immunodeficiency virus and p24 antigen in an ex vivo human placental model.
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.
Bawdon
R E
RE
Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas 75235-9032, USA.
Gravell
M
M
Hamilton
R
R
Sever
J
J
Miller
R
R
Gibbs
C J
CJ
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
D016655:HIV Core Protein p24