Ex vivo human placental transfer of human immunodeficiency virus-1 p24 antigen.
OBJECTIVE
Our purpose was to determine whether human immunodeficiency virus-1 p24 antigen crosses the human placenta and, if so, to determine its clearance index relative to antipyrine.


METHODS
Eight term human placentas from uncomplicated vaginal or cesarean section deliveries were studied by ex vivo placental perfusion to determine the incidence and concentration required to obtain passage of p24 antigen into the fetal circulation. The concentration of p24 antigen was determined by antigen-capture enzyme immunoassay.


RESULTS
The passage of p24 antigen into the fetal circulation was observed in three of five placentas studied when the p24 antigen concentration in the maternal circulation was 2942.8 +/- 401 pg/ml. When the p24 concentration in the maternal circulation was raised approximately fourfold to 14506 +/- 4124 pg/ml, p24 antigen passed to the fetal circulation in two of three placentas and in three of three placentas in the closed perfusion system.


CONCLUSIONS
p24 antigen crossed the human placenta to the fetal circulation in what appears to be a concentration-dependent manner.
Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas.
R E
RE
Bawdon
M
M
Gravell
S
S
Roberts
R
R
Hamilton
J
J
Dax
J
J
Sever
D000163:Acquired Immunodeficiency Syndrome / Q000635:transmission; D000983:Antipyrine / Q000493:pharmacokinetics; D018562:Disease Transmission, Infectious; D016655:HIV Core Protein p24 / Q000378:metabolism*; D015497:HIV-1; D006801:Humans; D066298:In Vitro Techniques; D010920:Placenta / Q000378:metabolism*
D016655:HIV Core Protein p24; D000983:Antipyrine