Ultrastructural findings in placentae of HIV-positive women.

ABSTRACT

PIP Transmission of human immunodeficiency virus (HIV) from an infected mother to the fetus has been shown to occur. The route of infection is probably through the placenta, yet the exact mechanism of how this occurs is still unclear. Researchers in Mexico report in this article their findings on placental tissue taken from 9 HIV-seropositive women. The placentas from new deliveries were sectioned and the tissue fixed and embedded in plastic. Thin sections were cut, stained, and examined using transmission electron microscopy (TEM). HIV-like particles were found near or inside the trophoblastic villi in 4 placental specimens examined. In one case these particles were found in the endothelium of the umbilical artery. Mast-like cells were found in the free villous stroma in 2 tissue samples. Vertical transmission of HIV has been a major source of HIV infections in Europe and the US. On the other hand, Mexico doesn't report similar findings. The authors suggest that this is the case because of lower female drug use. It is still unclear why some babies from HIV-seropositive mothers become infected while others do not.^ieng