Human immunodeficiency virus infection: In situ polymerase chain reaction localization in human placentas after in utero and in vitro infection, ,

Objective: We compared localization of human immunodeficiency virus type 1 within human placentas infected in utero with localization within human placental explants infected in vitro. Study Design: Placental tissues from 3 cases of vertical transmission of human immunodeficiency virus type 1 were studied. Human placental explants from 6 term pregnancies not complicated by human immunodeficiency virus type 1 infection were infected in vitro with human immunodeficiency virus type 1Ba-L. Sections from each placental explant and each placenta infected in utero were analyzed for human immunodeficiency virus type 1 localization by means of in situ polymerase chain reaction. Results:Human immunodeficiency virus type 1 was primarily localized within syncytiotrophoblast, Hofbauer cells, and extravillous mononuclear cells in placental tissue sections from cases of in utero infection. Within placental explants human immunodeficiency virus type 1 deoxyribonucleic acid was found in syncytiotrophoblast and Hofbauer cells. The distributions of viral localization were similar in placentas infected in utero and placental explants infected in vitro. Conclusion: Human immunodeficiency virus type 1 can be localized to specific human placental cells (eg, syncytiotrophoblast) after either in utero or in vitro infection, which demonstrates the specificity and selectivity of human immunodeficiency virus infection in the human placenta. (Am J Obstet Gynecol 2000;182:207-13.)