Decreased CD8 cell-mediated viral suppression and other immunologic characteristics of women who transmit human immunodeficiency virus to their infants

CD8 T cell function, lymphocyte surface phenotype, serum markers of immunol ogic activation, and viral burden were assessed in 75 human immunodeficienc y virus (HIV)-infected pregnant women, including 9 who transmitted infectio n to their infants. Serial studies during and after pregnancy showed no sig nificant differences in levels of cell-surface or serum activation molecule s in transmitting compared to nontransmitting mothers, with the exception o f a postpartum increase in tumor necrosis factor alpha in transmitting wome n. The transmitting women had a median plasma viral load of 65,516 RNA copi es/mL at delivery versus 5139 in nontransmitting women, During the third tr imester, the CD8 cells of 81% of the nontransmitting and 44% of the transmi tting mothers suppressed HIV production in vitro by >50%. Women with <50% s uppression had a 3.4 times greater risk of transmitting HIV to their infant s. CD8 suppression and viral load were interrelated, but when either CD4 pe rcent or AZT use was controlled for, suppression was still significant.