Problem: In HIV-1-infected pregnant women with low plasma viral load, risk factors associated with perinatal HIV-1 transmission are not clearly understood.
Method of study: We analyzed distribution of peripheral CD8 T-cell subsets, plasma cytokines and measured secretory leukocyte peptidase inhibitor (SLPI) and myeloid-related protein (MRP)-8 levels in whole-blood and cervico-vaginal fluid (CVF) specimens obtained from 35 HIV-1-infected pregnant women (group 1), 12 HIV-1-infected non-pregnant women (group 2) and 15 HIV-1 uninfected pregnant women (group 3).
Results: The group 1 women had higher expression of CD38, human leukocyte antigen-DR and CD95 on CD8 T-cells and higher levels of plasma tumor necrosis factor-alpha and epidermal growth factor. CVF-SLPI levels were the highest in group-3, while MRP-8 levels were the highest in group 1 women in plasma and CVF (P < 0.01). Although there were no cases of perinatal HIV-1 transmission, group 1 women undergoing HIV-1-indicated cesarean section had lower levels of CVF-SLPI as compared with those undergoing normal vaginal delivery.
Conclusion: Pregnancy contributes to the activation of peripheral CD8 T cells and increase in pro-inflammatory cytokines. Production of protective mucosal secretory factors such as SLPI is affected by HIV-1 infection in pregnant women and down-regulated SLPI levels may indirectly indicate a higher possibility of perinatal HIV-1 transmission.