Relationship between plasma selenium concentrations and lower genital tract levels of HIV-1 RNA and interleukin type 1beta.

OBJECTIVE: To examine the relationship between selenium nutritional status and intermediates of human immunodeficiency virus (HIV)-1 transmission.
DESIGN: Prospective cohort study.
SETTING: A study clinic at Muhimbili National Hospital, Dar es Salaam, Tanzania.
SUBJECTS: A total of 340 HIV-1-infected pregnant women with gestational ages 12-27 weeks.
METHODS: Women's plasma selenium concentrations were determined at enrollment and modeled as tertiles (tertile 1: <114 microg/l (reference); tertile 2: 114-131 microg/l; tertile 3: >131 microg/l). Cervicovaginal lavage specimens were obtained at 36 weeks of gestation to determine HIV-1 RNA and interleukin-1beta (IL-1beta) levels. In subgroup analyses, 123 women with genital tract infections at enrollment were excluded.
RESULTS: Plasma selenium concentrations >or=114 microg/l were related to increased risk of lower-genital shedding of HIV-1 RNA. Excluding women with genital tract infections strengthened the associations (relative risk (RR) tertile 2: 1.46, 95% confidence interval (CI)=1.10, 1.92; RR tertile 3: 1.39, 95% CI=1.05, 1.84). There was evidence for an association between plasma selenium concentrations >or=114 microg/l and increased HIV-1 RNA levels among the entire cohort and after excluding women with genital tract infections. There was no association between plasma selenium and IL-1beta concentrations.
CONCLUSIONS: High selenium status may lead to increased risk of genital HIV-1 shedding, but data from other studies indicate that the evidence is mixed. Results from ongoing selenium trials are awaited to clarify the impact of selenium on HIV-1-related transmission endpoints. SPONSORSHIP: National Institute of Child Health and Human Development (NICHD R01 32257) and the Fogarty International Center (NIH D43 TW00004).