Microbicides: In Vitro and In Vivo
Thursday, 1:30 - 3:30 pm
Background: Higher levels of cervicovaginal, cell-free HIV have been associated with increased heterosexual and perinatal HIV transmission. In prior studies, detection of cell-free HIV in cervicovaginal secretions has been reported in up to 65% of HIV-infected women. We report baseline cervicovaginal HIV virus load results among HIV-infected women enrolled in a clinical trial of a candidate vaginal microbicide’s effect on HIV shedding.
Methods: We enrolled 60 HIV-infected women 3 to 5 days following the end of menses. At baseline, blood and cervicovaginal lavage (CVL) specimens (in 5 mL of phosphate-buffered saline) were collected. Both vaginal walls and the external cervical os were rinsed with phosphate-buffered saline, and the CVL solution was collected using a 10-mL pipette. CD4+ cell count levels and cell-free HIV virus loads in plasma and CVL were determined. CVL specimens were processed using a modified, NucliSens RNA extraction assay with Roche Amplicor HIV-1 Monitor 1.5®.
Results: The median CD4+ count among study participants was 299 cells/µL (range 51 to 496 cells/µL). In 58 of 60 (97%) participants with detectable plasma HIV, median HIV plasma virus load was 42,812 copies/mL (range 2216 to 654,270 copies/mL); among women with detectable plasma HIV, 81% (47 of 58) had detectable CVL HIV (median = 454 copies per CVL [range 40 to 35,892 copies per CVL]); median CVL HIV was 1246 copies per CVL in women with CD4+ count < 200 cells/µL compared with 252 copies per CVL in women with CD4+ count ≥ 200 cells/µL (p < 0.05).
Conclusions: The high rate of detection of HIV in cervicovaginal specimens among study participants demonstrates the feasibility of using this method of measuring cell-free HIV to determine the effect of vaginal microbicides and other HIV prevention methods on HIV shedding. Consistent with prior findings, CVL HIV virus loads were higher among women with CD4+ counts < 200 cells/µL than among those with CD4+ count ≥ 200 cells/µL.
Keywords: HIV; transmission; microbicides