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Dynamics of Nevirapine-resistant HIV-1 following Single-dose NVP Assessed in Plasma and Cells by Consensus Sequencing and Oligonucleotide Ligation Assay
C Kress1, Thor Wagner*1,2, N Ngo-Giang-Huong3,4, N Luekamlung5, M Techapornroong6, S Banchongkit7, S Tunsuphasawasdikul8, G Jourdain3,4, M Lallemant3,4, L Frenkel1,2, and Perinatal HIV Prevention Trial
1Univ of Washington, Seattle, US; 2Children`s Hosp and Regional Med Ctr, Seattle, WA, US; 3Inst for Res and Devt, Paris, France and Chang Mai, Thailand; 4Harvard Sch of Publ Hlth, Boston, MA, US; 5Lamphun Hosp, Thailand; 6Prapokklao Hosp, Chantaburi, Thailand; 7Rayong Hospi, Thailand; and 8Buddhachinaraj Hosp, Pitsanuloke, Thailand
Background: Single-dose nevirapine (NVP) for
the prevention of HIV-1 mother-to-child transmission (MTCT) has been associated
with higher rates of virologic failure in women subsequently treated with NVP-based
ART. Detection of NVP resistance by consensus sequencing (CSeq) of plasma virus
at 10 days post partum was not predictive of virologic failure in multivariate
analysis. A sensitive predictor of an increased risk of failing NVP-ART might
prove useful for the management of women following single-dose NVP. We analyzed
NVP resistance longitudinally in a group of women who had selection of
NVP-resistant HIV-1 after single-dose NVP, and assessed the rate of NVP mutants
detectable in plasma and peripheral blood cells at 3 time-points by CSeq and an
oligonucleotide ligation assay (OLA).
Methods: Specimens from women enrolled in
PHPT2 who received single-dose NVP and started NVP-ART 4 to 18 months later
were screened for NVP resistance. Those with K103N, Y181C, or G190A by CSeq of
plasma from 10 days after single-dose NVP or by OLA of cells at 6 weeks or
later were selected to for further analysis. A minimum of 150 copies of HIV-1
RNA or DNA from plasma and cells, respectively, from 10 days, 6 weeks, and at
the initiation of ART was amplified by polymerase chain reaction (PCR). The
amplicons were analyzed for NVP resistance by CSeq and OLA. OLA with optical
densities >5% mutant control were classified as positive.
Results: Of 65 women who initiated NVP-ART 4
to 18 months after single-dose NVP and had detectable NVP-resistance mutations,
21 (32%) had longitudinal samples available. ART was started a median of 258 days
(range 120 to 504) after single-dose NPV in these 21 women. Specimens had 1 or
more NVP mutations detected as shown in the table: 71% (15 of 21) of women had
multiple mutations. Mutants persisting at ART start by OLA of cells: 4 of 16
(25%) K103N, 1 of 7 (14%) Y181C; and 4 of 19 (21%) G190A.
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CSeq of plasma/cells
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10 days
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52%/12%
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6 weeks
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45%/41%
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ART start, 10%/9%
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OLA of plasma/cells
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10 days
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90%/86%
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6 weeks
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71%/86%
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ART start, 10%/38%
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Conclusions: Selection of NVP-resistant HIV-1
mutants following single-dose NVP occurred more rapidly in plasma than in
cells. The concentration of mutant virus began to decay before 6 weeks post partum.
Mutants remained detectable at ART start in a subset of women. Decay of mutants
in cells appeared slower compared to plasma when evaluated by OLA. OLA on HIV-1
DNA from cells appeared more sensitive than CSeq, or testing of plasma RNA by
either method, to detect the persistence of NVP-resistant mutants. Additional
studies are needed to determine the clinical significance of the low-level
NVP-resistant HIV-1 persisting in cells.
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