title: Drug resistance mutations 18 months after discontinuation of nevirapine-based ART for prevention of mother-to-child transmission of HIV in Malawi.
abstract: OBJECTIVE
  The objective of this study was to determine the prevalence of drug resistance mutations among HIV-positive women in Malawi 18 months after discontinuing nevirapine-based ART for the prevention of mother-to-child transmission.
  
  
  METHODS
  HIV-infected antiretroviral-naive (except for single-dose nevirapine) pregnant Malawian women receiving a nevirapine-based triple antiretroviral regimen from Week 25 of gestation until 6 months of breastfeeding were included in this analysis. Drug resistance was assessed in HIV-DNA 24 months post-partum and at baseline (before the initiation of treatment). In patients with resistance, the presence of mutations was also evaluated in the corresponding plasma samples.
  
  
  RESULTS
  Seven out of 42 (16.7%) women studied had archived drug resistance at Month 24 [six cases had NNRTI-associated mutations and two cases the M184I mutation]. In four cases, resistance mutations were already present at baseline (all NNRTI mutations). In three cases, there was an emergence of 'new' resistance (also present in the plasma in one case). Of the 35 women without resistance mutations at Month 24, only one subject had resistance mutations at baseline. Baseline resistance was significantly more common among women with mutations at 24 months compared with those harbouring a WT virus (4/7 versus 1/35, P < 0.001).
  
  
  CONCLUSIONS
  Among women who had discontinued drugs 6 months post-partum, only 3/42 (7.1%) had accumulated new resistance mutations in HIV-DNA 2 years after delivery. These findings are reassuring in terms of the safety of the Option B strategy for the prevention of HIV mother-to-child transmission.
authors.affiliation: Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Palombi
authors.affiliation: Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Clementina Maria
authors.initials: CM
authors.lastname: Galluzzo
authors.affiliation: Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Andreotti
authors.affiliation: Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Liotta
authors.affiliation: DREAM Program, Community of S. Egidio, PO Box 30355, Blantyre, Malawi.
authors.forename: Haswel
authors.initials: H
authors.lastname: Jere
authors.affiliation: DREAM Program, Community of S. Egidio, PO Box 30355, Blantyre, Malawi.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Sagno
authors.affiliation: DREAM Program, Community of S. Egidio, PO Box 30355, Blantyre, Malawi.
authors.forename: Richard
authors.initials: R
authors.lastname: Luhanga
authors.affiliation: Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.
authors.forename: Sandro
authors.initials: S
authors.lastname: Mancinelli
authors.affiliation: Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Amici
authors.affiliation: LUMSA University, Via Transpontina 21, 00193 Rome, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Marazzi
authors.affiliation: Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Vella
authors.affiliation: Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy marina.giuliano@iss.it.
authors.forename: Marina
authors.initials: M
authors.lastname: Giuliano
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D024882:Drug Resistance, Viral; D005260:Female; D006678:HIV / Q000187:drug effects* / Q000235:genetics*; D015658:HIV Infections / Q000188:drug therapy* / Q000635:transmission / Q000821:virology*; D006801:Humans; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D008295:Malawi; D009154:Mutation; D019829:Nevirapine / Q000494:pharmacology* / Q000627:therapeutic use*; D011247:Pregnancy; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D013997:Time Factors; D019562:Viral Load; D055815:Young Adult
chemical_list: D018894:Reverse Transcriptase Inhibitors; D019829:Nevirapine