title: Drug resistance among HIV-infected pregnant women receiving antiretrovirals for prophylaxis.
abstract: OBJECTIVE
  To quantify primary resistance mutations (PRMs) among HIV-1-infected women receiving antiretroviral therapy (ART) for prevention of mother-to-child transmission (MTCT).
  
  
  METHODS
  Peripheral blood mononuclear cell samples from HIV-1-infected women enrolled in a prospective cohort study in Argentina, the Bahamas, Brazil, and Mexico (NISDI Perinatal Study) were assayed for PRMs. Eligible women were those enrolled by March 2005 and diagnosed with HIV-1 infection during the current pregnancy, and who received ART for MTCT prophylaxis and were followed for 6-12 weeks postpartum.
  
  
  RESULTS
  Of 819 women, 198 met the eligibility criteria. At enrollment, 98% were asymptomatic, 62% had plasma viral load < 1000 copies/ml, 53% had CD4+ cell count > or = 500 cells/microl, and 78% were ART-exposed (mean duration, 8.0 weeks; 95% confidence interval, 7.1-8.9). The most complex ART regimen during pregnancy was usually (81%) a three-drug regimen [two nucleoside reverse transcriptase inhibitors (NRTIs) + one protease inhibitor or two NRTIs + one non-nucleoside reverse transcriptase inhibitor). PRMs were observed in samples from 19 (16%) of 118 women that were amplifiable at one or both time points [11/76 (14%) at enrollment; 14/97 (14%) at 6-12 weeks]. The occurrence of PRMs was not associated with clinical, immunological, or virological disease stage at either time point, whether ART-naive versus exposed at enrollment, or the most complex or number of antiretroviral drug regimens received during pregnancy (P > 0.1). Of 55 women with amplifiable samples at both time points, PRMs were detected in 11 samples (20%).
  
  
  CONCLUSIONS
  PRMs occurred among 16.1% of relatively healthy HIV-1-infected mothers from Latin American and Caribbean countries receiving MTCT prophylaxis.
authors.affiliation: Hosp General de Agudos Jose Maria Ramos Mejia, Buenos Aires, Argentina. aduran@hivramos.org.ar
authors.forename: Adriana S
authors.initials: AS
authors.lastname: Duran
authors.forename: Marcelo H
authors.initials: MH
authors.lastname: Losso
authors.forename: Horacio
authors.initials: H
authors.lastname: Salomón
authors.forename: D Robert
authors.initials: DR
authors.lastname: Harris
authors.forename: Sandra
authors.initials: S
authors.lastname: Pampuro
authors.forename: Luis E
authors.initials: LE
authors.lastname: Soto-Ramirez
authors.forename: Geraldo
authors.initials: G
authors.lastname: Duarte
authors.forename: Ricardo S
authors.initials: RS
authors.lastname: de Souza
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Read
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D024882:Drug Resistance, Viral / Q000235:genetics*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000517:prevention & control* / Q000635:transmission / Q000821:virology; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control; D009154:Mutation; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy*; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents