Development of antiretroviral resistance among HIV-1-infected women first exposed to antiretrovirals during pregnancy: the NICHD international site development initiative (NISDI) perinatal study.

DURAN A; LOSSO M; SALOMON H; PAMPURO S; HARRIS R; SOTO-RAMIREZ L; READ J; NISDI PERINATAL STUDY GROUP

Toronto, Canadá

Congreso; XVI International AIDS Conference – Time to Deliver.; 2006

International AIDS Society

Background: To quantify primary resistance mutations (PRMs) among pregnant women receiving ARVs for prevention of MTCT of HIV-1.To quantify primary resistance mutations (PRMs) among pregnant women receiving ARVs for prevention of MTCT of HIV-1. Methods: Peripheral blood mononuclear cell (PBMC) samples at enrollment and 6-12 weeks postpartum were assayed for PRMs among HIV-1-infected women enrolled in a prospective cohort study in Argentina, the Bahamas, Brazil and Mexico. The study population was restricted to women enrolled by March 2005, who were diagnosed with HIV-1 infection during the current pregnancy, received ARVs for perinatal transmission prophylaxis, and were followed through 6-12 weeks postpartum.Peripheral blood mononuclear cell (PBMC) samples at enrollment and 6-12 weeks postpartum were assayed for PRMs among HIV-1-infected women enrolled in a prospective cohort study in Argentina, the Bahamas, Brazil and Mexico. The study population was restricted to women enrolled by March 2005, who were diagnosed with HIV-1 infection during the current pregnancy, received ARVs for perinatal transmission prophylaxis, and were followed through 6-12 weeks postpartum. Results: Of 819 women, 198 met the inclusion criteria (98% CDC Category A, 62% viral load <1000 copies/mL, 53% CD4 count >500 cells/mm3). At enrollment, 155 were ARV-experienced (median duration: 7.1 weeks), 43 ARV-naïve. The most complex ARV regimen during pregnancy was: 2NRTIs + either 1NNRTI or 1PI, 81%; similar proportions (~10%) received 1 or 2 NRTIs. Most (94%) received one (150) or two (35) ARV regimens during pregnancy. At enrollment, amplification could not be accomplished for samples from 122 women (and, at 6-12 weeks, for 101), primarily related to very low viral load. PRMs were observed in 16 (14%) of 118 samples amplifiable at either time point: four (enrollment only), seven (6-12 weeks postpartum only), five (both time points). At enrollment, 9/76 (12%) had PRMs (3 ARV-naïve). At 6-12 weeks postpartum, 12/97 (12%) had PRMs. Occurrence of PRMs was not associated with: viral load, CD4 count at either time point, CDC disease classification, whether ARV-naïve vs.experienced at enrollment, or most complex or number of ARV regimens during pregnancy (p>0.1). The most common mutations were K70R, K103N, M46I, D30N. The rate of MTCT [1.5% (3/198)] was not associated with the occurrence of resistance mutations.Of 819 women, 198 met the inclusion criteria (98% CDC Category A, 62% viral load <1000 copies/mL, 53% CD4 count >500 cells/mm3). At enrollment, 155 were ARV-experienced (median duration: 7.1 weeks), 43 ARV-naïve. The most complex ARV regimen during pregnancy was: 2NRTIs + either 1NNRTI or 1PI, 81%; similar proportions (~10%) received 1 or 2 NRTIs. Most (94%) received one (150) or two (35) ARV regimens during pregnancy. At enrollment, amplification could not be accomplished for samples from 122 women (and, at 6-12 weeks, for 101), primarily related to very low viral load. PRMs were observed in 16 (14%) of 118 samples amplifiable at either time point: four (enrollment only), seven (6-12 weeks postpartum only), five (both time points). At enrollment, 9/76 (12%) had PRMs (3 ARV-naïve). At 6-12 weeks postpartum, 12/97 (12%) had PRMs. Occurrence of PRMs was not associated with: viral load, CD4 count at either time point, CDC disease classification, whether ARV-naïve vs.experienced at enrollment, or most complex or number of ARV regimens during pregnancy (p>0.1). The most common mutations were K70R, K103N, M46I, D30N. The rate of MTCT [1.5% (3/198)] was not associated with the occurrence of resistance mutations. Conclusions: Among HIV-1-infected mothers from Latin American and Caribbean countries receiving ARVs for prevention of MTCT, PRMs are relatively common.Among HIV-1-infected mothers from Latin American and Caribbean countries receiving ARVs for prevention of MTCT, PRMs are relatively common.