ABSTRACT
HIV-1 drug resistance may limit the use of antiretrovirals when attempting to reduce the vertical transmission rate. Establishing the prevalence of the HIV-1 mutations associated with antiretroviral resistance in pregnant women will enable clinicians to maximize the chances of preventing vertical transmission. In order to determine the prevalence of HIV-1 resistant strains among antiretroviral-naive pregnant Thai women, the nucleotide sequences of the HIV-1 polymerase (pol) gene were evaluated. The plasma samples were collected from the women during the 34th week of pregnancy: numerous secondary mutations could be found in the reverse transcriptase (RT) and protease gene, while no primary mutations in the pol gene were found. The result also showed that by detecting the delta32bp deletion within the CCR 5 locus, it was evident that none of HIV-1 infected individuals had homozygous or heterozygous delta32bp deletions of the CCR5 gene; moreover, no CCR5 gene mutations were found in any individual.
Subject(s)
Adolescent , Adult , Anti-HIV Agents/therapeutic use , Drug Resistance, Viral/genetics , Endopeptidases/genetics , Molecular Epidemiology , Female , Gene Deletion , Genes, pol/genetics , HIV Infections/drug therapy , HIV Reverse Transcriptase/genetics , HIV-1/genetics , Heterozygote , Homozygote , Humans , Infectious Disease Transmission, Vertical/prevention & control , Mutation/genetics , Phylogeny , Population Surveillance , Pregnancy , Pregnancy Complications, Infectious/drug therapy , Prevalence , RNA, Viral/genetics , Receptors, CCR5/genetics , Reverse Transcriptase Polymerase Chain Reaction , Thailand/epidemiologyABSTRACT
Four human immunodeficiency virus type 1 (HIV-1) treatment-naïve Thai patients began antiretrovival therapy with a triple drug regimen -zidovudine plus lamivudine plus indinavir; this regimen was modified at week 20 of therapy because of drug toxicity. The virus in all patients was suppressed to lower than 400 copies/ml while they were taking the triple antiretroviral drug regimen. However, suppression was lost after changing the antiretroviral regimen. A comparison of HIV-1 DNA sequences taken from the baseline (day 0) and week 24 showed no significant overgrowth in HIV-1 drug-resistant strains. There was no difference in the protease and reverse transcriptase (RT) mutation profiles. Resistant variants did not emerge, even after sub-therapeutic levels of antiretroviral drugs had been introduced to these patients for 4 weeks. These findings may have clinical implications for long-term treatment strategies.