RESUMO
The objectives of this cross-sectional survey were to determine the prevalence and clinical significance of mutations conferring ZDV genotypic resistance among HIV-1 strains from HIV infected Canadian children. We screened for mutations at reverse transcriptase (RT) codons 215 and 219 by direct sequencing of polymerase chain reaction (PCR) products amplified from HIV-1 proviral DNA. An automated AB1 373A sequencer and a Taq Dye Dideoxy cycle seqencing kit were used for gentopic testing. Among 51 ZDV-experienced children evaluated prior to December 31, 1995, the mean (ñSD) age was 84.8 (ñ59) months. The RT mutations at 215 and 219 were deduced in 25/51 (49 percent) of subjects. The mean duration of ZDV treatment among children with mutations was 23.4 months (SDñ16.6) compared with 9.9 (SDñ17.5) months for those without mutations (P = <.007). Children with mutations had lower baseline CD4 counts (means ñ SD, 359 ñ 542/mm versus 705 ñ 548/mm, P = .03). Similarly, there was significant difference in CD4 counts (means ñ SD, 225 ñ 439/mm versus 559 ñ 556/mm, respectively; P = .04). HIV-1 RT mutations at codons 215 and 219 were found in a significant number of children in our cohort and were associated with evidence of advanced disease. Periodical genotypic surveys will guide antiretroviral therapy in HIV infected children in setting similar to ours. However, given the potential for transmission of resistant strains globally, such surveys may be of value in selected populations to assess the potential of drug resistance prior to initiation of antiretroviral therapy.(AU)
