Frequency and treatment-related predictors of thymidine-analogue mutation patterns in HIV-1 isolates after unsuccessful antiretroviral therapy

We investigated, in patients tested between 1991 and 2004, the patterns of mutually exclusive human immunodeficiency virus-1 thymidine-analogue mutations (TAMs) in 4039 reverse-transcriptase sequences with >= 1 TAM. TAM pattern 1, which included M41L and L210W and excluded K70R and is coupled with more-extensive cross-resistance to drugs, became the most frequent pattern after 1996. In 1465 genotypes from 684 patients in whom highly active antiretroviral therapy ( HAART) was unsuccessful, predictors of this pattern were the number of previous HAART regimens undergone ( adjusted odds ratio [ OR], 1.09 [ 95% confidence interval {CI}, 1.02-1.16]), use of stavudine/lamivudine (adjusted OR, 1.42 [ 95% CI, 1.05-1.99]), use of nevirapine (adjusted OR, 1.60 [ 95% CI, 1.14-2.24]), use of efavirenz (adjusted OR, 1.56 [ 95% CI, 1.08-2.27]), and use of ritonavir (adjusted OR, 1.35 [ 95% CI, 1.04-1.75]).