Prevalence of minor variants of HIV strains at reverse transcriptase position 103 in therapy-naive patients and their impact on the virological failure

Background and objectives: Minority HIV-1 populations with resistance mutations might result in therapy failure. The prevalence of transmitted minorities in therapy-naive patients and their influence on the virological outcome of the first-line-therapy need clarification. Study design: The HIV reverse transcriptase (RT) of 159 therapy-naive patients from the RESINA-cohort was genotyped. The relative amount of RT-K103N was measured by primer specific PCR. The response to first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-therapy was evaluated. Results: Bulk-sequencing detected 1 NNRT1 mutation (no K103N) in six patients (1.26%). K103N minorities were found in 20.1% of the samples, more frequently in HIV-1 non-B subtypes (40.6%) than in subtype B (15.0%) (p = 0.0025). NNRTI treatment failed after 12 weeks in 24% of 17 patients with minority, but only in 15% of 67 patients without minority. Conclusions: K103N minorities were found in 20.1% of the patients, whereas the prevalence of major K103N populations was 3% in the total RESINA-cohort. K103N minorities were more frequent in non-B subtypes. There is some evidence for a higher risk of NNRTI-treatment failure in patients with K103N minorities; however, the majority of patients with minority underwent a successful first-line-treatment. (C) 2009 Published by Elsevier B.V.