Intervirology 2017 12 07() doi 10.1159/000484692
Resistance-associated mutations (RAMs) in the integrase of different HIV-1 subtypes were investigated in a cohort of patients never exposed to integrase strand transfer inhibitors (INSTIs).
The viral RNA was extracted from plasma samples of 53 INSTI-naïve patients, and the integrase genetic region was sequenced and analyzed for subtype assignment and drug resistance.
The median viral load at sampling was 5.28 × 104 RNA copies/mL. Bayesian phylogenetic analysis showed 85% of the HIV-1 isolates were non-B subtypes, with a predominance of subtypes C (22.6%) and CRF01_AE (26.4%). A total of 52 and 110 mutations were found in the integrase region of HIV-1 B and non-B subtypes, respectively. Nonpolymorphic INSTI-RAMs were not detected in this study. However, the accessory mutation E157Q was found in 1 patient with CRF02_AG, and the polymorphic mutations L74M/I that may contribute to a reduced susceptibility to INSTIs in the presence of major mutations were observed in 6 (13.3%) patients with non-B subtypes and 1 (12.5%) patient with the B subtype. Polymorphic mutations at positions known to harbor primary and accessory RAMs were also detected in this study.
Our results highlight the importance of monitoring the emergence of INSTI-RAMS before and after the initiation of INSTI-based therapy.