HIV‐1 resistance to antiretroviral drugs among infected residents of Altai Krai with antiretroviral therapy failure

Aim. The objective was to assess the development of HIV‐1 resistance in patients with virological failure of antiretroviral therapy.  Resistance analysis of HIV‐1 and clinico‐epidemiological data was performed for 367 infected residents of Altai Krai. Nucleotide sequences of HIV‐1 protease and reverse transcriptase were obtained by PCR and sequencing of viral genome regions. Genotyping, phylogenetic, and mutation analyses were performed using specialised resources. In the sample studied, a predominance of HIV‐1 CRF63_02A6 (52.0 %) and subtype A6 (42.5 %) was detected. Drug resistance of HIV‐1 was found in 310 (84.5 %) of 367 samples. The most commonly used NRTI combination was TDF+3TC (60.8 %). The prevalence of HIV‐1 resistance to TDF was 46.9 % and to 3TC was 86.6 %. Drugs of the NNRTI group were taken by 51.5 % of persons; EFV was included in 38.1 % of prescribed regimens and the prevalence of viral resistance to EFV was 87.9 %. Protease inhibitors were taken by 25.8 % of patients; combinations LPV+RPV (36.8 %) and ATV+RPV (43.2 %) were more frequently prescribed. The prevalence of HIV‐1 resistance to LPV+RPV was 33.3 % and to ATV+RPV was 35.9 %. The most frequent resistance mutations among HIV were: to NRTIs – M184V/I (62.2 %), K65R/E (17.5 %); to NNRTIs – K103N/S (47.8 %), E138G/A/K/Q (23.7 %); to PIs – V82A/G and M46I/L (20.5 % each). The study underscores the importance of access to HIV‐1 resistance testing, since timely detection of resistant viral strains and appropriate adjustment of therapy can restore treatment effectiveness, prevent the emergence of new mutations and limit the development of crossresistance to other ARVs.