Genetic barrier to the development of resistance to integrase inhibitors in HIV-1 subtypes CRF01_AE and B.

Objective: The genetic barrier for the evolution of integrase inhibitors (INIs) including raltegravir (RAL), elvitegravir (EVG), and dolutegravir (DTG) resistance was compared between HIV-1 subtypes CRF01_AE and B.

Methods: Analysis of 66 substitutions associated with INI resistance at 41 amino acid positions in 144 nucleotide sequences (109 HIV-1 subtype CRF01_AE and 35 HIV-1 subtype B) of integrase-coding region of polymerase gene derived from INI-naive patients.

Results: 28/41 studied amino acid positions were conserved, leading to a similar genetic barrier between the two subtypes.

Minority HIV-1 resistant variants in recent infection and in patients who failed first-line antiretroviral therapy with no detectable resistance-associated mutations in Thailand.

Through the Thai National AIDS Program, approximately 200,000 patients infected with HIV are on antiretroviral (ARV) therapy. Although studies have shown low prevalence of primary HIV-1 resistance transmission in Thailand and in Southeast Asia where subtype CRF01_AE is predominant, minority HIV-1 drug resistance has not been studied. Two groups of patients, whose conventional genotyping results showed no drug resistance-associated mutations, were investigated: 104 homosexual men recently infected with HIV-1, naïve to ARV treatment and 22 first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based failure patients.