Absence of primary integrase resistance mutations in HIV type 1-infected patients in Venezuela.

The preexistence of mutations to integrase inhibitors in HIV-1-infected Venezuelan patients was evaluated. The integrase region of the HIV-1 genome was amplified by nested-PCR and sequenced in 57 isolates from both naive (n = 24) and treated patients who received protease and/or reverse transcriptase inhibitors (PI and RTI, n = 33), but were never exposed to integrase inhibitors. Only one primary integrase resistance mutation, not conferring drug resistance by itself, was found among these patients, although several minor viral mutations, equally distributed among naive and PI- and RTI-treated patients, were also found. In the limited number of samples, no relation was found among the presence of resistance mutations to PI or RTI and the presence of minor mutations to integrase. The absence of resistance to integrase inhibitors may be related to the recent introduction of these drugs in our country. The availability of in-house assays allows for a more comprehensive surveillance of drug resistance to integrase inhibitors in Venezuela.