Conflicting interpretations of the prevalence of mutations associated with drug resistance in antiviral naïve HIV-1 patients with acute and chronic infection.

The routine determination of drug resistance in newly HIV-1 infected individuals records a potential increase in transmissions of drug-resistant variants. Plasma samples from 38 individuals classified as newly infected (seroconversion time <12 months) and twenty four individuals with an established infection (seroconversion time ranging from 3 to 10 years) were analyzed for the presence of mutations by Trugene HIV-1 genotyping assay and Virtual phenotype. Results on the newly infected and the chronically infected individuals showed a limited number of relevant mutations associated with substantial resistance to reverse transcriptase and protease inhibitors. In particular, three patients (4.8%) carried viral major mutations (T69D and M41L) associated with resistance to reverse transcriptase inhibitors, whereas only one showed the presence of M46L, which is correlated with partial resistance to some protease inhibitors. The clinical interpretation based on different approaches to monitor resistance showed that the Virconet interpretation was less grave than Trugene, suggesting that these interpretations need standardization for the currently used sequencing methods and that they may be associated with different outcomes when eventually are used.