Reverse transcriptase and protease inhibitors mutational viral load in HIV infected pregnant women with transmitted drug resistance in Argentina.

OBJECTIVE: Argentina has reported high levels of transmitted drug resistance (TDR), in HIV-infected pregnant women by population sequencing. We aimed to describe, in patients with TDR, the percentage of quasispecies harboring resistance mutations (RAMs) and mutational load (ML). METHODS: Retrospective study in a cohort of 40 naïve HIV-infected pregnant women, whose pretreatment samples had been genotyped by TRUGENE (period 2008-2014). Samples were re-sequenced with Ultra-deep Sequencing and ML was calculated considering baseline HIV-1 RNA load multiplied by the frequency of quasispecies harboring RAMs. RESULTS: TDR for NNRTIs, NRTIs and PIs was 17.5% (n=7 patients), 10% (n=4), 12.5% (n=5) respectively. Predominant NNRTI RAMs were K103N (n=4; 10%) and G190A/E/S (n=3; 7.5%). For NNRTIs, 78% of RAMs were present in >93.5% of viral population and ML was >1000 copies/mL (c/mL) for 89%, with a median (IQR) of 8330 c/ml (7738-29796). The following NRTI RAMs were described (per patient: % of quasispecies, ML): T215I (99.7%, 11014 c/ml); D67G (1.28%, 502 c/mL); M41L (79.8%, 88578 c/mL) and M184I (1.02%, 173 c/mL). Most frequent PI-RAMs were I85V, M46I, I50V and L90M (n=2, 5% each). For PIs, quasispecies with RAMs were <2.3% of viral population and ML was <350 c/mL for 77.8% of them. CONCLUSIONS: NNRTI-RAMs are predominant within the viral population, usually exceeding the threshold of 1000 c/mL, indicating potential higher risk of perinatal transmission. Conversely, PI mutations appear mostly as minority variants, with potential lower risk of transmission. Among NRTI, quasispecies harboring RAMs and ML values were variable.

Pretreatment HIV-1 drug resistance in Argentina: results from a surveillance study performed according to WHO-proposed new methodology in 2014-15.

BACKGROUND: In Argentina, current national guidelines recommend starting with NNRTI-based regimens. Recently, there have been some local reports regarding concerning levels of NNRTI-transmitted resistance, but surveillance has never been carried out at a national level. OBJECTIVES: To determine the prevalence of HIV drug resistance in people starting ART in Argentina using a WHO-proposed methodology. METHODS: This was a cross-sectional, nationally representative study. Twenty-five antiretroviral-dispensing sites throughout the country were randomly chosen to enrol at least 330 persons starting ART, to generate a point prevalence estimate of resistance-associated mutations (RAMs) with a 5% CI (for the total population and for those without antiretroviral exposure). All consecutive patients older than 18 years starting or restarting ART in the chosen clinics were eligible. Samples were processed with Trugene and analysed using the Stanford algorithm. RESULTS: Between August 2014 and March 2015, we obtained 330 samples from people starting ART. The mean ±â€ŠSD age was 35 ±â€Š11 years, 63.4% were male, 16.6% had prior antiretroviral exposure and the median (IQR) CD4 count was 275 cells/mm3 (106-461). The prevalence of RAMs found was 14% (±4%) for the whole population (3% NRTI-RAMs; 11% NNRTI-RAMs and 2% PI-RAMs) and 13% (±4%) for those without prior antiretroviral exposure (3%, 10% and 2%, respectively). The most common mutation was K103N. CONCLUSIONS: This surveillance study showed concerning levels of HIV drug resistance in Argentina, especially to NNRTIs. Due to this finding, Argentina's Ministry of Health guidelines will change, recommending performing a resistance test for everyone before starting ART. If this is taken up properly, it also might function as a continuing surveillance tool.