Pretreatment HIV drug resistance and treatment failure in non-Italian HIV-1-infected patients enrolled in ARCA

Abstract BACKGROUND: An increase in pretreatment drug resistance (PDR) to first-line antiretroviral therapy (ART) in low-income countries has been recently described. Herein we analyze the prevalence of PDR and risk of virologic failure (VF) over time among migrants to Italy enrolled in ARCA. METHODS: HIV-1 sequences from ART-naïve patients of non-Italian-nationality were retrieved from ARCA database from 1998 to 2017. PDR was defined by at least one mutation from the reference 2009-WHO-surveillance-list. RESULTS: Protease/reverse-transcriptase sequences from 1,155 patients, mainly migrants from Sub-Saharan Africa (SSA) (42%), followed by Latin America (LA) (25%) and Western Countries (WE) (21%), were included. PDR was detected in 8.6% of sequences (13.1% vs 5.8% for B and non-B strains, respectively, p<0.001). 2.1% of patients carried a PDR for protease inhibitors (PIs) (2.1% vs 2.3%, p=0.893), 3.9% for nucleos(t)ide-reverse-transcriptase inhibitors (NRTI) (6.8% vs 2.1%, p<0.001) and 4.3% for non-nucleos(t)ide-reverse-transcriptase inhibitors (NNRTI) (6.3% vs 3.1%, p=0.013). Overall, prevalence of PDR over the years remained stable, while it decreased for PIs in LA (p=0.021), and for NRTI (p=0.020) among migrants from WE. Having more than 1 class of PDR (p=0.015 vs. absence of PDR), higher viral load at diagnosis (p=0.008) and being migrants from SSA (p=0.001 vs. WE) were predictive of VF, while a recent calendar year of diagnosis (p<0.001) was protective for VF. CONCLUSIONS: PDR appeared to be stable over the years in migrants to Italy enrolled in ARCA; however, it still remains an important cause of VF together with VL at diagnosis.