Prevalence of Antiretroviral Drug Resistance Mutations in HIV Seropositive Patients from an Outpatient Clinic of a Large University Hospital from Sao Paulo, Brazil

Abstract

Drug resistance mutations (DRMs) can affect the success of the therapy and compromise new prevention strategies. Increasing rates of resistance to antiretroviral (ARV) drugs have been reported in some areas. This study evaluated the DRMs prevalence among patients at Hospital das Clinicas (Sao Paulo). Among treatment-naive patients, the prevalence of transmitted DRMs (Stanford Calibrated Population Resistance) was 8.4% (21/249), with 69% (75/109) of acquired resistance among treatment-experienced patients. Rates of transmitted DRM showed an increase (6.6% in 2002-2009 vs. 15.1% in 2010-2015, p = .05), from the first to the second decade, mainly due to mutations to the NNRTI (non-nucleoside reverse transcriptase inhibitor) class. Among treatment-experienced cases, a nonsignificant decrease overall, significant for the protease inhibitors (PIs) class, was documented. Subtype B predominated in both groups (78%), followed by subtype F, BF recombinants, and subtype C. Our results add to the growing evidence of an increase in transmitted DRM, document extensive DRM among experienced patients, and a decrease in resistance to PIs class that may reflect the increased use of boosted PIs and newer ARV classes in more recent years.