Low level of baseline resistance in recently HCV-infected men who have sex with men with high-risk behaviours

Abstract

ObjectivesPresence of baseline hepatitis C virus (HCV) resistance-associated substitutions (RASs) can impair treatment outcome of direct-acting antivirals. We investigated the prevalence of pre-treatment HCV resistance among recently HCV-infected men who have sex with men (MSM) with high risk behaviours, either human immunodeficiency virus (HIV) co-infected or at high risk of HIV acquisition and under pre-exposure prophylaxis (PrEP). MethodsNS5A and NS3 fragments were deep sequenced on pre-treatment samples of 72 subjects using Illumina MiSeq paired-end sequencing technology. Ultra-deep sequencing data were analysed by SmartGene® platform. RASs mentioned in the literature were analysed and interpreted depending on genotype (GT) at 10% cut-off. ResultsHCV genotyping showed 36 (50.0%) GT1a, 31 (43.1%) GT4d and 5 (6.9%) GT3a infections. Fifty-five patients (76.4%) were co-infected with HIV and 15 (20.8%) received PrEP. In GT1a viruses, NS3 RASs were found in 4/30 viruses (13.3%; S122 G/N, R155 K and I170 V) and Q80 K polymorphism was present in 14/30 viruses (46.7%). No NS3 RASs were detected in GT4d and GT3a viruses. NS5A RASs were detected in 3/36 GT1a viruses (8.3%; Q30E/R, L31 M and H58 L). NS5A subtype-specific polymorphisms L30R and T58 P were found at high frequencies in 31/31 (100%) and 16/31 (51.6%) GT4d viruses, respectively. One RAS M31 L was also observed along with the polymorphisms L30R and T58 P. No NS5A RASs were detected in GT3a viruses. ConclusionA low level of RASs to NS3 and NS5A inhibitors in pre-treatment samples was detected in the study population. Our findings reassure the clinical management of HCV infection in this high-risk population.