Characterization of primary direct-acting antiviral (DAA) drugs resistance mutations in NS5A/NS5B regions of hepatitis C virus with genotype 1a and 1b from patients with chronic hepatitis.

The Hepatitis C virus (HCV) infection is a public health problem. The high level of HCV replication and its lack of post-transcriptional correction mechanisms results in the emergence of viral variants and the difficulty in determining polymorphisms and variants that contain the substitutions associated with resistance towards new antivirals. The main focus of this study was to map the NS5A and NS5B polymorphisms and resistance mutations to new antiviral drugs in HCV strains genotype 1 from patients with chronic hepatitis C infection.

Prevalence and Pattern of Resistance in NS5A/NS5B in Hepatitis C Chronic Patients Genotype 3 Examined at a Public Health Laboratory in the State of São Paulo, Brazil.

Purpose: Globally, it is estimated that 71 million people are chronically infected with hepatitis C, and 10-20% of these will develop cirrhosis and hepatocellular carcinoma. The development of new direct-acting antiviral (DAA) drugs has contributed to sustained virological response (SVR), eliminating the infection and achieving cure of chronic hepatitis C. However, treated patients can develop HCV resistance to DAAs, which can contribute to the failure of treatment.

Prevalence of resistance-associated substitutions to direct-acting antiviral agents in hemodialysis and renal transplant patients infected with hepatitis C virus.

Background: Direct-acting antiviral agents (DAAs) permit the use of interferon (IFN)-free regimens to treat hepatitis C (HCV) in patients with chronic kidney disease (CKD) on hemo-dialysis (HD) or renal transplant (RTx) recipients, with excellent response rates and safety. However, the occurrence of basal or therapy-induced resistance-associated substitutions (RASs) to DAAs can result in treatment failure. The aim of this study was to estimate the prevalence of RASs to NS3A, NS5A and NS5B inhibitors, and particularly the Q80K polymorphism, in CKD patients on HD and RTx recipients infected with HCV.

Prevalence of naturally occurring amino acid substitutions associated with resistance to hepatitis C virus NS3/NS4A protease inhibitors in São Paulo state.

Hepatitis C (HCV)-infected patients are treated with direct-acting antiviral agents (DAAs) in highly effective, well-tolerated, all-oral regimens. However, naturally occurring resistance-associated amino acid substitutions (RASs) may be selected during treatment. This study aimed to screen naturally occurring RASs NS3/NS4A inhibitors (PIs).