Genotyping of HBV and tracking of resistance mutations in treatment-naïve patients with chronic hepatitis B

Abstract

Background and aims

Resistance mutation analogs to nucleos(t)ides have been described in treatment-naïve patients with chronic hepatitis B (CHB), with clinical implications. The aim of this study was to investigate primary resistance mutations and genotypes circulating in patients naïve to chronic hepatitis B, in the Northern and Northeastern regions of Brazil.

Methods

We conducted a study of resistance mutations and genotypic characterization of hepatitis B virus (HBV) in 189 treatment-naïve patients chronically infected with HBV.

Results

Drug resistance-associated mutations located in the RT domain of the P gene (rtHBV) were found in 6% of the treatment-naïve patients from the Northeastern Region. The mutations were rtA194T, rtL180M + rtM204V, rtS202I, rtM204I, and rtA181S. No patient in the Northern Region had the resistance mutation. In the gene S region, the frequency of vaccine escape mutations was 2.4% in the Northeastern Region and 8.6% in the Northern Region.

Conclusion

This information before the start of treatment may contribute to clinical decision making, reducing treatment failure and the risk of progression to cirrhosis and hepatocellular carcinoma for CHB.

Keywords:

• Northeast
• North
• Brazil
• direct sequencing
• treatment failure

Acknowledgments

The authors thank Silvana Paz, technician on the sequencing facility of the Program for Technological Development in Tools for Health (PDTIS), Fiocruz, the workers from LACEN-BA, LACEN-AC, and Fundação Hospitalar do Acre (Fundhacre). Funding support was provided by the National Counsel of Technological and Scientific Development (CNPq) process 478322/2012-7 and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) “Brasil sem Miséria” (BSM, Brazil without Misery) fellowship.

Disclosure

The authors report no conflicts of interest in this work.