title: Analysis of hepatitis B virus genotype changes in patients with chronic hepatitis B infection on tenofovir therapy.
abstract: Antiviral therapy for chronic hepatitis B (CHB) is often required for prolonged periods. We investigated the instance of one HBV genotype switching to another during tenofovir therapy. Of the 67 patients, genotype A was present in 6 (8.9%), D in 43 (65.6%), C in 1 (1.5%), and mixed in 17 (23.8%) patients. Genotype changes were detected in 51 (76.1%) patients on therapy during a follow-up of 192 (range 52-312) weeks. Inter-genotype changes were seen in 17 (33.3%) and intra-genotype in 28 (55%) and both inter- and intra-genotype in 6 of 51 (11.7%) patients. The distribution of genotypes in patients achieving complete virological response was genotype D, 32/43 (74.4%); genotype A, 6/6 (100%); and mixed genotypes, 13/17 (76.47%). The cumulative time of genotype switch among genotype A was 12 months (range 6-18), in genotype D, 12 months (range 6-48), and mixed genotype, 18 months (range 6-24). The type of inter-genotype switch most frequently detected among genotype A1 was from A1 to D1 5/6 (83.3%), followed by mixed to genotype D3 7/13 (54%) and among intra-genotype changes, from D1 to D3 in 14/20 (70%). Pretreatment HBV genotype was the only factor predicting inter-genotype switches with genotype A or mixed genotypes more likely to undergo inter-genotype switches as compared to genotype D patients (OR 66.6 [13.6-327.0, P < 0.001]). Compared to genotype D, genotype A, and mixed genotypes are more inclined to switch while on tenofovir therapy. Genotypes tend to switch and select to a particular type possibly due to constant antiviral drug pressure. J. Med. Virol. 88:1364-1375, 2016. © 2016 Wiley Periodicals, Inc.
authors: Department of Gastroenterology, Govind Ballabh Pant Institute of Postgraduate Medical Education and Research, New Delhi, India.|Molecular Virology and Hepatology Research Group, Faculty of Medicine, Division of BioMedical Sciences, Health Science Centre, Memorial University, St John's, Newfoundland and Labrador, Canada.
authors: Ranjit
authors: R
authors: Chauhan
authors: Department of Research, Institute of Liver and Biliary Sciences, New Delhi, India.
authors: Avishek K
authors: AK
authors: Singh
authors: Department of Research, Institute of Liver and Biliary Sciences, New Delhi, India.
authors: Sheetalnath
authors: S
authors: Rooge
authors: Department of Research, Institute of Liver and Biliary Sciences, New Delhi, India.
authors: Aditi
authors: A
authors: Varshney
authors: Department of Hepatology, Institute of Liver and Biliary Sciences, New Delhi, India.
authors: Manoj
authors: M
authors: Kumar
authors: Department of Gastroenterology, Govind Ballabh Pant Institute of Postgraduate Medical Education and Research, New Delhi, India.|Department of Hepatology, Institute of Liver and Biliary Sciences, New Delhi, India.
authors: Shiv K
authors: SK
authors: Sarin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood; D005260:Female; D014644:Genetic Variation / Q000187:drug effects; D005838:Genotype; D006509:Hepatitis B / Q000821:virology; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000453:epidemiology / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D000068698:Tenofovir / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D000068698:Tenofovir
keywords: antiviral agents; genetic variation; genotypes; hepatitis B virus; tenofovir