title: High prevalence of the B2+C2 subgenotype mixture in patients with chronic hepatitis B in Eastern China.
abstract: OBJECTIVE
  To investigate the prevalence of hepatitis B virus (HBV) genotype mixtures among patients with chronic hepatitis B (CHB) in Eastern China.
  
  
  METHODS
  A total of 4908 chronic HBV patients from Eastern China were enrolled. HBV genotypes and subgenotypes were determined using a multiplex PCR technique. Serum viral loads and hepatitis B e antigen (HBeAg) levels detected using real-time fluorescent quantitative PCR and ELISA assay, respectively. The presence of precore/basic core promoter (PC/BCP) mutations was examined with PCR and direct sequencing of the amplified products.
  
  
  RESULTS
  HBV genotypes B, C, D, B+C, and B+D were found in 19.21%, 64.75%, 1.49%, 13.63%, and 0.92% of the patients, respectively. In 669 patients with the genotype mixture B+C, the subgenotypes B2+C2 and B2+C1 accounted for 68.13% and 31.87%, respectively, no other subgenotypes were identified. HBV B+C was more frequent in the patients with moderate CHB than in patients with mild CHB. In patients with moderate CHB, the subgenotype mixture B2+C2 was lower than B2+C1 (51.97% vs 63.38%), while the opposite situation was found in patients with severe CHB (22.15% vs 15.49%). The highest average viral load was found in patients with the genotype B+C mixture. The prevalence of HBV B2+C2 increased in patients from 50 to 59 years of age and was significantly different from the proportion of patients in the same age group with genotype B (23.2% vs 15.2%). A double mutation (G1896A) in the PC was significantly more common in subgenotype B2+C2 than in subgenotype B2+C1.
  
  
  CONCLUSIONS
  The HBV B2+C2 subgenotype was prevalent in CH patients with a high HBV replication status and correlated with a more severe course of the disease.
authors.affiliation: Shanghai University of Traditional Chinese Medicine Affiliated Shanghai Shuguang Hospital, Department of Infectious Diseases, Key Laboratory of Liver and Kidney Diseases, Shanghai University of Traditional Chinese Medicine, Ministry of Education E-institute of Shanghai Municipal Education Commission, Shanghai, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhong
authors.forename: Yue-Qiu
authors.initials: YQ
authors.lastname: Gao
authors.forename: Xue-Hua
authors.initials: XH
authors.lastname: Sun
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Zhu
authors.forename: Man
authors.initials: M
authors.lastname: Li
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002681:China / Q000453:epidemiology; D004279:DNA, Viral / Q000235:genetics; D005260:Female; D005838:Genotype; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000235:genetics* / Q000472:pathogenicity; D019694:Hepatitis B, Chronic / Q000453:epidemiology / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D015995:Prevalence; D011401:Promoter Regions, Genetic; D060888:Real-Time Polymerase Chain Reaction; D019562:Viral Load; D014779:Virus Replication / Q000235:genetics; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens