Prevalence of Hepatitis B Virus Genotypes and their Relationship to Clinical Laboratory Outcomes in Tibetan and Han Chinese

This study was designed to investigate the prevalence of hepatitis B virus (HBV) genotypes in Tibetan and Han nationalities in Sichuan Province, China, and their clinical significance. Sera from 376 patients (286 Han nationals, 90 Tibetan nationals) were genotyped by polymerase chain reaction. Of the 286 Han nationals, 127 were HBV asymptomatic carriers, 90 were symptomatic patients and 69 had hepatocellular carcinoma. The distribution of HBV genotypes was related to geography as well as ethnicity. The HBV genotype frequencies were: B, 57.9%; C, 16.0%; and BC, 26.1%. Association studies between genotypes and clinical laboratory outcomes showed HBV genotype C to be more virulent. There was a higher prevalence of mixed genotype BC in Tibetan nationals compared with Han nationals. There was no synergistic effect in terms of virulence in patients co-infecte with genotypes B and C.