Clearance of hepatitis B surface antigen and risk of hepatocellular carcinoma in a cohort chronically infected with hepatitis B virus.

Unlabelled: Some individuals who are chronically infected with hepatitis B virus (HBV) eventually lose hepatitis B surface antigen (HBsAg). Hepatocellular carcinoma (HCC) has been demonstrated to occur in a few patients after loss of HBsAg. Neither factors associated with loss of HBsAg nor the incidence of HCC thereafter have been clearly elucidated.

Classification of hepatitis B virus genotype B into 2 major types based on characterization of a novel subgenotype in Arctic indigenous populations.

Hepatitis B virus genotype B (HBV/B) has been classified into 5 subgenotypes. Except for Bj/B1 in Japan, the subgenotypes (Ba/B2-B5) have undergone recombination with HBV/C in the core promoter/precore/core genomic region. Phylogenetic analyses of complete sequences show that the Arctic strains belong to a novel subgenotype (HBV/B6) without the recombination, analogous to what is seen with Bj/B1.

Clearance of hepatitis B e antigen in patients with chronic hepatitis B and genotypes A, B, C, D, and F.

Background & Aims: Persistence of hepatitis B e antigen (HBeAg) in chronic hepatitis B has been associated with increased risk for development of cirrhosis and hepatocellular carcinoma. Five hepatitis B virus genotypes were identified in Alaska Native persons; we analyzed clearance of HBeAg by age and genotype.

Methods: In this prospective cohort study, 1158 Alaska Native persons throughout Alaska were tested serially for HBeAg for a median of 20.

Hepatitis B-associated vasculitis in Alaska Natives: viral genotype, clinical and serologic outcome.

Background: The highest incidence of hepatitis B virus (HBV)-associated vasculitis in the world has been reported in Alaska Natives. We examined the incidence of HBV-associated vasculitis before and after mass HBV vaccine immunization and the association between HBV genotype and vasculitis in a population-based cohort study in Alaska natives chronically infected with HBV.

Methods: Genotyping was performed in vasculitis cases and 644 hepatitis B-positive controls without vasculitis using polymerase chain reaction and sequencing of the S gene.

Hepatitis B virus genotypes in Alaska Native people with hepatocellular carcinoma: preponderance of genotype F.

Background: The development of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B virus (HBV) infection has been associated with specific HBV genotypes and the presence of specific mutations.

Methods: From a cohort of Alaska Native people with chronic HBV infection, we genotyped 47 patients with HCC and 1129 patients without HCC, and we tested patients with HCC and control patients for mutations in the basal core promoter and precore regions.

Results: Genotype F was found in 68% of patients with HCC, versus 18% of those without HCC (P<.

Comparison of different HCV viral load and genotyping assays.

Background: We report an interlaboratory comparison of methods for the determination of hepatitis C virus (HCV) serum load and genotype between a recently, established molecular laboratory at the Alaska Native Medical Center (ANMC) and two independent laboratories using different assays. At ANMC, a Real-time quantitative RT-PCR amplification methodology (QPCR) has been developed in which HCV viral loads are determined by interpolation of QPCR results to those of standards calibrated to the World Health Organization (WHO) First International Standard for HCV. HCV genotype is subsequently determined by direct sequencing of the DNA fragment generated from the QPCR assay.