Factors Associated With Hepatitis A Seropositivity at 23 Years After Childhood Vaccination.

We evaluated factors associated with the presence of hepatitis A virus antibodies 23 years after initiating vaccination at ages 6-15 months. Among 67 participants, 86% (42/49) of those vaccinated at ages 12-15 months and 61% (11/18) of those vaccinated at 6 months remained seropositive at 23 years. Lack of maternal antibodies at enrollment and higher initial vaccine response were independently associated with higher antibody concentrations at 23 years.

HBV Genotype: A Significant Risk Factor in Determining Which Patients With Chronic HBV Infection Should Undergo Surveillance for HCC: The Hepatitis B Alaska Study.

Background And Aims: Information is limited regarding HBV genotype and the outcome of chronic HBV (CHB) infection. We examined the effect of HBV genotype on HCC occurrence in Alaska Native (AN) persons with CHB, where five HBV genotypes are found: A2, B6, C2, D, and F1.

Approach And Results: We calculated HCC incidence per 1,000 person-years of follow-up to determine which groups by age, sex, and genotype met current American Association for the Study of Liver Diseases (AASLD) HCC surveillance criteria.

Hepatocellular Carcinoma Risk in Alaska Native Children and Young Adults with Hepatitis B Virus: Retrospective Cohort Analysis.

Objectives: To evaluate the hepatocellular carcinoma (HCC) risk in Alaska Native children and young adults with hepatitis B virus (HBV).

Study Design: Retrospective analysis of a population-based cohort of Alaska Native persons with HBV followed during 1982-2012. All individuals with HBV were offered HCC screening regardless of age using alpha-fetoprotein every 6 months; persons with an elevated alpha-fetoprotein or persons at high-risk for HCC, such as cirrhosis, family history of HCC, were offered ultrasound.

Infection With Hepatitis C Virus Genotype 3 Is an Independent Risk Factor for End-Stage Liver Disease, Hepatocellular Carcinoma, and Liver-Related Death.

Background & Aims: Few studies have examined factors associated with disease progression in hepatitis C virus (HCV) infection. We examined the association of 11 risk factors with adverse outcomes in a population-based prospective cohort observational study of Alaska Native/American Indian persons with chronic HCV infection.

Methods: We collected data from a population-based cohort study of liver-related adverse outcomes of infection in American Indian/Alaska Native persons with chronic HCV living in Alaska, recruited from 1995 through 2012.

A Longitudinal Hepatitis B Vaccine Cohort Demonstrates Long-lasting Hepatitis B Virus (HBV) Cellular Immunity Despite Loss of Antibody Against HBV Surface Antigen.

Background: Long-lasting protection resulting from hepatitis B vaccine, despite loss of antibody against hepatitis B virus (HBV) surface antigen (anti-HBs), is undetermined.

Methods: We recruited persons from a cohort vaccinated with plasma-derived hepatitis B vaccine in 1981 who have been followed periodically since. We performed serological testing for anti-HBs and microRNA-155 and assessed HBV-specific T-cell responses by enzyme-linked immunospot and cytometric bead array.

Incidence of hepatocellular carcinoma according to hepatitis B virus genotype in Alaska Native people.

Background & Aims: Most regions of the world have ≤3 co-circulating hepatitis B virus (HBV) genotypes, which limits direct comparisons of hepatocellular carcinoma (HCC) risk among HBV-infected persons by genotype. We evaluated HCC incidence by HBV genotype in a cohort of Alaska Native (AN) persons where five HBV genotypes (A, B, C, D, F) have been identified.

Methods: Our cohort comprised AN persons with chronic HBV infection identified during 1983-2012 who consented to participate in this study.

Persistence of seropositivity among persons vaccinated for hepatitis A during infancy by maternal antibody status: 15-year follow-up.

Unlabelled: The effect of passively transferred maternal antibody to hepatitis A virus (anti-HAV) on the duration of seropositivity after hepatitis A vaccination during infancy and early childhood is unclear. We obtained levels of anti-HAV at intervals through age 15-16 years among three groups of Alaskan Native children who initiated a two-dose inactivated hepatitis A vaccination series at ages 6 months (group 1), 12 months (group 2), and 15 months (group 3), each group randomized according to maternal anti-HAV status. Seropositivity (anti-HAV ≥20 mIU/mL) 30 years after the second vaccine dose among the three groups was predicted using a random effects model.

Hepatitis B virus antibody levels 7 to 9 years after booster vaccination in Alaska native persons.

Hepatitis B antibody persistence was assessed in individuals who had previously received a vaccine booster. We measured hepatitis B surface antigen antibody (anti-HBs) levels 7 to 9 years post-hepatitis B booster in individuals with primary vaccination at birth. While 95 (91.

Prevalence and causes of elevated serum aminotransferase levels in a population-based cohort of persons with chronic hepatitis B virus infection.

Background & Aims: Information delineating the possible causes for elevated serum aminotransferase activity among persons with chronic hepatitis B virus (HBV) infection is limited.

Methods: We analysed data collected from a population-based cohort of persons with chronic HBV infection followed from 2001 to 2010 to determine the frequency and causes of elevated aminotransferase activity. Any elevation concurrent with an HBV DNA level ⩾2000 IU/ml was attributed to immune active hepatitis B.

Relationship between level of hepatitis B virus DNA and liver disease: a population-based study of hepatitis B e antigen-negative persons with hepatitis B.

Background & Aims: There is little information on the proportion of persons with chronic hepatitis B virus (HBV) infection with active hepatitis. We aimed to determine the proportion of persons with hepatitis B e antigen-negative chronic HBV infection who develop immune-active HBV infection over time and the relationship between demographic and viral factors on severity of disease on liver biopsy.

Methods: We performed a longitudinal population-based cohort study of 754 Alaska Native patients with chronic HBV infection.

Rates and risk factors for hepatitis B reactivation in a cohort of persons in the inactive phase of chronic hepatitis B-Alaska, 2001-2010.

Background: A high prevalence of reactivation of hepatitis B has been documented among immunosuppressed individuals in the inactive phase of chronic hepatitis B; However, the proportion of and the risk factors for reactivation are largely unknown among non-immunosuppressed persons.

Objectives: Estimate the incidence rate of and risk factors for hepatitis B reactivation in a population-based cohort of persons in the inactive phase of chronic hepatitis B in Alaska.

Study Design: A cohort of 414 Alaska Native Persons in the inactive phase of hepatitis B (HBV DNA<2000 IU/mL and normal alanine aminotransferase (ALT) for 12 months) was followed-up for 10 years.

Duration of protection against hepatitis A for the current two-dose vaccine compared to a three-dose vaccine schedule in children.

Background: Hepatitis A is mostly a self-limiting disease but causes substantial economic burden. Consequently, United States Advisory Committee for Immunization Practices recommends inactivated hepatitis A vaccination for all children beginning at age 1 year and for high risk adults. The hepatitis A vaccine is highly effective but the duration of protection is unknown.

Persistence of hepatitis A vaccine induced seropositivity in infants and young children by maternal antibody status: 10-year follow-up.

Unlabelled: Persistence of seropositivity conferred by hepatitis A vaccine administered to children <2 years of age is unknown and passively transferred maternal antibodies to hepatitis A virus (maternal anti-HAV) may lower the infant's immune response to the vaccine. One hundred ninety-seven infants and young children were randomized into three groups to receive a two-dose hepatitis A vaccine: group 1 at 6 and 12 months, group 2 at 12 and 18 months, and group 3 at 15 and 21 months of age. Within each group, infants were randomized by maternal anti-HAV status.

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.

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.

Differences in response to a hepatitis B vaccine booster dose among Alaskan children and adolescents vaccinated during infancy.

Background: The duration of protection provided by hepatitis B vaccination is unknown, but the presence of immune memory can be evaluated indirectly by measuring the immune response to a booster dose of vaccine.

Methods: Participants included 74 adolescents (aged 11.7-14.

Immunogenicity of an inactivated hepatitis A vaccine in infants and young children.

Background: Infants with passively transferred maternal antibody, born to mothers immune to hepatitis A virus (HAV), have a blunted response to hepatitis A (HA) vaccine. We compared HA vaccine immunogenicity among infants born to immune and susceptible mothers, vaccinated on different schedules.

Methods: Infants were randomized into 3 groups, each receiving 2 doses of 720 EL.

Hepatitis A vaccine: immunogenicity following administration of a delayed immunization schedule in infants, children and adults.

Current immunization schedules for hepatitis A vaccine specify administration of a booster within 6-12 or 6-18 months of the primary dose. However, there may be circumstances that disrupt this schedule and the efficacy of administering a booster beyond the recommended time is a practical concern for healthcare providers. In this study, a booster was administered to 268 participants (137: <18 years old), an average of 27 months (range 20-31) after the primary dose.