Estimating numbers of persons with persistent hepatitis B virus infection transmitted vertically and horizontally in the birth cohort during 1950-1985 in Japan

Hepatitis B Virus Infection among Japanese Immigrants and Descendants: The Need to Strengthen Preventive and Control Measures

This cross-sectional study aimed to investigate the prevalence and risk factors of Hepatitis B virus infection among Japanese immigrants and their descendants from São Paulo (SP), and to verify the occurrence of occult hepatitis B and coinfection with HCV, Delta, and HTLV. All samples (n = 2.127) were tested for HBV serological markers by electrochemiluminescence. HBsAg and/or total anti-HBc positive samples were tested for HBV DNA by real-time PCR, and genotyped by sequencing using the Sanger methodology. The prevalence rate of HBV exposure was 13.4% (CI 95%: 11.9–14.9%), and 22 (1.1%) were HBsAg positive. A high rate of susceptibility to HBV infection was found (67.4%; CI 95%: 65.4–69.4%). In contrast, only 19.2% (CI 95%: 17.6–20.9%) presented a serological profile analogous to that elicited by Hepatitis B vaccination. HBV isolates (n = 8) were classified as genotypes HBV/B1 (62.5%), HBV/C2 (12.5%), HBV/F1b (12.5%), and HBV/A1 (12.5%). Hepatitis B vaccination strategies and educational measures to control this infection should be considered.

Burden of chronic hepatitis B and C infections in 2015 and future trends in Japan: A simulation study

Background

Determining the number of chronic hepatitis B (HBV) and C virus (HCV) infections is essential to assess the progress towards the World Health Organization 2030 viral hepatitis elimination goals. Using data from the Japanese National Database (NDB), we calculated the number of chronic HBV and HCV infections in 2015 and predicted the trend until 2035.

Methods

NDB and first-time blood donors data were used to calculate the number of chronic HBV and HCV infections in 2015. A Markov simulation was applied to predict chronic infections until 2035 using transition probabilities calculated from NDB data.

Findings

The total number of chronic HBV and HCV infections in 2015 in Japan was 1,905,187–2,490,873 (HCV:877,841–1,302,179, HBV:1,027,346–1,188,694), of which 923,661–1,509,347 were undiagnosed or diagnosed but not linked to care (“not engaged in care”), and 981,526 were engaged in care. Chronic HBV and HCV infections are expected to be 923,313–1,304,598 in 2030, and 739,118–1,045,884 in 2035. Compared to 2015, by 2035, the number of persons with HCV not engaged in care will decline by 59·8 – 76·1% and 86·5% for patients in care. For HBV, a 47·3 – 49·3% decrease is expected for persons not engaged in care and a decline of 26·0% for patients engaged in care.

Interpretation

Although the burden of HBV and HCV is expected to decrease by 2035, challenges in controlling hepatitis remain. Improved and innovative screening strategies with linkage to care for HCV cases, and a functional cure for HBV are needed.

Funding

Japan Ministry of Health, Labour and Welfare.

Dynamic evaluation of hepatocellular carcinoma prediction models in patients with chronic hepatitis B receiving nucleotide/nucleoside analogue treatment

Carcinogenesis risk scores for chronic hepatitis B have been proposed, but it remains unclear whether these scores during nucleoside/nucleotide analogue (NA) therapy are useful for risk assessment. In this study, we examined changes of these scores and the predictability during NA treatment. 432 patients with no history of hepatocellular carcinoma (HCC) treated with NA were enrolled. PAGE-B, modified PAGE-B (mPAGE-B), and REACH-B scores were calculated at NA administration, 1 and 2 years after administration. The median follow-up duration was 5.1 years, during which 37 patients (8.6%) developed HCC. Cumulative incidence HCC development in patients with high risk of PAGE at NA administration, and 1 and 2 years after NA administration was significantly higher than those with intermediate and low-risk groups (p < .05 for all time points), whereas HCC incidence in patients with high risk of mPAGE-B and REACH-B at 2 years after NA administration were equivalent to those with intermediate and low-risk groups (p = .2 for mPAGE-B, and p = .1 for REACH-B). The area under the receiver operating characteristic (AUROC) for HCC development of PAGE-B at NA administration, and 1 and 2 years after administration were 0.773, 0.803 and 0.737, respectively. The AUROCs of PAGE-B at each point were continuously higher than those of REACH-B (0.646, 0.725, and 0.653, respectively) and mPAGE-B (0.754, 0.734, and 0.678, respectively).PAGE-B score has a high diagnostic accuracy for HCC development at any time point during NA treatment, indicating its potential use as a real-time monitor of HCC development.

Pilot study of tenofovir disoproxil fumarate and pegylated interferon-alpha 2a add-on therapy in Japanese patients with chronic hepatitis B

BACKGROUND

A prospective pilot study of tenofovir disoproxil fumarate (TDF) and pegylated interferon alpha 2a (P-IFN) add-on therapy was conducted to evaluate its efficacy in reducing viral antigen levels in Japanese patients with chronic hepatitis B (UMIN 000020179).

METHODS

Patients with chronic hepatitis B receiving maintenance TDF therapy and exhibiting hepatitis B surface antigen (HBsAg) level > 800 IU/ml were divided into two arms. P-IFN was added for 48 weeks in the add-on arm (n = 32), while TDF monotherapy was maintained in the control arm (n = 51). Both groups were followed for 96 weeks after baseline measurements.

RESULTS

Almost all patients in the control arm displayed a slow and constant reduction in HBsAg during follow-up. In contrast, roughly half of the add-on arm exhibited a sharp decline in HBsAg during P-IFN administration, which disappeared after halting P-IFN. At 96 weeks after baseline, 41% (13/32) of patients in the add-on arm had shown a rapid decrease in HBsAg, versus 2% (1/51) in the control arm (p < 0.001). Add-on therapy and increased cytotoxic T-cell response were significant factors associated with a rapid decrease in HBsAg according to multivariate analysis. In addition, higher HB core-related antigen (HBcrAg) level at baseline (p = 0.001) and add-on therapy (p = 0.036) were significant factors associated with a rapid reduction in HBcrAg.

CONCLUSIONS

TDF and P-IFN add-on therapy in Japanese patients with chronic hepatitis B facilitated rapid decreases in HBsAg and HBcrAg. Further studies are needed to improve early HBsAg clearance rate.

Validation of hepatocellular carcinoma risk scores in Japanese chronic hepatitis B cohort receiving nucleot(s)ide analog

BACKGROUND AND AIM

The prediction of hepatocellular carcinoma (HCC) development during nucleotide/nucleoside analog (NA) therapy is clinically important in patients with chronic hepatitis B. Although several useful models for HCC prediction have been previously reported, their usefulness in the Japanese population is unclear. Therefore, this study examines the applicability of these models in Japanese patients.

METHODS

Four hundred forty-three patients with no history of HCC who were treated with entecavir, tenofovir alafenamide, or tenofovir disoproxil fumarate were enrolled. PAGE-B, modified-PAGE-B, and REACH-B scores were calculated, and subsequent HCC development was investigated.

RESULTS

The mean follow-up duration was 5.1 years, and a total of 33 patients (7.4%) developed HCC during the follow-up period. Multivariate analysis revealed that old age (hazard ratio [HR] 1.05, 95% confidence interval [CI] 1.01-1.09, P = 0.011), male gender (HR 2.62, 95% CI 1.06-6.49, P = 0.037), and low platelet count (HR 0.83, 95% CI 0.77-0.91, P < 0.001) were independent predictors of HCC development. These factors are the same as the factors identified in the PAGE-B model. Time-dependent area under the receiver operating characteristic (AUROC) curve revealed that the AUROCs for 3 and 7 years of PAGE-B (AUROC: 0.786 and 0.744 at 3 and 7 years, respectively) were continuously higher than those of REACH-B (0.658 and 0.543) and modified PAGE-B AUROC (0.772 and 0.731).

CONCLUSIONS

PAGE-B, which can easily identify high-risk cases, can be useful for predicting HCC development in Japanese patients treated with NA therapy.

Countermeasures against viral hepatitis B and C in Japan: An epidemiological point of view

Although the mortality rate due to hepatocellular carcinoma (HCC) has been gradually decreasing in Japan, approximately 30 000 people died of HCC in 2016. In 2007, the dominant etiology was persistent hepatitis C virus (HCV) infection, which accounted for 65% of total HCC deaths, and 15% of cases were due to chronic hepatitis B virus (HBV) infection. In managing chronic HBV and HCV infection, it is critically important to know the exact number of infected individuals in a particular country, which then assists in evaluating medical and financial needs in the foreseeable future. Therefore, from an epidemiological perspective, we estimated the numbers of HBV and HCV carriers in four categories: (i) undiagnosed carriers; (ii) carriers who were already hospitalized as patients or were receiving outpatient medical attention; (iii) diagnosed carriers who had not consulted any medical facility, or had discontinued consultation; and (iv) newly infected carriers. From these estimates we determined the current HBV and HCV burden and then reviewed the existing countermeasures for their prevention and control in Japan. While continuing the surveillance on the dynamics of hepatitis virus infections linked with preventive measures against hepatitis virus infection, it is crucially important to promote appropriate measures for each of the four groups of hepatitis virus carriers in society.

Meta-regression Analysis of Sex- and Birth Year-Specific Prevalence of HBsAg and Anti-HCV Among Un-diagnosed Japanese: Data From the First-time Blood Donors, Periodical Health Checkup, and the Comprehensive Health Checkup With Lifestyle Education (Ningen Dock)

Background

This study was aimed to precisely estimate the prevalence of hepatitis B surface antigen (HBsAg) and anti-hepatitis C virus antibody (anti-HCV) stratified by sex and birth year in Japan.

Methods

Three large-scaled cohorts: first-time blood donors, periodic health check-up, and comprehensive health check-up with lifestyle education (Ningen dock) were used for pooled prevalence of HBsAg and anti-HCV using meta-regression.

Results

Trends of birth year-specific prevalence of HBsAg and anti-HCV among the three cohorts were similar to one another, while birth year-specific pooled prevalence of HBsAg peaked in the 1941–1950 birth cohort. Prevalence of anti-HCV showed a decreasing trend by birth year.

Conclusion

We could estimate the pooled prevalence of HBsAg and anti-HCV based on nationwide data. The results can be used as reference data for various countermeasures for hepatitis eradication.

Host Genetic Determinants of Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection is still a major health problem worldwide. Recently, a great number of genetic studies based on single nucleotide polymorphisms (SNPs) and genome-wide association studies have been performed to search for host determinants of the development of chronic HBV infection, clinical outcomes, therapeutic efficacy, and responses to hepatitis B vaccines, with a focus on human leukocyte antigens (HLA), cytokine genes, and toll-like receptors. In addition to SNPs, gene insertions/deletions and copy number variants are associated with infection. However, conflicting results have been obtained. In the present review, we summarize the current state of research on host genetic factors and chronic HBV infection, its clinical type, therapies, and hepatitis B vaccine responses and classify published results according to their reliability. The potential roles of host genetic determinants of chronic HBV infection identified in these studies and their clinical significance are discussed. In particular, HLAs were relevant for HBV infection and pathogenesis. Finally, we highlight the need for additional studies with large sample sizes, well-matched study designs, appropriate statistical methods, and validation in multiple populations to improve the treatment of HBV infection.

Factors improving the utility of antiviral therapy for chronic hepatitis B: A nationwide multicenter study in Japan

AIM

The consideration of patients' needs in terms of research outcomes is emphasized in research promotion to eradicate hepatitis B virus according to the Basic Act on Hepatitis Measures in Japan. This study analyzed patients' attitudes toward experienced antiviral therapies for chronic hepatitis B and their need for future therapies.

METHODS

A self-administered questionnaire comprising 124 questions was completed among patients with chronic hepatitis B from 61 core-center hospitals designated to implement and research policies on hepatitis in 47 prefectures from August 2013 to January 2014 (n = 3021, response rate = 51%).

RESULTS

In decision-tree models with 333 variables generated from the questionnaire data, patients' satisfaction with therapy and reduction in anxiety about therapy were dependent on favorable therapeutic effects, sufficient information provided by the physician, and fewer lifestyle disturbances. Medical expenses were not selected at a superior branch because subsidy for antiviral therapy started in 2010. In correspondence analysis of free text answers, patients' need for therapy and support mechanisms differed among their attributes, including a great need for novel therapy in older men, hope for avoidance of lifestyle disturbance in younger men, and alleviation of painful experience with the disease in women.

CONCLUSIONS

Continual provision of sufficient information is necessary to improve the utility of antiviral therapy for chronic hepatitis B as well as for favorable therapeutic effects. The patients believed that novel drugs and support would reduce the diverse burden of the disease on their lives.

Reduced prevalence of hepatitis B surface antigen positivity among pregnant women born after the national implementation of immunoprophylaxis for babies born to hepatitis B virus-carrier mothers in Japan

AIM

We aimed to estimate hepatitis B surface antigen (HBsAg) positivity among birth year-stratified pregnant women in Hiroshima, Japan, and compare prevalence rates between women born before and after implementation of a national immunoprophylactic vaccination program for babies born to hepatitis B virus (HBV) carrier mothers in Japan.

METHODS

Pregnant women who gave birth at all delivery hospitals/clinics in Hiroshima prefecture between 1 April 2010 and 31 March 2011 were eligible. Lists collected from each institution included survey items such as age (pregnant woman's birth year) and HBsAg and hepatitis C virus (HCV) antibody (anti-HCV) test results, which were posted anonymously and non-consolidated from medical records. We calculated the HBsAg and anti-HCV prevalence in our cohort according to the mothers' birth year.

RESULTS

In 41 of 58 hospitals/clinics, 15 233 and 15 035 pregnant women underwent HBsAg and anti-HCV testing, corresponding to 59.6% and 58.9% of 25 546 births in the 2010 fiscal year, respectively. The overall HBsAg positive rate was 0.51% (95% confidence interval [CI], 0.40-0.63%), and an extremely low prevalence (0.10%; 95% CI, 0.00-0.25%) was observed among pregnant women born after 1986. However, the prevalence in this study was slightly higher than the nationwide value (0.31%) and the Chugoku region-specific value (0.46%) among first-time blood donors at Japanese Red Cross blood centers between 2001 and 2006. No significant difference in anti-HCV positivity was observed.

CONCLUSION

Only two pregnant women born after the preventive program implementation were HBsAg-positive. Perinatal HBV transmission is estimated to be almost completely inhibited in the next generation.

Is mother-to-infant transmission the most important factor for persistent HBV infection?

Of the infants born to hepatitis B surface antigen (HBsAg)-positive mothers globally, 42.1% who did not receive hepatitis B virus (HBV) passive-active immunoprophylaxis and 2.9% of infants who received the immunoprophylaxis acquired HBV infection perinatally. Moreover, perinatal infection occurred in 84.2% (18.8%-100%) and 8.7% (0.0-21.0%) of infants born to hepatitis B e-antigen (HBeAg)-positive mothers who did not and did receive immunoprophylaxis, respectively; by contrast, the infection rates were 6.7% (0.0-15.4%) and 0.4% (0.0-2.5%) for infants born to HBeAg-negative-carrier mothers, respectively. The chronicity rates of HBV infection acquired perinatally were 28.2% (17.4%-33.9%) in infants born to HBeAg-negative mothers and 64.5% (53.5%-100%) in infants born to HBeAg-positive mothers. HBV mother-to-child transmission was more frequent in East Asia relative to other areas. In addition to differences in the endemic HBV genotype, the interchange of allelic dominance in genetic polymorphisms in HLA class II and NF-κB between the Chinese and European populations may explain why chronic HBV infection frequently affects the Chinese. The risk of progressing into chronic infection was inversely related to the age of children at the time of horizontal transmission. To further diminish HBV chronic infection, it is necessary to enforce antiviral treatment after the 28th week of gestation for HBeAg-positive mothers and to improve the health habits of carrier mothers and household sanitary conditions.

High prevalences of hepatitis B and C virus infections among adults living in Binh Thuan province, Vietnam

AIM

Vietnam is one of the countries with the highest mortality from liver cancer, which is mostly attributed to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. For planning preventive strategies against these infections, we investigated prevalences of HBV and HCV infections among adults living in Binh Thuan, Vietnam.

METHODS

Our study consisted of a serological survey for HBV and HCV infections and a questionnaire survey on their risk factors. The sample size was calculated based on anticipated rate of hepatitis B surface antigen (HBsAg). Subjects were randomly sampled using a multistage method. Confirmation and family-tree surveys were conducted to examine persistent HBV infection and intrafamilial HBV transmission, respectively.

RESULTS

A total of 509 adults, comprised of 230 men (45.2%) and 279 women (54.8%), were enrolled. Prevalences of HBsAg, hepatitis B surface antibody and hepatitis B core antibody were 15.3%, 60.3% and 71.7%, respectively. Most HBV DNA positive sera were classified as genotype B (75.3%) and C (11.7%). Of HBsAg positive subjects, 96.7% were persistently infected and one acutely HBV infected person was identified. Family-tree surveys suggested that horizontal extrafamilial HBV transmission might have been frequent. Prevalences of anti-HCV and HCV RNA were 3.3% and 1.8%, respectively. HCV genotype 6a was prominent (55.6%).

CONCLUSION

In Binh Thuan, prevalences of HBV and HCV infections are high, HBV genotype B and HCV genotype 6a are predominant, and horizontal HBV transmission may still occur. Therefore, raising the coverage of a universal HBV vaccination program may be an effective liver cancer control in Vietnam.