Slow decline of hepatitis B burden in general population: Results from a population-based survey and longitudinal follow-up study in Taiwan

Time trends of chronic HBV infection over prior decades - A global analysis

BACKGROUND & AIMS

Information on trends in chronic hepatitis B virus (HBV) prevalence across countries is lacking. We studied changes in chronic HBV infection over previous decades by country, and assessed patterns of change between and within WHO-defined regions.

METHODS

Based on data from a published systematic review on chronic HBV, we applied a linear model on the logit scale to assess time trends in country-specific prevalence. Estimated HBsAg prevalence in 2000 and relative changes in prevalence over time were evaluated by country and region.

RESULTS

Sufficient data were available for 50 countries, mostly showing reductions in prevalence over time. Various degrees of heterogeneity were observed within regions, with a relatively homogenous pattern in the Eastern Mediterranean region with strong decreases in HBsAg prevalence. Europe showed a mixed pattern: higher and stable chronic HBsAg prevalence in Eastern, and constantly low prevalence in Western Europe. In Africa, some countries demonstrated no change in prevalence; increases were seen in Uganda (odds ratio 1.05 per year; 95% confidence interval 1.04-1.06), Nigeria (1.02; 1.02-1.02), Senegal (1.01; 1.01-1.02), and South Africa (1.02; 1.01-1.02). With some exceptions, country-patterns overlapped among countries of South East Asian and Western Pacific regions, characterized by low-medium HBsAg decreases, most prominent in China and Malaysia.

CONCLUSIONS

Most countries experienced decreases in HBsAg prevalence. Dynamics varied, even within regions; decreases occurred mostly before the direct effects of childhood vaccination may have manifested. These findings together with stable and increasing HBsAg prevalence in some countries of Africa and Eastern Europe indicate the need for further tailored country-specific prevention.

LAY SUMMARY

This study investigated time trends in prevalence of chronic HBV infection in 50 countries worldwide over the last decade, by estimating relative changes in prevalence. Results show decreases in chronic HBV infection in most countries; no changes or increases in prevalence are noted in some African countries. Reasons for time changes need to be investigated further; based on the results, various prevention measures have contributed to reductions, and further tailored HBV prevention is required to combat the disease on a global level.

Autoimmune liver diseases in the Asia-Pacific region: Proceedings of APASL symposium on AIH and PBC 2016

During the 25th annual meeting of the Asia-Pacific Association for the Study of the Liver (APASL 2016) in Tokyo, we organized and moderated an inaugural satellite symposium on the autoimmune liver diseases, autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC). Following the keynote lecture by John M. Vierling (USA), speakers from the Asia-Pacific region provided an up-to-date perspective on the epidemiology, clinical practice and research in AIH and PBC in the Asia-Pacific region. Although epidemiology and clinical features of AIH seem to be similar in East Asia compared to those in western countries, the majority of patients with AIH are detected at an advanced stage and have higher mortality rates in South Asia, indicating an unmet need for earlier diagnosis and the initiation of appropriate immunosuppressive treatment. PBC is more commonly seen in Australia and East Asia. As of 2016, clinical practice guidelines (CPG) for PBC have been published in Japan and China. Ursodeoxycholic acid (UDCA) is recommended as a first-line therapy by both CPG. Nevertheless, one of the unmet therapeutic needs in PBC is the treatment of patients refractory to or intolerant of UDCA. It is of interest that the prevalence of chronic hepatitis B (CHB) in PBC patients was low in Taiwan and mainland China where the prevalence of CHB is very high. In this review, we overview this exciting and epoch-making symposium.

Review article: long-term safety of nucleoside and nucleotide analogues in HBV-monoinfected patients

BACKGROUND

Nucleos(t)ide analogues (NUCs) for chronic hepatitis B treatment achieve high rates of viral suppression and are generally well tolerated. Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are the currently preferred first-line agents. The safety of these agents in clinical practice is particularly relevant since long-term treatment is usually required.

AIM

To summarise and critically discuss recent real-world evidence on the safety of treatment with ETV or TDF in hepatitis B virus (HBV)-monoinfected patients.

METHODS

PubMed and conference proceedings up to 15th June 2015 were searched using the terms ((((Hepatitis_B) OR HBV) AND ((tenofovir) OR entecavir)) AND (((lactic_acidosis) OR bone) OR renal)).

RESULTS

In selected populations included in registration studies, both ETV and TDF were well tolerated with no clinically significant renal toxicity or lactic acidosis. Growing 'real-world' clinical experience with these agents includes some reports of ETV-associated lactic acidosis and TDF-associated renal impairment; however, evidence from cohort studies appears to be conflicting. In the case of ETV-related lactic acidosis, a small number of cases have been reported, all in patients with decompensated cirrhosis. The degree of association between TDF treatment and changes in markers of renal function varies between studies: discrepancies may result from the use of different definitions and cut-offs for reporting renal toxicities, and differences in patient populations.

CONCLUSIONS

Pre-treatment and on-treatment monitoring of eGFR and phosphorus, with prompt appropriate dose adjustment or treatment switch can minimise the impact of NUC renal toxicity. Standardisation of measures of renal impairment and identification of early molecular markers remain an unmet need.

Cancer Incidence among Heart, Kidney, and Liver Transplant Recipients in Taiwan

Population-based evidence of the relative risk of cancer among heart, kidney, and liver transplant recipients from Asia is lacking. The Taiwan National Health Insurance Research Database was used to conduct a population-based cohort study of transplant recipients (n = 5396), comprising 801 heart, 2847 kidney, and 1748 liver transplant recipients between 2001 and 2012. Standardized incidence ratios and Cox regression models were used. Compared with the general population, the risk of cancer increased 3.8-fold after heart transplantation, 4.1-fold after kidney transplantation and 4.6-fold after liver transplantation. Cancer occurrence showed considerable variation according to transplanted organs. The most common cancers in all transplant patients were cancers of the head and neck, liver, bladder, and kidney and non-Hodgkin lymphoma. Male recipients had an increased risk of cancers of the head and neck and liver, and female kidney recipients had a significant risk of bladder and kidney cancer. The adjusted hazard ratio for any cancer in all recipients was higher in liver transplant recipients compared with that in heart transplant recipients (hazard ratio = 1.5, P = .04). Cancer occurrence varied considerably and posttransplant cancer screening should be performed routinely according to transplanted organ and sex.

Adaptive immunity in HBV infection

During hepatitis B virus (HBV) infection, the presence of HBV-specific antibody producing B cells and functional HBV-specific T cells (with helper or cytotoxic effects) ultimately determines HBV infection outcome. In this review, in addition to summarizing the present state of knowledge of HBV-adaptive immunity, we will highlight controversies and uncertainties concerning the HBV-specific B and T lymphocyte response, and propose future directions for research aimed at the generation of more efficient immunotherapeutic strategies.

Hepatitis B vaccination and prevention of hepatocellular carcinoma

Hepatitis B virus (HBV) infection is a global health threat; with 240 million people are chronic carriers of the virus. The infection can cause acute and chronic liver disease including liver cirrhosis and hepatocellular carcinoma (HCC). On the basis of disease burden and the availability of safe and effective vaccines, World Health Organization has recommended that hepatitis B vaccine be incorporated into routine infant and childhood immunization programs for all countries. The efficacy of universal immunization has been proven in many countries, with substantial reductions of the prevalence of HBV carriage in children, adolescents and young adults. Most important, hepatitis B vaccination can protect them from HCC, as has been demonstrated in Taiwan and other countries. Nevertheless, the implementation of worldwide vaccination against HBV indeed requires more effort to overcome the social and economic challenges. To have a global control of HBV infection, we have to continue the universal HBV vaccination, interrupt the possible transmission routes and treat eligible patients with antiviral agents. However, current treatments are still far from ideal as they cannot eradicate intrahepatic HBV cccDNA, and lifelong administration of these agents will pose a major economic burden, especially in the endemic Asia-Pacific region. Thus we need innovative treatment strategies and novel agents with difference modes of action to overcome the unmet medical need for an efficient HBV cure with subsequent global eradication of HBV infection, hopefully by the first half of 21st century.

Nonalcoholic Cirrhosis Increased Risk of Digestive Tract Malignancies: A Population-Based Cohort Study

Alcoholic cirrhosis is generally accepted as a risk factor for hepatocellular carcinoma (HCC) development; however, little research has examined the relationship between nonalcoholic cirrhosis (NAC) and HCC. Thus, the aim of this study was to investigate whether NAC is associated with the risk of HCC and extrahepatic malignancies in Taiwan.We conducted a populated-based retrospective cohort study by using data from the Taiwan National Health Insurance (NHI) program. A total of 2109 patients with NAC were identified from the NHI database between 2000 and 2011. For a control group, 4 patients without NAC were frequency-matched with each NAC patient according to sex, age, and index year. We used Cox proportional hazards regression analysis to calculate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) and determine the effects of NAC on cancer risk.The overall cancer risk was significantly higher in patients with NAC compared with those without NAC, and this association was consistent among age, sex, and comorbidity groups. The risk of developing HCC was remarkably high in the NAC group compared with in the control cohort (aHR = 122.7, 95% CI = 68.4-220.1); significantly higher risks of extrahepatic malignancies were observed in patients with digestive tract cancers and hematological malignancies. Further analyses stratified according sex, age, and follow-up duration revealed various patterns among the cancer types.The results indicate that patients with NAC in Taiwan have higher risks of HCC, digestive tract cancers, and hematological malignancies.

Association Between Chronic Hepatitis B Virus Infection and Risk of Osteoporosis: A Nationwide Population-Based Study

The effect of hepatitis B virus (HBV) infection on bone mineral density in patients without advanced liver disease remains unclear. Hence, we assessed the association between HBV infection and the risk of osteoporosis. From 2000 to 2011, patients older than 20 years with HBV infection were identified from the Longitudinal Health Insurance Database 2000. Of the 180,730 sampled patients, 36,146 and 144,584 patients were categorized into HBV infection and comparison cohorts, respectively. Compared with the comparison cohort, the HBV infection patients had a higher risk of osteoporosis (adjusted hazard ratio [aHR]: 1.14, 95% confidence interval [CI]: 1.03-1.25) after adjusting for age, sex, frequency of medical visits, and comorbidities of diabetes, hypertension, hyperlipidemia, heart failure, cirrhosis, chronic kidney disease, thyroid diseases, medication of steroid, PPI, warfarin, aspirin, and estrogen replacement therapy. The patients with HBV infection exhibited a 1.13-fold (95% CI = 1.03-1.25) higher risk of developing osteoporosis, but the risk of osteoporotic fracture was comparable between patients with HBV infection and the comparison cohort (aHR = 1.20, 95% CI = 0.77-1.86). The incidence of osteoporosis increased with the increment of age (age  ≤ 49: aHR = 1; age 50-64: aHR = 5.67, 95% CI = 5.09-6.32; age  ≧ 65: aHR = 13.3, 95% CI = 11.8-14.9) and coexisting cirrhosis (aHR = 1.62, 95% CI = 1.24-2.12). However, the osteoporosis risk contributed by HBV infection decreased with age and the age-specific risk analyses showed that patients with HBV infection exhibited the highest risk of osteoporosis than patients without HBV infection for the patients aged ≤49 (aHR = 1.42, 95% CI = 1.19-1.70). Furthermore, the osteoporosis risk contributed by HBV infection has decreased with the presence of comorbidity (aHR = 1.27, 95% CI = 1.09-1.48 vs aHR = 1.04, 95% CI = 0.91-1.15). HBV increases the risk of osteoporosis, but HBV infection may be less influential than other risk factors. Moreover, HBV has no detrimental effect on osteoporotic fracture in this study.