Hepatocellular carcinoma and other liver disease among Greenlanders chronically infected with hepatitis B virus: a population-based study

Incidence of Hepatocellular Carcinoma and Decompensated Liver Cirrhosis and Prognostic Accuracy of the PAGE-B HCC Risk Score in a Low Endemic Hepatitis B Virus Infected Population

Purpose

We aimed to determine incidence of hepatocellular carcinoma (HCC) and decompensated liver cirrhosis in persons with chronic hepatitis B virus (HBV) infection in Denmark stratified by disease phase, liver cirrhosis, and treatment status at baseline. Additionally, we aimed to assess the prognostic value of the PAGE-B HCC risk score in a mainly non-cirrhotic population.

Patients and Methods

In this register-based cohort study, we included all individuals over the age of 18, with chronic HBV infection first registered between 2002 and 2016 in at least one of three nationwide registers. The study population was followed until HCC, decompensated liver cirrhosis, death, emigration, or December 31, 2017, which ever came first.

Results

Among 6016 individuals included in the study, 10 individuals with and 23 without baseline liver cirrhosis developed HCC during a median follow up of 7.3 years (range 0.0-15.5). This corresponded to five-year cumulative incidences of 7.1% (95% confidence interval (CI) 2.0-12.3) and 0.2% (95% CI 0.1-0.4) in persons with and without baseline liver cirrhosis. The five-year cumulative incidence of decompensated liver cirrhosis was 0.7% (95% CI 0.5-1.0). Among 2038 evaluated for liver events stratified by disease phase, incidence of HCC was low in all who were non-cirrhotic and untreated for HBV at baseline. PAGE-B score was evaluated in 1529 persons. The 5-year cumulative incidence of HCC was 0, 0.8 (95% CI 0.5-1.8), and 8.7 (95% CI 1.0-16.4) in persons scoring <10, 10-17 and >17, respectively (c-statistic 0.91 (95% CI 0.84-0.98)).

Conclusion

We found low incidence of HCC and decompensated liver cirrhosis in persons with chronic HBV infection in Denmark. Moreover, the PAGE-B score showed good accuracy for five-year risk of developing HCC in the population with chronic HBV infection in Denmark.

Association between hepatitis B and E virus infection and hepatocellular carcinoma risk

The role of hepatitis E virus (HEV) in developing hepatocellular carcinoma (HCC) is unclear. Our study aimed to investigate the role of HE infection in HCC development and the effect of hepatitis B virus (HBV) and HEV coinfection on HCC risk. A hospital-based case-control study was conducted. A total of 474 eligible HCC cases and 586 control patients were successfully recruited. The fasting venous blood was collected from the patients at the first visited to hospital and HBV infection and HEV infection were examined within 5 days. Crude and adjusted odd ratios (ORs) with 95% confidence interval (95% CI) were estimated by using logistic regression model. HBV infection (OR: 63.10, 95% CI: 42.02-97.26) rather than HEV infection (OR: 1.08, 95% CI: 0.721-1.65) was associated with an increased risk of HCC after adjustment for confounders. The association between HBV infection and HCC risk was more remarkable in male (OR: 72.61, 95% CI: 45.10-121.38) than in female (OR: 61.89, 95% CI: 25.74-169.26). In comparison with patients who infected with neither HEV nor HBV, those who infected with only HBV (OR: 69.62, 95% CI: 40.90-123.52) and who coinfected with HEV and HBV (OR: 67.48, 95% CI:37.23-128.19) were significantly associated with an increased risk after adjustment for potential confounders. The results showed that HBV infection rather than HEV infection was associated with an increased risk of HCC, and the HEV infection may alleviate the promoting impact of HBV on HCC development.

Analysis of Hepatitis B Virus Genotype D in Greenland Suggests the Presence of a Novel Quasi-Subgenotype

A disproportionate number of Greenland's Inuit population are chronically infected with Hepatitis B virus (HBV; 5-10%). HBV genotypes B and D are most prevalent in the circumpolar Arctic. Here, we report 39 novel HBV/D sequences from individuals residing in southwestern Greenland. We performed phylodynamic analyses with ancient HBV DNA calibrators to investigate the origin and relationship of these taxa to other HBV sequences. We inferred a substitution rate of 1.4 × 10-5 [95% HPD 8.8 × 10-6, 2.0 × 10-5] and a time to the most recent common ancestor of 629 CE [95% HPD 37-1138 CE]. The Greenland taxa form a sister clade to HBV/D2 sequences, specifically New Caledonian and Indigenous Taiwanese sequences. The Greenland sequences share amino acid signatures with subgenotypes D1 and D2 and ~97% sequence identity. Our results suggest the classification of these novel sequences does not fit within the current nomenclature. Thus, we propose these taxa be considered a novel quasi-subgenotype.

Coverage rates of the children vaccination programme in Greenland

In order to estimate the current coverage rate among all children in Greenland, we conducted an observational cross-sectional study identifying all children in Greenland eligible for a vaccination between 1 March 2018 and 16 June 2019. we found an overall national coverage of 85.4%. The national coverage for the vaccinations given at birth was 97.1%, dropping to 94.3%, 87.7% and 83.6% at ages 3, 5 and 12 months. Among children eligible for the Measles, Mumps and Rubella-vaccinations, the national coverage was 76.9% for children aged 15 months and 64.1% for children aged 4 years, but dropping to 40.9% in the districts. At preschool, the national coverage was 79.9%. Among the 12-year-old, the national coverages of the two vaccinations against Human Papilloma Virus were 88.4% and 71.6%, respectively, and for the three Hepatitis B-vaccinations 89.8%, 84.1% and 69.6%. A subgroup-analysis and test of an SMS-reminder system in Nuuk improved the coverage from 57.8% to 75.5% locally. Overall, we found a high national coverage rate among the newborn in Greenland. The national coverage rates of the remaining vaccinations were below the WHO-recommendations, however with great regional differences.Abbreviations: CVP: Children Vaccination Programme; BCG: Bacille Calmette-Guerin; EMR: Electronic medical Record system; DTPHiB: Diphtheria, Tetanus, Pertussis, Polio, Haemophilus influenza B; HBV: Hepatitis B; HPV: Human Papilloma Virus; MMR: Measles, Mumps, Rubella; SMS: Short Text Message; WHO: World Health Organization; GVAP: Global Vaccine Action Plan; EVAP: The WHO European Vaccine Action Plan.

Incidence of hepatocellular carcinoma in untreated subjects with chronic hepatitis B: a systematic review and meta-analysis

BACKGROUND & AIMS

In the natural history of hepatitis B virus (HBV) chronic infection, the hepatocellular carcinoma (HCC) risk is unclear. We assessed incidence and predictors of HCC by a systematic review and meta-analysis.

METHODS

We included longitudinal studies and randomized controlled trials assessing HCC incidence in untreated patients with HBV chronic infection. Incidence rates and their 95% confidence intervals were extracted by each study and pooled together in random effects models.

RESULTS

Sixty-six studies were included with a total of 347 859 patients. According to liver disease status, the summary incidence rates were in Europe, North America and East Asia, respectively: (a) asymptomatic carriers: 0.07 (95% confidence interval: 0.05-0.09), 0.19 (0.07-0.31) and 0.42 (0.21-0.63) per 100 person-years, respectively; (b) inactive carriers: 0.03 (0.0-0.10), 0.17 (0.02-0.62) and 0.06 (0.02-0.10), respectively; (c) chronic hepatitis: 0.12 (0.0-0.27), 0.48 (0.22-0.91) and 0.49 (0.32-0.66), respectively; (d) compensated cirrhosis (Child-Pugh A): 2.03 (1.30-2.77), 2.89 (1.23-4.55) and 3.37 (2.48-4.26) respectively. Multivariate meta-regression showed a significant increase in incidence rates for age, and for status of a symptomatic carrier, chronic hepatitis and compensated cirrhosis compared to inactive carrier, but not for geographical area after adjusting for age. An increase in the incidence rates was also observed for alcohol intake ≥60 g/dl, HBV genotype C with respect to B and HBV-DNA serum levels >2000 IU/ml, in Asian studies.

CONCLUSIONS

Hepatocellular carcinoma risk in untreated subjects with HBV chronic infection is strongly related with age and liver disease status.

Hepatitis B among Inuit: A review with focus on Greenland Inuit

Hepatitis B virus (HBV) infection is a disease with a highly variable course. Chronic HBV infection may cause end-stage liver disease including cirrhosis and hepatocellular carcinoma, which is the 3^rd most common cause of cancer related death due to the poor prognosis. The prevalence of HBV infection is low in many countries. Still, it remains important due to the potential consequences of the disease. HBV is endemic in the Arctic with serologic markers of chronic HBV infection in up to 29% of the population in some areas in Greenland. Interestingly, Inuit populations rarely show signs of liver disease despite the fact that around half of all Inuit has been exposed to HBV and around 8% of Inuit are chronically infected with HBV. These findings have been consistent in surveys conducted for more than four decades among Arctic Inuit. We thus review HBV infection in the Arctic with focus on Greenland Inuit and compared with Inuit in Canada, Alaska and Siberia. The aspects described include epidemiology and monitoring of the disease, as well as treatment and the risk of liver cancer.

Hepatitis B prevalence and incidence in Greenland: a population-based cohort study

Greenland remains a highly endemic area for hepatitis B virus (HBV) infection. This is in sharp contrast to other modern societies, such as Denmark. To address this discrepancy, we investigated the natural history of HBV infection in Greenland by estimating the age-specific incidence of HBV infection, the proportion of chronic carriers, and the rates of hepatitis B surface antigen seroclearance. In total, 8,879 Greenlanders (16% of the population) from population-based surveys conducted in 1987 and 1998 were followed through March 2010. Data on HBV status were supplemented by HBV test results from all available HBV registries in Greenland to determine changes in HBV status over time. Incidence rates of HBV infection and hepatitis B surface antigen seroclearance were estimated after taking into account interval censoring. The incidence of HBV infection in 5-14-year-old subjects was less than 1 per 100 person-years and peaked at 5 per 100 person-years in persons 15-24 years of age. Overall, 17.5% of persons infected in adulthood were estimated to become chronic carriers. HBV is primarily transmitted in adolescence and adulthood in Greenland. In contrast to what is observed in most other populations, HBV-infected adults in Greenland have a high risk of progressing to chronic HBV carriage. This phenomenon might explain how the high rate of infection is maintained in Greenland.

Plasma YKL-40 in Inuit and Danes

AIMS

The aim of the present study was to investigate whether there are differences in plasma levels of YKL-40 between Inuit in Greenland and in Denmark and in Danes, as well as to study the relationship between alcohol intake, plasma YKL-40 and other factors in Inuit.

METHODS

Plasma YKL-40 levels were measured on 1645 people from The Greenland Population Study (a cross-sectional population study of Inuit from Denmark and West Greenland) and were compared with the plasma YKL-40 levels of 8899 people from The Copenhagen City Heart Study (a population-based, prospective study of the Danish general population).

RESULTS

The plasma concentrations of YKL-40 were significantly (P = 0.001) lower in Inuit living in Greenland (median 46 µg/l, range 10-2164, n = 1164) compared with the plasma YKL-40 levels of Inuit living in Denmark (median 63 µg/l, range 20-2827, n = 481) and of Danes living in Denmark (median 55 µg/l, range 10-2909, n = 8899). In Inuit, increased alcohol intake was significantly associated with increased plasma YKL-40 levels (P < 0.001), and high plasma YKL-40 levels were associated with high values of alkaline phosphatase and low values of albumin. Smoking, gender and bilirubin were not associated with the plasma YKL-40 level. High levels of YKL-40 and alcohol were associated with where people lived.

CONCLUSION

The plasma concentrations of YKL-40 are significantly lower in Inuit living in Greenland than Inuit and Danes living in Denmark. A number of factors, including different alcohol intake patterns, nutrition and genes may play a role in these findings.

A paucity of liver disease in Canadian Inuit with chronic hepatitis B virus, subgenotype B6 infection

Clinical observations suggest that chronic hepatitis B virus (HBV) infections in the Canadian Inuit are less often associated with serious adverse outcomes than has been described in other HBV-infected patient populations. The aim of this study was to document the clinical and biochemical features, liver-related morbidity and all-cause mortality in Canadian Inuit with chronic HBV infections. Administrative databases were reviewed for individuals identified as hepatitis B surface antigen (HBsAg) positive during a 1983-85 seroepidemiological survey of viral hepatitis in Baffin Island, Canada. An equal number of age- and gender-matched HBsAg-negative individuals from the same communities served as controls. Baseline HBV viral loads, genotypes and specific mutations were compared in HBsAg-positive survivors and nonsurvivors. A subset of surviving HBsAg-positive carriers were reassessed 25-30 years following their initial diagnosis for evidence of advanced liver disease and changes to their serological/virological findings. One hundred and forty four HBsAg-positive individuals were identified. All were Canadian Inuit. The mean age at diagnosis was 38 ± 17 years and 69 (61%) were male. Median follow-up was 23 years (range: 2-28 years). Viral quantitation from stored sera could be performed in 70 infected individuals. The median viral load was 4.3 log 10 IU/ml (range: 2.3-8.8 log 10 IU/ml), and all were genotype B, subgenotype B6. Liver biochemistry, morbidity and all-cause mortality rates were similar in HBsAg-positive carriers and controls. Following multivariate analyses, only age at diagnosis predicted mortality in HBsAg carriers. In a subset of 30 HBsAg-positive survivors who underwent follow-up assessments, clinical, biochemical and radiological examinations of the liver were essentially normal. 23/30 (77%) remained HBsAg positive and 17/19 (90%) HBV-DNA positive. The genotype and prevalence of genomic mutations in this cohort remained largely unchanged, but quantifiable viral loads were significantly lower (P < 0.003). The results of this study suggest that chronic HBV infections in the Canadian Inuit are infrequently associated with serious adverse outcomes. Whether this finding reflects unique features of the host, presence or absence of external factors that influence the course of HBV and/or intrinsic properties of the HBV B6 subgenotype remains to be determined.

The Arctic Human Health Initiative: a legacy of the International Polar Year 2007-2009

BACKGROUND

The International Polar Year (IPY) 2007-2008 represented a unique opportunity to further stimulate cooperation and coordination on Arctic health research and increase the awareness and visibility of Arctic regions. The Arctic Human Health Initiative (AHHI) was a US-led Arctic Council IPY coordinating project that aimed to build and expand on existing International Union for Circumpolar Health (IUCH) and Arctic Council human health interests. The project aimed to link researchers with potential international collaborators and to serve as a focal point for human health research, education, outreach and communication activities during the IPY. The progress of projects conducted as part of this initiative up until the end of the Arctic Council Swedish chairmanship in May 2013 is summarized in this report.

DESIGN

The overall goals of the AHHI was to increase awareness and visibility of human health concerns of Arctic peoples, foster human health research, and promote health strategies that will improve health and well-being of all Arctic residents. Proposed activities to be recognized through the initiative included: expanding research networks that will enhance surveillance and monitoring of health issues of concern to Arctic peoples, and increase collaboration and coordination of human health research; fostering research that will examine the health impact of anthropogenic pollution, rapid modernization and economic development, climate variability, infectious and chronic diseases, intentional and unintentional injuries, promoting education, outreach and communication that will focus public and political attention on Arctic health issues, using a variety of publications, printed and electronic reports from scientific conferences, symposia and workshops targeting researchers, students, communities and policy makers; promoting the translation of research into health policy and community action including implementation of prevention strategies and health promotion; and promoting synergy and strategic direction of Arctic human health research and health promotion.

RESULTS

As of 31 March, 2009, the official end of the IPY, AHHI represented a total of 38 proposals, including 21 individual Expressions of Intent (EoI), and 9 full proposals (FP), submitted to the IPY Joint Committee for review and approval from lead investigators from the US, Canada, Greenland, Norway, Finland, Sweden and the Russian Federation. In addition, there were 10 National Initiatives (NI-projects undertaken during IPY beyond the IPY Joint Committee review process). Individual project details can be viewed at www.arctichealth.org. The AHHI currently monitors the progress of 28 individual active human health projects in the following thematic areas: health network expansion (5 projects), infectious disease research (7 projects), environmental health research (7 projects), behavioral and mental health research (4 projects), and outreach education and communication (5 projects).

CONCLUSIONS

While some projects have been completed, others will continue well beyond the IPY. The IPY 2007-2008 represented a unique opportunity to further stimulate cooperation and coordination on Arctic health research and increase the awareness and visibility of Arctic regions.

The HIV epidemic in Greenland--a slow spreading infection among adult heterosexual Greenlanders

Introduction

We aimed to characterise the HIV epidemic in Greenland and to determine incidence, prevalence, mortality rates (MR) and specific causes of deaths.

Study design

The study design used was population-based nationwide cohort study.

Methods

We included all patients diagnosed with HIV in Greenland before 2011. Data were obtained from patient files, death certificates and the mandatory reports of HIV cases.

Incidence and prevalence were estimated as cases/100,000 adults/year and MR as deaths/1,000 person-years (PYR). MRs were estimated for the pre-HAART (≤1996), early-HAART (1997–2004) and late-HAART (≥2005) periods. Deaths were considered AIDS related, if CD4 count <6 months before death was <200 cells/µL and/or an AIDS-related event occurred <12 months of death.

Results

We identified 171 cases of HIV among adult Greenlanders. Of these, 133 (78%) were infected in Greenland, 17 (10%) in Denmark and 21 (12%) in other places. The majority was infected through heterosexual contact [127 (74%)], 30 (18%) through homosexual contact, 3 (2%) through intravenous drug use and 11 (6%) through other or unknown routes of transmission.

The median age at HIV diagnosis was 46 years (interquartile range 34–56). The incidence increased from 3.8 before 1989 to 29.7 cases/100,000 adults/year in the late 1990s. The incidence has slowly declined to approximately eight cases/100,000 adults/year. Prevalence increased to a maximum in 2009 (174.9/100,000 inhabitants), and slowly declined since then. A total of 79 have died and 25 have emigrated. MRs were high in the pre- and early-HAART periods, 65.3 [95% confidence intervals (CI) 40.0–106.6] and 87.0 [95% CI 63.5–119.0], and a large fraction of deaths were AIDS related. In the late-HAART period, MR has declined markedly to 53.4 (95% CI 35.8–79.7) with a substantial decline in AIDS-related MR.

Conclusion

Heterosexual contact is the main route of HIV infection and the patients are diagnosed at a median age of 46. The incidence of newly diagnosed HIV patients has decreased markedly since year 2000. Mortality is high although declining in recent years.

Genetic diversity of hepatitis B virus genotypes B6, D and F among circumpolar indigenous individuals

Hepatitis B virus (HBV) infection is highly prevalent in circumpolar indigenous peoples. However, the clinical outcome is extremely variable, such that while hepatocellular carcinoma (HCC) is uncommon in Canadian Inuit, the incidence of HCC is slightly higher in Greenlanders than in Danes, and it is especially high in Alaskan Native people infected with HBV genotypes F (HBV/F) and C (HBV/C). These differences may be associated with the genomic variability of the predominant HBV genotype in each group. The purpose of this study was to determine the rate, nature and regional susceptibility of HBV genomic mutations among circumpolar indigenous individuals. Paired serum samples, separated by 5-6 years, were analysed from Canadian and Greenlandic Inuit infected with HBV genotype B6 (HBV/B6) and HBV/D, respectively, and from Alaskan Native people infected with HBV/F, each having subsequently developed HCC. Phylogenetic and mutational analyses were performed on full-genome sequences, and the dynamic evolution within the quasispecies population of each patient group was determined by clonal analysis of the non-overlapping core coding region. Mutations associated with severe outcomes predominated in HBV/F, mostly within the precore/core and PreS1 region. HBV/B6 genomes exhibited higher diversity compared to HBV/D and HBV/F, particularly within the core coding region. Thus, differing mutational profiles and genetic variability were observed among different HBV genotypes predominating in circumpolar indigenous patients. The unusual observation of persistently high genetic variability with HBV/B6 despite clinical inactivity could be due to the evolution of a host-pathogen balance, but other possible factors also need to be explored.