Genotype prevalence, viral load and outcome of hepatitis B virus precore mutant infection in stable patients and in patients after liver transplantation

The impact of ethnicity on chronic hepatitis B infection course and outcome: big data analysis from Israel

OBJECTIVES

The effect of ethnicity on chronic hepatitis B virus (CHB) infection's course and outcome has attracted little research. We aimed to compare different aspects of ethnic disparities in CHB patients, including prevalence, phenotypes, management, and outcome between two major ethnic groups in Israel.

DESIGN

We conducted a large retrospective cohort study utilizing the Leumit-Health-Service database. Electronic reports of almost 700,000 members from different ethnicities and districts throughout Israel from 2000 to 2019 were reviewed. Patients' ethnicity was categorized based on the classification of the Israeli Central Bureau of Statistics into two main groups, Arabs and Jews. CHB diagnosis was based on ICD-9-CM codes and supportive serology results. Prevalence, clinical backgrounds, disease course, and patients' outcomes were compared between both groups.

RESULTS

The prevalence of CHB in the Arab minority group was almost twice and a half-higher when compared to their Jewish counterparts (4.3% vs. 1.8%), but they had a lower rate of referral for HBsAg testing (7% vs. 7.9%). The Arab CHB patients were significantly younger at the time of diagnosis (37.6± 13.5 vs. 45.3± 15; P < 0.001). Male predominance was noted in both groups. The Arab patients had a higher rate of active hepatitis (HBeAg-positive and/or negative hepatitis) phase (36.4% vs. 29.8%; P = 0.01), as well as a significantly higher rate of HBeAg seroconversion (45.2% vs. 35.4%; P = 0.033). Nucleos/tide analogue treatment figures were similar, with most patients in both groups receiving a high barrier to resistance treatment. Patients' outcome was similar in both groups as the rate of hepatocellular carcinoma, cirrhosis, and advanced fibrosis (after stratification analysis) were comparable between both groups.

CONCLUSION

Marked by a prominently higher prevalence of HBV infection, patients in the Arab ethnic group had a lower rate of referral for HBsAg testing but received comparable management and had a similar outcome compared to their Jewish counterparts.

HBV-RNA, Quantitative HBsAg, Levels of HBV in Peripheral Lymphocytes and HBV Mutation Profiles in Chronic Hepatitis B

A comprehensive characterization of chronic HBV (CHB) patients is required to guide therapeutic decisions. The cumulative impact of classical and novel biomarkers on the clinical categorization of these patients has not been rigorously assessed. We determined plasma HBV-RNA and HBsAg levels, HBV in peripheral lymphocytes (PBMCs) and HBV mutation profiles in CHB patients. Patient demographics (n = 139) and classical HBV biomarkers were determined during a clinical routine. HBV-RNA in plasma and HBV-DNA in PBMCs were determined by RT-PCR. HBsAg levels were determined using Architect. In samples with HBV-DNA viral load >1000 IU/mL, genotype mutations in precore (PC), basal core promoter (BCP), HBsAg and Pol regions were determined by sequencing. Most patients (n = 126) were HBeAg-negative (HBeAgNeg) with significantly lower levels of HBV-RNA, HBV-DNA and HBsAg compared to HBeAg-positive (HBeAgPos) patients (p < 0.05). HBV genotype D prevailed (61/68), and >95% had BCP/PC mutations. Escape mutations were identified in 22.6% (13/63). HBeAgNeg patients with low levels of HBsAg (log IU ≤ 3) were older and were characterized by undetectable plasma HBV-DNA and undetectable HBV-RNA but not undetectable HBV-DNA in PBMCs compared to those with high HBsAg levels. In >50% of the studied HBeAgNeg patients (66/126), the quantitation of HBsAg and HBV-RNA may impact clinical decisions. In conclusion, the combined assessment of classical and novel serum biomarkers, especially in HBeAgNeg patients, which is the largest group of CHB patients in many regions, may assist in clinical decisions. Prospective studies are required to determine the real-time additive clinical advantage of these biomarkers.

Precore and Basal Core Promoter Hepatitis B Virus (HBV) Variants Are Present From a Young Age and Differ Across HBV Genotypes

BACKGROUND AND AIMS

Hepatitis B virus (HBV) precore (PC) and dual basal core promoter (BCP) mutations halt and down-regulate hepatitis B e antigen (HBeAg) production respectively. PC mutation is rarely associated with HBV genotype A. We sought to examine the association of these variants with HBV genotypes, age, and HBeAg status in a racially diverse population in North America. Prospective study included 1,036 (808 adults, 228 children) participants in the Hepatitis B Research Network. PC and BCP variants were determined by Sanger sequencing, and dominant HBV species (>50%) were reported.

APPROACH AND RESULTS

Median age was 36.3 years (range, 2-80), 44.6% HBeAg(+), 74.2% Asians, 13.3% black, and 9.7% white. The dominant PC variant was present in 29.4% participants, including 20 with subgenotype A1 or A2. Seventeen of 20 participants with genotype A and PC had a compensatory C1858T mutation. In the HBeAg(+) cohort, the prevalence of PC and/or BCP variants increased from 14.4% in the first two decades to 51% after 40 years of age. Among those aged 2-18, 52% and 83% with dominant PC and BCP variants were HBeAg(+) compared to 3.8% and 29% in the >40 years age group. HBeAg clearance rates were significantly higher for those with dominant PC or BCP variants: 24.4 and 15.0 per 100 person-years compared to 6.0 in wild-type HBV (P < 0.0001).

CONCLUSIONS

PC variants can be present in HBV genotype A and are usually associated with C1858T, which preserves the pregenome encapsidation sequence. Selection of PC and BCP variants occurred at a young age, with increasing prevalence across age groups. HBeAg(+) participants with dominant PC and BCP variants progressed to the HBeAg(-) phase of chronic HBV infection significantly faster. This finding has potential clinical and therapeutic implications.

Hepatitis B and liver transplantation: molecular and clinical features that influence recurrence and outcome

Hepatitis B virus (HBV) continues to be a major cause of morbidity and mortality worldwide. It is estimated that about 350 million people throughout the world are chronically infected with HBV. Some of these people will develop hepatic cirrhosis with decompensation and/or hepatocellular carcinoma. For such patients, liver transplantation may be the only hope for cure or real improvement in quality and quantity of life. Formerly, due to rapidity of recurrence of HBV infection after liver transplantation, usually rapidly progressive, liver transplantation was considered to be contraindicated. This changed dramatically following the demonstration that hepatitis B immune globulin (HBIG), could prevent recurrent HBV infection. HBIG has been the standard of care for the past two decades or so. Recently, with the advent of highly active inhibitors of the ribose nucleic acid polymerase of HBV (entecavir, tenofovir), there has been growing evidence that HBIG needs to be given for shorter lengths of time; indeed, it may no longer be necessary at all. In this review, we describe genetic variants of HBV and past, present, and future prophylaxis of HBV infection during and after liver transplantation. We have reviewed the extant medical literature on the subject of infection with the HBV, placing particular emphasis upon the prevention and treatment of recurrent HBV during and after liver transplantation. For the review, we searched PubMed for all papers on the subject of "hepatitis B virus AND liver transplantation". We describe some of the more clinically relevant and important genetic variations in the HBV. We also describe current practices at our medical centers, provide a summary and analysis of comparative costs for alternative strategies for prevention of recurrent HBV, and pose important still unanswered questions that are in need of answers during the next decade or two. We conclude that it is now rational and cost-effective to decrease and, perhaps, cease altogether, the routine use of HBIG during and following liver transplantation for HBV infection. Here we propose an individualized prophylaxis regimen, based on an integrated approach and risk-assessment.

Long-term results of liver transplantation for over 60 years old patients with hepatitis B virus-related end-stage liver disease

BACKGROUND

Hepatitis B virus (HBV)-related end-stage liver disease is the leading indication for liver transplantation in China, but long-term results of liver transplantation in patients aged over 60 years are not clear. The present study was to reveal the natural history of liver recipients with hepatitis B older than 60 years.

METHODS

The recipients who had received liver transplantation between December 2003 and December 2005 were divided into two groups: those equal or older than 60 years (older group, n=60) and those younger than 60 years (younger group, n=305). Risk factors for poor long-term outcome in patients aged over 60 years were also analyzed.

RESULTS

Except for age and preexisting chronic disease (P<0.05), no significant differences were observed in perioperative characteristics between the two groups. There was also no significant difference in HBV and hepatocellular carcinoma recurrence (P>0.05). The actuarial 1-, 3-, 5- and 8-year survival rates were 81.6%, 71.6%, 66.7% and 63.3% respectively for the older group vs 84.9%, 77.7%, 70.8% and 65.6% for the younger group (P>0.05). Multivariate analyses showed that pre-liver transplant renal insufficiency was a risk factor for poor outcome in the older group (odds ratio=3.615, P=0.014).

CONCLUSIONS

Liver transplantation is safe and feasible for patients with HBV-related end-stage liver disease aged over 60 years. Older patients with renal insufficiency should undergo transplantation earlier than younger patients.

A novel model for evaluating the risk of hepatitis B recurrence after liver transplantation

BACKGROUND

Hepatitis B virus (HBV) recurrence is a major risk factor affecting the long-term survival of recipients for liver transplantation (LTx). Therefore, a model that can assess this risk before transplantation is highly desirable.

METHODS

One hundred and eighty-five consecutive liver transplant recipients because of HBV-related end-stage liver diseases were selected. Their perioperative laboratory examination results, treatment protocol and the status of HBV recurrence were the primary parameters used to assess their risk of post-transplant HBV recurrence. A model that may be generally used to evaluate the risk of post-transplant HBV recurrence was thus established. A cohort for further validation and a cross-validation were designed.

RESULTS

After a follow-up time of 26.0 ± 10.8 months, the overall HBV recurrence rate was 8.6%. The 1-, 2- and 3-year cumulative survival rates were 98.5, 89.2 and 83.4% respectively. By correlation with the pretransplant presence of hepatocelluar carcinoma (HCC), serum HBV DNA level and status of antiviral treatment (AVT), the risk assessment model can be summarized using the following equation: RISK=-4.378 + 1.493 × HCC + 1.286 × DNA - 2.426 × AVT. The HBV recurrence rate and survival were found to be significantly different between the recipients with risk scores ≤-2.8 and >-2.8. The model was well validated in this work.

CONCLUSIONS

Pretransplant HBV DNA level, presence of HCC, AVT status and post-transplant viral mutation were identified as the major risk factors associated with HBV recurrence after LTx. A novel model incorporating these factors could effectively evaluate the risk of post-transplant HBV recurrence before transplantation.

Geographical and genetic diversity of the human hepatitis B virus

Hepatitis B virus (HBV) is one of the most widely distributed viruses that infect humankind. Distinct clinical and virological characteristics of the HBV-infection have been reported in different geographical parts of the world and are increasingly associated with genetic diversity of the infecting virus. HBV is classified into genotypes and subgenotypes that are associated with ethnicity and geography. The genetic diversity of HBV in its various aspects has been the subject of extensive investigations during the last few decades. Since molecular epidemiology research tools have become widely available, the number of new publications in this field has grown exponentially. This review summarises the recent publications on the geographical distribution of genetic variants of HBV, and proposes updated criteria for the identification of new genotypes and subgenotypes of the virus.

Genotype D amongst injection drug users with acute hepatitis B virus infection in British Columbia

The eight genotypes of hepatitis B virus (HBV) exhibit distinct geographical distributions. This study identified HBV genotypes and transmission modes associated with acute infection in British Columbia (BC), Canada, from 2001 to 2005. Seventy cases of acute HBV in BC were identified from laboratory reports using a standardized case definition. Interviews for risk factors and hepatitis history were conducted for each case. HBV genotypes were determined by BLAST comparison analysis of the surface (S) or preS gene sequence. To illustrate the distribution of genotypes identified amongst acute cases in BC, an annotated map was produced showing the global occurrence of HBV genotypes. The majority of acute HBV cases occurred in Caucasian, Canadian-born males, with 30% of cases reporting injection drug use (IDU) and 21% reporting incarceration. The most common genotype observed was genotype D (62.9%), followed by genotypes A (18.6%), C (11.4%), B (4.3%), and E (1.4%). A significant association was observed between Genotype D and IDU (P = 0.0025) and previous incarceration (P = 0.0067). Phylogenetic analysis of the S gene sequence demonstrated identical or high genetic relatedness amongst genotype D viral strains (86% sub-genotype D3), thus verifying transmission clustering amongst BC injection drug users. The association between acute HBV genotype and reported transmission modes has not been previously described in North America. Tracking of genotypes can help identify disease transmission patterns and target at-risk populations for preventive immunization.

Prevention of hepatitis B virus recurrence after liver transplantation

Liver transplantation for hepatitis B virus (HBV)-related liver disease has changed from a contraindication to outcomes comparable with non-HBV-related liver transplantations during the last two decades. Mainly the implementation of immunoprophylaxis with hepatitis B immunoglobulin (HBIG) and the use of nucleoside analogs such as lamivudine and adefovir account for this dramatic change. The standard of care in most centers today consists of lamivudine treatment in replicating hepatitis B pre-orthotopic liver transplantation (OLT) and a combination regimen of lamivudine and HBIG post-OLT. With adefovir, a potent antiviral drug became available in recent years that allows for the treatment of patients with lamivudine-resistant tyrosine-methionine-aspartate-aspartate (YMDD)-mutant HBV. In the transplantation setting, first studies indicate that a triple prophylactic therapy consisting of lamivudine, adefovir, and HBIG will become the standard of care for YMDD-mutant-related hepatitis B. With new drugs emerging for the treatment of chronic HBV, there is optimism for new options also in the transplant setting.

Management of HBV Infection in Liver Transplantation Patients

In the absence of preventative therapy, reinfection of allografts with hepatitis B virus (HBV) after orthotopic liver transplantation (OLT) resulted in dismal allograft and patient survival. Major advances in the management of HBV-infected recipients of OLT during the past 15 years have steadily reduced the rate of reinfection, resulting in improved outcomes. Initially, long-term use of hepatitis B immune globulin (HBIG) as a source of anti-HBs antibodies was effective in preventing or delaying reinfection. Lamivudine monotherapy made it possible to suppress HBV replication prior to OLT, markedly decreasing the risk of reinfection. Although lamivudine monotherapy used before and after OLT could prevent reinfection, its effectiveness was limited by progressive development of lamivudine-resistant mutant infections. Combination therapy with HBIG and lamivudine after OLT reduced both HBV recurrence and the risk of lamivudine resistance even in patients with active HBV replication. Introduction of adefovir provided a safe, alternative oral antiviral able to treat effectively lamivudine-resistant mutants HBV. Available strategies to prevent reinfection have resulted in OLT outcomes for HBV-infected patients comparable to those for patients transplanted for non-HBV indications. In the future, combination therapies of HBIG and both nucleoside and/or nucleotide agents will undoubtedly be optimized. Development of new drugs to treat HBV will increase opportunities to combine agents to enhance safety, efficacy and prevent emergence of HBV escape mutants. New vaccines and adjuvants may make it possible to generate anti-HBs in immunosuppressed patients, eliminating the need for HBIG.