Hepatitis B virus genotype A and D and clinical outcomes of liver transplantation for HBV-related disease

Reactivation of hepatitis B after liver transplantation: Current knowledge, molecular mechanisms and implications in management

Chronic hepatitis B (CHB) is a major global health problem affecting an estimated 350 million people with more than 786000 individuals dying annually due to complications, such as cirrhosis, liver failure and hepatocellular carcinoma (HCC). Liver transplantation (LT) is considered gold standard for treatment of hepatitis B virus (HBV)-related liver failure and HCC. However, post-transplant viral reactivation can be detrimental to allograft function, leading to poor survival. Prophylaxis with high-dose hepatitis B immunoglobulin (HBIG) and anti-viral drugs have achieved remarkable progress in LT by suppressing viral replication and improving long-term survival. The combination of lamivudine (LAM) plus HBIG has been for many years the most widely used. However, life-long HBIG use is both cumbersome and costly, whereas long-term use of LAM results in resistant virus. Recently, in an effort to develop HBIG-free protocols, high potency nucleos(t)ide analogues, such as Entecavir or Tenofovir, have been tried either as monotherapy or in combination with low-dose HBIG with excellent results. Current focus is on novel antiviral targets, especially for covalently closed circular DNA (cccDNA), in an effort to eradicate HBV infection instead of viral suppression. However, there are several other molecular mechanisms through which HBV may reactivate and need equal attention. The purpose of this review is to address post-LT HBV reactivation, its risk factors, underlying molecular mechanisms, and recent advancements and future of anti-viral therapy.

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.

Current status of liver transplantation for hepatitis B virus

The management of hepatitis B in liver transplantation has evolved significantly over the past 2 decades. Introduction of hepatitis B immune globulin and subsequently nucleos(t)ide analogues has revolutionized transplantation for hepatitis B virus (HBV), increasing survival for patients transplanted for this indication. With the availability of new and potent antivirals for HBV, the need for liver transplant should continue to decrease in the coming years. Moreover, the newer antivirals with high resistance barriers will allow effective long-term viral prophylaxis and therefore, prevention of recurrence.

Impact of the hepatitis B virus genotype on pre- and post-liver transplantation outcomes

Emerging data suggest that the hepatitis B virus (HBV) genotype and the precore and core promoter variants impact the outcome of orthotopic liver transplantation (OLT) for hepatitis B. The aim of this study was to determine if there is a correlation between HBV genotype, precore and core promoter variants, and pre- and post-OLT outcomes. Serum samples from patients participating in the National Institutes of Health HBV-OLT study were tested for HBV genotype and precore and core promoter variants. A total of 123 patients were studied: 43% were Asians, 46% were Caucasians, and 8% were African Americans. HBV genotypes A (35%) and C (35%) were the most prevalent, followed by genotypes D and B. Precore and core promoter variants were detectable in 44% and 90% of patients. Patients with genotype C were more likely to have hepatocellular carcinoma (HCC) at listing (P < 0.001). Waitlist mortality was highest among patients with genotype D, while posttransplant mortality was highest among patients with genotype C. Precore or core promoter variants did not correlate with pre- or post-OLT survival. In conclusion, in this US patient population, patients with genotype C were more likely to have HCC at the time of transplant listing and to die after transplant than patients with non-C genotypes. Patients with genotype D had the highest posttransplant survival, but this was offset by higher waitlist mortality. Our study suggests that HBV genotypes but not precore or core promoter variants may have an impact on pre- and post-OLT outcomes of hepatitis B patients.

Common genotypes of Hepatitis B virus prevalent in injecting drug abusers (addicts) of North West Frontier Province of Pakistan

BACKGROUND

The epidemiological significance of Hepatitis B virus genotypes has been well established and becoming an essential concern day by day however, much little is known about the mixed infection with more than one Hepatitis B virus genotypes and their clinical relevance.

METHODS

Intravenous drug abusers are considered as a major risk group for the acquisition and transmission of blood borne infections like hepatitis B, however, in Pakistan, no such data has ever been reported about the epidemiology of HBV and its genotypes in Injecting Drug Users. 250 individuals were analyzed for hepatitis B virus genotypes after prior screening with serological assay for the detection of HBsAg.

RESULTS

56 (22.4%) individuals were found positive on ELSIA for HBsAg. The genotype distribution was found to be as: genotype D, 62.5%; genotype A, 8.92% while 28.57% individuals were found to be infected with a mixture of genotype A and D.

CONCLUSION

There is an urgent need of the time to develop public health care policies with special emphasis towards the control of HBV transmission through high risk groups especially Injecting Drug Users.

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.

Treatment alternatives for hepatitis B cirrhosis: a cost-effectiveness analysis

BACKGROUND

Hepatitis B virus (HBV) patients with cirrhosis are at risk for developing costly, morbid, or mortal events, and therefore need highly effective therapies. Lamivudine is effective but is limited by viral resistance. In contrast, adefovir and entecavir have lower viral resistance, but are more expensive. The most cost-effective approach is uncertain.

METHODS

We evaluated the cost-effectiveness of six strategies in HBV cirrhosis: (1) No HBV treatment ("do nothing"), (2) lamivudine monotherapy, (3) adefovir monotherapy, (4) lamivudine with crossover to adefovir on resistance ("adefovir salvage"), (5) entecavir monotherapy, or (6) lamivudine with crossover to entecavir on resistance ("entecavir salvage"). The primary outcome was the incremental cost per quality-adjusted life-year (QALY) gained.

RESULTS

The "do nothing" strategy was least effective yet least expensive. Compared with "do nothing," using adefovir cost an incremental US dollars 19,731. Entecavir was more effective yet more expensive than adefovir, and cost an incremental US dollars 25,626 per QALY gained versus adefovir. Selecting between entecavir versus adefovir was highly dependent on the third-party payer's "willingess-to-pay" (e.g., 45% and 60% of patients fall within budget if willing-to-pay US dollars 10K and US dollars 50K per QALY gained for entecavir, respectively). Both lamivudine monotherapy and the "salvage" strategies were not cost-effective. However, between the two salvage strategies, "adefovir salvage" was more effective and less expensive than "entecavir salvage."

CONCLUSION

Both entecavir and adefovir are cost-effective in patients with HBV cirrhosis. Choosing between adefovir and entecavir is highly dependent on available budgets. In patients with HBV cirrhosis with previous lamivudine resistance, "adefovir salvage" appears more effective and less expensive than "entecavir salvage."

Proline-Directed Protein Kinase FAIs a Powerful and Independent Prognostic Predictor for Progression and Patient Survival of Hepatocellular Carcinoma

Purpose

Molecular, cellular, and animal studies have established that overexpressed proline-directed protein kinase FA(PDPK FA) is essential for the development of tumorigenesis, invasion, and metastasis of human cancer cells. However, the prognostic role of PDPK FAin cancer patients remains largely unknown. In this study, association of PDPK FAexpression with poor prognosis of hepatocellular carcinoma (HCC) patients was examined.

Patients and Methods

PDPK FAexpression in the resected tumors of 134 HCC patients (112 men and 22 women) with ages ranging from 33 to 83 years (mean, 55 years) was analyzed by immunohistochemistry. Highly condensed cytoplasmic and nuclear PDPK FAassociated with tumor cells was used as the major scoring parameter for positive PDPK FAexpression.

Results

Approximately 68% of the patients (91 of 134) exhibited positive PDPK FAexpression. Patients with positive PDPK FAshowed poorer disease-free survival and overall survival (P < .001). Cox multivariate regression analysis further established PDPK FAas the strongest independent prognosticator for progression and patient survival of HCC (hazard ratio [HR], 2.878; 95% CI, 1.634 to 5.067 for disease-free survival; and HR, 5.035; 95% CI, 2.137 to 11.866 for overall survival; P < .001).

Conclusion

Consistent with PDPK FA’s essential role in the development of highly malignant phenotypes, the present study establishes the potential prognostic role of PDPK FAin progression and patient survival of surgically resected primary HCC. Taken together, PDPK FArepresents a new modifiable signal-transducing target for prognostic prediction and adjuvant treatment of patients with aggressive HCC after hepatic resection.

Hepatitis B virus genotypes in children with chronic hepatitis B in Poland

OBJECTIVES

To analyse the distribution of HBV genotypes in Polish children with chronic hepatitis B, and to assess the relation between the viral genotype and the severity of liver damage.

METHODS

Serum samples from children with chronic hepatitis B were used for biochemical and serological testing, and for determination of HBV genotypes by a nested-multiplex-polymerase chain reaction. Liver biopsies were obtained for histological assessment, which was performed according to the Batts and Ludwig scoring system of chronic hepatitis.

RESULTS

Of 78 children with chronic hepatitis B, 74 had an identifiable HBV genotype: 86.5% were infected with genotype A, and 13.5% were carriers of genotype D. The frequency of HBeAg clearance and the levels of alanine aminotransferase and serum aspartate transaminase were comparable in both genotype groups. There was no correlation between the HBV genotype and either activity of liver inflammation or liver fibrosis.

CONCLUSIONS

This study shows that the distribution of HBV genotypes in Polish children with chronic HBV infection reflects the general prevalence of HBV genotypes in Europe. The course of chronic hepatitis B in children is not significantly influenced by viral genotypes A or D.

Significance of hepatitis B virus genotype in liver transplantation for chronic hepatitis B

Hepatitis B virus (HBV) genotype influences chronic hepatitis B disease profile but its relevance in liver transplantation (LTx) is not known. HBV genotype was identified by direct sequencing from pre-transplant sera of 119 patients who underwent LTx using lamivudine prophylaxis (genotype A,1; B,43; C,74; D,1). The baseline characteristics and outcome of 43 genotype B and 74 genotype C patients were compared. Genotype B patients had significantly more pre-transplant acute flare, worse liver functions and higher model for end-stage liver disease score. Fewer genotype B patients had HBeAg (13% vs. 32%; p=0.017), but HBV DNA seropositivity (by bDNA assay) was comparable (26% vs. 23%; p=0.727). The 3-year graft survival was 83% for genotype B and 89% for genotype C (p=0.2). The rate of HBsAg clearance or seroreversion was the same. The cumulative rate of viral breakthrough due to lamivudine-resistant mutants at 3 years was 4% for genotype B and 21% for genotype C (p=0.017). Liver biopsy after viral breakthrough showed recurrent hepatitis B in 7 of 10 genotype C patients, including 2 with fibrosing cholestatic hepatitis, and no histologic recurrence in 2 genotype B patients. In conclusion, HBV genotypes B and C are associated with different patterns of end-stage liver diseases that required transplantation, and genotype C may carry a greater risk and severity of recurrence due to lamivudine-resistant mutants.

Genotipos del virus de la hepatitis B en portadores crónicos en la isla de Gran Canaria. Características clinicoepidemiológicas

OBJECTIVE

To investigate the prevalence of hepatitis B virus (HBV) genotypes in Spanish hepatitis B carriers, and to study the differences in epidemiological characteristics, e antigen (HBeAg) seroconversion, serum DNA viral levels (VL) and liver function alterations.

METHODS

This study included 108 patients. Genotyping was carried out in 84 with the INNO-LiPA HBV genotyping assay (Innogenetics).

RESULTS

There were 41 women and 67 men, with a mean age of 44.1 years. The source of transmission was family contact in 26 patients (24.1%); transfusions in 10 (9.3%); sexual promiscuity in 9 (8.3%), intravenous drug use in 3 (2.8%), health care accident in 2 (1.8%); and unknown causes in 58 (53.7%). Forty patients had chronic hepatitis and 68 (63%) were healthy carriers. The time of evolution of the infection was known in only in 45 patients, and was over 10 years in 42 of them. One hundred patients (92.6%) were HbeAg-negative and 90 (83.3%) had detectable viral DNA. Genotype A was present in 46 (54.8%), D in 20 (23.8%), F in 2 (2,4%), C in 1 (1.2%), A-G coinfection in 7 (8.3%), A-D in 4 (4.8%), D-G in 2 (2,4%), A-C in 1 (1.2%), and A-D-G in 1 (1.2%). There were no significant differences between genotypes. A trend towards an association was found between VL <or= 10(5) copies/mL and the presence of chronic hepatitis in genotype A (28.9%) as opposed to genotype D (7.7%) (p non significant).

CONCLUSIONS

HBV genotypes A and D, and coinfections with G are predominant in our area. Genotype A showed a tendency to produce greater inflammatory activity when VL was <or= 10(5) copies/mL.

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.