Lamivudine monoprophylaxis and adefovir salvage for liver transplantation in chronic hepatitis B: a seven-year follow-up study

Biological effects of bone marrow mesenchymal stem cells on hepatitis B virus in vitro

The aim of the present study was to explore the effects of co‑culturing bone marrow‑derived mesenchymal stem cells (BM-MSCs) cultured with hepatitis B virus (HBV)‑infected lymphocytes in vitro. BM‑MSCs and lymphocytes from Brown Norway rats were obtained from the bone marrow and spleen, respectively. Rats were divided into the following five experimental groups: Group 1, splenic lymphocytes (SLCs); group 2, HepG2.2.15 cells; group 3, BM‑MSCs + HepG2.2.15 cells; group 4, SLCs + HepG2.2.15 cells; and group 5, SLCs + BM‑MSCs + HepG2.2.15 cells. The viability of lymphocytes and HepG2.2.15 cells was assessed using the MTT assay at 24, 48 and 72 h, respectively. Levels of supernatant HBV DNA and intracellular HBV covalently closed circular DNA (cccDNA) were measured using quantitative polymerase chain reaction. Supernatant cytokine levels were measured by enzyme‑linked immunosorbent assay (ELISA). T cell subsets were quantified by flow cytometry using fluorescence‑labeled antibodies. In addition, the HBV genome sequence was analyzed by direct gene sequencing. Levels of HBV DNA and cccDNA in group 5 were lower when compared with those in group 3 or group 4, with a significant difference observed at 48 h. The secretion of interferon‑γ was negatively correlated with the level of HBV DNA, whereas secretion of interleukin (IL)‑10 and IL‑22 were positively correlated with the level of HBV DNA. Flow cytometry demonstrated that the percentage of CD3+CD8+ T cells was positively correlated with the levels of HBV DNA, and the CD3+CD4+/CD3+CD8+ ratio was negatively correlated with the level of HBV DNA. Almost no mutations in the HBV DNA sequence were detected in HepG2.2.15 cells co‑cultured with BM‑MSCs, SLCs, or in the two types of cells combined. BM‑MSCs inhibited the expression of HBV DNA and enhanced the clearance of HBV, which may have been mediated by the regulation of the Tc1/Tc2 cell balance and the mode of cytokine secretion to modulate cytokine expression.

Diagnostic and therapeutic progress of multi-drug resistance with anti-HBV nucleos(t)ide analogues

Nucleos(t)ide analogues (NA) are a breakthrough in the treatment and management of chronic hepatitis B. NA could suppress the replication of hepatitis B virus (HBV) and control the progression of the disease. However, drug resistance caused by their long-term use becomes a practical problem, which influences the long-term outcomes in patients. Liver transplantation is the only choice for patients with HBV-related end-stage liver disease. But, the recurrence of HBV after transplantation often caused by the development of drug resistance leads to unfavorable outcomes for the recipients. Recently, the multi-drug resistance (MDR) has become a common issue raised due to the development and clinical application of a variety of NA. This may complicate the antiviral therapy and bring poorly prognostic outcomes. Although clinical evidence has suggested that combination therapy with different NA could effectively reduce the viral load in patients with MDR, the advent of new antiviral agents with high potency and high genetic barrier to resistance brings hope to antiviral therapy. The future of HBV researches relies on how to prevent the MDR occurrence and develop reasonable and effective treatment strategies. This review focuses on the diagnostic and therapeutic progress in MDR caused by the anti-HBV NA and describes some new research progress in this field.

Adefovir dipivoxil in chronic hepatitis B: history and current uses

INTRODUCTION

The nucleotide analogue adefovir dipivoxil (ADV) was approved in 2002 for the treatment of chronic infection with hepatitis B virus (HBV), in both hepatitis B e antigen (HBeAg)-positive and -negative patients. ADV 10 mg daily has been associated with improved liver histology, decreased levels of HBV DNA and alanine aminotransferase (ALT), and seroconversion of HBeAg.

AREAS COVERED

This paper reviews the use of ADV as a first-line treatment for chronic hepatitis B and as an add-on therapy in chronic HBV-infected patients with lamivudine resistance. In the years since its launch, clinical resistance to ADV has emerged, and tenofovir and entecavir have shown greater efficacy in reducing viral load.

EXPERT OPINION

Many patients who started antiviral therapy with ADV (either as monotherapy or in combination with lamivudine) remain on this agent because they have undetectable viremia, but its future use will probably diminish because of the availability of more potent drugs. ADV is generally well tolerated, though the 10 mg dose is associated with low risk of nephrotoxicity.

Outcome of liver transplantation for recipients with hepatitis B and hepatitis C virus coinfection: analysis of the UNOS data

BACKGROUND

Coinfection by Hepatitis B virus (HBV) and hepatitis C virus (HCV) has been reported to increase risk of graft failure for liver transplant recipients. But other studies have controverted that finding. The aim of this study was to determine whether-after adjustments for other important predictors-HBV/HCV coinfection was associated with worse liver graft survival than HBV or HCV mono-infection.

METHODS

A retrospective cohort study examined Organ Procurement and Transplantation Network/United Network Organ Sharing data for 48,654 deceased-donor primary liver-only transplants that were performed on adults between January 1, 1995, and August 31, 2009, and that included recipient and donor HBV/HCV status. Recipients were classified into four groups: the HBV/HCV coinfected [B+/C+]; HBV mono-infected [B+/C-]; HCV mono-infected [B-/C+]; and hepatitis uninfected [B-/C-]. Kaplan-Meier methods were used to calculate liver graft survival rates, Cox proportional hazard models were used to estimate the effect of hepatitis virus infection, and adjusted for potential confounders.

RESULTS

Graft survival rates were highest with B+/C-: 85.3% 1-year survival and 63.0% 10-year survival. Graft survival with B+/C+ was superior to survival with B-/C+: 83.5% 1-year survival and 53.6% 10-year survival vs. B-/C+: 82.9% 1-year survival and 46.1% 10-year survival. Survival with B-/C-: 83.6% 1-year survival and 56.6% 10-year survival was superior to survival with B+/C+ (shown above). After adjustment for confounders, and with the coinfected as reference, B-/C+ recipients had a higher risk of graft loss (hazard ratio, 1.35; 95% CI, 1.10-1.66); the other two groups had a lower risk.

CONCLUSIONS

Our results suggested-despite reports to the contrary-statistically better graft outcomes with HBV/HCV coinfection than with HCV mono-infection.

Nucleoside analogue can improve the long-term prognosis of patients with hepatitis B virus infection-associated acute on chronic liver failure

BACKGROUND

The prognosis of patients with hepatitis B virus (HBV)-associated acute on chronic liver failure (ACLF) is extremely poor.

AIM

This study was designed to evaluate the efficacy and safety of nucleoside analogue treatment of patients with HBV-associated ACLF.

METHODS

We used a retrospective review of eligible patients from April 2006 to December 2008. Eligible subjects received 0.5 mg entecavir daily until October 2009 (group A), 100 mg lamivudine daily until October 2009 (group B), or no nucleoside analogue (group C). The primary endpoints were three-month survival and the rate of recurrence of HBV-associated ACLF. The secondary endpoints were HBV DNA levels, liver function, the model of end-stage liver disease (MELD) score, and adverse events.

RESULTS

A total of 104 consecutive patients were recruited, and 33, 34, and 37 patients were randomly allocated to groups A, B, and C, respectively. Although no significant difference in three-month survival was observed, levels of HBV DNA and rates of recurrence of HBV-associated ACLF were lower. Liver function and MELD score were not significantly improved despite significantly reduced HBV DNA levels.

CONCLUSIONS

These data indicated that nucleoside analogue treatment did not improve the short-term prognosis of patients with HBV-associated ACLF although it was efficacious and safe in the management of HBV DNA levels. Intriguingly and importantly, continuous nucleoside analogue treatment can significantly reduce the rate of recurrence, which might be indicative of the further benefit of long-term survival.

Current therapeutic strategies for recurrent hepatitis B virus infection after liver transplantation

Hepatitis B virus (HBV)-related liver disease is the leading indication for liver transplantation (LT) in Asia, especially in China. With the introduction of hepatitis B immunoglobulin (HBIG) and oral antiviral drugs, the recurrent HBV infection rate after LT has been evidently reduced. However, complete eradication of recurrent HBV infection after LT is almost impossible. Recurrent graft infection may lead to rapid disease progression and is a frequent cause of death within the first year after LT. At present, the availability of new oral medications, especially nucleoside or nucleotide analogues such as adefovir dipivoxil, entecavir and tenofovir disoproxil fumarate, further strengthens our ability to treat recurrent HBV infection after LT. Moreover, since combined treatment with HBIG and antiviral agents after liver re-transplantation may play an important role in improving the prognosis of recurrent HBV infection, irreversible graft dysfunction secondary to recurrent HBV infection in spite of oral medications should no longer be considered an absolute contraindication for liver re-transplantation. Published reviews focusing on the therapeutic strategies for recurrent HBV infection after LT are very limited. In this article, the current therapeutic strategies for recurrent HBV infection after LT and evolving new trends are reviewed to guide clinical doctors to choose an optimal treatment plan in different clinical settings.

Severe acute exacerbation of chronic hepatitis B: a unique presentation of a common disease

Severe acute exacerbation is a unique presentation of chronic hepatitis B characterized by very high alanine aminotransferase level accompanied by jaundice and hepatic decompensation. The underlying pathogenesis is likely related to excessive immune clearance, which may be related to the genotype of hepatitis B virus. The mortality is very high once hepatic encephalopathy develops, but some patients can recover to almost normal liver function in contrast to patients with end-stage liver cirrhosis. This condition should be differentiated from acute hepatitis B and other causes of acute hepatitis must be excluded. Conventional prognostic systems may not be applicable to severe acute exacerbation of chronic hepatitis B. In general, patients who have thrombocytopenia, hyperbilirubinemia and coagulopathy have a higher risk of mortality regardless of the serum alanine aminotransferase levels. There is no evidence that lamivudine treatment can reduce the short-term mortality of severe acute exacerbation. However, patients with severe acute exacerbation tend to have a higher rate of maintained virological response, higher rate of hepatitis B e antigen seroconversion and low rate of drug resistance on extended lamivudine treatment as compared to other chronic hepatitis B patients. Virological relapse and severe hepatitis reactivation is common after treatment cessation and therefore long-term antiviral treatment is recommended. Liver transplantation, particularly living donor liver transplantation, should be considered for patients who develop hepatic failure secondary to severe acute exacerbation.

Current prophylactic strategies against hepatitis B virus recurrence after liver transplantation

Prophylactic strategies against hepatitis B virus (HBV) recurrence after liver transplantation (LT) are essential for patients with HBV-related disease. Before LT, lamivudine (LAM) was proposed to be down-graded from first- to second-line therapy. In contrast, adefovir dipivoxil (ADV) has been approved not only as first-line therapy but also as rescue therapy for patients with LAM resistance. Furthermore, combination of ADV and LAM may result in lower risk of ADV resistance than ADV monotherapy. Other new drugs such as entecavir, telbivudine and tenofovir, are probably candidates for the treatment of hepatitis-B-surface-antigen-positive patients awaiting LT. After LT, low-dose intramuscular hepatitis B immunoglobulin (HBIG), in combination with LAM, has been regarded as the most cost-effective regimen for the prevention of post-transplant HBV recurrence in recipients without pretransplant LAM resistance and rapidly accepted in many transplant centers. With the introduction of new antiviral drugs, new hepatitis B vaccine and its new adjuvants, post-transplant HBIG-free therapeutic regimens with new oral antiviral drug combinations or active HBV vaccination combined with adjuvants will be promising, particularly in those patients with low risk of HBV recurrence.