Virological and biochemical relapse after discontinuation of lamivudine monotherapy for chronic hepatitis B in Japan: comparison with breakthrough hepatitis during long-term treatment

Ten-year follow-up of hepatitis B relapse after cessation of lamivudine or telbivudine treatment in chronic hepatitis B patients

The high rate of relapse after cessation of nucleos(t)ide analogues (NUCs) treatment in chronic hepatitis B (CHB) patients leads us to reassess the feasibility for off-therapy, but long-term follow-up data are scarce. We assessed the feasibility for off-therapy by a long-term observation of relapse in response to lamivudine (LAM) and telbivudine (LdT). Eighty-six NUC-naive CHB patients, treated with LAM (n = 46) or LdT (n = 40) who reached the guidelines recommended for off-therapy, were followed for up to 10 years. Hepatitis B virus (HBV), viral serology and biochemistries were periodically determined. COX model was used to predict the risk of relapse. A total of 52.3% of patients experienced relapse within a median of 115 months (range, 61-122 months). A total of 93.3% of relapses occurred within 48 months. Relapse rates in hepatitis B e antigen (HBeAg)-positive (n = 56) and HBeAg-negative (n = 30) patients were 39.3% and 76.7%, respectively (p < 0.01). HBeAg-positive patients who achieved an early viral response (EVR), defined as undetectable HBV DNA within 6 months, had a lower relapse rate compared to non-EVR patients (21.4% vs. 59.2%, p < 0.01). EVR patients who had both lower HBV DNA (<10(6) copies/mL) at baseline and lower hepatitis B surface antigen (HBsAg) at end of treatment had a relapse rate of 10.7%. The high relapse rates in CHB patients over this 10-year follow-up make LAM or LdT off therapy infeasible in most of the cases, except in the case of HBsAg loss and/or seroconversion. HBeAg-positive patients with EVR, lower HBV DNA and HBsAg had lower relapse rates and could be good candidates for off-therapy. Long-term monitoring, especially during the first 4 years, is critical for patients off-therapy.

Clinical course of chronic hepatitis B patients who were off-treated after lamivudine treatment: analysis of 138 consecutive patients

BACKGROUND/AIMS

Little is known about the long-term outcome of chronic hepatitis B (CHB) patients who discontinued antiviral therapy. We intended to analyze the long-term outcome of CHB patients who discontinued lamivudine therapy and to evaluate predictors for post-treatment outcome.

MATERIAL/METHODS

From 2007 to 2008, 138 lamivudine off-treated CHB patients with alanine aminotransferase normalization were consecutively enrolled. Post-treatment virologic relapse, biochemical breakthrough, hepatitis flare, and retreatment results were retrospectively analyzed.

RESULTS

Among 138 patients, 102 were initially HBeAg-positive at the start of lamivudine treatment. Virologic relapse, biochemical breakthrough, and hepatitis flare were observed in 45.2, 52.9, and 12.7% of HBeAg-positive and 29.4, 30.6, and 8.3% of HBeAg-negative patients during the median follow-up of 28 and 30 months, respectively. The cumulative virologic relapse and biochemical breakthrough rates were significantly lower in patients with HBV DNA <50 copies/mL than 50-104 copies/mL at lamivudine cessation. Hepatitis flare was observed in 4.8 and 11.8% of HBeAg-positive and HBeAg-negative patients with HBV DNA <50copies/mL, respectively. Thirty-eight among 138 patients received retreatment and most of them achieved biochemical (37/38) and virologic response (35/38) within 1 year of retreatment. Undetectable serum HBV DNA (<50 copies/mL) and young age at lamivudine cessation were inversely associated with virologic relapse. Undetectable HBV DNA at cessation, female, and initial HBeAg-negative were inversely associated with biochemical breakthrough.

CONCLUSIONS

Post-treatment virologic relapse and biochemical breakthrough incidence were low in patients who achieved undetectable viral titer at lamivudine cessation. Retreatment after biochemical breakthrough or virologic relapse was safe and effective. Intermittent antiviral therapy might be cautiously considered in appropriately selected CHB patients.

Analysis of interferon signaling by infectious hepatitis C virus clones with substitutions of core amino acids 70 and 91

Substitution of amino acids 70 and 91 in the hepatitis C virus (HCV) core region is a significant predictor of poor responses to peginterferon-plus-ribavirin therapy, while their molecular mechanisms remain unclear. Here we investigated these differences in the response to alpha interferon (IFN) by using HCV cell culture with R70Q, R70H, and L91M substitutions. IFN treatment of cells transfected or infected with the wild type or the mutant HCV clones showed that the R70Q, R70H, and L91M core mutants were significantly more resistant than the wild type. Among HCV-transfected cells, intracellular HCV RNA levels were significantly higher for the core mutants than for the wild type, while HCV RNA in culture supernatant was significantly lower for these mutants than for the wild type. IFN-induced phosphorylation of STAT1 and STAT2 and expression of the interferon-inducible genes were significantly lower for the core mutants than for the wild type, suggesting cellular unresponsiveness to IFN. The expression level of an interferon signal attenuator, SOCS3, was significantly higher for the R70Q, R70H, and L91M mutants than for the wild type. Interleukin 6 (IL-6), which upregulates SOCS3, was significantly higher for the R70Q, R70H, and L91M mutants than for the wild type, suggesting interferon resistance, possibly through IL-6-induced, SOCS3-mediated suppression of interferon signaling. Expression levels of endoplasmic reticulum (ER) stress proteins were significantly higher in cells transfected with a core mutant than in those transfected with the wild type. In conclusion, HCV R70 and L91 core mutants were resistant to interferon in vitro, and the resistance may be induced by IL-6-induced upregulation of SOCS3. Those mechanisms may explain clinical interferon resistance of HCV core mutants.

Clinical and virological effects of long-term (over 5 years) lamivudine therapy

Ideally, long-term lamivudine therapy should not induce tyrosine-methionine-aspartate-aspartate (YMDD) mutants (reverse transcription [rt]; rt M204I/V) in patients with chronic hepatitis B. There is little or no information on the clinical features of patients who do not develop such mutants. We analyzed 368 patients who received lamivudine therapy for more than 6 months between 1995 and 2003. Among them, 98 patients were negative for YMDD mutants during 5-year lamivudine therapy. Multivariate analysis identified hepatitis B e antigen (HBeAg) negativity, lack of cirrhosis, and high gamma glutamyltranspeptidase (GGTP) level as independent factors associated with lack of emergence of YMDD mutants during 5-year treatment. In these 98 patients, 21 patients developed YMDD mutants in the 5-year posttreatment follow-up. Old age was identified as the only factor associated with the emergence of YMDD mutants during that period. For all patients, 53 showed no elevation of alanine aminotransferase (ALT) or viral load after emergence of YMDD mutants during 5 years. Short latency to emergence of YMDD mutants, mixed (tyrosine-isoleucine-aspartate-aspartate (YIDD) [rtM204I] + tyrosine-valine-aspartate-aspartate (YVDD) [rtM204V]) type, and low ALT level were identified as independent factors associated with elevation ALT or viral load. HBeAg negativity, lack of cirrhosis, and high GGTP level were associated with lack of emergence of YMDD mutants during 5-year period. Young age protected against emergence of YMDD mutants over the 5-year period. Moreover, after the emergence of YMDD mutants, short latency to the emergence of YMDD mutant, mixed type mutants, and low baseline ALT level were associated with elevation of ALT or viral load.

Endpoints of therapy in chronic hepatitis B

Because clearance of hepatitis B virus (HBV) infection is rarely, if ever, achievable, the goals of therapy necessarily focus on prevention of bad clinical outcomes. Ideally, therapies would be shown to prevent tangible clinical endpoints like development of cirrhosis, end-stage liver disease and hepatocellular carcinoma. However, these endpoints typically take years or decades to occur and are therefore impractical targets for clinical trials which last only 1-2 years. As a result, surrogate biomarkers that are believed to correlate with long-term outcome are used to evaluate therapy. Of the clinical, biochemical, serological, virological, and histological endpoints that have been evaluated, none has been shown to be ideal on its own. Symptoms are uncommon and aminotransferase levels fluctuate spontaneously. Loss of hepatitis B e antigen (HBeAg) has been the traditional therapeutic endpoint; however, the indefinite durability off treatment and the emergence of HBeAg-negative disease have made it inadequate as the sole goal of therapy. Loss of hepatitis B surface antigen is associated with improved clinical outcomes, but it is rarely achieved with current therapies. Suppression of viral replication, as measured by serum HBV DNA levels, has become the major goal of therapy, particularly if maintained off therapy. Although useful, the significance of viral levels depends on the stage of disease, degree of liver damage, and the type of therapy. Finally, liver biopsy, often considered the gold standard, is invasive, prone to sampling error, and may take years to change significantly.At present, there is no ideal biomarker for evaluation of therapies for hepatitis B. Future research should be directed at development and validation of surrogate markers that accurately predict or reflect clinically relevant outcomes of chronic hepatitis B.

Lamivudine resistance and other mutations in the polymerase and surface antigen genes of hepatitis B virus associated with a fatal hepatic failure case

BACKGROUND AND AIM

Resistance to lamivudine therapy of chronic hepatitis B virus (HBV) infection occurs by mutation in the YMDD motif of the reverse transcriptase (rt) domain (rtM204V/I) of the virus polymerase, and is usually accompanied by rtL180M mutation. Here we investigated virological factors associated with hepatic failure in a 58-year-old male, chronically HBV-infected patient who died after 33 months of lamivudine therapy.

METHODS

Nucleotide sequencing was performed from one sample collected before and two samples collected during lamivudine therapy.

RESULTS

A peak of alanine aminotransferase and aspartate aminotransferase levels occurred after 19 months of lamivudine treatment, associated with the rtM204I mutation. After 32 months, the rtM204V mutation was predominant, accompanied by the lamivudine-resistant rtL180M mutation. Furthermore, two rare polymerase (rtS117Y and rtV142A) and three HBsAg (L109I, F134L, and I208T) substitutions were observed. At that time, the patient was hospitalized with hepatic decompensation, followed by hepatic failure, and died one month later. HBV-DNA was detected at moderate levels (8.3 x 10(4)-2.6 x 10(6) copies/mL) throughout.

CONCLUSION

The results suggest that substitutions in polymerase (rtS117Y, rtV142A) and surface antigens (L109I, F134L, and I208T), associated with lamivudine-resistant mutations at positions 180 and 204, were involved in this case of fatal hepatitis B.

Novel approaches towards conquering hepatitis B virus infection

Currently approved treatments for hepatitis B virus (HBV) infection include the immunomodulatory agent, IFN-α, and nucleos(t)ide analogues. Their efficacy is limited by their side effects, as well as the induction of viral mutations that render them less potent. It is thus necessary to develop drugs that target additional viral antigens. Chemicals and biomaterials by unique methods of preventing HBV replication are currently being developed, including novel nucleosides and newly synthesized compounds such as capsid assembling and mRNA transcription inhibitors. Molecular therapies that target different stages of the HBV life cycle will aid current methods to manage chronic hepatitis B (CHB) infection. The use of immunomodulators and gene therapy are also under consideration. This report summarizes the most recent treatment possibilities for CHB infection. Emerging therapies and their potential mechanisms, efficacy, and pitfalls are discussed.

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Novel approaches to new therapies for hepatitis B virus infection

Hepatitis B is one of the most prevalent viral diseases in the world. It leads to chronic liver disease in 10% of infected individuals, putting them at an increased risk for liver-related morbidity and mortality from complications of cirrhosis and hepatocellular carcinoma. Despite the success of universal hepatitis B vaccination in many countries, this disease remains a major public health problem, resulting in more than 500,000 deaths per year. Although the current therapy for chronic hepatitis B (CHB) is effective, it is not optimal; novel approaches to the management of CHB are needed. An improved understanding of virus-host interactions, advances in gene therapy, the development of molecular therapies targeted at different stages of the hepatitis B virus life cycle, and new insights into various approaches of immune modulation will lead to the development of better therapeutic agents for the management of CHB. These advances herald a new era of combination therapy. In this review, we will discuss emerging therapies and potential mechanisms, and highlight the promises and pitfalls of these new treatment strategies.