Viral hepatitis in a Canadian street-involved population

BACKGROUND

Data on the prevalence and compliance with management of viral hepatitis in the street-involved population are limited.

METHOD

Hepatitis A (HAV), B (HBV) and C (HCV) serology and compliance with HBV vaccination were documented in 533 street-involved individuals.

RESULTS

The mean age of the study population was 25.7 years (range: 11-65) and 53% were female. Serologic evidence of HAV infection was present in 53%; HBV, 12% (3% ongoing infection); and HCV, 17%. HAV infections were associated with Aboriginal/Metis ethnicity and age over 25 years; HBV with injection drug use (IDU); and HCV with IDU, sex trade work and age over 25 years. Compliance with three-step HBV vaccination was 98%, 77% and 63%.

CONCLUSIONS

HAV, HBV and HCV are common infections in urban street-involved persons. Successful HBV (and presumably HAV) vaccination can be achieved in the majority of this population, but concerns exist regarding compliance with more long-term, parenterally-based antiviral therapies.

Survival and prognostic indicators in patients with hepatitis B virus-related cirrhosis after onset of hepatic decompensation

GOALS

To determine the 2-year survival and prognostic indicators of hepatitis B virus-related cirrhosis after the onset of hepatic decompensation.

BACKGROUND

Chronic hepatitis B (CHB) patients with cirrhosis and resultant hepatic decompensation have reduced survival. However, the natural history of these patients has not been well characterized in previous studies. Better understanding of survival and prognostic indicators is essential in management of these patients, especially in determining who should be candidates for orthotopic liver transplantation.

STUDY

This is a retrospective longitudinal study of 96 patients with CHB-related cirrhosis after the onset of hepatic decompensation. The overall survival was ascertained, and clinical and laboratory variables were analyzed. Significant prognostic indicators for survival at 2 years were determined using univariate and multivariate analyses with Cox regression model.

RESULTS

The overall survival was 80% at 2 years after onset of decompensation. With univariate and multivariate analyses, hepatic encephalopathy and hypoalbuminemia less than 2.8 g/dL were significant prognostic indicators of poor survival probability. The hazard ratios were 5.22 (95% confidence interval, 1.67-16.3) and 8.57 (95% confidence interval, 1.94-37.8), respectively. Patients with hypoalbuminemia less than 2.8 g/dL had a 2-year survival of only 62%.

CONCLUSIONS

Our study showed that of CHB patients who developed the first episode of hepatic decompensation, those with hepatic encephalopathy or significant hypoalbuminemia or both have worse prognoses. They should be considered potential candidates for liver transplantation.

Effect of virological response on post-treatment durability of lamivudine-induced HBeAg seroconversion

Lamivudine-induced HBeAg seroconversion may not be durable in Korean patients with hepatitis B virus (HBV) infection. It is unknown whether virological response during lamivudine treatment affects the post-treatment outcome. We retrospectively analysed 124 consecutive HBeAg-positive chronic hepatitis B (CHB) patients treated with lamivudine. Lamivudine was given at a dose of 100 mg per day. HBV DNA levels in sera obtained before and during therapy were measured by the Digene Hybrid Capture II assay and Digene Ultrasensitive Hybrid Capture II assay, respectively. HBeAg seroconversion was achieved in 42 of the 124 patients (33.8%) treated with lamivudine. Mean duration of treatment in HBeAg seroconverters was 12.86 +/- 4.44 months. During the follow-up period, the cumulative relapse rates at 3 months and 6 months post-treatment in 42 patients with HBeAg seroconversion were 40.5% and 57.4%, respectively. Among 31 seroconverted patients whose sera were available at the second month of treatment, HBV DNA remained at > 4.7 x 103 genomes/mL in 15 patients and decreased to < 4.7 x 103 genomes/mL in the remaining 16 patients. HBV DNA levels at the second month of treatment was not related with relapse after discontinuation of treatment (66.7% vs. 43.8%, P= 0.2). At the time of HBeAg seroconversion, HBV DNA remained at > 4.7 x 103 genomes/mL in five patients and decreased to < 4.7 x 103 genomes/mL in the remaining 37 patients. Relapse rates were increased in patients who remained at > 4.7 x 103 genomes/mL compared with patients with HBV DNA levels < 4.7 x 103 genomes/mL (100% vs. 51.4%, P < 0.001). Thus, monitoring of serum HBV DNA at the time of HBeAg seroconversion may be helpful for predicting relapse in patients with lamivudine-induced HBeAg seroconversion.

Relationship of clinical and virological factors with hepatitis activity in hepatitis B e antigen-negative chronic hepatitis B virus-infected patients

To investigate the factors associated with active disease among hepatitis B surface antigen (HBsAg) positive/hepatitis B e antigen (HBeAg)-negative chronic hepatitis B virus (HBV) infection we studied chronic HBV infected patients who had undetectable HBeAg at the first visit. HBV DNA was determined by the cross-linking assay (NAXCOR) and polymerase chain reaction (PCR). Mutations in the core promoter and precore regions and viral genotypes were studied. Clinical outcome of these patients were followed and categorized as: (i) relapse (ALT > 200 IU/L or three times the previous levels); (ii) active hepatitis (elevated ALT < 200 IU/L with concomitant detectable HBV DNA); or (iii) remission. A total of eighty-five patients were followed up for 5.5 +/- 1.0 years. At first visit, 31 (36.5%) patients had elevated ALT levels, 12 (14.1%) had measurable HBV DNA by the cross-linking assay and 26 (30.6%) by PCR. Sixteen (18.8%) patients had hepatitis relapse, 13 (15.3%) had active hepatitis, and 56 (65.9%) remained in remission. Core promoter and precore stop codon mutants were found in 27 and 12 patients, respectively. Eleven and 20 had genotype B and C HBV, respectively. Initial elevated ALT and detectable HBV DNA were associated with active liver disease. Patient demographics, viral mutants or genotypes failed to predict disease activity. Hence, serum ALT and HBV DNA levels offer the best prediction of natural course of HBeAg-negative chronic HBV infection.

Interaction of alcohol and hepatitis viral proteins: implication in synergistic effect of alcohol drinking and viral hepatitis on liver injury

Alcohol drinking and viral hepatitis are both recognized as major causes of liver disease worldwide, and they frequently coexist and synergistically cause liver injury in patients with chronic liver disease. Several mechanisms have been implicated in exacerbation of liver injury in patients with alcohol drinking and viral hepatitis. These include impairment of host defense and liver regeneration by alcohol consumption. The findings obtained from my laboratory have demonstrated that alcohol potentiates cooperatively several signals activated by hepatitis B virus X protein (HBX) or hepatitis C virus core protein, and HBX sensitizes hepatocytes to tumor necrosis factor-alpha (TNF-alpha)- and ethanol-induced apoptosis by a caspase-3-dependent mechanism, which may also contribute to the synergistic effect of alcohol drinking and viral hepatitis on liver injury.

Hepatitis B associated fulminant polyarteritis nodosa: successful treatment with pulse cyclophosphamide, prednisolone and lamivudine following emergency surgery

For hepatitis B virus associated polyarteritis nodosa, alpha interferon and plasma exchanges have been proposed to be the first-line treatment. We report a case of hepatitis B surface antigen (HBsAg)-positive fulminant polyarteritis nodosa with predominant gastrointestinal involvement who showed good response to pulse cyclophosphamide, prednisolone, and lamivudine therapy. The patient, a 22-year-old man, presented with a short history of epigastric pain. Initial upper gastrointestinal endoscopy revealed gastritis and duodenal erosions. His pain did not respond to H2-receptor antagonists. He had slightly impaired liver function tests, and was HBsAg and hepatitis B e antigen (HBeAg) positive. Around 3 weeks after initial presentation, he developed massive gastrointestinal haemorrhage requiring resuscitation and emergency laparotomy. Microscopic examination of the resection specimens revealed necrotizing vasculitis of small and medium-sized arteries in the submucosa compatible with polyarteritis nodosa. The patient was treated with pulse cyclophosphamide and prednisolone, with lamivudine being added when he showed an acute rise in liver enzymes. He subsequently developed HBeAg seroconversion, and remained well 18 months after cessation of all immunosuppressives. We believe that the efficacy of pulse cyclophosphamide, prednisolone, and lamivudine in the treatment of hepatitis B virus associated polyarteritis nodosa, especially in comparison with interferon and plasma exchanges, deserves further evaluation.

Sequential analysis of hepatitis B virus core promoter and precore regions in cancer survivor patients with chronic hepatitis B before, during and after interferon treatment

We analysed the hepatitis B virus (HBV) core-promoter (CP) and precore (PC) regions before, during and after interferon treatment in young Caucasian cancer survivors who had acquired HBV infection during chemotherapy for malignancies. Fourteen patients with chronic hepatitis B [hepatitis B e antigen (HBeAg) /HBV-DNA positive] received alpha-2a interferon (IFN), 5 MU/m2 t.i.w. for 12 months. HBV CP and PC region sequences were analysed following polymerase chain reaction (PCR) amplification. Sera from responders were studied at: T(0) (before starting IFN), T(1) [at alanine aminotransferase (ALT) peak preceding HBeAg seroconversion], T(2) (at ALT normalization), T(3) (at end of IFN) and T(4) (at one year after IFN) and in nonresponders at time points T(0), T(3) and T(4). Amplified HBV-DNA was cloned and sequenced automatically. Six of 14 patients (43%) responded to IFN treatment. Five of the six (83%) responders displayed the double CP mutation A1762T/G1764A always in association with a T1753C change. None of the nonresponders showed these mutations at any time point. The G1896A change creating the PC stop codon mutation was never detected in any of the patients. In our cancer survivors, IFN-induced HBeAg/anti-HBe seroconversion appeared to correlate with CP mutations and was not influenced by previous chemotherapy. These mutations in addition to low HBV DNA levels and elevated ALT can be considered favourable factors of response to IFN-induced anti-HBe seroconversion.

Passive immunization of chronic hepatitis B patients on lamivudine therapy: a feasible issue?

In view of the limited efficacy of lamivudine monotherapy for chronic hepatitis B (HBV) infection, combination with other drugs seems logical. Intravenous neutralization of circulating HBsAg by specific hepatitis B immunoglobulin (HBIg) has been shown to protect hepatocytes against (re-)infection with HBV in the setting of liver transplantation and postexposure prophylaxis. Large controlled vaccination trials have revealed that HBV can be prevented by HBIg therapy in the majority of newborns after perinatal infection. A benefit of anti-HBs in HBV patients has so far only been investigated in three small studies. In this pilot study we investigated the effects of polyclonal i.v. HBIg (HepatectR, Biotest) administration in HBV-infected patients. Six liver biopsy-proven HBV-infected patients, all on lamivudine treatment and HBV DNA negative by PCR, were investigated. Pre-treatment HBsAg levels varied between 120 and 9760 ng/mL. On day 1, 10.000 IU HBIg was given, followed by 10.000 IU once, twice or three times on day 29. Long-term follow-up lasted at least 4 months. HBsAg and anti-HBs were measured quantitatively by standard MEIA and also by an experimental EIA. In vitro neutralization of HBsAg by Hepatect was mimicked in an 'inhibition in solution assay'. Complete neutralization of HBsAg by HBIg in vitro was possible, 50% inhibition concentrations varied between 100 and 250 IU/L HBIg with HBsAg levels of 68 and 120 ng/mL. No HBIg-related side-effects were observed. In two patients with low pretreatment HBsAg levels HBsAg reached levels below the detection limit of the assay, which persisted a maximum of 31 and 7.5 h, respectively. Peak anti-HBs concentrations were 5100 and 4648 IU/L. In the other four patients, with higher pretreatment HBsAg levels, HBsAg concentrations in serum hardly changed. For the whole population, the drop in HBsAg did not reach statistical significance. However, in four of the six patients a further decrease in HBsAg [18%-66%] was observed. In conclusion, HBIg was well tolerated; however, efficacy was limited due to high HBsAg levels in spite of maximum inhibition of virion production. 'Neutralization' was achieved only in two patients with low HBsAg levels. Passive immunization in HBV-DNA negative patients is not a feasible option. This strategy seems only feasible if agents inhibiting both the production of viral proteins and Dane particles more selectively, become available.

Successful long-term control with lamivudine against reactivated hepatitis B infection following intensive chemotherapy and autologous peripheral blood stem cell transplantation in non-Hodgkin's lymphoma: experience of 2 cases

It is well documented that cytotoxic treatment in patients carrying the hepatitis B virus (HBV) enhances the risk of severe hepatic damage. Recently lamivudine has been reported to be effective in suppressing the replication of HBV under such conditions. Here we report two cases with HBV carrier status and with non-Hodgkin's lymphoma who were successfully treated with high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation with the administration of lamivudine to prevent HBV flare-up. The antiviral effect of lamivudine was fair, and no objective side effect was experienced during the transplant procedure. Both patients were followed carefully for more than a year without the appearance of the resistant virus. The rebound phenomenon in which HBV proliferates abruptly has not been experienced after withdrawal of lamivudine. We suggest that lamivudine is indicated both in the treatment of HBV viremia and in the prevention of proliferation of HBV in patients with HBV carrier status undergoing high-dose myeloablative chemotherapy.

Effect of lamivudine treatment on survival of 309 North American patients awaiting liver transplantation for chronic hepatitis B

The primary aim of this study is to determine whether treatment with lamivudine improved pre-liver transplantation (pre-LT) and LT-free survival of patients awaiting LT for hepatitis B virus (HBV)-related cirrhosis. Data from 162 lamivudine-treated and 147 untreated transplant candidates managed at 20 North American transplant centers between 1996 and 1998 were collected and compared. Lamivudine-treated patients were more likely to be men, hepatitis B e antigen positive, HBV DNA positive, and have lower serum albumin levels at listing (P <.05). Actuarial pre-LT and LT-free survival were similar in lamivudine-treated and untreated patients. Using Cox regression analysis, the only significant predictor of pre-LT patient survival was the modified Child-Turcotte-Pugh (mCTP) score, whereas significant predictors of LT-free survival included ethnic background, lamivudine treatment, indication for LT, baseline serum alanine aminotransferase level, and baseline mCTP score. Lamivudine had no apparent effect on liver disease severity in patients undergoing LT, but appeared to improve disease severity in patients still awaiting LT. Breakthrough infection was noted in 11% of lamivudine-treated patients. We conclude that lamivudine therapy is not associated with improved pre-LT or LT-free survival in LT candidates with chronic hepatitis B. However, a subset of patients with less advanced liver failure may derive clinical benefit from lamivudine therapy, thus delaying the need for LT. In the absence of prospective, randomized, controlled trials of lamivudine in patients with decompensated cirrhosis, careful selection of patients and optimal timing of treatment are needed to balance the risk versus benefit of lamivudine therapy in LT candidates.

Hepatitis B virus resistance to lamivudine and its clinical implications

Lamivudine is the first orally available drug approved for treatment of chronic hepatitis B, but hepatitis B virus (HBV) resistance to lamivudine appears to be a sine qua non in the therapy of HBV. The mutations at the FLLA and YMDD motif in the domains B and C of HBV polymerase contribute to this resistance. These mutations are found at codon (or AA) rtL180M and rtM204V/I in the reverse transcriptase (RT) domain of the HBV polymerase for all genotypes according to a new standardized RT domain numbering system. The resistant HBV may be less replication-competent in vitro and in vivo, and it is rarely associated with markedly increased HBV replication or liver injury. Therefore, certain physicians favour continuing lamivudine therapy even after emergence of HBV resistance with the expectation of maintaining lower-than baseline HBV DNA, alanine amino-transferase, and histological improvement, and avoiding reversion to wild-type HBV until additional antiviral strategies are developed. Ultimately, once several antiviral agents are approved, combination strategy is likely to be incorporated in antiviral treatment for chronic HBV to suppress, prevent or minimize the emergence of resistant virus.

The nonstructural NS5A protein of hepatitis C virus: an expanding, multifunctional role in enhancing hepatitis C virus pathogenesis

The hepatitis C virus (HCV) NS5A gene product is a phosphorylated 56- to 58-kD nonstructural protein that displays a multitude of activities related to enhancement of viral pathogenesis. Although associated with other viral encoded proteins as part of the viral replicase complex positioned on the cytoplasmic side of the endoplasmic reticulum, a role for NS5A in viral replication has not been defined. Post-translational modifications of NS5A include phosphorylation and potential proteolytic processing to smaller molecular weight forms able to translocate to the nucleus. Both the identification of a putative interferon (IFN) sensitivity-determining region within NS5A, as well as the direct interaction with and inhibition of the IFN-induced double-stranded RNA-dependent protein kinase (PKR) by NS5A remain controversial. Truncated versions of NS5A can act as transcriptional activators, while other recently characterized interactions of NS5A with cellular proteins indicate its pleiotropic role in HCV-host interactions. NS5A itself has no direct effect on IFN-alpha signaling or activation, but other abundant interactions with members of the cellular signaling apparatus, transcription activation machinery and cell cycle-regulatory kinases have been described (e.g. growth factor receptor-bound protein 2, p53, p21/waf and cyclins). Many of these interactions block the apoptotic cellular response to persistent HCV infection. More recently, another altogether different mechanism attenuating the IFN-alpha response was reported based on induction of interleukin (IL)-8. IL-8, in model systems, potentiates viral replication and mutes the nonspecific intracellular IFN antiviral response. Evidence supporting a complex multimechanistic role of NS5A in promoting viral persistence, pathogenesis and, indirectly, viral-related hepatocarcinogenesis indicates its key role in HCV pathobiology.

[Study of hepatitis B virus replication and infection by other hepatitis viruses in patients with chronic hepatitis B virus infection]

AIM

To study hepatitis B virus (HBV) replication in a series of patients with HBV infection and to analyze the frequency of associated hepatitis C virus (HCV) and hepatitis D (HDV) infection.

PATIENTS AND METHOD

Serological markers of HBV, HCV and HDV, transaminase values and HBV DNA were studied in serum samples from 463 patients with chronic HBV infection.

RESULTS

Three hundred ninety-six (85.5%) were classified as hepatitis B, 33 (7.1%) as hepatitis B and C, 17 (3.6%) as hepatitis B and D and 17 (3.6%) as hepatitis B, C and D. Sixty-seven percent of patients with hepatitis B and 33% of those with chronic hepatitis B were asymptomatic HBsAg carriers. HVB DNA was identified in 27.7% of patients with hepatitis B, in 24% of those with hepatitis B and C, in 11.7% of those with hepatitis B and D and in 29.4% of those with hepatitis B, C and D. HBV DNA and elevated transaminase levels were found in 63% of HBeAg-positive patients and in only 16% of those who were anti-HBe-positive. These latter were considered candidates for antiviral treatment.

CONCLUSIONS

In our environment, most patients with HBV infection are asymptomatic HBsAg carriers. Viral replication and elevated alanine aminotransferase levels were found in 22% of the patients. Consequently, these patients are candidates for antiviral treatment. Between 3.6% and 7.1% of patients with hepatitis B presented coinfection with HCV or HDV, or both. No significant differences were found in HBV replication among the different groups.

Subtype-dependent response of hepatitis B virus during the early phase of lamivudine treatment

We conducted a 12-month longitudinal investigation of the subtype-dependent response of hepatitis B virus (HBV) to lamivudine treatment in 43 consecutive patients with chronic hepatitis B. HBV subtype ayw appears to respond better to lamivudine monotherapy than does HBV subtype adw (P=.005). This might be the reason for the lower incidence of lamivudine-resistant strains observed in persons infected with HBV subtype ayw during follow-up.

Molecular diagnosis of viral hepatitis

Molecular biology-based assays are invaluable tools for the management of chronic viral hepatitis. They can be used to test blood donations, diagnose active infection, help to establish the prognosis, guide treatment decisions, and assess the virological response to therapy. This article reviews current molecular biology-based techniques and assays, and their practical use in the management of hepatitis B and C virus infection.

Viral dynamics in chronic hepatitis B patients during lamivudine therapy

RATIONALE AND AIM

Recently, we described a first-order decay model for the description of a decrease in viral load during treatment with lamivudine for a chronic hepatitis B virus infection (HBV). However, more frequent sampling of viral load during the first month of treatment shows a bi-phasic viral decline. We therefore compared several mathematical models which are currently in use to describe the dynamics of various viruses and treatments.

METHODS

HBV DNA positive chronic hepatitis B patients were treated with lamivudine 150-600 mg daily for four weeks. During the first two days, blood samples were drawn every 6 h, then daily during the first week and weekly during the following three weeks. HBV DNA was measured with the Digene Hybrid Capture II HBV DNA test and the sensitive Roche PCR assay, both calibrated on the Eurohep standard.

RESULTS

Our HBV DNA data are most accurately described if we use the bi-phasic model previously described by Neumann et al. while introducing all consecutive data of all patients simultaneously (mixed effects model). This results in an effectiveness of blocking of viral replication of 93%, a half-life of free virus of 17 h and a half-life of infected hepatocytes of 7 day in patients treated with 150 mg of lamivudine.

CONCLUSION

HBV dynamics during treatment with lamivudine can be explained by blocking of virion production with or without blocking of de novo infection. The bi-phasic model as described by Neumann et al. in combination with frequent blood sampling provides the most accurate fit and can be used to compare new nucleoside analogue profiles to lamivudine therapy.

Genotypes and clinical phenotypes of hepatitis B virus in patients with chronic hepatitis B virus infection

Genotype C of hepatitis B virus (HBV) has been shown to be associated with a poor clinical outcome, compared to genotype B. To explore the clinical phenotypes, with special reference to the seroconversion of hepatitis B e antigen (HBeAg) and frequency of acute exacerbation between patients infected with HBV genotypes B and C, a cohort of 272 Taiwanese patients with chronic HBV infection was analyzed. According to the status of HBeAg at enrollment and frequency of acute exacerbation during the follow-up period, five groups of patients with distinct clinical phenotypes were categorized. Of the 272 HBV carriers, 185 (68%) were infected with HBV genotype B and the remaining 87 (32%) were infected with genotype C. Among them, 150 (55%) were positive for HBeAg and patients with genotype C infection tended to have a higher positive rate of HBeAg than those with genotype B infection (63 versus 51%). Genotype B was more prevalent than genotype C in different groups of HBV carriers. However, the prevalence of genotype C in patients with multiple episodes of acute exacerbation who failed to have HBeAg seroconversion was significantly higher than in all 272 patients (50 versus 32%, P = 0.025), in those with HBeAg seroconversion after only one episode of acute exacerbation (50 versus 12%, P = 0.01), or in those negative for HBeAg at enrollment and without acute exacerbations (50 versus 23%, P = 0.002). In conclusion, patients with genotype C infection have a more aggressive clinical phenotype than do those with genotype B infection, which contributes to the former group's progressive liver disease and poor clinical outcomes.

Management of patients with chronic hepatitis B

Better understanding of hepatitis B virus (HBV) replication and the natural history and immunopathogenesis of chronic hepatitis B, together with the introduction of effective agents with different mechanisms of action, is the basis for better therapeutic strategies against chronic hepatitis B. Substantial experience has now been accumulated in the use of some of these drugs, and an Asia-Pacific Consensus has been reached on indications for their use. The goals of therapy and aspects of general management will be reviewed here. Among currently available drugs, alpha-interferon therapy gives a response rate (hepatitis B e antigen (HBeAg) seroconversion) of 30-40% compared with 10-20% in matched controls, but patients with lower alanine aminotransferase (ALT), higher HBV-DNA, and immunosuppressed patients have a poorer response, and alpha-interferon can be dangerous in cirrhosis. Meta-analysis of four controlled trials also suggests that thymosin-alpha1 is effective, but more studies are needed. Lamivudine has been most extensively studied. It is effective in terms of HBV-DNA loss, ALT normalization, HBeAg seroconversion, and improvement in histology, as well as being well tolerated. After 1 year of treatment, HBeAg seroconversion rate increased with higher pretherapy ALT levels, suggesting that patients with stronger endogenous antiviral defenses to kill hepatocytes harboring covalently closed circular DNA have a better response to direct antiviral effects. Lamivudine is also beneficial in HBeAg negative chronic hepatitis B, and patients with decompensated cirrhosis and HBV replication. However, genotypic-resistant tyrosine-methionine-aspartate-aspartate (YMDD) mutations start to emerge after 9-10 months of lamivudine therapy, and their incidence increases more quickly than the HBeAg seroconversion rate durating prolonged therapy. Thus the benefits of long-term lamivudine must be balanced against concern about YMDD mutations, and the durability of treatment response. There are encouraging preliminary results for adefovir dipivoxil, entecavir, emtricitabine, clevudine and other nucleoside/nucleotide analogs in the early stages of appraisal; entecavir and adefovir dipivoxil appear effective in patients with YMDD mutants. Further development of new drugs and new strategies, such as combination or sequential therapy, may help to better achieve the goals of treatment for chronic hepatitis B in the new century.

The cutaneous manifestations of viral hepatitis

Viral hepatitis is a common disease with significant morbidity and mortality that is found throughout the world. It is a known cause of acute and chronic liver disease. Because the disease can be asymptomatic in its acute stages, the diagnosis is often missed. This article reviews the extrahepatic manifestations of the disease, in particular the visible cutaneous lesions, which offer clues to the diagnosis of viral hepatitis. Familiarity with the most common skin lesions associated with each type of hepatitis virus will be useful in identifying previously undiagnosed individuals. This article serves as a review of the most widely published associations between skin diseases and specific subtypes of viral hepatitis.

Clinical and immunological efficacy of intradermal vaccine plus lamivudine with or without interleukin-2 in patients with chronic hepatitis B

To evaluate therapeutic immunostimulation nine chronic hepatitis B patients received six monthly intradermal vaccinations with HBsAg in combination with daily lamivudine. Another five patients received six doses of the vaccine and daily lamivudine together with daily Interleukin-2 (IL-2) s.c. within 3 months in an open-labeled trial. Clinical efficacy was assessed by alanine transaminase levels and HBV serology. The induction of specific T and B cell responses was analyzed serially by 3H-thymidine uptake, ELISA and ELISPOT assays. After the therapy was stopped, seven of nine vaccine/lamivudine and two of five vaccine/lamivudine/IL-2 recipients did not have detectable HBV DNA. Four complete responders cleared the virus and had normalized ALT levels, however, one of these patients showed transient disease reactivation followed by spontaneous viral clearance and normal ALT five months later. Low frequencies of anti-HBs producing B cells and HBV specific T helper cells secreting predominantly interferon-gamma were induced by i.d. vaccine therapy. The ELISPOT technique demonstrated transient induction of HBV peptide specific cytotoxic T cells in seven HLA-A2 positive chronic HBV carriers. The preliminary data from this study demonstrate that the HBV surface antigen vaccine in combination with antiviral or immunomodulating drugs induced antiviral immune responses and consequently viral elimination may be achieved in patients with unfavorable prognosis.

Development of hepatitis B virus resistance for lamivudine in chronic hepatitis B patients co-infected with the human immunodeficiency virus in a Dutch cohort

INTRODUCTION

With the introduction of HAART, the HIV-1 has turned from a lethal into a chronic infection in the majority of patients. In homosexual populations, 20% of HIV-1 infected patients suffer from a chronic HBV infection, which may eventually lead to complications of the liver disease because of prolonged survival. Lamivudine is effective in reducing both HIV-1 and HBV viral replication. However, resistance for lamivudine may complicate the course of the HBV disease in HIV-1-infected patients. We, therefore, conducted a retrospective study in HIV-1-HBV co-infected patients on lamivudine therapy.

PATIENTS AND METHODS

All HIV-1-HBV co-infected patients who were treated with lamivudine for over 6 months in five major referral clinics in The Netherlands with HBV DNA above 2.0 x 10(5) geq ml(-1) at baseline, were evaluated. Retrospectively, the course of HBV DNA in available serum samples was established. If HBV DNA was detectable with the sensitive PCR-assay, YMDD-analyses of the polymerase gene of the hepatitis B virus was executed with the INNO-LiPA-DR-strip.

RESULTS

Forty-six patients were evaluated. The median level of HBV DNA at start of lamivudine therapy was 1.31 x 10(9) geq ml(-1) (range 3.5 x 10(5) - 2.0 x 10(10), n=43). Of three patients no baseline sample was available, but since HBV DNA was still above 2.0 x 10(5) geq ml(-1) at week 3, 7 and 11, these patients were included. Median duration of lamivudine therapy was 97 weeks (range 27-263). The percentage of detected mutations was 25 and 52% at 1 and 2 years, respectively. Twenty-two patients ultimately developed a mutation. Both baseline Body Mass Index (BMI) and the decrease in CD4 cell count as a time dependent factor were significantly related to the emergence of mutations. In 10 out of 12 evaluated patients, HBV DNA levels returned to baseline level or even above baseline level after the development of mutant virus. One patient (5%) developed a flare of serum transaminases (ALT>10 x ULN) 24 weeks after first detection of variant virus.

CONCLUSION

There is a linear time-dependent appearance of HBV mutations for lamivudine in our population. In a minority of patients (5%), development of a mutation was followed by a significant elevation of serum transaminases. A decline in CD4 cell count, which may indicate less response to HAART, induces a faster emergence of mutations and close surveillance of HBV co-infected patients on therapy may be indicated due to the prolonged survival of HIV-1 patients.

Retrospective study on the impact of hepatitis B and hepatitis C virus infection on hematopoietic stem cell transplantation in Japan

We performed a retrospective survey in 62 hematopoietic cell transplantation (HCT) centers in Japan in which all HCTs performed between 1986 and 1998 were reviewed, and those involving hepatitis B virus surface antigen (HBsAg)-positive donors were identified. One hundred and thirty-five patients who underwent allogeneic HCT (alloHCT) were studied for complications related to hepatitis B virus (HBV) or hepatitis C virus (HCV). The median follow-up period was 24 months. Positivity for HBsAg was observed in 32 patients (24%) throughout the study. Twenty-six of the 32 patients were HBsAg carriers before alloHCT, whereas the remaining 6 became HBsAg(+) after alloHCT. Forty-two recipients were anti-HBs antibody (HBsAb)-positive, and 58 recipients (43%) were HCV Ab(+). Eleven of 26 (42%) HBsAg(+) recipients survived between >4 and >119 months. Six of 26 cases received transplants from HBsAg(+) donors, and, although they had not developed acute graft-versus-host disease, 4 of 6 died of hepatic and renal failure within 10 months after HCT. After transplantation, 5 patients showed serologic evidence of HBV reactivation, whereas 4 patients showed evidence of an immune response to HBV. Viral reactivation occurred during the tapering of the immunosuppressive agent. However, 3 of 5 were alive at the time of this report, suggesting that reactivation is not directly correlated with severe liver dysfunction. Seventeen patients (13%) of 135 recipients developed hepatic failure. Eight (47%) of 17 were diagnosed with fulminant hepatitis and 5 (29%) with veno-occlusive disease (VOD). VOD was observed in 12% of both HBsAg(+) and HCVAb(+) patients. In this study, the relatively high incidence of HBV events occurred after alloHCT, and, therefore, we should consider a protocol for active immunization of donors and recipients against HBV. Moreover, although the presence of HBV or HCV is not a contraindication for alloHCT, we recommend a careful follow-up of recipients after transplantation, especially during immunosuppression tapering.

High hepatitis B virus (HBV) DNA viral load as the most important risk factor for HBV reactivation in patients positive for HBV surface antigen undergoing autologous hematopoietic cell transplantation

The risk factors for hepatitis due to hepatitis B virus (HBV) reactivation in patients positive for hepatitis B surface antigen (HBsAg) treated with autologous hematopoietic cell transplantation (HCT) are unknown. We evaluated 137 consecutive patients (23 positive for HBsAg, 37 positive for hepatitis B surface antibody, and 77 negative for HBV) who underwent HCT. Serial serum ALT were measured before transplant and after transplant at 1 to 4 weekly intervals for the first year and then at 2 to 12 weekly intervals thereafter. Before HCT, basic core promoter (T(1762)/A(1764)) and precore (A(1896)) HBV variants were determined in HBsAg-positive and HBV DNA-positive (by polymerase chain reaction assay) patients by direct sequencing and serum HBV DNA quantitation using the Digene Hybrid Capture II assay. Cox proportional hazards analysis was used to assess the association between pretransplantation HBV virologic and host factors and occurrence of hepatitis due to HBV reactivation. After HCT, hepatitis due to HBV reactivation was more common in HBsAg-positive patients than in HBsAg-negative patients (hazard ratio, 33.3; 95% confidence interval [CI], 7.35-142.86; P <.0001). HBsAg-positive patients with detectable serum HBV DNA before HCT (on Digene assay) had a significantly higher risk of hepatitis due to HBV reactivation than HBsAg-positive patients with no detectable serum HBV DNA (adjusted hazard ratio, 9.35; 95% CI, 1.65-52.6; P =.012). Thus, we found that hepatitis due to HBV reactivation is common in HBsAg-positive patients undergoing autologous HCT. A high HBV DNA level (>10(5) copies/mL) was the most important risk factor for HBV reactivation, and its lowering by administration of nucleoside analogues before transplantation should be considered.

Changes in serum albumin during treatment of chronic hepatitis B with lamivudine: effects of response and emergence of drug resistance

OBJECTIVES

In chronic hepatitis B patients treated with lamivudine, the incidence of drug resistance increases with the duration of therapy. The effect of drug resistance on hepatic synthetic function is not well defined. The aim of the present study was to assess the effect of lamivudine therapy on hepatic synthetic function in patients with moderately severe chronic hepatitis B and, particularly, to determine the effect of drug resistance.

METHODS

Hepatic synthetic function was assessed using serial measurements of serum albumin in 38 patients (26 with cirrhosis) in an open-label treatment program.

RESULTS

An initial antiviral response (hepatitis B virus [HBV] DNA undetectable by hybridization assay) occurred in all patients, and nine of 22 (41%) hepatitis B e antigen-positive cases underwent hepatitis B e antigen seroconversion. Among 29 patients with undetectable serum HBV DNA at the end of observation, the mean serum albumin concentration rose from 39.9 +/- 0.7 to 43.2 +/- 0.6 g/L, corresponding to a yearly increase of 1.85 g/L (p < 0.001). This was largely attributable to an increase among cirrhotic patients. Nine patients (24%) developed resistance to lamivudine, all after 12 months of treatment. Among them, the mean serum albumin concentration had increased from 39.6 +/- 1.2 to 42.9 +/- 0.8 g/L before resistance emerged, but then decreased to 39.3 +/- 1.7 g/L (p = 0.01) at the time of reappearance of HBV DNA.

CONCLUSION

Suppression of viral replication by lamivudine improves hepatic synthetic function in chronic hepatitis B patients, but emergence of drug resistance is associated with a rapid decline in serum albumin, at least to pretreatment levels.

Treatment of chronic hepatitis B: case selection and duration of therapy

Hepatitis B viral (HBV) infection is a major health burden in the Asia-Pacific region. The seriousness of chronic hepatitis B (CHB) is often realized at a late stage. The resultant morbidity and mortality from cirrhosis complications is considerable, with a high human cost. The most affected patients are men aged 40 years or older. Two decades ago, the prognosis for the 300 million "Australia antigen"-positive people (people with chronic HBV infection) was gloomy, with no effective intervention. Twenty years on, research and development have changed their outlook. Chronic hepatitis should now be diagnosed early, at the asymptomatic stage. Proper assessment and judicial introduction of therapy can suppress replication of HBV and resolve liver inflammation, thereby preventing the silent progression of chronic liver disease to end-stage cirrhosis. Interferon (IFN) monotherapy has been available for nearly 20 years, but various limitations restrict its general application. Injection-based therapies are inconvenient, the response rate is low (33% hepatitis B e antigen (HBeAg) seroconversion rate among optimal cases), side-effects are many, and some serious, and the cost is unaffordable for most people. However, in non-cirrhotic patients with mild to moderate disease activity, IFN is still a worthwhile option because the treatment course is shorter, mutation seems less of a problem and most responses are permanent and reduce or abolish late complications. Lamivudine, an oral nucleoside analog with potent antiviral effects, has been approved in many countries. Daily dosing of 100 mg reduces serum HBV-DNA to below detectable levels within 6 weeks. In HBeAg-positive patients, approximately 16% of treated patients seroconverted with the first year. This was associated with significant improvement in liver histology. Long-term treatment induces further HBeAg seroconversion, but overall clinical benefit is undermined by continuous emergence of drug-resistant YMDD mutants. In an Asian multicentre study, 58 patients on 5 years lamivudine therapy showed annual cumulative HBeAg seroconversion rates at 1, 2, 3, 4 and 5 years of 22, 29, 40, 47 and 50%, respectively. The best predictor of response is pretreatment alanine aminotransferase (ALT). Among patients with ALT > 2x the upper limit of normal (ULN), annual HBeAg seroconversion is increased to 38, 42, 65, 73 and 77%, respectively. However, emergence of YMDD mutants occurred at a cumulative rate of 15, 38, 55, 67 and 69%, respectively. The impact of this emergence on disease activity is unpredictable. Thus, while continued disease suppression, or even HBeAg seroconversion, still occurred in some patients, in others hepatitis may relapse and liver failure has been reported despite continuation of lamivudine. While the duration of lamivudine therapy is difficult to define, the best strategy may be to define only active CHB with major ALT elevation (par-ticularly ALT > 5x ULN) for a duration of 1 year or less. Lamivudine can be stopped in responders. The response is durable in approximately 80% of responders. Non-responders should be monitored closely for rebound off treatment. Therapy can be re-instituted if ALT is over 5x ULN. Management of patients with YMDD mutants can be challenging, but there is no clear evidence to recommend stopping or continuing lamivudine, or to add other possible effective agents, such as adefovir dipivoxil. More data are required to help draw up guidelines. Hepatitis B e antigen-negative CHB has been less well studied. Both IFN and lamivudine can suppress disease activity, but permanent responses are few. Without a distinct marker as an end-point for response, the duration of treatment is even more difficult to define. Quantitative polymerase chain reaction for low viral levels may give a clue, but definitive studies are required. Monotherapy is clearly not the answer for the majority of CHB patients with active disease. Combination therapy has the theoretical advantage of additional or synergistic efficacy. Preliminary results on IFN and lamivudine are promising and further clinical trials are ongoing. Emtricitabine (FTC), adefovir dipivoxil, entecavir, BL-thymidine (L-dT), DAPD, clevudine (l-FMAU), thymosin, therapeutic vaccines and various herbal medicines are potential candidates. Antiviral action in conjunction with immune modulation may have a better chance of eradicating HBV and its cccDNA in the hepatocytes as the basis for an eventual successful outcome. The key points are: (i) approved therapeutic agents for chronic hepatitis B (CHB) are IFN, lamivudine and thymosin (in a few countries only); (ii) indications for IFN therapy are viremia in compensated CHB patients with moderately raised ALT; (iii) lamivudine has broader therapeutic indications: it is effective in subgroups of CHB patients with compensated or decompensated liver diseases, but generally works better if patients have raised ALT; (iv) lamivudine has a potent suppressive action on HBV replication, including HBeAg-negative variants, but cannot eliminate cccDNA; this is the reason for the relapse of disease after discontinuing treatment, unless HBeAg seroconversion is obtained; (v) successful use of lamivudine aims at HBeAg seroconversion or profound suppression of HBV-DNA to serum levels of less than 100 000 viral copies/mL, in order to prevent emergence of drug-resistant YMDD mutants (which commences from 6 months onward); (vi) YMDD mutants may cause a flare of hepatitis, resulting in deterioration of liver histology and, occasionally, liver failure; (vii) combination therapy of lamivudine with IFN (standard or pegylated) or other nucleoside analogs should be the next advance. Preliminary data from IFN and lamivudine combination therapy show some promise, but there are conflicting results.

Transcriptional activation of the promoter of human cytomegalovirus immediate early gene (CMV-IE) by the hepatitis B viral X protein (HBx) through the NF-kappaB site

The reactivation of latent cytomegalovirus (CMV) in a human by another viral infection may induce virus-related symptoms. Based on this presumption, we investigated the effect of HBx on the activation of the CMV-IE, which is also known as a transactivator and potential oncogene. The HBx transactivated the CMV-IE promoter by up to 4- and 18-fold factors in human liver HepG2 and lung fibroblast MRC-5 cells, respectively. Cotransfection of HBx with each transcription factor presented in the CMV-IE promoter showed that only NF-kappaB synergistically activated the promoter by up to a 14-fold factor. Serial deletion assays and point mutation analysis showed that the third NF-kappaB site (nt -267 to -258) and the second one (nt -162 to -153) appeared as the major responsible site and minor one, respectively, for the transactivation. These results suggest the possibility that the HBV infection of a cell previously infected by CMV would exert influence on the reactivation of the latent cytomegalovirus in a human to induce virus-related symptoms.

Ultrasound screening and risk factors for death from hepatocellular carcinoma in a high risk group in Taiwan

Although previous studies have demonstrated the ability of ultrasonography (US) screening to detect small asymptomatic hepatocellular carcinoma (HCC), the efficacy of US screening in reducing deaths from HCC still remained unresolved. A 2-stage screening program was designed to identify a high risk group in 7 townships in Taiwan by 6 markers (of risk for HCC) and repeated US screening was further applied to those with at least 1 positive result for the 6 markers, with a range of 3- to 6-month inter-screening intervals to those with liver cirrhosis or other chronic liver diseases and an annual screening regime for the remaining subjects with normal findings according to US. The 4,843 subjects in this cohort were followed up for an average of 7 years. We compared 4,385 attenders with 458 non-attenders, in conjunction with baseline assessment for self-selection bias. In addition, we assessed baseline variables with respect to their effects on risk of incidence of and mortality from HCC and on risk of incidence of liver cirrhosis. The difference in mortality between attenders and non-attenders was then re-estimated adjusting for significant predictors of cirrhosis, HCC incidence and HCC death as a further guard against baseline differences between attenders and non-attenders in risk profiles. Results of US screening for this high risk group found the mortality was lower by 24% (95% CI: -52 to 62%) in the attenders compared to the non-attenders. After adjustment for sensitivity, the mean sojourn time (MST) were 1.57 (95% CI: 0.94-4.68) for subjects with liver cirrhosis and 2.66 (95% CI: 1.68-6.37) years for non-cirrhotic patient. Significant increases in risk of HCC incidence were associated with increasing age, male gender, hepatitis B surface antigen positive (HbsAg), hepatitis C antibody positive (Anti-HCV), high levels of alanine transaminase (ALT) and alpha-fetoprotein (AFP) and a family history of HCC. Significantly increased risks of liver cirrhosis were associated with predictors of cirrhosis were increasing age, HbsAg, high levels of ALT and of AFP. Significant or borderline significant increases in risk of HCC death were associated with increasing age, male gender, HbsAg, high levels of AST and AFP. Adjusted for the significant variables, the mortality was lower by 41% (95% CI: -20 to 71%, p = 0.1446) in the attenders compared to the non-attenders. The present study provides suggestive evidence on the efficacy of US screening in a selective high risk group in an endemic area of hepatitis B. A randomized controlled trial would yield definitive evidence. Within the protocol of such a trial, a shorter interscreening interval for patients with liver cirrhosis is suggested.

Four cases of hepatitis B virus-related fibrosing cholestatic hepatitis treated with lamivudine

Fibrosing cholestatic hepatitis (FCH) is a rare and extremely severe form of hepatitis B virus (HBV) infection. This condition was originally described in HBV-infected recipients after a liver transplantation. Recently, FCH has been reported not only in liver transplant recipients, but also in other immunosuppressed patients. It is characterized clinically by cholestatic hepatic dysfunction, and pathologically by severe periportal fibrosis, cholestasis, widespread balloon degeneration of hepatocytes, and only a mild infiltration of inflammatory cells. Without treatment, FCH is universally fatal within a few months of diagnosis. There have been only two isolated case reports of FCH with long-term patient survival, and one case report with treatment failure after lamivudine therapy. Because of the rarity of this clinical entity, the therapeutic efficacy of lamivudine in patients with FCH cannot be evaluated systematically. Here, we present four patients with HBV-related FCH treated with lamivudine. One received antineoplastic therapy for acute lymphoblastic leukemia, and the other three were renal graft recipients. Two patients who developed FCH after a renal transplantation survived with an improvement in liver function and were followed up for 20 and 30 months, respectively, and were found to be in good health. However, the other two patients died of sepsis, possibly as a consequence of the immunosuppression with hepatic failure despite lamivudine treatment. Our experience suggests that lamivudine can alter the grave natural history of FCH.

Clinical evaluation (phase I) of a combination of two human monoclonal antibodies to HBV: safety and antiviral properties

Treatment of chronic hepatitis B virus (HBV) infection with interferon alfa and lamivudine is characterized by lack of viral clearance, loss of response, or emergence of drug-resistant mutants. Thus, new and multiple drug approaches are needed. We have developed two fully human monoclonal antibodies, directed against different epitopes of hepatitis B surface antigen (HBsAg) that bind to all major HBV subtypes. A phase I clinical study was conducted to evaluate the safety, tolerability, and efficacy of a mixture of these two monoclonal antibodies, HBV-AB(XTL). A total of 27 chronic HBV patients were enrolled. In part A of the study 15 patients in 5 cohorts received a single intravenous infusion of antibodies with doses ranging from 0.26 mg (260 IU) to 40 mg (40,000 IU). All patients completed 16 weeks of follow-up. In the second part of the study (part B), 12 patients in 4 cohorts received 4 weekly infusions of 10, 20, 40, or 80 mg each of HBV-AB(XTL) and were followed for 4 additional weeks. Administration of antibodies was well tolerated. Patients administered doses at an Ab:Ag molar ratio of 1:2 to 1:20 showed a rapid and significant decrease in HBsAg to undetectable levels, with a corresponding reduction of HBV-DNA levels. In part B, HBV-AB(XTL) induced a significant reduction in both HBsAg and HBV-DNA levels repeatedly after administration. In conclusion, these data suggest that HBV-AB(XTL) binds HBV particles and reduces serum viral titers and HBsAg levels. HBV-AB(XTL) could be combined with other monotherapies that are currently used to treat HBV carriers.

Management of chronic viral hepatitis in HIV-infected patients: Spanish Consensus Conference. October 2000

Co-infection by human immunodeficiency virus and hepatitis B and C viruses is quite common because they share similar routes of transmission. The introduction of highly active antiretroviral therapy has significantly improved the life expectancy of HIV-infected patients in the last few years. However, chronic viral hepatitis represents an emerging cause of morbidity and mortality in this population, either as a result of end-stage liver disease or as a consequence of hepatotoxicity induced by antiretroviral drugs. The main goal of the Consensus Conference was to establish specific recommendations for the management of chronic viral hepatitis B and C in HIV-infected patients. The role of orthotopic liver transplantation for co-infected individuals with end-stage liver disease was also assessed.

A 1-year trial of lamivudine for chronic hepatitis B in children

We carried out a 1-year trial to evaluate the efficacy and tolerability of lamivudine, an oral nucleoside analogue, in a small group of children with vertically acquired chronic hepatitis B. Patients were assessed for serum alanine aminotransferase (ALT) and serum hepatitis B virus (HBV) DNA at baseline and every 4 weeks thereafter, and for hepatitis B s antigen, hepatitis B e antigen and their antibodies every 12 weeks. Analysis of HBV mutation was undertaken at entry and on the occasion of the last positive control of HBV DNA. Lamivudine suppressed serum HBV DNA to undetectable levels in all treated patients within 24 weeks. Serum ALT levels returned to normal values within 36 weeks. Therapy was well tolerated, and although nausea and vomiting were reported in one child, it was not necessary to stop treatment. A new observation was that, contrary to previous data, seroconversion appeared to occur earlier in children with lower ALT levels at baseline.

Construction of HCV-core gene vector and its expression in cholangiocarcinoma

AIM: To establish an experimental model for exploring the role of hepatitis C virus (HCV) in the development of cholangiocarcinoma.

METHODS: Recombinant plasmid of HCV-core gene was constructed with molecular cloning technique and transfected into QBC939 cells with lipofection. After it was selected with G418, resistant colonies were obtained. The colonies were analysed by immunocytochemistry and Western blotting.The morphology was observed under transmission electron microscope(TEM) and microscope.

RESULTS: The recombinant plasmid was proved to carry the target gene by PCR and restriction enzymed mapping. Moreover, it could express HCV-C protein efficiently in QBC939 cells. The HCV-like particles were found in the cytoplasm by electron microscope, which were spherical with a diameter of 50 nm-80 nm possessing outer membrane.The transfected cells had lower differentiation and higher malignant degree under microscope.

CONCLUSION: Because HCV-core gene could express steadily in cholangiocarcinoma cells,the transfected tumor cells(QBC939-HCVC) could be used to study the effect of HCV in the development of cholangiocarcinoma.

Management of chronic hepatitis B and C virus infections

Hepatitis B and C virus (HBV and HCV) infections present an important health problem causing significant morbidity and mortality on a worldwide scale. The younger the subjects infected, the higher the risk predisposing to progression towards chronic infection. Treatment of chronic HBV and HCV infections is aimed at reducing hepatic inflammation and thus improving the symptoms, decreasing the likelihood of long-term sequelae such as hepatocellular carcinoma, and increasing the survival rate. Interferon accelerates the spontaneous course of chronic HBV infection in children with greater disease activity and lower levels of replication. There is limited information on the use of lamivudine and its long-term benefit in children with chronic HBV infection. The response of combination therapy with IFN and ribavirin in children with chronic HCV infection is still under investigation. The long-term clinical and virological effects of various drugs used in chronic HBV and HCV infections on children remain to be evaluated.

Management of viral hepatitis B

Hepatitis B virus (HBV) infection is a major global health concern and is the most common cause of chronic liver disease worldwide. The natural history and clinical outcomes of chronic HBV infection are determined by the viral replication cycle and the host immune responses. Treatment of chronic hepatitis B is directed at interrupting the natural history by suppressing HBV replication before development of any significant irreversible liver cell damage. Effective antiviral therapies should be followed by sustained suppression of HBV-DNA, normalization of transaminases levels and a stable stage of HBeAg seroconversion with persistence of circulating anti-HBeAg antibodies. Two major classes of antiviral therapeutic agents that have been approved for treatment of chronic hepatitis B are immunomodulating agents (i.e. interferon) and the nucleoside analogs (i.e. lamivudine). A 4-6 month course of interferon-alpha has resulted in improvement of survival in 20%-30% of patients with chronic hepatitis B who had elevated serum ALT levels without hepatic decompensation. Interferon-alpha therapy is associated with HBeAg seroconversion; normalization of ALT levels, reduced hepatic inflammation, and possibly reduced disease progression to cirrhosis and hepatocellular carcinoma. Interferon can also be used with caution in patients with early compensated cirrhosis. A 12-month course of lamivudine has been shown to be well tolerated and effective. Lamivudine can be used in decompensated cirrhosis and immunosuppressed patients and for prevention of recurrent HBV infection after liver transplantation. The response rates after 3 years of lamivudine therapy account for 40-65%. A major problem of antiviral treatment is the emergence of drug resistance conferred by mutations in the YMDD motif of HBV reverse transcriptase. The prevalence of YMDD mutations increases with longer durations of antiviral therapies and this has been detected in 20% of immunocompetent patients receiving lamivudine per year. Contentious issues remain when to stop the treatment if HBeAg seroconversion does not occur. Many new immunomodulatory therapies and antiviral agents are in various stages of clinical development and have shown some promise. Among newer HBV antivirals, adefovir dipivoxil, entecavir, emtricitabine, DAPD and clevudine appear to be at least as potent as lamivudine in suppressing HBV replication. In vitro studies have shown that YMDD mutations confer cross-resistance between lamivudine and emtricitabine. However, adefovir, dipivoxil, lobucavir, DAPD and possibly clevudine suppress replications of both YMDD mutants and wild types of HBV. Immunomodulatory approaches for treatment of chronic hepatitis B are conceptually attractive, but newer agents used to date (thymosin-alpha, interleukin-12, therapeutic vaccines) have not demonstrated sufficient efficacy for widespread use. Combinations of an immunomodulatory agent and nucleoside analog may improve the therapeutic efficacy and reduce the emergence of drug resistance. Nevertheless, combinations of interferon and lamivudine therapies do not confer such additional benefits. The next challenge for HBV treatment is to use antivirals in combination and/or in cyclical therapy to minimize the emergence of drug resistance and increase efficacy, particularly to achieve sustainable post-treatment suppression of HBV. Randomized prospective control trials of combined antiviral therapies given simultaneously or sequentially are needed to establish safe and effective combined regimens that can be recommended for future treatment strategies.

Inhibitory effect of adefovir on viral DNA synthesis and covalently closed circular DNA formation in duck hepatitis B virus-infected hepatocytes in vivo and in vitro

The elimination of viral covalently closed circular DNA (CCC DNA) from the nucleus of infected hepatocytes is an obstacle to achieving sustained viral clearance during antiviral therapy of chronic hepatitis B virus (HBV) infection. The aim of our study was to determine whether treatment with adefovir, a new acyclic nucleoside phosphonate, the prodrug of which, adefovir dipivoxil, is in clinical evaluation, is able to suppress viral CCC DNA both in vitro and in vivo using the duck HBV (DHBV) model. First, the effect of adefovir on viral CCC DNA synthesis was examined with primary cultures of DHBV-infected fetal hepatocytes. Adefovir was administered for six consecutive days starting one day before or four days after DHBV inoculation. Dose-dependent inhibition of both virion release in culture supernatants and synthesis of intracellular viral DNA was observed. Although CCC DNA amplification was inhibited by adefovir, CCC DNA was not eliminated by antiviral treatment and the de novo formation of CCC DNA was not prevented by pretreatment of the cells. Next, preventive treatment of experimentally infected ducklings with lamivudine or adefovir revealed that both efficiently suppressed viremia and intrahepatic DNA. However, persistence of viral DNA even when detectable only by PCR was associated with a recurrence of viral replication following drug withdrawal. Taken together, our results demonstrate that adefovir is a potent inhibitor of DHBV replication that inhibits CCC DNA amplification but does not effectively prevent the formation of CCC DNA from incoming viral genomes.

Successful allogeneic bone marrow transplantation from an HBV-positive donor into an HBV-positive recipient using lamivudine

A 21-year-old woman with severe aplastic anemia underwent allogeneic bone marrow transplantation from an HLA-identical sibling donor. The patient also had chronic hepatitis B and the donor was an HBV carrier. To decrease HBV and improve hepatic dysfunction before BMT, the patient had received lamivudine for 6 months. After marrow transfusion, administration of lamivudine was continued to inhibit replication of donor-derived HBV. The patient showed hematological engraftment on day 13 without any serious liver dysfunction. Eight months after BMT, she is now alive and well without chronic liver GVHD or reactivation of hepatitis B. HBV-DNA was not detected in the patient's serum. Administration of lamivudine to a BMT recipient with chronic hepatitis B may be a safe and promising way to prevent fatal liver dysfunction in the setting of allogeneic BMT, even in the event of BMT from an HBV-positive donor.

Lamivudine therapy for hepatitis B in renal transplantation

Antiviral therapies are associated with an increased risk of acute rejection in transplant patients. The aim of the present study was to evaluate the efficacy and safety of lamivudine therapy for hepatitis B virus (HBV) infection in renal transplant patients. Six patients were included in this study. They received 150 mg/day of lamivudine during a follow-up period of 24 months. The laboratory tests monitored were HBV DNA, HBsAg, HBeAg, ALT, gamma-GT, serum creatinine and blood cyclosporine levels. The HBV DNA became undetectable in four patients as early as in the third month of treatment. After six months, the viral load was also negative in the other two patients, and remained so until 18 months of follow-up. The medication was well tolerated with no major side effects. Lamivudine was safe and effective in blocking HBV replication in renal transplant patients without any apparent increase in the risk of graft failure for the 24-month period of study.

Selection of hepatitis B virus polymerase mutants with enhanced replication by lamivudine treatment after liver transplantation

BACKGROUND & AIMS

Lamivudine has become a main therapeutic option for treating hepatitis B virus (HBV) infection. Although drug resistance develops, the clinical course after selection of antiviral-resistant HBV mutants seems to be benign. However, we observed a severe clinical course of hepatitis B infection in several liver transplant recipients after the emergence of lamivudine resistance. This was associated with high viral load in the blood.

METHODS

In this report, we characterize the molecular mechanisms underlying drug-dependent enhanced replication of particular lamivudine-resistant HBV mutants selected in these patients, which were associated with sudden onset of liver failure.

RESULTS

The clinical course was characterized by a sudden rise in serum bilirubin, prothrombin time, and transaminase. HBV sequence analysis of these patients revealed both mutations in the "a-determinant" of the envelope and the YMDD (tyrosine, methionine, aspartate, aspartate) motif (domain C) of the polymerase protein. Transfection experiments with replication competent vectors indicated that the "a-determinant" changes were not associated with resistance, whereas mutations in the YMDD motif conferred resistance to lamivudine. More importantly, combinations of mutations in the "a-determinant" and the YMDD motif in patients with a severe hepatitis were not only resistant to lamivudine treatment, but showed enhanced replication in vitro in the presence of lamivudine. This observation was confirmed in separate laboratories.

CONCLUSIONS

Severe and fatal hepatitis B infection can occur during lamivudine therapy and may be associated with certain HBV mutants selected during sequential nucleoside and HBIg treatment. The lamivudine-enhanced replication shown by these mutants suggests that continuation of therapy with lamivudine could be deleterious in some patients.

How will we use the new antiviral agents for hepatitis B?

There are two licensed drugs for chronic hepatitis B virus (HBV), interferon alfa and lamivudine, with similar efficacy rates. Lamivudine is less expensive and better tolerated than interferon alfa and is the drug of choice for patients with decompensated cirrhosis and recurrent HBV infection after liver transplantation. The major problem with lamivudine monotherapy has been the emergence of drug-resistant HBV polymerase (YMDD) mutants. Thus, long-term use of lamivudine in other settings remains somewhat controversial. Alternative nucleoside analogues that are active against both wild-type and YMDD-mutant HBV are currently being tested. It is hoped that a combination of one or more of these agents with lamivudine will not only prove more effective than lamivudine alone but also decrease the rate of lamivudine resistance. Preliminary studies suggest that the combination of interferon and lamivudine is associated with an enhanced rate of virologic response when compared with either agent alone. From a theoretical perspective, the combination of interferon with one or more nucleoside analogues may be the most effective way to treat HBV infection in many clinical situations.

Outcome of anti-HBe positive chronic hepatitis B in alpha-interferon treated and untreated patients: a long term cohort study

BACKGROUND/AIMS

We studied the influence of biochemical and virologic patterns and interferon on the outcome of anti-HBe positive chronic hepatitis B in 164 (103 treated) consecutive patients, followed-up prospectively for a mean of 6 years (21 months-12 years).

METHODS

Histology, biochemical and virologic profiles were characterized by monthly monitoring during the first 12 months of follow-up. Thereafter patients underwent blood and clinical controls every 4 and 6 months, respectively. Cirrhosis at follow-up histology or end stage complications of cirrhosis served as end points for the analysis of factors influencing disease progression in patients with baseline chronic hepatitis or cirrhosis, respectively.

RESULTS

Disease progression was associated with older age (P<0.001), absence of previous HBeAg history (P=0.017) and higher serum HBV-DNA levels (P=0.009) (more frequently observed in unremitting disease profile, P=0.012) at multivariate analysis. Fluctuations of IgM anti-HBc levels (associated with disease exacerbations, P=0.045) correlated with end stage complications in cirrhotics (P=0.011). Disease improved in 14.6 and 1.6% of treated and untreated patients, respectively (P=0.015): interferon slowed disease progression (P<0.001).

CONCLUSIONS

The outcome of anti-HBe positive chronic hepatitis B is worsened by older age and persistent viral replication or hepatitis exacerbations in chronic hepatitis or in cirrhotic patients, respectively. Interferon reduces by 2.5-folds disease progression.

Introduction of lamivudine for the treatment of chronic hepatitis B: expected clinical and economic outcomes based on 4-year clinical trial data

BACKGROUND

Chronic hepatitis B (CHB) is associated with a significant burden of illness and treatment involves substantial health-care costs. This study estimates clinical outcomes and cost-effectiveness of lamivudine compared with other treatment scenarios for CHB, from an Australian health-care provider perspective.

METHODS

A two-step modeling approach depicted clinical progression of hepatitis B in hypothetical patient cohorts using three different treatment scenarios: scenario A, lamivudine and alpha-interferon (IFN-alpha) available; scenario B, IFN-alpha available only; and scenario C, no treatment available. Assumptions were based on clinical trials, published studies, a hepatologist's questionnaire and an expert panel follow up. One-year clinical outcomes and costs were estimated using a decision tree, while lifetime costs and outcomes were estimated using available clinical trial data for lamivudine (up to 4 years therapy duration) and a Markov model.

RESULTS

The analysis considered only patients with pretreatment elevated alanine aminotransferase levels > or = 2 x upper limit of normal. In the short term, the introduction of lamivudine is expected to result in almost 3.5 times more CHB patients receiving therapy (lamivudine or IFN-alpha) compared to IFN-alpha only (67% compared to 20%, respectively). Hence, scenario A subsequently doubled the seroconversion rate. The incremental cost-effectiveness ratio was $3341 Australian per additional seroconversion. Also, non-seroconverted lamivudine patients are less likely to progress to cirrhosis than those receiving IFN-alpha/no treatment. One-year progression to cirrhosis was estimated at 5.1% with scenario A, compared to 12.2% and 12.7%, scenarios B and C, respectively. From the long-term analysis, lamivudine is expected to increase life expectancy by years and reduce the lifetime risk of compensated cirrhosis, decompensated cirrhosis and hepatocellular carcinoma by 6%, 12% and 12%, respectively. Additionally, the introduction of lamivudine decreases lifetime costs by $548, thus making it a cost-saving and life-extending strategy. In both short- and long-term models, worst case scenarios in sensitivity analyses still associate lamivudine with a favorable cost-effectiveness ratio.

CONCLUSION

Introduction of lamivudine is expected to improve health outcomes in CHB patients, resulting in overall savings in health-care costs. In this model, compared with IFN-alpha only and no treatment, lamivudine allowed more CHB patients to be treated, increased the seroconversion rate, delayed disease progression and prolonged life expectancy.