Hepatitis B Virus Suppression Research Articles

A great deal of learning from the natural course of chronic hepatitis B virus infection

A great deal of learning from the natural course of chronic hepatitis B virus infection

Tumor Necrosis Factor Activates a Conserved Innate Antiviral Response to Hepatitis B Virus That Destabilizes Nucleocapsids and Reduces Nuclear Viral DNA

Tumor necrosis factor (TNF) is critical for the control of hepatitis B virus (HBV) in the clinical setting and in model systems. TNF induces noncytopathic suppression and clearance of HBV in animal models, possibly through reduction of viral nucleocapsids, but the mechanism is not well described. Here, we demonstrate the molecular mechanism and broad host range for TNF action against HBV. We show that TNF rapidly blocks HBV replication by promoting destabilization of preexisting cytoplasmic viral nucleocapsids containing viral RNA and DNA, as well as empty nucleocapsids. TNF destabilized human HBV nucleocapsids in a variety of human hepatocytic cell lines and in primary rat hepatocytes and also destabilized duck HBV (DHBV) nucleocapsids in chicken hepatocytic cells. Lysates from TNF-treated uninfected cells also destabilized HBV nucleocapsids in vitro. Moreover, inhibition of DHBV DNA replication by TNF blocks nuclear accumulation of the viral transcription template, maintenance of which is essential for the establishment and maintenance of chronic infection. We show that TNF destabilization of HBV nucleocapsids does not involve ubiquitination or methylation of the viral core protein and is not mediated by the nitric oxide free radical arm of the TNF pathway. These results define a novel antiviral mechanism mediated by TNF against multiple types of HBVs in different species.

A case for treating high hepatitis B DNA levels before starting HIV therapy

A case for treating high hepatitis B DNA levels before starting HIV therapy

Long-term inhibition of hepatitis B virus in transgenic mice by double-stranded adeno-associated virus 8-delivered short hairpin RNA

RNA interference (RNAi) was reported to block hepatitis B virus (HBV) gene expression and replication in vitro and in vivo. However, it remains a technical challenge for RNAi-based therapy to achieve long-term and complete inhibition effects in chronic HBV infection, which presumably requires more extensive and uniform transduction of the whole infected hepatocytes. To increase the in vivo transfection efficiency in liver, we used a double-stranded adeno-associated virus 8-pseudotyped vector (dsAAV2/8) to deliver shRNA. HBV transgenic mice were used as an animal model to evaluate the inhibition effects of the RNAi-based gene therapy. A single administration of dsAAV2/8 vector, carrying HBV-specific shRNA, effectively suppressed the steady level of HBV protein, mRNA and replicative DNA in liver of HBV transgenic mice, leading to up to 2-3 log(10) decrease in HBV load in the circulation. Significant HBV suppression sustained for at least 120 days after vector administration. The therapeutic effect of shRNA was target sequence dependent and did not involve activation of interferon. These results underscore the potential for developing RNAi-based therapy by dsAAV2/8 vector to treat HBV chronic infection, and possibly other persistent liver infections as well.

Hepatitis B Virus Replication and Liver Disease Progression: The Impact of Antiviral Therapy

Chronic hepatitis B virus (HBV) infection is a serious health issue worldwide. The presence of HBV replication markers--hepatitis B e antigen (HBeAg) or HBV DNA--is associated with continuing hepatitis activity or intermittent hepatitis flares and subsequent disease progression, including hepatic decompensation and development of liver cirrhosis or hepatocellular carcinoma (HCC). Long-term (>10 years) prospective studies in patients >30 years of age have shown that HBeAg seropositivity is associated with increased risk of disease progression, and the risk of cirrhosis and HCC begins to increase at an HBV DNA level of 10(4) copies/ml. Therefore, elimination of HBV, or at least sustained or maintained suppression of HBV, is the key to reducing hepatitis and thereby halting or preventing disease progression. Therapy with interferon-alpha or a direct antiviral agent has been shown to reduce the risk of cirrhosis and prevent further disease worsening. In both the woodchuck hepatitis model and in HBV patients, maintained suppression of HBV replication by a direct antiviral agent may reduce the progression to HCC. However, the efficacy of current antiviral therapy is still far from satisfactory. The ability to achieve a high rate of sustained or maintained HBV suppression with a low risk of drug resistance would be the ultimate goal in the treatment of chronic HBV infection.

Single (B or C), dual (BC or BD) and triple (BCD) viral hepatitis in HIV-infected patients in Madrid, Spain

There are very limited data about the prevalence of multiple hepatitis virus infections in HIV infected individuals. In HIV uninfected individuals with triple BCD hepatitis, hepatitis D virus (HDV) appears to be the dominant virus. However, in HIV infected patients with triple hepatitis it is not known if HDV replication inhibits hepatitis B virus (HBV) and/or hepatitis C virus (HCV) replication. We calculated the prevalence of single (B or C), dual (BC) and triple (BCD) hepatitis in 423 HIV-infected patients with positive HCV serum antibodies and/or positive serum HBsAg. In patients with multiple infections we performed an evaluation of serum markers of HBV, HCV and HDV replication. The prevalence of multiple hepatitis was 4.7% (95% confidence interval, 2.7-6.7%). Multiple hepatitis occurred only among patients who acquired HIV through injection drug use. The most common multiple hepatitis was triple BCD. Patients with hepatitis BC and past or chronic hepatitis D were significantly more likely to have cirrhosis and a negative serum HBeAg and HCV PCR than patients with single hepatitis B or hepatitis C. Patients with chronic hepatitis D showed uniform suppression of HBV and HCV replication markers. In our geographic area approximately 5% of HIV infected patients with hepatitis suffer multiple hepatitis virus infection. In patients with triple hepatitis BCD virus infection, HDV appears to be the dominant virus causing inhibition of both HBV and HCV replication.

Management of HIV Infection in Persons Co-infected With Hepatitis

Co-infection with hepatitis C virus (HCV) and/or hepatitis B virus (HBV) is becoming a rampant disparity in HIV-infected patients. The advent of antiretroviral therapy has led to agents that are effective for suppression of both HIV and HBV; however, this can not be extrapolated to patients who are coinfected with HCV. Treatment of HCV disease is often strenuous and can lead to untoward adverse effects. Co-infection with HIV often leads to higher rates of cirrhosis and liver failure in patients with HBV or HCV, compromising antiretroviral treatment in this patient population due to the hepatotoxicity of these agents. The purpose of this review is to familiarize health care providers to the management of HIV infection in patients who are also co-infected with HBV or HCV.

Long-Term Lamivudine Monotherapy in Renal-Transplant Recipients with Hepatitis-B-Related Cirrhosis

Chronic hepatitis B virus (HBV) infection is an important cause of morbidity and mortality in renal-transplant recipients. The aim of the study was to assess the efficacy and safety of long-term lamivudine monotherapy in renal-transplant recipients with HBV-related cirrhosis. Seventeen such patients [median age: 45 years; 7 with hepatitis B e antigen (HBeAg)] received daily oral doses of 75-150 mg lamivudine for a median of 48 (range 11-81) months. All patients had baseline serum levels of HBV DNA of over 6 log10 copies per ml and of alanine transaminase (ALT) of over 1.5 times the upper normal limit (UNL). Clinical lamivudine resistance was defined as a rebound of serum HBV DNA above 5.3 log10 copies per ml and of serum ALT of over 1.5 times the UNL in patients who initially responded with HBV DNA levels of less than 5.3 log10 copies per ml and normal ALT values. Controls were 14 renal-transplant patients (median age 44 years; 3 with HBeAg) with HBV-related cirrhosis, naive to any anti-HBV therapy, followed for 58 months (4-135). Thirteen (77%) treated patients had a persistent response throughout the study period, including three (18%) who developed genotypic resistance, compared with none of the untreated controls (77% versus 0%, P < 0.0001). Four (23%) developed clinical resistance. Two of three patients with initially decompensated cirrhosis had a durable response and clinical improvement compared with the transient responder, whose liver function worsened following lamivudine resistance. Two responders developed chronic rejection requiring chronic haemodialysis. Overall, one treated patient developed liver-related complications, compared with eight untreated controls (6% versus 57%, P < 0.01). Most renal-transplant patients treated with lamivudine achieved a rapid and durable suppression of HBV, which substantially lowered the risk of liver decompensation and death.

Intrahepatic Hepatitis B Virus Covalently Closed Circular DNA Can Be a Predictor of Sustained Response to Therapy

This study aimed to determine whether intrahepatic hepatitis B virus (HBV) covalently closed circular (ccc) DNA and total HBV DNA levels at the end of therapy would predict sustained response to therapy. Hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients receiving either lamivudine monotherapy or combination of peginterferon and lamivudine had liver biopsy at the end of 1 year therapy and were followed for 52 more weeks after cessation of therapy. Serum HBV DNA, intrahepatic HBV ccc DNA, and total HBV DNA levels were determined. Forty-seven patients, including 34 males and 13 females, were studied. Twenty-seven patients received combination therapy, and 20 patients received lamivudine monotherapy. Twenty-nine patients had end-of-treatment virologic response, and 15 patients had sustained response 52 weeks after therapy. At the end of treatment, log serum HBV DNA levels correlated well with log intrahepatic HBV cccDNA and log intrahepatic total HBV DNA levels. Log intrahepatic cccDNA and log intrahepatic total DNA levels were significantly lower among patients with sustained virologic response. The adjusted odds ratio for log cccDNA was 5.3 (95% CI: 1.5-18.2, P = .009) and, for log intrahepatic HBV DNA, was 4.4 (95% CI: 1.3-14.7, P = .015) to predict sustained virologic response. Using log cccDNA at -0.80 copies/genome equivalent as cutoff, the sensitivity, specificity, and positive and negative predictive values and accuracy of predicting sustained virologic response were 73%, 78%, 56%, 86%, and 77% respectively. Intrahepatic HBV cccDNA and intrahepatic total HBV DNA levels at the end of therapy are superior to serum HBV DNA as surrogates of sustained virologic response.

HBV-DNA Suppression and Disease Course in HBV Cirrhosis Patients on Long-Term Lamivudine Therapy

In hepatitis B virus (HBV) cirrhosis patients on long-term lamivudine (LAM), the relationships between HBV suppression, development of viral resistance and disease outcome are unclear. We analysed the dynamic of serum HBV-DNA and its relationship with the clinical course of 59 patients (52 males, mean age 51.4 +/- 8.4 years, 12 HBeAg positive and 47 HBeAg negative, and 57 genotype D and two genotype A) with cirrhosis (45 in Child-Turcotte-Pugh class A) and high levels of serum HBV-DNA (median 14.7 x 10(7) genomes/ml) treated with LAM [median (range): 44 (15-78) months]. A total of 50 patient (84.7%) achieved a virological response (serum HBV-DNA negative by PCR) during the first 6 months of therapy, and nine (13.3%) achieved a reduction in viral load of > 3 log10. Mutations in the YMDD motif of HBV polymerase were documented in 26 patients [median (range) 18: (7-42) months]. At the time of the emergence of mutants, 22 patients had HBV-DNA < 10(5) genomes/ml and normal alanine aminotransferase (ALT) levels. The appearance of virological resistance was followed by an increase of HBV-DNA to > 10(5) genomes/ml and of ALT values in 19 out of 26 patients [median (range): 8 (3-19) months]. Event-free survival was significantly longer (P = 0.001) in patients who maintained virological suppression than in those who did not have a complete virological response or suffered a breakthrough. Patients with advanced cirrhosis were more likely to develop liver failure after the emergence of YMDD mutants. The risk of development of hepatocellular carcinoma in patients with compensated cirrhosis and YMDD mutations was maintained, regardless of HBV-DNA serum levels. Profound and maintained HBV-DNA suppression correlates with a better outcome. Early identification of LAM resistance mutations allows switching to other antivirals before liver decompensation or hepatocellular carcinoma development.

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.

Repression of hepatitis B virus (HBV) transgene and HBV-induced liver injury by low protein diet.

Persistent infection with hepatitis B virus (HBV) is one of the primary risk factors for human hepatocellular carcinoma (HCC). In a human ecological study, we have shown that, in addition to HBV, animal food consumption also significantly contributes to the variance of HCC. To test the interacting effect of HBV and animal food consumption on the development of HCC, we investigated HBV expression in HBV transgenic mice fed three levels of casein diet. HBV expression in transgenic animals was substantially inhibited when dietary casein was reduced from the traditional level of 22% to the level of 6%. Northern analysis revealed that suppression of HBV was derived from both the upstream albumin promoter and the internal HBV promoter. Immunochemical staining of liver sections indicated that only a few hepatocytes around the central vein expressed viral surface antigen (HBsAg) in the 6% casein animals, whereas virtually all hepatocytes stained positively for HBsAg in the 22% dietary casein animals. Serum HBsAg concentrations at 4 months were increased by 1.6-, 2.1-, and 5.1- fold over baseline for animals fed the 6%, 14%, and 22% casein diets, respectively. Correspondingly, liver injury was much less severe in animals fed 6% casein diet than in those fed 14% and 22% casein diets. These results demonstrate that a low casein diet is a potent suppresser of HBV transgene and HBV-induced liver injury, suggesting that diet management may be a practical means to aid in the control HBV infection.

A randomized, controlled trial of a 24-month course of interferon alfa 2b in patients with chronic hepatitis B who had hepatitis B virus DNA without hepatitis B e antigen in serum

Short-term interferon treatment of serum hepatitis B e antigen (HBeAg)-negative carriers with serum hepatitis B virus (HBV) DNA and histological features of chronic hepatitis B has been largely unsuccessful. In a pilot study of long-term treatment, 42 such patients were randomly assigned to 6 million units of interferon alfa 2b (IFN-alpha2b) three times per week for 24 consecutive months (n = 21, 4 with cirrhosis) or to no therapy (n = 21, 3 with cirrhosis). Five patients (24%) discontinued therapy because of treatment-related adverse reactions. Serum levels of alanine transaminase (ALT) became persistently normal and HBV DNA undetectable by dot-blot assay in 8 patients receiving interferon and in 2 untreated controls (38% vs. 10%; P = .03). Hepatitis flare-ups disappeared in 17 patients during therapy compared with 6 controls (81% vs. 29%; P < .001). During a median period of 22 months after interferon was stopped, 2 treated patients (10%) lost serum hepatitis B surface antigen (HBsAg) and seroconverted to antibodies to hepatitis B surface antigen (anti-HBs). Serum ALT remained persistently normal and HBV DNA undetectable by dot-blot assay in 6 initial responders and 1 initial nonresponder, compared with none of the 21 untreated controls (sustained response: 33% vs. 0; P < .001). Comparative analysis of pre- and posttreatment liver biopsies showed that mean Knodell scores dropped in the treated group (10.3 to 5.3; P = .01), but not in the untreated group (9.3 to 9.8; not significant). In conclusion, a 24-month course of treatment with 6 MU IFN-alpha2b was well tolerated by most patients, led to sustained suppression of HBV in one third, and attenuated hepatitis in 81% of patients. (Hepatology 1997 Dec;26(6):1621-5)

Natural history of hepatitis D viral superinfection: Significance of viremia detected by polymerase chain reaction

Background/Aims : Polymerase chain reaction (PCR) is very sensitive. The aim of the study was to reevaluate viral replication in hepatitis D virus (HDV) superinfection by PCR. Methods : HDV and hepatitis B virus (HBV) were detected by PCR in 185 patients. Results : The acute hepatitis group had the highest detection rate of HDV RNA compared with chronic hepatitis, cirrhosis, hepatocellular carcinoma, and remission groups (63 of 64 vs. 35 of 47, 17 of 23, 19 of 30, and 7 of 21) and the highest alanine aminotransferase (ALT) levels (mean, 1741 U/L vs. 266 to 27 U/L; P < 0.05). The detection rate of HBV DNA was the lowest in the acute group (41%) compared with 66%, 70%, 80%, and 57% in the remaining groups ( P < 0.02). At the chronic stage, 13%–25% of cases had HDV RNA, and 30%–48% of cases had HBV DNA detected by PCR but not by traditional method. HDV RNA was associated with ALT levels in horizontal and longitudinal analyses. Conclusions : HDV superinfection may be divided into the following three phases: acute phase, active HDV replication and suppression of HBV with high ALT levels; chronic phase, decreasing HDV and reactivating HBV with moderate ALT levels; and late phase, development of cirrhosis and hepatocellular carcinoma caused by replication of either virus or remission resulting from marked reduction of both viruses.