Insulin Resistance Predicts Virological Response to Interferon-α in Chronic Hepatitis B Patients

GOALS

To elucidate impact of insulin resistance (IR) on the response to interferon-α (IFN-α) therapy in chronic hepatitis B (CHB) patients.

BACKGROUND

Metabolic factors influencing the virological response of CHB patients on IFN-α treatment are still unexplored.

STUDY

Eighty CHB patients were treated with IFN-α for 48 weeks. The IR was evaluated by homeostasis model assessment of IR (HOMA-IR) before treatment. Viral load and biochemical parameters were measured at 12, 24, and 48 weeks after starting treatment, and then 24 weeks after the end of treatment. IFN-γ and tumor necrosis factor-α were tested at baseline and 12 weeks of treatment.

RESULTS

Pretreatment HOMA-IR proved to be the only independent predictor of primary nonresponse, as well as the pretreatment HOMA-IR, viral load and primary nonresponse were independently associated with virological response at 24, 48 weeks of treatment and at the follow-up endpoint. The significant higher virological relapse rate in patients with IR was observed in patients with virological response at 48 weeks of treatment. The mean HOMA-IR was significantly lower in virological responders than in virological nonresponders. The secretion of IFN-γ and tumor necrosis factor-α was not induced in patients with IR at 12 weeks after IFN-α treatment.

CONCLUSIONS

Our data suggest that IR is strongly associated with virological response, thus reflecting the important role played by metabolic factors in the viral kinetics during IFN-α treatment. These findings suggested clinical application of pretreatment HOMA-IR could enable treatment outcome to be predicted and treatment regimens to be determined.

Treatment predictors of a sustained virologic response in hepatitis B and C

Treatment predictors are important tools for the management of therapy in patients with chronic hepatitis B and C virus (HBV, HCV) infection. In chronic hepatitis B, several pretreatment parameters have been identified for prediction of virologic response to interferon alfa-based antiviral therapies or treatment with polymerase inhibitors. In interferon alfa and pegylated interferon alfa-treated patients, low baseline HBV DNA concentrations, HBV genotype A (B), and high baseline ALT levels are significantly associated with treatment response. In patients treated with nucleos(t)ide analogues, low baseline HBV DNA but not viral genotype is positively associated with virologic response. During treatment the best predictor of response is HBV DNA kinetics. Early viral suppression is associated with favourable virologic response and reduced risk for subsequent resistance mutations. For the current standard treatment with pegylated interferon alfa and ribavirin in patients with chronic hepatitis C, infection with HCV genotypes 2 and 3, baseline viral load below 400,000-800,000 IU/ml, Asian and Caucasian ethnicity, younger age, low GGT levels, absence of advanced fibrosis/cirrhosis, and absence of steatosis in the liver have been identified as independent pretreatment predictors of a sustained virologic response. After initiation of treatment, initial viral decline with undetectable HCV-RNA at week 4 of therapy (RVR) is the best predictor of sustained virologic response independent of HCV genotype.

Management of chronic hepatitis B virus infection: a new era of disease control

When assessing patients with chronic hepatitis B virus (HBV) infection, consider the state of viral replication, the immune response and whether viral mutations could be present, as well as evidence for liver disease or extrahepatic manifestations. In wild-type infections, loss of hepatitis B e antigen (HBeAg), gain of anti-HBe and disappearance of HBV DNA from serum indicate immunosuppression of viral replication, or 'nonreplicative chronic HBV infection'. This 'healthy carrier' state must be distinguished from HBeAg-negative chronic hepatitis B (CHB) resulting from precore and core promoter mutations. HBeAg-negative CHB is common with genotypes D (Mediterranean region, south Asia) and C (north Asia) infections. Age, disease activity (alanine aminotransferase level) and severity (fibrosis stage, cirrhosis) influence treatment decisions. Following the marginal effectiveness of interferon and often temporary effectiveness of lamivudine due to drug resistance, treatment of CHB is entering a new era. Adefovir, entecavir, tenofovir, telbivudine and clevudine have equal or superior antiviral efficacy to lamivudine, whereas several agents are effective against lamivudine-resistant HBV. Pegylated-interferon (peginterferon) is superior to conventional interferon for obtaining sustained immunosuppression of HBV without drug resistance. Antiviral suppression of HBV replication for 2-5 years reverses hepatic fibrosis, prevents cirrhosis and, when cirrhosis is established, improves liver function, prevents hepatic decompensation and lowers the risk of liver cancer. Before embarking on immunosuppressive chemotherapy or organ transplantation in patients with chronic HBV infection, it is important to start antiviral therapy to prevent hepatitis flares. Antiviral therapy can be effective against membranous glomerulonephritis and polyarteritis nodosa caused by HBV. Further improvements in treatment of CHB are needed to prevent drug resistance and permanently suppress viral replication by eradicating viral templates or stimulating host immune responsiveness to HBV.

Severe acute exacerbation of liver disease may reduce or delay emergence of YMDD motif mutants in long-term lamivudine therapy for hepatitis B e antigen-positive chronic hepatitis B

The pretherapy factors that could influence the emergence of resistant hepatitis B virus (HBV) tyrosine-methionine-aspartate-aspartate (YMDD) motif mutants against lamivudine are not fully known in prolonged lamivudine therapy for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B. We analyzed prospectively 116 consecutive lamivudine-naïve patients who received long-term lamivudine therapy (>1 year) by using multivariate regression analyses. The cumulative HBeAg loss rates were 29, 44, and 47% at 1, 2, and 3 years of treatment, respectively. Stepwise Cox's regression analyses indicated that pretherapy viral load was a significant factor associated with HBeAg loss (P = 0.0068). The cumulative emergence rates of YMDD mutants were 23% at 1 year, 45% at 2 year, and 47% at 3 year of treatment. Stepwise Cox's regression analyses indicated that patient age and presence or absence of severe acute exacerbation of liver disease were independent significant factors associated with emergence of YMDD mutants (P = 0.018 and 0.048, respectively). For the development of virological breakthrough, patient age, the presence or absence of severe acute exacerbation, and pretherapy viral load were independent significant factors (P = 0.028, 0.043, and 0.044, respectively). Severe acute exacerbation tended to reduce or delay development of biochemical breakthrough. The present study provides important information for the development of more effective and rational long-term lamivudine therapy for HBeAg-positive chronic hepatitis B patients infected exclusively with genotype

Prognostic factors and early predictability of sustained viral response with peginterferon alfa-2a (40KD)

BACKGROUND/AIMS

Baseline factors and early decline in serum hepatitis C virus RNA are predictive of sustained virological response to interferon therapy in patients with chronic hepatitis C. We evaluated the prognostic value of baseline factors and early viral RNA among patients treated with peginterferon alfa-2a (40KD).

METHODS

Data were pooled from three randomized trials involving 814 patients treated with peginterferon alfa-2a (40KD) (90, 135, or 180 mirog). Stepwise and multiple logistic regression identified independent baseline factors associated with response. Receiver operating characteristic curves for both absolute values and log(10) decline in viral RNA at 4, 8, 12 and 24 weeks of therapy were created.

RESULTS

Independent prognostic factors for sustained virological response included viral genotype non-1, low pretreatment viral load, age (<40 years), no cirrhosis and body weight (<85 kg). In addition, alanine aminotransferase quotient (>3) and histological activity index score (>10) were also independently prognostic. Receiver operating characteristic curves showed that detectable or less than 2-log(10) decline in viral RNA at week 12 predicted sustained virological non-response (negative predictive value is 98%) .

CONCLUSIONS

In patients with chronic hepatitis C treated with peginterferon alfa-2a (40KD), the decision to continue or stop treatment can be made as early as week 12.

Improvement of human interferon HUIFNalpha2 and HCV core protein expression levels in Escherichia coli but not of HUIFNalpha8 by using the tRNA(AGA/AGG)

High-level expression from one particular heterologous gene in Escherichia coli generally requires the optimization of codon usage. Genes encoding for Hepatitis C virus core protein (HCcAg), human interferon alpha2 and 8 subtypes (HUIFNalpha2 and HUIFNalpha8) show a high content of AGA/AGG codons. These are encoded by the product of the dnaY gene in E. coli. The proteins used in this work have a high therapeutic value and were used as models for studying the effects of these rare codons on the efficiency of heterologous gene expression in E. coli. Expression plasmids were constructed to express any of these proteins and the dnaY gene product simultaneously in E. coli. After dnaY gene expression, HCcAg, and HUIFNalpha2 expression levels increased 5 and 3 times, respectively. However, HUIFNalpha8 expression was barely detected either supplying or not the additional dnaY gene product. These results suggest that the high frequency of AGA/AGG codons present in the HCcAg and HUIFNalpha2 genes could be one of the factors limiting its expression in E. coli. Nevertheless, for HUIFNalpha8 it seems that other factors prevail upon the lack of dnaY product. Data presented here for HCcAg and HUIFNalpha2 expressions proved the value of this approach to obtain therapeutic proteins in E. coli.

The cost-effectiveness of alternative therapeutic strategies for the management of chronic hepatitis B in Poland

OBJECTIVE

The aim of the study was to estimate the cost-effectiveness of alternative therapeutic strategies for the management of chronic hepatitis B (CHB) in Poland.

METHODS

The model for the Polish health-care context was based on clinical data from the literature and local data on health-care resource utilization and unit costs. Costs and effects of a population of CHB patients were modeled using four scenarios, which attempt to reflect real-life practice in which patients may receive any of the treatment options available and in which a proportion of patients may still receive no treatment because therapy is not suitable. Strategies A and B assumed the availability of both treatment options: the first choice of treatment is in A, lamivudine, and in B, interferon alpha (IFN-alpha). In strategy C, the only approved treatment is IFN-alpha, and in strategy D, the patients receive no antiviral treatment. The outcome measures were HBeAg seroconversion and nonprogression to cirrhosis-the surrogate marker with predictive value for improved survival. Only direct medical costs were analyzed. The payer's perspective and time horizon of 1 year were adopted. One-way sensitivity analysis and extreme scenario analysis were performed.

RESULTS

The best results in terms of seroconversion and nonprogression to cirrhosis were achieved for strategy A, costs were lowest for strategy D, and strategies B and C were dominated by strategy A. The incremental cost/effectiveness ratio (ICER) comparing strategy A with strategy D was 57,855 Polish new zloty (PLN) per extra seroconversion and 79,550 PLN per cirrhosis case avoided.

CONCLUSIONS

Cirrhosis reduces estimated life expectancy by 37.76 years and by 20 years among 30- and 50-year-olds, respectively. The ICER for strategies A and D was 2105 PLN and 3978 PLN per life-years gained for the population at ages 30 and 50, respectively, and was below the suggested threshold for cost-effectiveness, based on treatment costs for 1 year of hemodialysis in Poland (62,400 PLN). Changing the value of key drivers for sensitivity analysis did not have a significant effect on the ICER.

Predictors of HBeAg loss after lamivudine treatment for chronic hepatitis B

Elevated alanine transaminase (ALT) levels and low serum hepatitis B virus (HBV) DNA predict a higher likelihood of hepatitis B e antigen (HBeAg) loss in patients with chronic hepatitis B treated with interferon. Predictors of HBeAg loss in patients treated with lamivudine are not known. The objective of this analysis of 4 lamivudine-controlled Phase III trials was to determine patient-dependent or laboratory variables that predict HBeAg loss. Predictors of HBeAg loss in patients treated with interferon, lamivudine plus interferon, or placebo are also described. A total of 805 adults with chronic hepatitis B were treated either with lamivudine (n = 406), matching placebo (n = 196), interferon (n = 68), or the combination of lamivudine plus interferon (n = 135). Demographic and baseline disease characteristics were used in stepwise multivariate analyses to identify features that were predictive of lamivudine-induced HBeAg loss. HBeAg loss correlated with increased pretreatment ALT levels in all groups. The rate of HBeAg loss was highest among patients with pretreatment ALT levels greater than 5 times the upper limit of normal (ULN) and was most pronounced in the lamivudine group (56%). Multivariate modeling indicated that elevated baseline ALT levels (P <.001) and histologic activity index (HAI) score (P <.001) were important predictors of HBeAg loss in response to lamivudine. The effect of pretreatment ALT levels on HBeAg loss was similar for Asians and Caucasians. In conclusion, elevated pretreatment ALT levels and/or active histologic disease were the most important predictors of lamivudine-induced HBeAg loss. Asians and Caucasians had similar rates of response to lamivudine at comparable ALT levels.

Cost-effectiveness analysis of lamivudine for the treatment of chronic hepatitis B

OBJECTIVE

To estimate the short term and long term cost effectiveness, from a healthcare perspective, associated with the introduction of lamivudine for chronic hepatitis B.

DESIGN

The analysis used a 2-step modelling approach. A decision tree was used to estimate clinical outcomes and costs after 1 year. The 1-year results were then extrapolated to 70 years using a Markov model.

PATIENTS

The study population comprised hypothetical cohorts of patients with chronic hepatitis B, representative of those likely to receive treatment in clinical practice in Australia.

MAIN OUTCOME MEASURES AND RESULTS

In the short term, more patients sero-converted when lamivudine was available, with an incremental cost-effectiveness ratio of 3341 Australian dollars ($A) per additional seroconversion. In the long term, the introduction of lamivudine increased life expectancy by 3.9 years [3.2 quality-adjusted life-years (QALYs)] compared with when interferon-alpha was the only treatment, or 4.6 years (3.8 QALYs) compared with no treatment. There were reductions in lifetime risk of developing compensated cirrhosis, decompensated cirrhosis and hepatocellular carcinoma of 5, 11 and 11%, respectively, when lamivudine was available. The incremental cost of having lamivudine available, as opposed to interferon-alpha only, was $A633 per year of life saved or $A735 per QALY.

CONCLUSION

The introduction of lamivudine is expected to reduce and delay the progression of chronic hepatitis B, increasing the life expectancy and quality of life of patients for a small overall increase in healthcare costs.

Long-term follow-up of a randomized trial of interferon therapy for chronic hepatitis B in a predominantly homosexual male population

BACKGROUND/AIMS

Extended follow-up of a previously published therapeutic trial with interferon alfa is now available to further clarify the long-term outcome of HIV-negative and HIV-positive subjects with chronic hepatitis B virus infection after interferon alfa therapy.

METHODS

Forty-five subjects with compensated liver disease and chronic hepatitis B infection with evidence of active hepatitis B replication were studied. These subjects were enrolled between 1986 and 1991 and had been randomized, stratified by HIV status, to either receive interferon therapy (10 MU/m2 of lymphoblastoid interferon alfa 3 times per week for 12 weeks) or no treatment. Hepatitis B serology, serum hepatitis B viral DNA and alanine aminotransferase were measured on an annual to biannual basis. CD4-positive T lymphocyte counts and HIV RNA concentration were also obtained.

RESULTS

From 9 months post-interferon alfa treatment to the end of the extended follow-up (4 to 9 years), the relative risk of seroconverting to anti-HBe positive for subjects who had received interferon alfa therapy compared to those who did not was not significant in either HIV-negative (p = 0.80) or HIV-positive (p = 0.62) subjects.

CONCLUSIONS

Unlike the first 9 months following interferon alfa therapy, the rate of elimination of markers of hepatitis B virus replication, regardless of HIV status, was not increased above the natural rate beyond 9 months following interferon alfa therapy.

The long-term effect of treatment with interferon-alpha 2a in chronic hepatitis B. The Long-Term Follow-up Investigator Group. The European Study Group on Viral Hepatitis (EUROHEP). Executive Team on Anti-Viral Treatment

This study was performed to evaluate the long-term effects of interferon-alpha 2a (IFN-alpha 2a) vs no treatment in patients with chronic hepatitis B and to determine whether viral clearance, following therapy or occurring spontaneously, was sustained. Patients originating from three previously published multicentre, randomized, controlled trials were analysed. Information about survival and response during long-term follow-up was available in 340 (73%) and 308 (66%) of 469 randomized patients respectively. Response to therapy (viral clearance) was defined as: loss of hepatitis B virus (HBV) DNA and loss of hepatitis B e antigen (HBeAg) and improvement in alanine aminotransferase level. Scheduled treatment-free follow-up was 12 months in all studies. Median long-term follow-up time after inclusion in the individual studies was 4.7 years (range: 0.2-7.5 years). Viral clearance after IFN-alpha 2a, or occurring spontaneously, was sustained in 70 out of 80 evaluable patients (88%) who were responders at the end of the original trials and 21 (30%) lost hepatitis B surface antigen (HBsAg). A total of 80 patients received (re)treatment during the long-term follow-up period and 33% of them responded, irrespective of previous treatment category. Overall response rate was not significantly affected by gender, sexual inclination or ethnic origin. Durability of response did not depend upon ethnic origin or presence of cirrhosis. At the end of the original trial periods, 253 patients were histologically evaluated and 22 (9%) had histologically confirmed progression to cirrhosis. During long-term follow-up an additional five patients developed cirrhosis. Hepatocellular carcinoma developed in three patients (1%): in one patient during the follow-up period of the original trial and in two patients (one untreated) during the long-term follow-up period. Ten of 25 deaths were liver-related (hepatocellular carcinoma in three, gastrointestinal bleeding in two and liver failure in five). The distribution of clinical events (progression to cirrhosis, hepatocellular carcinoma and liver-related deaths) was unrelated to original treatment category and response to treatment. Hence, 90% of responding patients will, irrespective of treatment category, have a sustained response. At least 30% of responding patients will eventually lose HBsAg. For a number of reasons, the present patient population and observation period are insufficient to establish a presumed beneficial effect of IFN-alpha 2a on disease progression and survival.

Safety and efficacy of interferon retreatment in children with chronic hepatitis B

More than 50% of children with chronic hepatitis B do not respond to treatment with alpha-interferon. Since these patients continue to display high viral replication and progressive liver disease, retreatment should be considered. To date it has not been well evaluated whether a second course of treatment could increase the response rate. In two alpha-interferon retreatment trials in adult patients the response rate, defined by seroconversion from HBeAg to anti-HBe, ranged between 11% and 44%. One beta-interferon retreatment study in children reported a seroconversion rate of 32%. Regrettably, none of the studies included a control group observing the 'spontaneous' seroconversion rate after a first interferon cycle. Thus, a nonrandomized alpha-interferon retreatment study in children including control patients was performed. Alpha-interferon for retreatment was administered 3 times a week for 16-24 weeks in 15 children (5-16 years) at least 6 months after ceasing the first cycle. Four children received 5 MU/m2 of a natural alpha-interferon and 11 children 9 MU/m2 recombinant alpha-interferon 2b. Follow up was 18-47 months after initial treatment. In parallel, a control group of 19 unretreated children with comparable clinical and demographic data was followed for 12-39 months. HBeAg seroconversion was observed in 5 (33%) of the retreated children and in 5 (26%) of the control patients during follow up. The difference is not significant. In the initially nonresponding children, those with high ALT levels before the first treatment showed late HBeAg seroconversion more frequently than those with low ALT levels (P=0.017) irrespective of retreatment. The ALT level before retreatment was not a predictor for response.

CONCLUSIONS

A second cycle of alpha-interferon during the 3 years following the first treatment in nonresponding children with chronic hepatitis B can be safely performed but did not increase HBeAg/anti-HBe seroconversion compared with the spontaneous seroconversion rate of patients without retreatment.

Duration of HCV infection as a predictor of nonresponse to interferon

Duration of hepatitis C virus (HCV) infection is a key feature in determining responsiveness to interferon (IFN). Studies assessing its value as a predictive factor in chronic HCV infection show that a long duration of infection reduces the likelihood of a sustained response to IFN (defined as ALT normalization and clearance of serum HCV-RNA). The effect of HCV infection duration is independent of the presence of cirrhosis and level of HCV viremia. Meta-analysis of IFN trials in acute HCV infection shows an obvious effect of the drug on long-term ALT normalization and HCV-RNA clearance. Treatment of HCV infection during the acute or early chronic phase could therefore maximize therapeutic effectiveness.