Hemolytic anemia induced by ribavirin therapy in patients with chronic hepatitis C virus infection: role of membrane oxidative damage

Inhibition of Henipavirus infection by RNA interference

Nipah virus (NiV) and Hendra virus (HeV) are recently emerged zoonotic paramyxoviruses exclusively grouped within a new genus, Henipavirus. These viruses cause fatal disease in a wide range of species, including humans. Both NiV and HeV have continued to re-emerge sporadically in Bangladesh and Australia, respectively. There are currently no therapeutics or vaccines available to treat Henipavirus infection and both are classified as BSL4 pathogens.

RNA interference (RNAi) is a process by which double-stranded RNA directs sequence-specific degradation of messenger RNA in animal and plant cells. Small interfering RNAs (siRNAs) mediate RNAi by inhibiting gene expression of homologous mRNA and our preliminary studies suggest RNAi may be a useful approach to developing novel therapies for these highly lethal pathogens. Eight NiV siRNA molecules (four L and four N gene specific), two HeV N gene specific, and two non-specific control siRNA molecules were designed and tested for their ability to inhibit a henipavirus minigenome replication system (which does not require the use of live virus) in addition to live virus infections in vitro. In the minigenome assay three out of the four siRNAs that targeted the L gene of NiV effectively inhibited replication. In contrast, only NiV N gene siRNAs were effective in reducing live NiV replication, suggesting inhibition of early, abundantly expressed gene transcripts may be more effective than later, less abundant transcripts. Additionally, some of the siRNAs effective against NiV infection were only partially effective inhibitors of HeV infection. An inverse correlation between the number of nucleotide mismatches and the efficacy of siRNA inhibition was observed. The demonstration that RNAi effectively inhibits henipavirus replication in vitro, is a novel approach and may provide an effective therapy for these highly lethal, zoonotic pathogens.

Management complexities of HIV/hepatitis C virus coinfection in the twenty-first century

Because of shared routes of transmission, hepatitis C virus (HCV) coinfection is common among HIV-infected persons. Because of the effectiveness of antiretroviral therapy, chronic HCV has now emerged as a major cause of morbidity and mortality in this population. Because chronic HCV is highly prevalent among HIV-infected patients and has a rapid disease progression, antiviral therapy with pegylated interferon plus ribavirin is critical for the long-term survival of HIV/HCV-coinfected patients. In this article, the authors review the (1) epidemiology of HCV among HIV-infected individuals, (2) effect of HIV on the natural history of chronic HCV, (3) impact of antiretroviral therapy on HCV coinfection, and (4) management of chronic HCV in the HIV-infected person.

Optimizing the current therapy for chronic hepatitis C virus: peginterferon and ribavirin dosing and the utility of growth factors

Achieving a sustained virologic response depends on the patient achieving three sequential independent milestones: virologic response, maintaining this response throughout treatment, and not relapsing after treatment has been completed. The ability to achieve these milestones depends on the doses of interferon/peginterferon and ribavirin used and on whether treatment with these medications is adjusted, interrupted, or prematurely discontinued in response to adverse events. This review discusses strategies to optimize peginterferon and ribavirin dosing and the impact that growth factors may have on the ability to achieve a sustained virologic response.

Does a rapid decline in the hematological and biochemical parameters induced by interferon and ribavirin combination therapy for the hepatitis C virus predict a sustained viral response?

BACKGROUND AND OBJECTIVES

To analyze whether rapid myelosuppression and a decrease in alanine aminotransferase (ALT) induced by standard interferon (IFN) and ribavirin (RBV) combination therapy predict a sustained viral response (SVR) in hepatitis C virus patients.

PATIENTS AND METHODS

Data from 111 patients (mean age 48.1 years) with chronic hepatitis C virus were retrospectively analyzed. All patients were treated with the same initial doses of IFN and RBV combination therapy. The following laboratory values were measured at baseline, and then at weeks 2, 4, 8, 12 and 24 of treatment: hemoglobin, white blood cells (WBCs), neutrophils, platelets and ALT. A delta value was then calculated for each interval from baseline (baseline values minus two weeks, etc). The delta value of each variable was then compared between the responders and nonresponders using Wilcoxon's signed rank test.

RESULTS

Sixty patients (54%) achieved an SVR. There were no significant differences between the responder and nonresponder groups for baseline variables. The delta value of ALT was the only significant marker in the prediction of an SVR. The mean +/- SD delta values for the ALT at week 2 of treatment were 71+/-92 U/L and 44+/-85 U/L for the responders and nonresponders, respectively (P<0.0046). At week 4, the values were 101+/-96 U/L and 84+/-100 U/L for the responders and nonresponders, respectively (P<0.0154). The decline was then calculated for the ALT as a percentage decrease from baseline: at weeks 2 and 4, the decreases were 64% and 66%, respectively, for the responders, and 43% and 41%, respectively, for the nonresponders. At week 2, the delta values for WBC count were found to be significant in predicting failure to achieve an SVR, with mean +/- SD delta values of 0.85 x 10(9)/L+/-1.48 x 10(9)/L and 1.53 x 10(9)/L+/-2.16 x 10(9)/L for the responders and nonresponders, respectively (P<0.0173). The same trend emerged at two weeks for neutrophils: 0.72 x 10(9)/L+/-1.33 x 10(9)/L for the responders and 1.02 x 10(9)/L+/-1.20 x 10(9)/L for the nonresponders (P<0.0150). The delta values were insignificant for hemoglobin, lowest hemoglobin values and platelets.

CONCLUSIONS

The decline rates of ALT from baseline to week 2 and 4 of IFN and RBV combination therapy are good predictors of an SVR. A significant drop in WBC and neutrophil values is a predictor of failure to achieve an SVR. The hemoglobin, platelets and lowest hemoglobin values failed to predict an SVR.

Ribavirin in the treatment of chronic hepatitis C

BACKGROUND AND AIM

Current practice guidelines recommend that individuals chronically infected with the hepatitis C virus (HCV) be treated with pegylated interferon plus ribavirin. Ribavirin, however, is associated with serious adverse events (AE), especially anemia. We review its mechanism of action, its importance in treating chronic hepatitis C (CHC) patients, the AE associated with its use, and techniques used to lessen these AE.

METHODS

Medline searches were performed using the keywords ribavirin and hepatitis, together with the keywords mechanism, anemia, liver transplant, renal function, pharmacokinetics, and dose reduction. Searches of abstracts of recent Digestive Diseases Week, American Association for the Study of Liver Diseases, and European Association for the Study of Liver Diseases meetings were also performed.

RESULTS

Ribavirin may be effective in treating CHC by affecting the virus or the host; for example by inducing viral mutations, blocking cellular enzymes, or affecting the host immune response. Although the pegylated interferons are the primary drugs used to treat CHC, a combination with ribavirin is more effective than pegylated interferon alone. Ribavirin-associated AE may be lessened by ribavirin dose reductions and by maintenance of the hematocrit.

CONCLUSIONS

Treatments of ribavirin toxicities, especially anemia, can allow patients to continue full-dose combination therapy with peginterferon and ribavirin, enhancing their probability of attaining a sustained virologic response (SVR). Treatment of CHC should be tailored to individual patients, especially those with renal dysfunction, and should include agents that treat the side-effects of CHC treatment. Monitoring of plasma ribavirin concentrations during treatment may help in the future.

Synthesis of 1-beta-D-ribofuranosyl-3-ethynyl-[1,2,4]triazole and its in vitro and in vivo efficacy against Hantavirus

There are no FDA approved drugs for the treatment of hemorrhagic fever with renal syndrome (HFRS), a serious human illnesses caused by hantaviruses. Clinical studies using ribavirin (RBV) to treat HFRS patients suggest that it provides an improved prognosis when given early in the course of disease. Given the unique antiviral activity of RBV and the lack of other lead scaffolds, we prepared a diverse series of 3-substituted 1,2,4-triazole-beta-ribosides and identified one with antiviral activity, 1-beta-d-ribofuranosyl-3-ethynyl-[1,2,4]triazole (ETAR). ETAR showed an EC(50) value of 10 and 4.4 microM for Hantaan virus (HTNV) and Andes virus, respectively. ETAR had weak activity against Crimean Congo hemorrhagic fever virus, but had no activity against Rift Valley fever virus. Intraperitoneally delivered ETAR offered protection to suckling mice challenged with HTNV with a approximately 25% survival at 12.5 and 25mg/kg ETAR, and a MTD of 17.1+/-0.7 days. ETAR was phosphorylated in Vero E6 cells to its 5'-triphosphate and reduced cellular GTP levels. In contrast to RBV, ETAR did not increase mutation frequency of the HTNV genome, which suggests it has a different mechanism of action than RBV. ETAR is an exciting and promising lead compound that will be elaborated in further synthetic investigations as a framework for the rational design of new antivirals for treatment of HFRS.

Development and validation of a chemiluminescent immunodetection assay amenable to high throughput screening of antiviral drugs for Nipah and Hendra virus

There are currently no antiviral drugs approved for the highly lethal Biosafety Level 4 pathogens Nipah and Hendra virus. A number of researchers are developing surrogate assays amenable to Biosafety Level 2 biocontainment but ultimately, the development of a high throughput screening method for directly quantifying these viruses in a Biosafety Level 4 environment will be critical for final evaluation of antiviral drugs identified in surrogate assays, in addition to reducing the time required for effective antiviral drug development. By adapting an existing immunoplaque assay and using enzyme linked immunodetection in a microtitre plate format, the current experiments describe a simple two step assay protocol involving an overnight virus inoculation of Vero cell monolayers (with or without antiviral drug treatment) at Biosafety Level 4, followed by cell fixation and virus inactivation enabling removal of plates from the Biosafety Level 4 laboratory and a subsequent immunodetection assay using a chemiluminescent horse radish peroxidase substrate to be performed at Biosafety Level 2. The analytical sensitivity (limit of detection) of this assay is 100 tissue culture infectious dose50/ml of either Nipah or Hendra virus. In addition this assay enables linear quantitation of virus over three orders of magnitude and is unaffected by dimethyl sulfoxide concentrations of 1% or less. Intra-assay coefficients of variation are acceptable (less than 20%) when detecting a minimum of 1000 tissue culture infectious dose50/ml of either virus although inter-assay variation is considerably greater. By an assessment of efficacies of the broad spectrum antiviral Ribavirin and an experimental fusion inhibitory peptide, this assay reveals a good correlation with previously published fluorescent immunodetection assays. The current experiments describe for the first time, a high throughput screening method amenable for direct assessment of live henipavirus antiviral drug activity.

Approach to the management of patients with chronic hepatitis C who failed to achieve sustained virologic response

The combination of PEGIFN and RBV is the most effective therapy for patients with chronic hepatitis C. Although more than half of all patients are able to achieve SVR, a significant proportion of patients, particularly those with genotype 1, fail to have undetectable HCV RNA during treatment or relapse after completing therapy with return of detectable HCV RNA. An approach in the management of these patients is to identify factors that could have led to the NR or relapse and that could be corrected before or during a second course of therapy. Because fibrosis progression occurs slowly over decades for many patients with chronic hepatitis C, avoiding alcohol or other factors that could lead to fibrosis progression may be sufficient for the vast majority of patients. Other options that could be considered in patients who have more advanced disease include retreating with one of several new antiviral agents; retreating with higher doses of IFN or PEGIFN and RBV; or using IFN, PEGIFN, or RBV monotherapy long-term as maintenance therapy. The safety and efficacy of these approaches is being evaluated in numerous clinical trials.

Early decline of hemoglobin can predict progression of hemolytic anemia during pegylated interferon and ribavirin combination therapy in patients with chronic hepatitis C

AIM

Ribavirin, used to treat chronic hepatitis C, can induce hemolytic anemia, forcing the discontinuance of treatment. To establish a predictive measure to help circumvent this, we evaluated the relationship of hemoglobin (Hb) decline with the discontinuance of treatment during the progression of ribavirin-induced anemia.

METHODS

One hundred and sixteen patients (71% male) with genotype 1 chronic hepatitis C were treated with pegylated interferon (PegIFN) alpha-2b and ribavirin. The mean age was 50.6 years and 55% were IFN naïve. A decline of Hb concentration by 2 g/dL at two weeks from the start of the treatment ("2 by 2" standard) was adopted as the predictive factor for the progression of anemia.

RESULTS

By applying the "2 by 2" standard, with DeltaHb >/= 2 g/dL (34%, n = 39), treatment was discontinued in 12 cases (31%), three of which (8%) because of severe anemia. ForDeltaHb < 2 g/dL (64%, n = 76), treatment was discontinued in 11 (14%) cases; none due to severe anemia. Ten percent (4/39) of patients showed the minimum Hb </= 8.5 g/dL in the DeltaHb >/= 2 g/dL group, with none in the DeltaHb < 2 g/dL group (P = 0.001). Furthermore, the patients with minimum Hb </= 8.5 g/dL were found only in the "2 by 2" standard-positive and low CL/F (<15) group (4/29, 14%).

CONCLUSION

Monitoring the Hb decline using the "2 by 2" standard can identify patients who are prone to developing severe anemia. Further prospective studies are needed using ribavirin reduction based on the "2 by 2" standard.

Ribavirin considerations in treatment optimization

Ribavirin is a guanosine analogue that has little antiviral activity when used alone, but considerably enhances the efficacy of conventional and pegylated interferon in the treatment of hepatitis C virus (HCV). The precise mode of action of ribavirin is not fully understood; however, it is crucial for the achievement of high sustained virological response (SVR) rates by enhancing virological response and reducing relapse rates. Data from several studies have confirmed that higher initial doses of ribavirin lead to higher SVR rates. Furthermore, intensified ribavirin dosing might also improve SVR rates in ‘difficult-to-cure’ patients. It is also important to minimize ribavirin dose reductions to promote high SVR rates and to maintain ribavirin levels throughout treatment to prevent viral breakthrough and relapse. The pharmacokinetic profile of ribavirin reveals a long elimination half-life due to accumulation in the blood, such that its side-effect profile includes haemolytic anaemia. Therefore, finding the optimal ribavirin dose requires a balance between efficacy and its associated side effects to ensure improved patient outcomes. Here, we discuss how optimizing the ribavirin component of combined therapy for HCV is an essential part of treatment optimization.

Zinc supplementation prevents the increase of transaminase in chronic hepatitis C patients during combination therapy with pegylated interferon alpha-2b and ribavirin

We investigated the effects of zinc supplementation on clinical observations in chronic hepatitis C patients receiving pegylated interferon (PEG-IFN) alpha-2b plus ribavirin combination therapy. Patients were randomly allocated to receive 150 mg polaprezinc (zinc group, n=11) or no supplement (control group, n=12) daily in addition to PEG-IFN alpha-2b plus ribavirin therapy and 300 mg vitamin E and 600 mg vitamin C supplementation daily for 48 wk. Among the patients who continued treatment, the serum alanine aminotransferase (ALT) level at 12 wk in the zinc group was significantly lower than that in the control group. All patients in the zinc group (9/9) and 67% (8/12) of the control patients at 24 wk, and all patients in the zinc group (7/7) and 60% (6/10) of the control patients at 48 wk showed a decrease in serum ALT levels to within the normal range (7-44 U/L). HCV RNA disappeared in all patients (7/7) in the zinc group and in 8 of 10 control patients at 48 wk. Polaprezinc supplementation decreased plasma thiobarbituric acid reactive substances and prevented the decrease of polyunsaturated fatty acids of erythrocyte membrane phospholipids. No significant differences were observed in the dosage of medicines or other clinical data during the treatment. These observations indicate that polaprezinc supplementation may have induced some antioxidative functions in the liver which resulted in reduced hepatocyte injury during PEG-IFN alpha-2b plus ribavirin therapy.

Predictors of Severe Haematological Toxicity Secondary to Pegylated Interferon plus Ribavirin Treatment in HIV-HCV-Coinfected Patients

Background

Haematological adverse events related to pegylated interferon (PEG-IFN) and ribavirin (RBV) therapy could affect the patients’ quality of life; however, the risk factors for severe haematological toxicity associated with this therapy in patients coinfected with hepatitis C virus (HCV) and HIV are unclear. The objective of this study was to identify predictors of severe haematological toxicity among HIV-HCV-coinfected patients treated with PEG-IFN plus RBV.

Methods

This retrospective multicentric study included 237 HIV-HCV-coinfected patients on PEG-IFN plus RBV. Predictors of severe anaemia, neutropenia, thrombocytopenia and overall haematological toxicity were analyzed.

Results

Eighty (34%) individuals showed an episode of severe haematological toxicity. Severe anaemia, neutropenia and thrombocytopenia occurred in 32 (13%), 42 (18%) and 26 (11%) patients, respectively. In the multivariate analysis, zidovudine use (adjusted odds ratio [AOR] 3.3; 95% confidence interval [CI] 1.6–10; P=0.001), baseline body weight <65 kg (AOR 2.5; 95% CI 1.1–5; P=0.024), cirrhosis (AOR 5; 95% CI 1.6–16.6; P=0.006), PEG-IFN-α2a (AOR 2.7; 95% CI 1.1–6.6; P=0.029) and pretreatment haemoglobin level <14 g/dl (AOR 2.7; 95% CI 1.3–5.5; P=0.005) were associated with any kind of severe haematological toxicity. Likewise, haemoglobin level <13 g/dl, neutrophil counts <2,500 cells/mm3 and platelet counts <175,000 cells/mm3 were independent predictors of severe anaemia, neutropenia and thrombocytopenia, respectively.

Conclusions

Zidovudine treatment, cirrhosis, baseline low body weight, use of PEG-IFN-α2a, and baseline haemoglobin level <14 g/dl are predictors of overall severe haematological toxicity secondary to PEG-IFN plus RBV in HIV-infected individuals. Low pretreatment levels of each haematological series predict a significant decrease of their values during therapy.

Milk thistle for alcoholic and/or hepatitis B or C virus liver diseases

BACKGROUND

Alcohol and hepatotoxic viruses cause the majority of liver diseases. Randomised clinical trials have assessed whether extracts of milk thistle, Silybum marianum (L) Gaertneri, have any effect in patients with alcoholic and/or hepatitis B or C virus liver diseases.

OBJECTIVES

To assess the beneficial and harmful effects of milk thistle or milk thistle constituents versus placebo or no intervention in patients with alcoholic liver disease and/or viral liver diseases (hepatitis B and hepatitis C).

SEARCH STRATEGY

The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and full text searches were combined (July 2007). Manufacturers and researchers in the field were contacted.

SELECTION CRITERIA

Only randomised clinical trials in patients with alcoholic and/or hepatitis B or C virus liver diseases (acute and chronic) were included. Interventions encompassed milk thistle at any dose or duration versus placebo or no intervention. The trials could be double blind, single blind, or unblinded. The trials could be unpublished or published and no language limitations were applied.

DATA COLLECTION AND ANALYSIS

The primary outcome measure was mortality. Binary outcomes are reported as relative risks (RR) with 95% confidence interval (CI). Subgroup analyses were performed with regard to methodological quality.

MAIN RESULTS

Eighteen randomised clinical trials assessed milk thistle in 1088 patients with alcoholic and/or hepatitis B or C virus liver diseases. The methodological quality was low: only 28.6% of the trials reported high methodological quality characteristics. Milk thistle versus placebo or no intervention had no significant effect on mortality (RR 0.78, 95% CI 0.53 to 1.15), complications of liver disease (RR 0.95, 95% CI 0.83 to 1.09), or liver histology. Liver-related mortality was significantly reduced by milk thistle in all trials (RR 0.50, 95% CI 0.29 to 0.88), but not in high-quality trials (RR 0.57, 95% CI 0.28 to 1.19). Milk thistle was not associated with a significantly increased risk of adverse events (RR 0.83, 95% CI 0.46 to 1.50).

AUTHORS' CONCLUSIONS

Our results question the beneficial effects of milk thistle for patients with alcoholic and/or hepatitis B or C virus liver diseases and highlight the lack of high-quality evidence to support this intervention. Adequately conducted and reported randomised clinical trials on milk thistle versus placebo are needed.

Redox regulation of hepatitis C in nonalcoholic and alcoholic liver

Hepatitis C virus (HCV) is an RNA virus of the Flaviviridae family that is estimated to have infected 170 million people worldwide. HCV can cause serious liver disease in humans, such as cirrhosis, steatosis, and hepatocellular carcinoma. HCV induces a state of oxidative/nitrosative stress in patients through multiple mechanisms, and this redox perturbation has been recognized as a key player in HCV-induced pathogenesis. Studies have shown that alcohol synergizes with HCV in the pathogenesis of liver disease, and part of these effects may be mediated by reactive species that are generated during hepatic metabolism of alcohol. Furthermore, reactive species and alcohol may influence HCV replication and the outcome of interferon therapy. Alcohol consumption has also been associated with increased sequence heterogeneity of the HCV RNA sequences, suggesting multiple modes of interaction between alcohol and HCV. This review summarizes the current understanding of oxidative and nitrosative stress during HCV infection and possible combined effects of HCV, alcohol, and reactive species in the pathogenesis of liver disease.

Treatment of chronic hepatitis C virus genotype 1 with peginterferon, ribavirin, and epoetin alpha

Successful treatment of chronic HCV with peginterferon (PEGIFN) and ribavirin (RVN) is often limited by anemia. We performed the present study to determine if utilizing epoetin alpha (EPO) with or without a higher dose of RVN could enhance sustained virologic response (SVR). We randomized 150 treatment-naive patients with chronic HCV genotype 1 into 3 treatment groups: (1) PEGIFN alpha-2b (1.5 microg/kg/week) + weight-based RVN (WBR) 13.3 mg/kg/day (800 to 1400 mg/day); (2) PEGIFN alpha-2b + WBRVN + EPO (40,000 U/week); or (3) PEGIFN alpha-2b + higher dose WBR 15.2 mg/kg/day (1000 to 1600 mg/day) + EPO. We initiated EPO at the onset of therapy to maintain the hemoglobin between 12 and 15 g/dL. When required, we reduced RVN by 200-mg steps. African Americans compose 36% of the population. A significantly smaller percentage of group 2 patients had a decline in hemoglobin to less than 10 g/dL (9% versus 34%; P < 0.05) and required that the RVN dose be reduced (10% versus 40%; P < 0.05) compared to group 1 patients. Despite this, SVR was similar in these groups (19% to 29%). SVR was significantly greater (P < 0.05) in group 3 patients (49%). This resulted from a significant decline (P < 0.05) in relapse rate; only 8% versus 38% for groups 1 and 2.

CONCLUSION

We conclude that using EPO in all subjects at the initiation of PEGIFN and RVN treatment will not enhance SVR given the same starting dose of RVN. In contrast, a higher starting dose of RVN was associated with a lower relapse rate and higher rate of SVR.

WITHDRAWN: Ribavirin with or without alpha interferon for chronic hepatitis C

BACKGROUND

Hepatitis C is a major cause of liver-related morbidity and mortality. Ribavirin plus interferon combination therapy is presently considered the optimal treatment of interferon naive patients with chronic hepatitis C, but its role in relapsers and non-responders to previous interferon therapy is not established.

OBJECTIVES

To assess the efficacy and safety of ribavirin alone or in combination with alpha interferon in interferon naive patients, relapsers, and non-responders with chronic hepatitis C.

SEARCH STRATEGY

Eligible trials were identified through searches on electronic databases: The Cochrane Hepato-Biliary Group Controlled Trials Register (August 2001), The Cochrane Controlled Trials Register on The Cochrane Library Issue 3, 2001, MEDLINE (1966 - August 2001), and EMBASE (1985 - August 2001). Manual searches of bibliographies and journals were done as well as authors of trials and pharmaceutical companies producing ribavirin or interferon were contacted.

SELECTION CRITERIA

We included all randomised trials comparing ribavirin with or without alpha interferon versus no intervention, placebo, or alpha interferon for chronic hepatitis C.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were the 'sustained' (six months after treatment) virological response, and morbidity plus mortality. The secondary outcome measures were the 'end of treatment' and 'sustained' biochemical response, the 'end of treatment' virologic response, histology, quality of life, and adverse events.

MAIN RESULTS

We included eight trials in which 271 patients were randomised to ribavirin versus placebo or no intervention and 48 trials in which 6585 patients were randomised to interferon with or without ribavirin. Compared with placebo or no intervention, ribavirin monotherapy had no significant effect on the virological response or histology and only a transient effect on the biochemical response. Compared with interferon, combination therapy reduced the risk of not having a sustained virological response by 26% in naive patients (relative risk (RR) 0.74; 95% confidence interval (CI) 0.70-0.78), 33% in relapsers (RR 0.67; 95% CI 0.57-0.78), and 11% in non-responders (RR 0.89; 95% CI 0.83-0.96). There was no significant effect on morbidity plus mortality (Peto odds ratio 0.45; 95% CI 0.19-1.06). Irrespective of previous therapy, combination therapy significantly reduced the risk of not having a sustained biochemical response (RR 0.76; 95% CI 0.59-0.84) or improved histology (RR 0.67; 95% CI 0.56-0.81). Combination therapy also significantly increased the risk of treatment discontinuation (RR 1.28; 95% CI 1.07-1.52) and several types of adverse events.

AUTHORS' CONCLUSIONS

Combination therapy increased the number of naive patients, relapsers, and non-responders with a sustained virological, biochemical, or histological response, but also the occurrence of adverse events.

Recent progress in henipavirus research

Following the discovery of two new paramyxoviruses in the 1990s, much effort has been placed on rapidly finding the reservoir hosts, characterising the genomes, identifying the viral receptors and formulating potential vaccines and therapeutic options for these viruses, Hendra and Nipah viruses caused zoonotic disease on a scale not seen before with other paramyxoviruses. Nipah virus particularly caused high morbidity and mortality in humans and high morbidity in pig populations in the first outbreak in Malaysia. Both viruses continue to pose a threat with sporadic outbreaks continuing into the 21st century. Experimental and surveillance studies identified that pteropus bats are the reservoir hosts. Research continues in an attempt to understand events that precipitated spillover of these viruses. Discovered on the cusp of the molecular technology revolution, much progress has been made in understanding these new viruses. This review endeavours to capture the depth and breadth of these recent advances.

Early ribavirin pharmacokinetics, HCV RNA and alanine aminotransferase kinetics in HIV/HCV co-infected patients during treatment with pegylated interferon and ribavirin

BACKGROUND/AIMS

We evaluated whether early ribavirin pharmacokinetics differ comparing hepatitis C/human immunodeficiency virus coinfected sustained virological responders and nonresponders.

METHODS

Twenty-four treatment-naive coinfected patients received pegylated-interferon alfa-2b (12 kDa) (1.5 microg/kg) once weekly plus daily ribavirin (13.6 mg/kg/d) for up to 48 weeks. Serum HCV RNA, serum alanine aminotransferase, and plasma ribavirin levels were measured frequently during the first 16 days of therapy and monthly thereafter.

RESULTS

Six patients were sustained responders. During the first 4 weeks of treatment, median plasma ribavirin levels and area under the ribavirin curve were significantly lower (p<0.0001 and p<0.01, respectively) in sustained responders compared with nonresponders. Compared to ribavirin levels at weeks 2 and 4, ribavirin levels in sustained responders continued to increase significantly until week 8 (p<0.02). At week 4, hemoglobin declines were significantly (p=0.002) greater in sustained responders than nonresponders. At week 1, serum HCV RNA levels and changes in alanine aminotransferase levels relative to baseline could identify likely responders better than plasma ribavirin levels.

CONCLUSIONS

We conjecture that intracellular ribavirin accumulation may be enhanced early in treatment in coinfected sustained responders, although this hypothesis should be investigated further. At week 1, serum HCV RNA and changes in alanine aminotransferase levels relative to baseline might identify likely responders.

Anemia in liver transplant recipients undergoing antiviral treatment for recurrent hepatitis C

Adherence to antiviral therapy is essential to achieve sustained virological responses in patients treated for hepatitis C. An important limitation to use of appropriate doses of ribavirin is development of anemia. The aim of this study is to identify risk factors associated with anemia in liver transplant recipients undergoing treatment for recurrent hepatitis C virus (HCV). Retrospective analysis was performed on 115 adult liver transplantation (LT) recipients who received antiviral treatment. Anemia was defined as hemoglobin of <10 gm/dL or the use of erythropoietin replacement therapy. Variables found to be significant in univariate analysis were further studied in multivariate analysis. The mean (+/- standard deviation [SD]) age of our cohort was 52.1 (+/- 8.8) yr. Anemia developed in 44 patients (38.3%). Mean (+/- SD) onset of anemia was 8.9 (+/- 6.8) weeks after initiation of antiviral therapy. A total of 30 patients (26%) required erythropoietin replacement, at a mean (+/- SD) of 7.9 (+/- 6.0) weeks after start of antiviral treatment. A total of 27 patients (24%) required ribavirin dose reduction, at a mean (+/- SD) time to dose reduction of 8.1 (+/- 6.3) weeks. In univariate analysis, body mass index (BMI) (P < 0.01), mycophenolate mofetil use (P = 0.05), trimethoprim-sulfamethoxazole (P = 0.02), and age (P = 0.02) were statistically significant. In conclusion, in multivariate analysis, BMI (P < 0.01) and age (P = 0.02) were found to be independent predictors of anemia. Anemia is common in liver transplant recipients treated for recurrent HCV. Special vigilance is required for older patients and patients with a low BMI.

High-dose vitamins E and C supplementation prevents ribavirin-induced hemolytic anemia in patients with chronic hepatitis C

AIM

In combination therapy using interferon (IFN) and ribavirin for chronic hepatitis C, reduced doses should be used due to ribavirin-induced hemolytic anemia. The present study aimed to elucidate whether high-dose vitamins E and C supplementation attenuated ribavirin-induced hemolytic anemia.

METHODS

Twenty-one consecutive patients with chronic hepatitis C were enrolled in this study between July 2003 and December 2004, and received high-dose vitamins E (2000 mg) and C (2000 mg) supplementation, daily, in addition to IFN alfa-2b and ribavirin combination therapy (vitamins E/C group). Twenty-one sex- and age-matched patients who received a standard regimen of IFN alfa-2b and ribavirin for chronic hepatitis C between January 2001 and June 2003 were evaluated as the control group.

RESULTS

Decrease in hemoglobin level was significantly prevented in the vitamins E and C group compared to that in the control group (P = 0.029). Three (14.3%) patients in the control group discontinued treatment because of anemia, while no treated patient dropped out of the study due to anemia. Sustained virological response was not significantly different between the two groups.

CONCLUSION

High-dose vitamins E and C supplementation prevented ribavirin-induced hemolytic anemia during combination therapy with ribavirin and IFN alfa-2b in patients with chronic hepatitis C.

Strategies for managing anemia in hepatitis C patients undergoing antiviral therapy

Anemia is a common side effect that begins soon after the initiation of peginterferon/ribavirin in the treatment of hepatitis C virus (HCV) infection. It can cause symptoms that negatively impact quality of life (QOL) and is the most common reason for reducing the dose and temporarily or permanently discontinuing ribavirin. Such dose modifications have been shown to reduce the efficacy of treatment. Administering erythropoietin can improve anemia caused by peginterferon and ribavirin therapy and is more effective than dose reduction at improving QOL during treatment. However, erythropoietin, which is not approved by the U.S. Food and Drug Administration (FDA) for use in patients with HCV infection, adds another parenteral drug to the patient's treatment regimen, and is associated with additional costs, inconvenience, and potential side effects. A new ribavirin analog, viramidine, is expected to be associated with a lower incidence of anemia and, if proven effective, may eventually be substituted for ribavirin in combination with peginterferon to treat chronic hepatitis C. In the meantime, physicians must make the best possible use of the available options for managing anemia, especially in select patient groups who are most at risk for anemia and its complications.

Activation of the ER stress gene gadd153 by hepatitis C virus sensitizes cells to oxidant injury

HCV induces endoplasmic reticulum (ER) stress which correlates with transcriptional induction of ER stress genes. Previously, we reported that expression of HCV structural proteins activates the ER stress and pro-apoptotic gene gadd153 which plays a relevant role in cell death induced by oxidative stress. In the present study, using human hepatic cell lines Huh7 carrying a full-length HCV replicon, we demonstrated that replication and expression of the complete set of HCV proteins were associated with elevated expression of gadd153. Analysis of gadd153 promoter activity revealed that both the ATF4 and the ATF6 pathways, which are typically induced during ER stress response, contribute to the induction of gadd153 in HCV replicon cells. Activation of the ATF4 pathway was confirmed by identification of increased levels of ATF4 protein in replicon cells. Importantly, we showed that, following H2O2 treatment, gadd153 gene reached higher levels of expression in replicon cells. Consistent with the marked induction of the pro-apoptotic gene gadd153, HCV replicon cells showed an increased vulnerability to oxidant injury. Treatment of replicon cells with a specific small interfering RNA, targeted to gadd153 gene, reduced basal expression of gadd153 and decreased cell death following H2O2. These findings suggest that gadd153 may play a major role in sensitivity of HCV replicon cell to oxidative stress.

Changing treatment paradigms: hepatitis C virus in HIV-infected patients

The evaluation of hepatic histology and treatment of hepatitis C virus (HCV)/HIV-coinfected patients is rapidly changing. HCV has become an important cause of mortality in HIV-infected patients. Consequently, assessment of liver histology in all coinfected patients is particularly important. The evaluation of hepatic histology is shifting from reliance on the liver biopsy toward noninvasive modalities. Additionally, the importance of HCV-associated morbidity and mortality in HIV-infected patients has prompted increasing numbers of these patients to be HCV treatment candidates. Prospective trials in coinfected patients have reported lower sustained virologic responses compared to HCV-monoinfected patients. Consequently, the numbers of coinfected nonresponders to pegylated interferon/ribavirin continues to increase. Because none of the presently available treatment modalities for pegylated interferon/ribavirin nonresponders are clearly efficacious, management decisions must be individualized. The options include, HCV-specific medications, maintenance therapy, the use of alternative interferon formulations, and observation. HCV-specific agents, particularly protease and polymerase inhibitors, show early promise in HCV-monoinfected individuals. Their use in coinfected patients, however, is likely to be delayed for several years, and they are likely to be used in combination with interferon. Low-dose pegylated interferon, administered in an attempt to slow fibrosis progression (maintenance therapy), is being evaluated in several large prospective trials in monoinfected and coinfected patients. Observation may be best for nonresponders with relatively mild hepatic histology. In summary, HCV treatment will likely follow the example forged by HIV. In the near future, combinations of different drugs will likely be used simultaneously to result in durable viral suppression.

Viusid, a nutritional supplement, in combination with interferon alpha-2b and ribavirin in patients with chronic hepatitis C

BACKGROUND

The pathogenesis of chronic hepatitis C (CHC) is associated to severe oxidative stress that leads to necro-inflammation and progression of fibrosis. Previous trials suggested that antioxidative therapy may have a beneficial effect. We evaluated the efficacy and safety of Viusid in combination with interferon alpha-2b (IFN alpha-2b) and ribavirin in patients with CHC.

METHODS

We randomly assigned 100 patients, between October 2002 and December 2004, in two arms: IFN alpha-2b (5 MU on alternate days), ribavirin at a dose of 13 mg/kg daily and Viusid (three sachets daily) vs. IFN alpha-2b (5 MU on alternate days) and ribavirin at a dose of 13 mg/kg daily. Subjects were treated for 48 weeks and then followed for an additional 24 weeks. The primary end point was the histologic response (reduction of at least two points without fibrosis worsening in the total score on the Histological Activity Index).

RESULTS

A significantly high proportion of patients who received combined therapy plus Viusid had a histologic response better than those patients who received IFN alpha-2b and ribavirin (57% vs. 37%, P=0.03). The patients with virologic response achieved the highest percentages of histologic response, irrespective of assigned treatment. Among non-responders, the highest reduction in the mean change from baseline score for necro-inflammatory activity (NA) and fibrosis (F) was reported in patients treated with Viusid [NA, -1.50 (Viusid), -1.20 (without Viusid); F, -0.31 (Viusid), 0.00 (without Viusid)]. Sustained normalization of serum alanine aminotransferase concentration was highest in the Viusid group compared with standard therapy (67% vs. 41%, P=0.009). The overall safety profile was similar in both groups, but interestingly, the anemia was less intense in the group with Viusid (P=0.04).

CONCLUSIONS

Our results suggest that triple therapy with Viusid, IFN alpha-2b and ribavirin was well tolerated and may have a beneficial effect on histologic and biochemical variables. The intensity of anemia is reduced in patients treated with Viusid.

Impaired Filterability of Erythrocytes from Patients with Chronic Hepatitis C and Effects of Eicosapentaenoic Acid on the Filterability

Although erythrocyte filterability plays a key role in microcirculation, it is unknown whether the filterability of erythrocytes from patients with chronic hepatitis C (CH-C) is impaired. This study aimed to investigate erythrocyte filterability in CH-C patients in relation to medical treatment. The mean erythrocyte filterability (%) for all 24 patients with CH-C (69.2 +/- 10.8%) was significantly lower than that for 5 normal controls (80.5 +/- 1.7%, P < 0.03). In 8 patients, the combination therapy of ribavirin (RBV) and interferon improved liver function but caused anemia. The filterability after treatment (57.8 +/- 12.8%) was lower than that before treatment (70.8 +/- 9.7%, P < 0.05). Decreased filterability showed no correlation with the mean corpuscular volume or mean corpuscular Hb concentration during treatment, suggesting that the decrease in filterability mainly arises from changes in erythrocyte membrane properties. We investigated the protective effects of eicosapentaenoic acid (EPA) on the RBV-induced anemia. Filterability in 7 responders was markedly improved from 68.4 +/- 4.6% to 77.4 +/- 2.4% (P < 0.001), but not in 3 nonresponders. In the responders, the progression of anemia was restrained. In conclusion, we found an obvious impairment of the filterability of erythrocytes from CH-C patients, further impairment of the filterability induced by oxidative membrane damage caused by RBV leading to hemolytic anemia, and amelioration of the filterability caused by the antioxidative effects of EPA.

Role of erythrocytes as a reservoir for ribavirin and relationship with adverse reactions in the early phase of interferon combination therapy for chronic hepatitis C virus infections

We investigated the relationship between serum ribavirin concentrations and clearance, as well as therapeutic efficacy and adverse reactions, in 97 Japanese patients with chronic hepatitis C virus infections treated with a 6-month course of high-dose alpha2b interferon (6 million units/day) plus ribavirin (600 to 800 mg/day) combination therapy. This randomized trial showed that the saturation of ribavirin uptake after taking ribavirin capsules does not occur within a dose range of 600 to 800 mg/day, which is a standard dosage used clinically in Japan. Serum ribavirin concentrations and clearance did not correlate with sustained virological response rates. Fourteen patients discontinued therapy because of adverse reactions, and sustained virological response rates were significantly reduced by discontinuation of therapy, while dose reduction of ribavirin did not alter the therapeutic effects. Ribavirin concentrations after 1 week and ribavirin clearance were significantly correlated with discontinuation of ribavirin; however, a multiple-regression analysis revealed that only hemoglobin concentration, but not ribavirin clearance, was a significant factor for discontinuation of therapy (odds ratio, 0.514; 95% confidence interval, 0.311 to 0.85; P = 0.0095). It appears that peripheral erythrocytes may act as a reservoir for ribavirin and regulate serum ribavirin levels in the very early phase of treatment.

Optimizing Treatment Outcomes in Chronic Hepatitis C: Management of Non-Response

The overarching goal in treating chronic hepatitis C (CHC) is the prevention of serious hepatic complications such as cirrhosis, end-stage liver disease and hepatocellular carcinoma. Successful eradication of the hepatitis C virus has been shown to prevent liver disease progression and even promote regression of fibrosis. The treatment of CHC has improved significantly over the past decade with the introduction of interferons (IFNs), and more recently, pegylated IFNs. Up to two-thirds of all patients treated with a pegylated IFN combined with ribavirin can now achieve viral eradication if treated according to current guidelines. Despite this success rate, limited treatment options currently exist for the growing number of patients who do not respond to this combination, and those who have previously failed treatment with conventional IFN-based regimens. There are numerous host-and viral-related factors that can contribute to these outcomes. In addition, treatment insufficiency, whether due to treatment type, side effects or non-compliance, can result in inadequate antiviral pressure and a reduced likelihood of response. This review explores putative management strategies for patients who have previously failed to achieve a response to IFN-based therapy, and summarises retreatment options that have been, and are currently being evaluated.

Impaired erythropoietin production in liver transplant recipients: the role of calcineurin inhibitors

Anemia is common following liver transplantation. Because cyclosporine inhibits erythropoietin (Epo) production in experimental models, we investigated whether Epo production was impaired in liver transplant recipients receiving a cyclosporine- or tacrolimus-based immunosuppressive regimen. First, serum Epo levels were measured before and 1 year after transplantation in 35 liver transplant recipients. Second, serum Epo levels were compared in a large series of liver transplant recipients with stable graft and renal functions: 27 receiving a cyclosporine-based and 31 receiving a tacrolimus-based immunosuppressive regimen. A reference group was made up of 22 blood donors and 21 nontransplanted subjects with iron-deficiency anemia. Serum Epo levels were significantly lower after than before liver transplantation, especially in cyclosporine-treated patients. Serum Epo concentrations correlated with hematocrit values in both transplant recipients and control subjects. Using multiple linear regression models, the polynomial relationship between hematocrit and serum Epo values was similar to the control group in patients under tacrolimus, whereas Epo production was significantly reduced in patients under cyclosporine-based immunosuppression. Hematocrit values and the type of calcineurin inhibitor were the only parameters independently related to Epo levels. In conclusion, cyclosporine, but not tacrolimus, inhibits Epo production at the doses used in clinical practice.

Membrane skeletal protein S-glutathionylation and hemolysis in human red blood cells

In this work, protein-glutathione mixed disulfide formation in human red blood cells (RBCs) was evaluated in vitro by using the thiol-specific reagent diamide. We investigated what mechanism could lead to S-glutathionylation of membrane skeletal proteins, what are the main target proteins, and the correlation between protein S-glutathionylation and RBC hemolysis. Diamide caused a decrease in the reduced form of glutathione (GSH), which was accompanied by an increase in the basal level of glutathione disulfide (GSSG) and in S-glutathionylation of protein 4.2 and spectrin. The increase in membrane skeletal protein S-glutathionylation was correlated with a lower susceptibility of RBCs to osmotic hemolysis, suggesting that S-glutathionylation of protein 4.2 and spectrin could contribute to regulate RBC membrane stability.

Zidovudine use but not weight-based ribavirin dosing impacts anaemia during HCV treatment in HIV-infected persons

Anaemia during peginterferon (PEG-IFN) and ribavirin (RBV) therapy is common in human immunodeficiency virus/hepatitis C virus (HIV/HCV)-coinfected patients despite the use of lower doses of RBV than are recommended for HIV-seronegative persons. In addition, concurrent zidovudine (ZDV) may exacerbate the anaemia caused by PEG-IFN and RBV. We retrospectively analysed the incidence of anaemia, RBV dose reduction and epoetin-alpha (EPO) use among coinfected patients treated with PEG-IFN and weight-based RBV (800-1400 mg/day) who enrolled in two clinical trials and had haemoglobin (Hb) levels assessed at baseline and after 4 and/or 12 weeks of HCV treatment. Overall, 217 patients were included; pre-treatment Hb levels (mean 14.7 g/dL) were similar in all patients, including ZDV users (29% of patients). After 4 weeks of therapy, the mean Hb decline was greater among ZDV recipients (3.13 g/dL) compared with those on other anti-retroviral treatment (ART) (2.13 g/dL) or on no ART (1.47 g/dL) (P < 0.0001). RBV dose reduction and EPO use were more common in patients taking ZDV compared with those not taking ZDV (P < 0.0001). RBV dose was not associated with Hb reduction, RBV dose reduction or EPO use. Virologic response after 12 weeks of therapy and the treatment discontinuation rate did not differ by ZDV use. The use of ZDV but not weight-based RBV dosing was associated with an increased risk of anaemia, RBV dose reduction or EPO use in coinfected patients treated with PEG-IFN/RBV. However, ZDV use was not associated with higher rates of treatment discontinuation or lower early virologic response rates. HIV and hepatitis C care providers should be cognizant of these data.

Feline model of acute nipah virus infection and protection with a soluble glycoprotein-based subunit vaccine

Nipah virus (NiV) and Hendra virus (HeV) are paramyxoviruses capable of causing considerable morbidity and mortality in a number of mammalian species, including humans. Case reports from outbreaks and previous challenge experiments have suggested that cats were highly susceptible to NiV infection, responding with a severe respiratory disease and systemic infection. Here we have assessed the cat as a model of experimental NiV infection and use it in the evaluation of a subunit vaccine comprised of soluble G glycoprotein (sG). Two groups of two adult cats each were inoculated subcutaneously with either 500 or 5,000 50% tissue culture infective dose(s) (TCID(50)) of NiV. Animals were monitored closely for disease onset, and extensive analysis was conducted on samples and tissues taken during infection and at necropsy to determine viral load and tissue tropism. All animals developed clinical disease 6 to 9 days postinfection, a finding consistent with previous observations. In a subsequent experiment, two cats were immunized with HeV sG and two were immunized with NiV sG. Homologous serum neutralizing titers were greater than 1:20,000, and heterologous titers were greater than 1:20,000 to 16-fold lower. Immunized animals and two additional naive controls were then challenged subcutaneously with 500 TCID(50) of NiV. Naive animals developed clinical disease 6 to 13 days postinfection, whereas none of the immunized animals showed any sign of disease. TaqMan PCR analysis of samples from naive animals revealed considerable levels of NiV genome in a wide range of tissues, whereas the genome was evident in only two immunized cats in only four samples and well below the limit of accurate detection. These results indicate that the cat provides a consistent model for acute NiV infection and associated pathogenesis and an effective subunit vaccine strategy appears achievable.

Decline in haemoglobin A1c values in diabetic patients receiving interferon-alpha and ribavirin for chronic hepatitis C

Haemoglobin A1c (A1c) levels are lower during haemolysis because of the shorter exposure of haemoglobin (Hb) to plasma glucose. Ribavirin (RBV) used in combination with interferon-alpha (IFN) for chronic hepatitis C causes reversible haemolytic anaemia. This study examined the extent to which RBV treatment influences A1c levels in diabetic patients. A retrospective analysis identified 32 diabetic patients who underwent hepatitis C treatment with IFN and RBV. Each subject had at least three measures of A1c, Hb and glucose: before, during and after therapy. A1c values decreased from a mean pretreatment level of 7.2% to an on-treatment A1c level of 5.2% [mean paired difference -2.01%; 95% confidence interval (CI) -1.59% to -2.43%; P < 0.001]. During therapy, mean Hb levels decreased from 15.1 g/dL at baseline to a nadir of 11.7 g/dL (P < 0.001) with a rise in lactose dehydrogenase levels and reticulocyte counts, and unchanged mean corpuscular volume values confirming haemolysis. At the same time, glucose levels declined by a mean of 38.4 mg/dL (95% CI 13.4-63.5 mg/dL; P = 0.002) as did body weights by a mean of 3.15 kg (P < 0.001). According to published glucose-A1c correlation tables, this decline of glucose concentration by 38.4 mg/dL correlates to a decline in A1c level of 1.08%. In conclusion, reductions of A1c levels by a mean of 2.01% during hepatitis C therapy with IFN + RBV are due to a combination of decreased glucose levels (1.08%) and RBV-induced haemolysis (0.93%). A1c levels should not be measured during hepatitis C treatment with IFN + RBV because they do not adequately reflect glycaemic control.

Early decline of hemoglobin correlates with progression of ribavirin-induced hemolytic anemia during interferon plus ribavirin combination therapy in patients with chronic hepatitis C

BACKGROUND

The aim of this study was to examine the factors correlated with the progression of ribavirin-induced hemolytic anemia in patients with chronic hepatitis C treated by interferon and ribavirin combination therapy.

METHODS

This study was conducted on 505 patients by the Osaka Liver Disease Study Group. A decline of hemoglobin (Hb) concentration by 2 g/dl at the end of 2 weeks from the start of the treatment ("2 by 2" standard) was adopted as a predictive factor for progression to severe anemia. The ribavirin apparent clearance (CL/F) was also examined.

RESULTS

Of 482 patients whose Hb value was more than 12 g/dl before the treatment, 68 patients (14%) had to discontinue ribavirin owing to severe anemia. Patients in the "2 by 2"-positive group (Hb decline over 2 g/dl) and the group with lower CL/F were significantly more likely to discontinue ribavirin owing to severe anemia. Discontinuation was more common among patients aged 60 years or older than for those under 60 years old (21% vs. 9%, P < 0.001). Among patients aged 60 years or older, only the "2 by 2" standard was significantly associated with the discontinuance of ribavirin owing to severe anemia in a multivariate analysis (odds ratio, 4.18; P < 0.001).

CONCLUSIONS

The "2 by 2" standard of Hb decline can be used to identify patients likely to develop severe anemia. The early reduction of ribavirin can help prevent progression to severe anemia, thus allowing ribavirin therapy to be completed even in older patients.

Alpha-tocopherol [corrected] and ascorbic acid attenuates the ribavirin [corrected] induced decrease of eicosapentaenoic acid in erythrocyte membrane in chronic hepatitis C patients

BACKGROUND

Oxidative damage of the erythrocyte membrane plays an important role in ribavirin-induced anemia. The purpose of the present paper was to assess whether supplementation of alpha-tocopherol and ascorbic acid (vitamins) causes changes in the erythrocyte membrane fatty acid composition during interferon and ribavirin combination therapy for chronic hepatitis C patients.

METHODS

Fatty acid compositions in erythrocyte membrane phospholipids were determined by gas chromatography at 0, 2, 4, 8 weeks, and at the end of combination therapy (26 weeks) for interferon with ribavirin in 32 patients with chronic hepatitis C who were randomized to receive vitamins or not (controls).

RESULTS

Good compliance with orally administered vitamins and ribavirin were confirmed by their concentrations in erythrocytes or plasma. The hemoglobin level was negatively correlated with the ribavirin concentration at 8 weeks (r = 0.59, P = 0.01) after initiation of therapy in controls, but not in the vitamin group. Among the 26 kinds of fatty acids analyzed, only eicosapentaenoic acid (EPA) significantly decreased at 8 weeks after initiation of therapy (P = 0.03) and at the end of therapy (P = 0.004) in controls. Vitamins did not inhibit ribavirin-induced anemia, but attenuated the decrease of EPA in erythrocytes. The EPA level was negatively correlated with the drop in hemoglobin levels at 8 weeks after initiation of therapy in controls (r = 0.58, P = 0.015), but not in the vitamin group.

CONCLUSIONS

Supplementation of alpha-tocopherol and ascorbic acid attenuates the ribavirin-induced decrease of EPA in erythrocyte membrane phospholipids in chronic hepatitis C patients.

Vitamin E and C supplementation prevents decrease of eicosapentaenoic acid in mononuclear cells in chronic hepatitis C patients during combination therapy of interferon alpha-2b and ribavirin

OBJECTIVE

We investigated the effects of vitamin E and C supplementation on the fatty acid composition of mononuclear cells and on the clinical observations in patients who had chronic hepatitis C and received interferon-alpha-2b (IFN-alpha-2b) and ribavirin combination therapy.

METHODS

Patients were randomly allocated to receive daily 500 mg of vitamin E and 750 mg of vitamin C (vitamin group, n = 14) or no supplement (non-vitamin group, n = 16) in addition to IFN-alpha-2b and ribavirin therapy. The fatty acid composition of mononuclear cell phospholipids was analyzed before and at 2, 4, and 8 wk after treatment.

RESULTS

After vitamin supplementation, plasma and red blood cell alpha-tocopherol and plasma ascorbic acid levels increased in the vitamin group. Serum levels of alanine aminotransferase decreased significantly after 2 wk of treatment in both groups. At the start of treatment, a lower level of eicosapentaenoic acid (EPA) and a higher level of the molar ratio of arachidonic acid to EPA in mononuclear cells were observed in the present patients compared with healthy volunteers, and a significant correlation between the molar ratio and serum alanine aminotransferase level was found. The EPA level of mononuclear cells was maintained in the vitamin group during treatment, whereas a significant decrease was observed in the non-vitamin group at 4 and 8 wk after treatment.

CONCLUSIONS

Antioxidant vitamin supplementation during IFN-alpha-2b and ribavirin therapy prevented a decrease in EPA of mononuclear cell phospholipids. If a further decrease in the ratio of arachidonic acid to EPA can be achieved by using oral EPA supplementation, the efficacy of IFN-alpha-2b and ribavirin therapy may be improved.

Antiviral hepatitis and antiretroviral drug interactions

More and more HIV-infected patients are treated for viral hepatitis, increasing interactions. HEPATITIS C: The concomitant use of didanosine and ribavirin increases the risk of mitochondrial toxicity, responsible for pancreatitis and/or lactic acidosis. Lactic acidosis is characterized by a high mortality rate. Thus, didanosine, but also stavudine, should not be co-administered with ribavirin. Cases of hepatic decompensation have been reported in cirrhotics concomitantly receiving ribavirin and didanosine. Thus, this co-admininistration should be contraindicated in patients with advanced liver fibrosis. Anemia is a frequent side effect of ribavirin. In patients with zidovudine-related anemia, this drug should be discontinued before prescribing ribavirin. Erythropoietin may help to improve the haemoglobin level. HEPATITIS B: Adefovir significantly decreases the plasma levels of saquinavir. Pancreatitis may occur with the co-administration of didanosine and tenofovir. Thus this co-administration should be avoided. Atazanavir concentrations are decreased when tenofovir is co-administered. Thus, atazanavir should be boosted with ritonavir, when combined with tenofovir. Atazanavir increases the concentrations of tenofovir, with the potential risk of increasing the adverse events of tenofovir, including renal disorders. Tenofovir area under the curve is increased if lopinavir-ritonavir are co-administered. The main interactions, with a fatal risk, are observed with didanosine, when co-administered with ribavirin (hepatitis C) or with tenofovir (hepatitis B). Anemia is frequent, but usually moderate, when zidovudine is co-administered with ribavirin. Other interactions are usually easy to manage.

Future Therapies for Hepatitis C

Although pegylated interferon-α plus ribavirin has become the standard for treating chronic hepatitis C virus infection, a substantial number of patients do not tolerate therapy and require dose reduction or discontinuation, or do not respond to this combination therapy. Thus, new therapeutic options are needed. An increased knowledge of the hepatitis C virus and an understanding of its replication cycle, as well as advances in biotechnology, have stimulated the development of numerous new antiviral treatments for patients with hepatitis C virus infection. This review focuses on four classes of new agents: new interferons, ribavirin-like molecules, specific small-molecule hepatitis C virus inhibitors and new immune therapies, with particular emphasis on medications in the later stages of development.

Definition and management of anemia in patients infected with hepatitis C virus

Chronic infection with hepatitis C virus (HCV) can progress to cirrhosis, hepatocellular carcinoma, and end-stage liver disease. The current best treatment for HCV infection is combination therapy with pegylated interferon and ribavirin. Although this regimen produces sustained virologic responses (SVRs) in approximately 50% of patients, it can be associated with a potentially dose-limiting hemolytic anemia. Hemoglobin concentrations decrease mainly as a result of ribavirin-induced hemolysis, and this anemia can be problematic in patients with HCV infection, especially those who have comorbid renal or cardiovascular disorders. In general, anemia can increase the risk of morbidity and mortality, and may have negative effects on cerebral function and quality of life. Although ribavirin-associated anemia can be reversed by dose reduction or discontinuation, this approach compromises outcomes by significantly decreasing SVR rates. Recombinant human erythropoietin has been used to manage ribavirin-associated anemia but has other potential disadvantages. Viramidine, a liver-targeting prodrug of ribavirin, has the potential to maintain the virologic efficacy of ribavirin while decreasing the risk of hemolytic anemia in patients with chronic hepatitis C.

Ribavirin Levels and Haemoglobin Decline in Early Virological Responders and Non-Responders to Hepatitis C Virus Combination Therapy

Therapeutic drug monitoring of ribavirin has been claimed to predict virological response and/or haematological side effects in patients with chronic hepatitis C undergoing peginterferon/ribavirin combination treatment. In the present study, steady-state ribavirin levels were retrospectively analyzed in serum samples from patients at week 12 of combination therapy with peginterferon alpha-2a or alpha-2b and ribavirin. Patients were classified as early virological responders on the basis of undetectable HCV-RNA or HCV-RNA drop >or=2 log from baseline at week 12. The mean ribavirin level was not different between early virological responders (2.3 +/- 0.1 microg/ml, n = 45) and early virological non-responders (2.0 +/- 0.2 microg/ml, n = 10). There was no correlation between ribavirin levels at week 12 and early virological response. In patients with early virological response, haemoglobin (Hb) levels were found to be decreased by 18% on average from the basal values; however, in only 2 patients Hb levels declined below 100 g/l. There was a moderate negative correlation between ribavirin levels and Hb levels at week 12 (R = -0.50, p < 0.001); however, ribavirin levels did not correlate with relative or absolute decline in Hb as compared to basal levels or with ribavirin dose per kilogram body weight. In addition, a significant negative correlation between ribavirin levels and glomerular filtration rate was found (R = -0.31, p < 0.05). Based on our results, monitoring of ribavirin serum levels at week 12 of HCV combination therapy does not appear to predict early virological response or reductions in Hb levels. Further research is needed to assess their diagnostic value at other time points of peginterferon/ribavirin combination treatment and/or in patients with renal insufficiency.

Traitements complémentaires de l’hépatite chronique virale C

Pegylated interferon and ribavirin combination therapy represent the standard-of-care treatment for chronic hepatitis C, that allows to cure more than half of the patients. However, the success of this bitherapy is in balance with numerous side effects, especially hematologic and psychiatric. This review is focused on complementary treatments (erythropoietin, G-CSF, vitamin E, glutathion, ursodeoxycholic acid and antidepressants) likely to bring a benefit in maintaining adequate interferon and ribavirin dosages and in improving quality of life. This analysis has been performed by using the Medline(R) data base and with data from laboratories which commercialized these molecules. Erythropoietin, G-CSF and antidepressants are the best tools to optimize the bitherapy in its dose and its duration while privileging the quality of life of HCV-infected patients.