Recombinant human interferon alfa-2b treatment for acute non-A, non-B hepatitis

Acute hepatitis C

Symptomatic acute hepatitis C occurs in only about 15% of patients who are infected with hepatitis C virus (HCV). Acute hepatitis C is most often diagnosed in the setting of post-exposure surveillance, or seroconversion in high-risk individuals (eg, health-care professionals or injecting drug users) previously known to be seronegative. Although transmission via transfusion and injecting drug use has declined in developed countries, unsafe blood products and medical practices continue to increase transmission of HCV in many developing countries. Clinically, acute hepatitis C can increase concentrations of alanine aminotransferase to ten times the upper limit of normal but almost never causes fulminant hepatic failure. Diagnosis of HCV infection in the acute phase is difficult since production of antibodies against HCV can be delayed by up to 12 weeks, and about a third of infected individuals might not have detectable antibody at the onset of symptoms. Therefore, testing for HCV RNA by PCR is the only reliable test for the diagnosis of acute infection. Symptomatic patients with jaundice have a higher likelihood of spontaneous viral clearance than do asymptomatic patients, and thus should be monitored for at least 12 weeks before initiating antiviral therapy. By contrast, asymptomatic patients have a much lower chance of spontaneous clearance, and might benefit from early antiviral therapy. Antiviral therapy for 12 weeks is generally effective in treating patients who are HCV RNA negative after 4 weeks of treatment; lengthier courses could be needed for those who relapse or fail to show early virological clearance.

The Early HCV RNA Dynamics in Patients with Acute Hepatitis C Treated with Pegylated Interferon-α2B

Interferon and pegylated interferon (peg-IFN) are highly effective in patients with acute hepatitis caused by hepatitis C virus (acute hepatitis C, AHC), but the optimal timing of treatment is still under debate. In this open-labelled, uncontrolled trial, 19 patients with AHC, including 12 intravenous drug users (IVDUs), were treated early in the course of the infection with peg-IFN-α2b for 12 weeks. Diagnosis was made according to standardized criteria. The HCV RNA decay was analysed during the first 4 weeks of treatment by quantitative branched-DNA and by qualitative RT-PCR. Of the patients, 11 (58%) had genotype 1. Sustained virological response (SVR) was achieved in 14 out of 19 patients (74%) and the mean time to achieve a negative RT-PCR for HCV RNA was 2.5 weeks. The SVR was associated by univariate analysis with peg-IFN dosage ≥1.33 μg/kg/week ( P=0.026) and HCV RNA level at onset of therapy ( P=0.017). Using a logistic regression model, only peg-IFN dosage ≥1.33 μg/kg/weekly was significantly associated with SVR ( P=0.0379, OR: 14.7; 95% CI: 1.16–185.2). The SVR was 100% and 83.3%, respectively, in genotype 1 and non-1 infected patients treated with a dosage equal to or higher than 1.33 μg/kg, compared with 40% and 50%, respectively, in those who received a lower dosage. Efforts should be made to propose a 12-week treatment with peg-IFN-α2b for AHC, and to maximize peg-IFN dosage. Early treatment is associated with early disappearance of HCV RNA.

When and how to treat acute hepatitis C?

BACKGROUND

Appropriate treatment of acute hepatitis C is still a matter of controversy due to the lack of large controlled trials.

AIM

To assess the effectiveness of interferon as treatment for acute hepatitis C by meta-analysis.

METHODS

MEDLINE search (1985-2002) was supplemented with manual searches of reference lists. Studies were included if they were controlled trials comparing interferon to no treatment and if they included patients with either post-transfusion or sporadic acute hepatitis C. Twelve trials were analyzed (414 patients). The outcome assessed was the sustained virological response (SVR) rate (undetectable hepatitis C virus RNA in serum at least 6 months after cessation of therapy).

RESULTS

Interferon significantly increased the SVR (risk difference 49%; 95% confidence interval 32.9-65%) in comparison to no treatment. The risk difference of SVR increased from 5 to 90% when trials were ordered by increasing interferon weekly dose. Delaying therapy by 8-12 weeks after the onset of disease does not compromise the SVR rate.

CONCLUSIONS

Current evidence is sufficient to recommend interferon treatment of patients with acute hepatitis C. A later initiation of therapy yields the same likelihood of response as early treatment. A daily induction dose during the 1st month is the best option of treatment.

Acute hepatitis C: high rate of both spontaneous and treatment-induced viral clearance

BACKGROUND & AIMS

Acute hepatitis C virus infection accounts for approximately 20% of cases of acute hepatitis today. The aim of this study was to define the natural course of the disease and to contribute to the development of treatment strategies for acute hepatitis C virus.

METHODS

The diagnosis of acute hepatitis C virus in 60 patients was based on seroconversion to anti-hepatitis C virus antibodies or clinical and biochemical criteria and on the presence of hepatitis C virus RNA in the first serum sample.

RESULTS

Fifty-one of 60 (85%) patients presented with symptomatic acute hepatitis C virus. In the natural (untreated) course of acute symptomatic hepatitis C (n = 46), spontaneous clearance was observed in 24 patients (52%), usually within 12 weeks after the onset of symptoms, whereas all asymptomatic patients (n = 9) developed chronic hepatitis C. The start of antiviral therapy (interferon-alpha with or without ribavirin) beyond 3 months after the onset of acute hepatitis induced sustained viral clearance in 80% of treated patients.

CONCLUSIONS

The management of acute hepatitis C has to take into account the high rate of spontaneous viral clearance within 12 weeks after the onset of symptomatic disease. Treatment of only those patients who remain hepatitis C virus RNA positive for more than 3 months after the onset of disease led to an overall viral clearance (self-limited and treatment induced) in 91% of patients, and unnecessary treatment was avoided in those with spontaneous viral clearance. Patients with asymptomatic acute hepatitis C virus infection are unlikely to clear the infection spontaneously and should be treated as early as possible.

Spontaneous viral clearance in patients with acute hepatitis C can be predicted by repeated measurements of serum viral load

Early interferon (IFN) therapy prevents viral persistence in acute hepatitis C, but in view of the resulting costs and morbidity patients who really need therapy have to be identified. Twelve consecutive patients with acute hepatitis C (9 women, 3 men, mean age: 39.5 +/- 18.8 y, genotype 1: 7, genotype 3a: 3, 2 could not be genotyped) were studied. The sources of infection were medical procedures in 6, sexual transmission in 3, and intravenous drug abuse in 3 patients. Viral load was measured by Cobas Amplicor HCV Monitor v2.0 (Roche Diagnostic Systems, Branchburg, NY). The time from infection to clinical symptoms was 43.3 +/- 8.6 (mean +/- SD) days. Eight patients cleared hepatitis C virus (HCV) spontaneously and remained HCV-RNA negative with a follow-up of 9.0 +/- 3.9 months. In these patients viral load declined fast and continuously. The time from exposure to HCV-RNA negativity was 77.4 +/- 25.3 and from the first symptoms was 34.7 +/- 22.1 days. In 4 patients HCV-RNA levels remained high or even increased. Two of them became sustained responders to treatment initiated after a 6-week observation period. The 2 remaining patients were not treated (one because of contraindications for IFN, the other declined therapy) and are still HCV-RNA positive. In conclusion, patients with acute icteric hepatitis C have a high rate of spontaneous viral clearance within the first month after the onset of symptoms. IFN therapy appears only needed in patients who fail to clear the virus within 35 days after onset of symptoms. By this approach, IFN therapy was not necessary in two thirds of patients with acute hepatitis C.

Therapy of acute hepatitis C

Acute hepatitis C has a high propensity to become chronic, which provides the rationale for treating patients with acute disease attempting to prevent chronicity. Almost all published studies on therapy of acute hepatitis C have been small in size, uncontrolled, and highly heterogeneous as to patient features, dose and duration of treatment, follow-up evaluation, and criteria used to define efficacy and safety. The published studies on treatment of acute hepatitis C have used standard alfa or beta interferon monotherapy: none have evaluated combination therapy of interferon and ribavirin or peginterferon. Several meta-analyses of published studies have concluded that initiation of interferon monotherapy during the acute phase of hepatitis C virus (HCV) infection significantly reduces (by 30% to 40%) evolution to chronic hepatitis. The tolerability of interferon in acute hepatitis C has been excellent, even in symptomatic and icteric patients; the side effects and adverse events being similar in type and frequency to those seen when treating chronic cases. Thus, currently available data support treatment of patients with acute hepatitis C, but data are insufficient to draw firm conclusions about which patients to treat, when therapy should be started, or what regimen is optimal. Future studies of adequate size and design should focus on efficacy and tolerability of peginterferons and whether therapy should be started immediately after diagnosis or delayed for 2 to 4 months to avoid treatment of patients who spontaneously recover.

Therapy of acute hepatitis C

Acute hepatitis C has a high propensity to become chronic, which provides the rationale for treating patients with acute disease attempting to prevent chronicity. Almost all published studies on therapy of acute hepatitis C have been small in size, uncontrolled, and highly heterogeneous as to patient features, dose and duration of treatment, follow-up evaluation, and criteria used to define efficacy and safety. The published studies on treatment of acute hepatitis C have used standard alfa or beta interferon monotherapy: none have evaluated combination therapy of interferon and ribavirin or peginterferon. Several meta-analyses of published studies have concluded that initiation of interferon monotherapy during the acute phase of hepatitis C virus (HCV) infection significantly reduces (by 30% to 40%) evolution to chronic hepatitis. The tolerability of interferon in acute hepatitis C has been excellent, even in symptomatic and icteric patients; the side effects and adverse events being similar in type and frequency to those seen when treating chronic cases. Thus, currently available data support treatment of patients with acute hepatitis C, but data are insufficient to draw firm conclusions about which patients to treat, when therapy should be started, or what regimen is optimal. Future studies of adequate size and design should focus on efficacy and tolerability of peginterferons and whether therapy should be started immediately after diagnosis or delayed for 2 to 4 months to avoid treatment of patients who spontaneously recover.

Interferon for acute hepatitis C

BACKGROUND

Acute hepatitis C virus (HCV) infection progresses to chronicity in the majority of patients. In order to prevent the progression to chronic disease, several studies have assessed interferon in patients with acute hepatitis C.

OBJECTIVES

The aim of this review was to assess the efficacy of interferon in acute HCV infection.

SEARCH STRATEGY

We searched MEDLINE, the Cochrane Controlled Trials Register, and the abstracts of the American Association for the Study of Liver Diseases (June 2001). We also contacted pharmaceutical companies to obtain unpublished trials.

SELECTION CRITERIA

Randomised clinical trials comparing interferon with placebo or no treatment, and published as an article, abstract, or letter were selected. No language limitations were used.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. The following endpoints were analysed: normalization of alanine aminotransferase (ALT) activity at the end of treatment (biochemical ETR); sustained ALT normalization at the end follow-up (biochemical SR); disappearance of serum HCV RNA by polymerase chain reaction assay at the end of treatment (virologic ETR) and at the end of follow-up (virologic SR). Histologic data and adverse events were also recorded. Assessment of drug efficacy used the methods of Peto and Der Simonian and Laird.

MAIN RESULTS

Six randomised trials involving 206 patients with acute hepatitis C met the inclusion criteria. Four trials assessing interferon alfa-2b in 141 patients, all with transfusion-acquired acute hepatitis C, were included. They demonstrated no significant heterogeneity in the outcomes assessed. When compared with no treatment, interferon alfa-2b was associated with an increase in the rates of virologic ETR and SR by 45% (95% CI 31-59%, P < 0.00001) and 29% (95% CI 14-44%, P = 0.0002), respectively. The virologic ETR was 42% (95% CI: 30-56%) in the interferon alfa-2b group versus 4% (95% CI 0-13%, P < 0.00001) in the control group. At the end of follow-up, a virologic SR was seen in 32% (95% CI 21-46%) of interferon-treated patients versus only 4% (95% CI 0-13%, P = 0.00007) of controls. The tolerability of therapy, or the impact of interferon alfa-2b on hepatic histology, was not reported. Two trials assessed interferon beta in a total 65 patients. The efficacy of interferon beta could not be assessed, however, due to heterogeneity of these trials.

REVIEWER'S CONCLUSIONS

Interferon alfa is effective in improving biochemical outcomes and achieving sustained virologic clearance in patients with transfusion-acquired acute hepatitis C. The effect on long-term clinical outcomes could not be assessed due to limitations in the current data.

Treatment of acute hepatitis C with interferon alfa-2b

BACKGROUND

In people who are infected with the hepatitis C virus (HCV) chronic infection often develops and is difficult to eradicate. We sought to determine whether treatment during the acute phase could prevent the development of chronic infection.

METHODS

Between 1998 and 2001, we identified 44 patients throughout Germany who had acute hepatitis C. Patients received 5 million U of interferon alfa-2b subcutaneously daily for 4 weeks and then three times per week for another 20 weeks. Serum HCV RNA levels were measured before and during therapy and 24 weeks after the end of therapy.

RESULTS

The mean age of the 44 patients was 36 years; 25 were women. Nine became infected with HCV through intravenous drug use, 14 through a needle-stick injury, 7 through medical procedures, and 10 through sexual contact; the mode of infection could not be determined in 4. The average time from infection to the first signs or symptoms of hepatitis was 54 days, and the average time from infection until the start of therapy was 89 days. At the end of both therapy and follow-up, 43 patients (98 percent) had undetectable levels of HCV RNA in serum and normal serum alanine aminotransferase levels. Levels of HCV RNA became undetectable after an average of 3.2 weeks of treatment. Therapy was well tolerated in all but one patient, who stopped therapy after 12 weeks because of side effects.

CONCLUSIONS

Treatment of acute hepatitis C with interferon alfa-2b prevents chronic infection.

Interferon therapy in haemodialysis patients with acute hepatitis C virus infection and factors that predict response to treatment

In view of the high rate of chronicity of acute hepatitis C and the low efficacy of interferon (IFN) treatment in advanced liver disease, it may be beneficial to treat patients during the acute phase of the infection. Here we assessed the effects of variable-dose IFNalpha-2b treatment in haemodialysis patients with acute hepatitis C virus (HCV) infection, and identified factors that may predict response to this therapy. The study population included 67 patients, but 14 were excluded due to side-effects or because they were lost to follow-up. Seventeen patients who received no specific treatment were used as controls (Group 1). Sixteen and 20 patients received low-(3 MU) and high-dose (6-10 MU) IFNalpha-2b three times weekly for 3 months (Groups 2 and 3, respectively). Virological end-of-treatment response (ETR) was observed in 1 (5.6%), 13 (56.5%), and 17 (65.4%) patients in Groups 1, 2, and 3, respectively, and virological sustained response (SR) was observed in 1 (5.6%), 6 (26.1%), and 13 (50%) patients in the three groups. The rates of virological ETR and SR in the treated groups were significantly higher than those of the control group (P < 0.01 for all comparisons). In multivariate logistic regression analysis, single stranded confirmational polymorphysm (SSCP) band number (P=0.02) was the only factor that was significantly associated with virological SR. In conclusion, IFN-alpha treatment initiated during the acute phase of HCV infection is associated with a higher rate of virological ETR and SR. This study suggested that quasispecies heterogeneity has predictive value with regard to virological SR.

Treatment of acute hepatitis C virus infection

Chronic hepatitis C is the leading cause of liver-related morbidity and mortality in the Western world. Treatment response in the chronic phase of the disease is still unsatisfactory. Acute hepatitis C takes a chronic course in more than 50% of cases. Interferon therapy treatment in the acute presentation phase is, according to some studies, more efficient than in the chronic phase of disease. The aim of this study was to analyse the response to interferon in acute hepatitis C. This review is based on three published meta-analyses performed using the methods of DerSimonian and Laird. Outcome was assessed by normalisation of serum aminotransferases and clearance of HCV-RNA. Data were presented by calculating the risk difference, which estimated efficacy by calculating the proportion of patients in treatment groups who responded better (0 to 1.0) or worse (0 to -1.0) than untreated control groups. Three mega units of interferon-a2b (IFN) three times a week for 6-24 weeks produced a significant response as measured by long-term normalisation of aminotransferases and clearance of HCV-RNA. Overall rate differences were +0.31 (p<0.01; 95% confidence interval +0.19-0.43) and +0.33 (p<0.001; 95% confidence interval +0.08-0.58). Six MU of IFN three times a week for 16-24 weeks produced better results with a risk difference of +0.53 (95% confidence interval +0.17-0.89) for normalisation of aminotransferases and +0.44 (95% confidence interval +0.06-0.82) for clearance of HCV-RNA. In an uncontrolled trial, 10 MU IFN daily for 4-6 weeks produced clearance of HCV-RNA and normalisation of transaminases in 90% of patients. Twelve weeks' treatment of symptomatic acute hepatitis C with interferon produced a response similar to that of long-term treatment for chronic hepatitis C. More studies are needed to define the role of a higher dose and the start of treatment.

Interferon therapy for acute hepatitis C viral infection--a review by meta-analysis

BACKGROUND

Hepatitis C viral (HCV) infection poses a major health problem for Australia. Currently interferon therapy is approved only for people with chronic infection, yet the literature contains a number of studies that show that there is a better response to interferon in symptomatic acute HCV.

AIM

To review the response to interferon therapy in acute HCV by way of meta-analysis.

METHODS

This study was a retrospective review of the data on the use of interferon therapy in acute HCV. The meta-analysis was performed using the methods of DerSimonian and Laird. Data were presented by calculating the risk difference which estimated efficacy by calculating the proportion of patients in treatment groups who responded better (0 to +1.0) or worse (0 to -1.0) than untreated control groups.

RESULTS

A meta-analysis of six studies on the use of 3MU of interferon alpha 2b (IFN-alpha 2b) three times a week for six to 24 weeks showed a significant response as measured by long term (> 12 months) normalisation of alanine aminotransferase (ALT) and clearance of HCV RNA (as measured by polymerase chain reaction). The risk of difference was +0.31 (95% CI of +0.19 to +0.43, p < 0.01) and +0.33 (95% CI of +0.08 to +0.58, p < 0.001) respectively. Slightly better results were seen with daily doses of 3MU of interferon beta (IFN-beta) given intravenously over four to seven weeks. This produced a risk difference of +0.57 (95% CI of +0.26 to +0.88, p < 0.02) for normalisation of ALT and +0.83 (95% CI of +0.61 to 1.00, p < 0.001) for clearance of HCV. Results for higher daily doses of both IFN alpha and beta were limited to a few studies and most were uncontrolled. 6MU of IFN-alpha 2b three times a week for 16 to 24 weeks produced a risk difference of +0.53 (95% CI +0.17 to +0.89, p < 0.05) for normalisation of ALT and +0.44 (95% CI +0.06 to +0.82) for clearance of HCV RNA. Results with 6MU daily for eight weeks of IFN-beta in an uncontrolled study, showed up to 90% patients cleared HCV long term. Preliminary results with 10MU of IFN-alpha 2b daily for four to six weeks also showed long term clearance of HCV RNA and normalisation of ALT in 90% of treated patients.

CONCLUSION

Short term (six weeks to six months) treatment of symptomatic acute HCV with interferon (both alpha and beta) produced a better long term response rate than prolonged therapy (> 12 months) in chronic HCV. Daily doses of 6MU and 10MU produced better responses than 3MU but more studies are needed to determine the optimum regime.

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.

Interferon as treatment for acute hepatitis C. A meta-analysis

The efficacy of short-course (three months), low-dose (3 million units three times a week) interferon as treatment for acute hepatitis C was evaluated in a meta-analysis of controlled trials. Nine studies (five randomized and four nonrandomized) found by MEDLINE search were eligible for analysis. The outcomes assessed were the rate of patients with normal serum aminotransferases (all trials) and without HCV RNA in blood (five trials) after posttreatment follow-up. Eight trials compared interferon to no treatment, and one compared different schedules of interferon. The methodological quality of the studies was high. However, all trials had been planned for a short-term evaluation based on biochemical and virological outcomes alone. Significant differences were observed between interferon and control groups for both the assessable end points. Overall rate differences were +0.31 (P < 0.0001; 95% confidence interval +0.20 to +0.41) for aminotransferases normalization and +0.44 (P < 0.0001; 95% confidence interval +0.33 to +0.56) for HCV RNA clearance. In conclusion, a short course of low-dose interferon administered to patients with acute hepatitis C is significantly more effective than no treatment in obtaining viral clearance and normal aminotransferases 12 months after stopping treatment. Further long-term prospective cohort studies assessing outcomes of clinical relevance (ie, the rate of chronicity of infection and disease) are necessary before recommending interferon for acute hepatitis C.