Interferon alfa-2b alone or in combination with ribavirin as initial treatment for chronic hepatitis C. Hepatitis Interventional Therapy Group

BACKGROUND: Only 15 to 20 percent of patients with chronic hepatitis C have a sustained virologic response to interferon therapy. We compared the efficacy and safety of recombinant interferon alfa-2b alone with those of a combination of interferon alfa-2b and ribavirin for the initial treatment of patients with chronic hepatitis C. METHODS: We randomly assigned 912 patients with chronic hepatitis C to receive standard-dose interferon alfa-2b alone or in combination with ribavirin (1000 or 1200 mg orally per day, depending on body weight) for 24 or 48 weeks. Efficacy was assessed by measurements of serum hepatitis C virus (HCV) RNA and serum aminotransferases and by liver biopsy. RESULTS: The rate of sustained virologic response (defined as an undetectable serum HCV RNA level 24 weeks after treatment was completed) was higher among patients who received combination therapy for either 24 weeks (70 of 228 patients, 31 percent) or 48 weeks (87 of 228 patients, 38 percent) than among patients who received interferon alone for either 24 weeks (13 of 231 patients, 6 percent) or 48 weeks (29 of 225 patients, 13 percent) (P<0.001 for the comparison of interferon alone with both 24 weeks and 48 weeks of combination treatment). Among patients with HCV genotype 1 infection, the best response occurred in those who were treated for 48 weeks with interferon and ribavirin. Histologic improvement was more common in patients who were treated with combination therapy for either 24 weeks (57 percent) or 48 weeks (61 percent) than in those who were treated with interferon alone for either 24 weeks (44 percent) or 48 weeks (41 percent). The drug doses had to be reduced and treatment discontinued more often in patients who were treated with combination therapy. CONCLUSIONS: In patients with chronic hepatitis C, initial therapy with interferon and ribavirin was more effective than treatment with interferon alone.     

Immunoglobulin M antibody response to hepatitis C virus core protein in patients with chronic hepatitis C

We retrospectively assessed the frequency and clinicopathologic and virologic significance of production of immunoglobulin M (IgM) antibody to hepatitis C virus (HCV) core protein in patients with chronic hepatitis C. Sera from 60 patients with chronic hepatitis C were tested for IgM anti-HCVcore (anti-HCc). Twenty of these patients received ribavirin plus interferon-alpha for 24 weeks, and were classified as sustained, transient, or nonresponders on the basis of alanine aminotransferase levels and the presence of HCV RNA at the end of treatment and 24 weeks later. IgM anti-HCc was detected in 21 patients. There was no correlation between the presence of IgM anti-HCc and clinical features such as sex, age, mode of transmission, serum levels of alanine aminotransferase, HCV genotype, serum HCV titer, or histologic findings. Among the patients who received ribavirin plus interferon-alpha, the mean IgM anti-HCc level before therapy was comparable between sustained (n = 10), transient (n = 8), and nonresponders (n = 2). A statistically significant decrease in IgM anti-HCc response during antiviral therapy was observed in the 18 responders who became negative for serum HCV RNA at the end of therapy. These data suggest that IgM anti-HCc is of limited clinical usefulness as a marker of chronic HCV infection. Serial testing for IgM anti-HCc may provide a marker of antiviral response.     

Treatment of chronic hepatitis C with amantadine

Treatment of chronic hepatitis C infection with interferon has been disappointing, with less than one third of patients achieving a sustained response and most experiencing significant side effects. For these reasons, an open-labeled prospective pilot study was conducted to test the safety and efficacy of the antiviral drug, amantadine, in patients with chronic hepatitis C infection who had previously failed therapy with interferon-alpha 2b. Twenty-two patients with chronic hepatitis C were enrolled into the study and treated with amantadine 100 mg orally twice daily for six months. Control groups included the same cohort followed off therapy for 29-36 months or during therapy with interferon. Serum alanine aminotransferase (ALT) values decreased in 64% (P = 0.01) of patients with amantadine therapy compared to intervals without therapy or to interferon therapy. Twenty-seven percent of patients treated with amantadine had normalization of ALT values and loss of HCV RNA after six months while 18% achieved a sustained response with loss of HCV RNA by PCR six months after discontinuation of amantadine. Therapy with amantadine improved both biochemical and virological markers in patients with hepatitis C who had previously not responded to treatment with interferon.     

A pilot study of ribavirin and interferon beta for the treatment of chronic hepatitis C

BACKGROUND: Chronic hepatitis C is a common and often progressive liver disease for which interferon alfa therapy widely spreads, but the beneficial response is frequently transient. Ribavirin is a nucleoside analog with a broad spectrum of antiviral action, and we investigated the efficacy of it in patients with chronic active hepatitis C. METHODS: We conducted a pilot study of oral ribavirin in patients with chronic active hepatitis C. Twenty-seven patients with hepatitis C virus RNA were randomly assigned to receive either 0.8-1.0 g of ribavirin daily or 3 MU of interferon beta three times weekly or combination of the two for 24 weeks. RESULTS: Ribavirin was tolerated well, and all completed the treatment schedule. Ribavirin decreased aminotransferase levels in all instances, and the mean value at termination decreased to half of the baseline level (P < 0.01), but the enzyme level increased after cessation of therapy in most cases. Ribavirin suppressed amounts of hepatitis C virus RNA in 4 of 9 patients, and 1 became negative during follow-up. Interferon alone (P < 0.05) or with ribavirin (P < 0.01) significantly decreased the viral population, resulting in sustained loss of viremia with normal enzyme levels in 2 of 9 and 3 of 9 patients, respectively, in each therapy during follow-up. CONCLUSIONS: These results indicate that ribavirin has a beneficial effect in some patients with chronic hepatitis C, although the antiviral effect is less than interferon beta. Large-scale trials are needed to determine whether the combination of interferon and ribavirin is of more benefit than interferon alone.     

Serum hepatitis G virus RNA in patients with chronic viral hepatitis

OBJECTIVES: The hepatitis G virus (HGV) is a newly described flavivirus that affects a high proportion of patients with chronic viral hepatitis: our objective was to determine what role HGV might play in the course of disease. METHODS: We evaluated stored serum samples from 108 patients with chronic hepatitis B and 99 patients with chronic hepatitis C who participated in trials of alpha-interferon or ribavirin for the presence of hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA by branched DNA and for the presence of HGV RNA by polymerase chain reaction (PCR), using primers from the NS5 region of the genome. RESULTS: Initially, 20 (19%) patients with hepatitis B and 11 (11%) with hepatitis C had HGV RNA in their serum. Patients with and without HGV infection were similar with regard to clinical features, laboratory tests, and hepatic histology. HGV RNA levels fell during interferon therapy and became undetectable in those receiving the highest doses; however, HGV RNA levels returned to pretreatment values when therapy was stopped. With ribavirin therapy, HGV RNA levels did not change. Two- to 12-yr follow-up serum samples were available from 17 initially HGV RNA-positive patients, of whom only 10 (59%) were still positive. CONCLUSIONS: HGV infection is common among patients with chronic hepatitis B and C but has little effect on the short-term course of disease or response to therapy. HGV RNA levels are suppressed but not eradicated by alpha-interferon and are unaffected by ribavirin treatment. Spontaneous loss of HGV RNA occurs over time in a proportion of patients.     

Efficacy of ribavirin plus interferon alpha on viraemia of GB virus-C/hepatitis G virus: comparison with interferon alpha alone

We investigated the efficacy of ribavirin plus interferon (IFN) alpha on GB virus-C (GBV-C)/hepatitis G virus (HGV) viraemia and compared it with that of interferon alpha alone in patients coinfected with hepatitis C virus (HCV) and GBV-C/HGV. Serum HCV and GBV-C/HGV-RNA were studied in eight patients with HCV and GBV-C/HGV coinfection, five received IFN alpha and three received oral ribavirin plus IFN alpha. Mean serum GBV-C/HGV titre at the end of therapy was significantly lower than the titre just before therapy and patients with lower pretreatment titre had a better sustained response rate. Sustained virological response of GBV-C/HGV to IFN alpha alone and ribavirin plus IFN alpha at the end of follow up was observed in one each, respectively. Thus, GBV-C/HGV in patients with HCV and GBV-C/HGV coinfection does respond to IFN alpha and ribavirin plus IFN alpha may not induce a higher sustained response.     

Randomised trial of interferon alpha2b plus ribavirin for 48 weeks or for 24 weeks versus interferon alpha2b plus placebo for 48 weeks for treatment of chronic infection with hepatitis C virus. International Hepatitis Interventional Therapy Group (IHIT)

BACKGROUND: Only 15-20% of patients with chronic hepatitis C achieve a sustained virological response with interferon therapy. The aim of this study was to compare the efficacy and safety of interferon alpha2b in combination with oral ribavirin with interferon alone, for treatment of chronic infection with hepatitis C virus (HCV). METHODS: 832 patients aged 18 years or more with chronic HCV who had not been treated with interferon or ribavirin, were enrolled and randomly allocated one of three regimens: 3 mega units (MU) interferon alpha2b three times a week plus 1000-1200 mg ribavirin per day for 48 weeks; 3 MU interferon alpha2b three times a week plus 1000-1200 mg ribavirin per day for 24 weeks; or 3 MU interferon alpha2b three times a week and placebo for 48 weeks. All patients were assessed for safety, tolerance, and efficacy at the end of weeks 1, 2, 4, 6, and 8, and every 4 weeks during treatment. After treatment was completed patients were followed up on weeks 4, 8, 12, and 24. The primary endpoint was loss of detectable HCV-RNA (serum HCV-RNA <100 copies/mL) at week 24 after treatment. FINDINGS: Sustained virological response at 24 weeks after treatment, was found in 119 (43%) of the 277 patients treated for 48 weeks with the combination regimen, 97 (35%) of the 277 patients treated for 24 weeks with the combination regimen (p=O.055), and 53 (19%) of the 278 patients treated for 48 weeks with interferon alone (p<0.001 vs both combination regimens, intention-to-treat analysis). Logistic regression identified five independent factors significantly associated with response: genotype 2 or 3, viral load less than 2 million copies/mL, age 40 years or less, minimal fibrosis stage, and female sex. Among patients with fewer than three of these factors the odds ratio of sustained response was 2.6 (95% Cl 1.4-4.8; p=0.002) for the 48 week combination regimen compared with 24 weeks of the combination regimen. Discontinuation of therapy for adverse events was more frequent with combination (19%) and monotherapy (13%) given for 48 weeks than combination therapy given for 24 weeks (8%). INTERPRETATION: An interferon alpha2b plus ribavirin combination is more effective than 48 weeks of interferon alpha2b monotherapy and has an acceptable safety profile. Patients with few favourable factors benefit more from extending the duration of combination therapy to 48 weeks.     

Peginterferon alfa-2a (40KD) (Pegasys) for the treatment of patients with chronic hepatitis C

Compared with conventional interferon alfa, peginterferon alfa-2a (40KD) has improved pharmacokinetics, provides sustained therapeutic plasma levels, and can be administered once weekly. In randomised, multinational trials, peginterferon alfa-2a (40KD) 180 microg once weekly was significantly more effective than three times weekly interferon alfa-2a in patients with chronic hepatitis C, including patients with cirrhosis. Peginterferon alfa-2a (40KD) and ribavirin 1000/1200 mg/day for 48 weeks produced significantly higher sustained responses than three times weekly interferon alfa-2b and ribavirin 1000/1200 mg/day in patients with chronic hepatitis C including those with HCV genotype 1, genotypes 2/3 and those with high or low viral loads at baseline. The drug is well tolerated when given alone or in combination with ribavirin. Health-related quality of life was significantly less impaired during treatment with peginterferon alfa-2a (40KD) than interferon alfa-2a in randomised trials. Peginterferon alfa-2a (40KD) is widely approved for use in patients with chronic hepatitis C.     

Effects of interferon-alpha on serum hepatitis C virus in patients with chronic hepatitis C

Interferon is beneficial in some patients with chronic hepatitis C. To assess the efficacy of interferon, we used the polymerase chain reaction (PCR) to measure HCV RNA in serial serum samples from 13 chronic hepatitis C patients who were treated with interferon-alpha. Serum alanine aminotransferase (ALT) values normalized in association with the disappearance of serum HCV RNA in nine cases during the therapy. Serum HCV remained negative after the therapy in the three patients who had no relapse, while serum HCV RNA reappeared in the six patients with elevation of ALT values. The persistence of normal ALT levels appears to be correlated with the clearance of the serum HCV. There were two patients whose ALT became normal immediately after the cessation of interferon. Serum HCV was detectable at the end of treatment when serum ALT was elevated, and thereafter serum HCV disappeared. This result suggests an immunomodulatory effect of interferon in the clearance of HCV in some cases. Furthermore, the semiquantitative PCR assay showed that all five patients in whom ALT values were normal at the end of follow-up without detectable serum HCV genome had lower HCV titers in the pretreatment sera than the other eight patients. The detection of HCV RNA by the PCR assay is useful in determining the efficacy of interferon and its mechanisms.     

Influence of labour on epidermal growth factor receptor distribution of the human chorion at term gestation

Ten patients with biopsy verified chronic hepatitis C virus (HCV) infection were treated with oral ribavirin at a dose of 1,000-1,200 mg per day in two divided doses for 12 weeks. Serum alanine aminotransferase (ALT) levels and hepatitis C viral ribonucleic acid (RNA) levels in serum were followed prior to, during, and 12 weeks posttreatment. ALT levels decreased significantly in all patients during therapy from a mean level of 3.21 mukat/l (range 1.22 to 7.79) before, to 1.25 mukat/l (range 0.78 to 2.04) at the end of treatment (P < 0.005). Hereafter, relapse to pretreatment levels was seen within 12 weeks after treatment stop. The hepatitis C viral RNA levels decreased from a mean 10 log titer of 4.1 (range 1-6) before treatment to 3.4 (range 1-5) at treatment stop. Five patients did not change their HCV RNA titers during treatment. Twelve weeks posttreatment only 3 patients had lower titers than prior to treatment. We conclude that oral ribavirin seems to reduce the viral load, at least temporarily, in some patients with chronic viremic HCV infection. Further studies are needed to evaluate fully the effect of oral ribavirin on chronic HCV infection.     

Long-term follow-up of patients with chronic hepatitis C after interferon-alpha treatment

In this study, 72 patients with chronic hepatitis C virus (HCV) were followed prospectively for a mean period of 27 months after interferon treatment. Fifty-seven percent (20/35) of the patients with complete response, 18/20 with HCV-RNA-negative serum, had a sustained biochemical remission. Reactivation was seen in 43% of these patients after a mean follow-up of 7.3 months. A late relapse after more than 12 months of follow-up occurred in only 2/15 patients. Patients with a long-term complete response had significantly lower pretreatment serum HCV RNA levels than complete responders with relapse (106,239 vs. 345,649 mEq/ml, p = 0.0213). A delayed sustained biochemical remission was seen in 3/37 patients with partial or no response. Thus, long-term response is achieved in 32% of the patients treated with interferon, clearly associated with a suppression of serum HCV RNA. Patients with normal ALT values and undetectable levels of HCV RNA for more than 12 months of follow-up may usually be considered as sustained responders. Thus, for the first time, the pretreatment HCV RNA level in serum was identified as predictive of long-term response.     

The prognostic relevance of the nonstructural 5A gene interferon sensitivity determining region is different in infections with genotype 1b and 3a isolates of hepatitis C virus

Hepatitis C virus (HCV) RNA serum concentration, quasispecies complexity, and sequence and phylogenetic analysis of the nonstructural 5A gene (NS5A) interferon sensitivity determining region (ISDR) were determined in pretreatment serum samples from 47 patients with chronic hepatitis C (36 infected by HCV genotype 1b and 11 by 3a). Among HCV genotype 1b-infected patients, virus load was lower (P = .003) and the number of NS5A-ISDR amino acid changes was higher (P = .001) in long-term responders than in non-long-term responders, but there were no differences in quasispecies complexity. Multivariate analysis showed a close association between response to interferon and NS5A-ISDR phenotype. Phylogenetic analysis showed that isolates from non-long-term responders clustered apart from the majority of isolates from long-term responders. There was no association between virologic features and therapeutic response in HCV genotype 3a-infected patients. In conclusion, low virus load and mutant NS5A-ISDR phenotype are closely associated with long-term response to interferon in HCV genotype 1b- but probably not in 3a-infected patients.     

Prevention and treatment of hepatitis C

Interferon is the only treatment shown to be effective on hepatitis C in controlled trials. The response to treatment is generally assessed in terms of a return to normal transaminase activity, but also negative PCR testing for viral RNA and histopathological examination of the liver. At a dose of 3 MU three times a week for 6 months, 25% of patients have a persistent return to normal transaminase activity, 25% relapse when interferon is withdrawn, and the remaining 50% have persistently high levels at the end of treatment and are considered resistant. The rate of persistent responses increases to 40% when treatment is extended to one year. Viral RNA becomes undetectable in the serum of 80% of these responders. Most also have a histological improvement, but so do a number of patients who relapse or who are resistant. In the longer term, interferon could prevent the onset of liver cancer in patients with viral C cirrhosis. Interferon is generally well tolerated at the doses currently used, most side effects (hematologic, neuropsychiatric and thyroid disorders) resolving when treatment is stopped. The following factors are clearly predictive of the response to interferon : young age, short time since onset, absence of cirrhosis, lower-level viremia, and infection by HCV genotypes other than 1b. Interferon is markedly less effective in immunodeficient patients (transplant, HIV infection, etc.). Several add-on treatments have been tried, but ribavirin appears to be the most promising, both during initial interferon therapy and for patients who relapse or are resistant to a first course. Interferon therapy of the acute phase of hepatitis C significantly reduces the risk of chronic liver disease. There is no vaccine against HCV infection.     

Prediction of response during interferon alfa 2b therapy in chronic hepatitis C patients using viral and biochemical characteristics: a comparison

Patients with chronic hepatitis C (n = 103) were treated for 24 weeks with interferon alfa 2b and followed up for 24 weeks after cessation of therapy (week 48). When hepatitis C virus (HCV) RNA at week 48 was used to assess interferon response, 15 (14.6%) were virological complete responders, and all have remained HCV RNA negative for a mean of 3 years. At week 48, 3 of 15 virological complete responders had elevated alanine transaminase (ALT) values. When serum ALT level was used at week 48 to determine response to interferon, 20 (19.4%) were biochemical complete responders. However, 8 of the 20 patients with normal ALT levels were HCV RNA positive at week 48, and 7 of these individuals have had a recurrence of elevated ALT levels within 3 years after cessation of treatment. These findings indicate that measurement of HCV RNA was more accurate than ALT in determining true responses to interferon therapy. Identification of nonresponders early during the course of interferon treatment showed that an elevated ALT level at week 12 was 92% predictive (odds ratio 3.7) but misidentified 33% (5 of 15) of the patients who were virological complete responders at week 48. In contrast, a positive HCV RNA at week 12 of treatment was 98% predictive (odds ratio 35.5) and misidentified only 6.7% (1 of 15) of the virological complete responders. Thus, positive HCV RNA at week 12 of therapy was more accurate in identifying eventual virological nonresponders than measurement of ALT at this time. Termination of interferon therapy in patients who were HCV RNA positive at week 12 would result in a 27% reduction in the direct medical costs and keep patients from undergoing unnecessary treatment. Therefore, testing for HCV RNA at week 12 to identify nonresponders and then discontinuing their treatment is practical, cost-efficient and beneficial both to patients and to third-party payers.     

Responsiveness to interferon alpha treatment in patients with chronic hepatitis C coinfected with hepatitis G virus

BACKGROUND/AIMS: Patients with chronic hepatitis C are often coinfected with the new identified Flaviviridae-like agent, termed hepatitis G virus (HGV). The aim of the study was to investigate the responsiveness of hepatitis G virus to interferon alpha and to evaluate whether a hepatitis G virus coinfection negatively influences the outcome of treatment in chronic hepatitis C. METHODS: One hundred and fifteen patients with histologically proven chronic hepatitis C were treated with interferon alpha and investigated for the presence of hepatitis G virus coinfection by nested polymerase chain reaction with primers from the helicase region of hepatitis G virus. All patients received at least 3 MU (range 3-6) interferon alpha thrice weekly for at least 6 months (mean 8, range 6-12). Polymerase chain reaction products of seven pre- and post-treatment hepatitis G virus positive patients were directly sequenced for identification of sequence variability during the follow-up. RESULTS: Eighteen (16%) patients were coinfected with hepatitis G virus. Although nine (50%) of these patients became HGV RNA negative during interferon alpha therapy, only three patients (17%) remained HGV RNA negative at the end of follow-up (mean 24 months). The rate of sustained response of chronic hepatitis C was not significantly different between patients with hepatitis C virus infection and HCV/HGV coinfection (19% vs 28%). Severity of liver disease as determined by alanine aminotransferase levels, histology and hepatitis C virus viremia was not significantly different in patients with hepatitis C virus or HCV/HGV coinfection. Sequence analysis of the helicase region revealed that our isolates all belonged to the hepatitis G virus and not to the GBV-C like genotype. No amino acid exchanges during the observation period of up to 48 months were observed, indicating that this region is highly conserved. CONCLUSIONS: The responsiveness of hepatitis G virus to interferon alpha in chronic HCV/HGV coinfected patients is similar to that observed in chronic hepatitis C. Hepatitis G virus coinfection seems not to interfere with the efficacy of interferon alpha treatment in patients with chronic hepatitis C.     

Large dose natural interferon alpha therapy for patients with chronic hepatitis C

To evaluate the efficacy of large dose interferon treatment for patients with chronic hepatitis C virus (HCV) infection, we studied 99 Japanese patients treated with either 6 million units (MU) or 9 MU natural interferon alpha. Serum samples were tested for HCV RNA by polymerase chain reaction (PCR). HCV RNA genotypes were determined by PCR with type-specific preimers, and the HCV RNA level was measured by competitive PCR. HCV RNA was detected in all patients, prior to the initiation of treatment. We examined interleukin-1 receptor antagonist (IL-1 Ra) by enzyme-linked immunosorbent assay. Forty-four patients were treated with 9 MU natural interferon alpha for 24 weeks (group A), and fifty-five patients were treated with 6 MU natural interferon alpha for 24 weeks (group B). There were no significant differences in HCV RNA levels, HCV RNA genotype or histological activity index (HAI) score between the two groups. Of the 94 patients who completed this treatment, nine (23.1%) in group A and 14 (25.5%) in group B sustained elimination of HCV RNA throughout a 6-month follow-up. There were no differences in the rate of complete response when comparing HCV RNA genotype, levels and HAI score and no significant differences in elevation of IL-1 Ra levels between the two groups. Five of group A patients refused further treatment because of severe side effects such as retinal hemorrhage, while no patient in group B had severe side effects. Thus, large dose natural interferon alpha treatment confers no additional benefit to the patient, compared with the current use of a lower dose.     

Sutton''s disease

Acute and chronic liver diseases related to hepatitis viruses are the main indications for liver transplantation. The risk of viral reinfection after transplantation is the main limitating factor in these indications. HCV reinfection was demonstrated by demonstrating a sequence homology of the hypervariable region of HCV RNA in 2 patients before and after liver transplantation. HCV reinfection is almost constant, assessed by the persistence of HCV RNA in serum in 90% of cases. Acute lobular hepatitis appeared in 75% of patients at a median of 4 months post-transplantation with extremes between 23 days and 4 years. In our series, the 5 year actuarial rate of HCV acute hepatitis on the graft, chronic hepatitis and cirrhosis was 75%, 60% and 8%, respectively. HCV RNA level is dramatically increased after transplantation and seems to correlate with the occurrence of acute hepatitis on the graft. A positive relationship between genotype 1 b and prevalence and severity of HCV hepatitis on the graft have been suggested in European series. There is no demonstrated way to prevent HCV reinfection. The use of interferon for the treatment of HCV hepatitis on the graft was disappointing due to a poor antiviral effect and the occurrence of chronic rejection episodes in some patients. Promising results of the combination of interferon and ribavirin have been reported and need confirmation. The 5 year survival of patients transplanted for viral C cirrhosis in our Center is 78%. In conclusion, patients with endstage HCV cirrhosis are candidates for liver transplantation. Viral C reinfection is frequent, but medium term survival is good. However, longterm graft and patient survival remains unknown, and methods to prevent and treat HCV reinfection on the graft are needed.     

Prolonged therapy of chronic hepatitis C with ribavirin

Therapy with ribavirin for 6-12 months is associated with decreases in serum aminotransferases in some patients with chronic hepatitis C. We have assessed the practicality and safety of prolonged therapy with ribavirin. Six patients with chronic hepatitis C were given 1000-1200 mg of ribavirin daily for 24 months. Serum aminotransferases and hepatitis C virus (HCV) RNA levels were monitored during and after therapy. Liver biopsies were carried out before and at the end of treatment. With therapy, mean serum alanine aminotransferase (ALT) levels fell from 161 U/L to 45 U/L at 12 months and to 39 U/L at 24 months. HCV RNA levels did not change. Liver histology improved in five and was unchanged in one patient. When therapy was stopped, aminotransferases rose to pretreatment levels. Side effects included mild fatigue and headaches. Two patients developed gallstones during therapy, perhaps caused by the chronic haemolysis that occurred in all patients. In conclusion, prolonged therapy with ribavirin can result in sustained improvements in serum aminotransferases and hepatic histology in a proportion of patients with chronic hepatitis C. Ribavirin therapy does not cause decreases in viraemia and, therefore, probably must be continued indefinitely to provide lasting benefit. The advantages of such therapy must be weighed against possible long-term side-effects.