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.     

Interferon treatment for hepatitis C virus infection in patients on haemodialysis

BACKGROUND: This study examined the efficacy and tolerability of interferon alpha-2b (IFN) in the treatment of chronic hepatitis C virus (HCV) infection in patients on maintenance haemodialysis. METHODS: A 24-month prospective cohort study was performed in 11 HCV RNA-positive haemodialysis patients, who were treated with IFN at 3 MU thrice weekly for 6 months. Serial biochemical and virological monitors included serum alanine aminotransferase levels, and HCV RNA by both qualitative PCR assay and quantitative bDNA assay. HCV genotypes were determined by PCR and nucleotide sequencing. Ten patients had baseline liver biopsy. RESULTS: HCV genotypes 1b and 2b were identified in 10 and one patients respectively. Six (55%) patients had biochemical and/or histological features of chronic active hepatitis before treatment. All 11 patients became HCV RNA-negative by PCR, with normalization of deranged aminotransferase levels, within 2-8 weeks of IFN therapy. HCV RNA reappeared in eight (73%) patients 2-8 weeks after the cessation of IFN, while biochemical relapse occurred in six (55%) patients. Sustained eradication of HCV was achieved in three (27%) patients. Sustained responders were characterized by pretreatment HCV RNA level < 3.5 x 10(5) Eq/ml as determined by the bDNA assay, and less severe histological abnormalities ('Total score' 1.7 +/- 1.2 compared to 5.4 +/- 2.2 in relapsers, P < 0.05). HCV RNA levels were similar before and after IFN treatment in non-responders and relapsers. Persistent malaise and poor appetite were noted in eight (73%) patients during IFN therapy. Other side-effects of IFN included the exacerbation of anaemia, induction of resistance to erythropoietin, weight loss, and reduced serum albumin level. CONCLUSIONS: Eradication of chronic HCV infection with IFN can be achieved in 27% of haemodialysis patients. Predictors of sustained response include low baseline HCV RNA level and mild liver pathology. Virological relapse can occur despite normal liver biochemistry. Exacerbation of anaemia, erythropoietin resistance, and malnutrition constitute the side-effects of IFN that deserve special attention in uraemic subjects.     

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.     

High-dose (9 MU) long-term (60 weeks) alfa-interferon therapy for chronic hepatitis patients infected with HCV genotype 1b

Efficacy of standard regimens (e.g., 3-6 MU for 24 weeks) of alfa-IFN therapy for chronic hepatitis C has been limited, particularly in patients with HCV/1b. To see if higher-dose longer term treatment is more effective, we tried a 9 MU 60-week regimen. HCV/1b-infected chronic hepatitis patients received 9 MU IFN alpha 2a everyday but Sunday for 2 weeks and thrice a week for next 10 weeks, and 76 patients became HCV RNA-negative while 81 remained positive. The RNA-negative patients were then randomized to receive 3 MU (group I, n = 37) or 9 MU (group II, n = 39) for 48 weeks. Of the RNA-positive patients, only those with normal ALT received another 9 MU 48-week treatment (group III, n = 45). Sustained responders (SR) were defined as those with negative RNA and normal ALT 6 months after the therapy. SR rates based on intent-to-treat principle did not differ significantly between groups I and II (30% vs 41%), but those based on the protocol-compatible cases showed a significantly lower than those in group II. Adverse effects of IFN, developed more frequently in groups II and III than in group I, were mostly reversible. In conclusion, our results encourage 9 MU 60-week IFN alpha treatment in HCV/1b-infected patients with careful attention to adverse effects, and suggest that the treatment should be discontinued if HCV RNA does not disappear within 12 weeks.     

Mutations in the nonstructural 5A region of hepatitis C virus and response of chronic hepatitis C to interferon alfa

BACKGROUND & AIMS: Mutations in hepatitis C virus (HCV) nonstructural protein 5A (NS5A) may correlate with response to interferon in Japanese patients with chronic hepatitis C. The aim of this study was to examine whether these findings could be expanded to European patients infected with genotypes associated to low (1b) or high (3a) response rates. METHODS: Pretreatment serum samples of 66 patients with chronic HCV infection, 48 infected with genotype 1b and 18 with 3a, were analyzed. RESULTS: Among patients infected with genotype 3a, 1 of 7 long-term responders and none of 11 nonresponders showed NS5A amino acid mutations. Among patients infected with genotype 1b, all 7 long-term responders, but also 27 of 41 nonresponders, showed NS5A mutations. There was no correlation between number of mutations and response to therapy. In 10 patients, sequences obtained before and after treatment were compared and failed to show any change. Serum HCV RNA levels did not differ between patients with and without mutations in NS5A sequence. CONCLUSIONS: No significant correlation was found in patients infected with genotypes 1b or 3a between NS5A sequence and response to interferon alfa. NS5A mutations do not correlate with viral load. Changes in this region were not found during interferon alfa treatment.     

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.     

Combination therapy with thymosin alpha1 and interferon for the treatment of chronic hepatitis C infection: a randomized, placebo-controlled double-blind trial

Hepatitis C is a major cause of liver disease leading to cirrhosis. Although interferon (IFN) is the only approved therapy, treatment is characterized by low response rates and dose-limiting side effects. We evaluated the addition of thymosin alpha1 (TA1), an immunomodulatory peptide, to the standard treatment regimen for hepatitis C to determine if combination therapy shows biological activity using outcome measures including normalization of alanine aminotransferase levels, histological activity, and viral load during treatment. We performed a randomized, double-blind, placebo-controlled trial to compare the biological activity of a combination TA1 and IFN with that seen for IFN alone in patients with chronic hepatitis C infection. One hundred nine patients were randomized for intention to treat and received 1.6 mg of TA1 subcutaneously twice weekly and 3 MU of IFN three times weekly; 3 MU of IFN three times weekly and placebo TA1; or placebo for both agents. All patients had chronic HCV infection with confirmation of chronic hepatitis on liver biopsy. Biochemical responders were followed up until alanine aminotransferase (ALT) levels became abnormal or for 26 weeks, and relapsers were retreated for 26 weeks in the same treatment arm. One hundred three patients completed treatment for 26 weeks, and six patients dropped out. The groups were similar with regard to sex, gender distribution, baseline histological activity index (HAI) score, risk factors, and viral titers. End-of-treatment biochemical response was seen in 37.1% of patients treated with combination therapy, 16.2% of patients treated with IFN alone, and 2.7% of untreated controls by intent-to-treat analysis (IFN/TA1 vs. IFN, chi2 = 4.05, P = .04). HCV RNA clearance was seen in 37.1% of IFN/TA1-treated patients and 18.9% of IFN-treated subjects. Mean HCV RNA titers were significantly lower than baseline at weeks 8, 16, and 24 after drug initiation among patients treated with IFN/TA1 but not in the other treatment arms. Histological improvement, as evidenced by a decrease in HAI of more than two points, occurred in the combination therapy arm more frequently than in comparison groups. Cumulative sustained biochemical responses were 14.2% and 8.1% in the IFN/TA1 and IFN arms, respectively, based on an intention-to-treat model. The combination of TA1 and standard IFN treatment for chronic hepatitis C showed evidence of biological activity at the completion of treatment by biochemical, histological, and virological outcome measures. Further research involving longer duration and varied dosing is needed.     

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.     

Efficacy of interferon dose and prediction of response in chronic hepatitis C: Benelux study in 336 patients

BACKGROUND/AIMS: In an attempt to improve the limited efficacy of treatment of chronic hepatitis C with interferon-alpha 3 MU tiw, we studied the effects of double-dose therapy followed by downward titration, and analyzed the pre- and pertreatment factors associated with response or non-response. METHODS: Three hundred and fifty-four consecutive patients in 19 centers were randomized to interferon-alpha 3 MU tiw for 6 months or 6 MU tiw for 8 weeks followed by down-titration (3,1 MU tiw) till alanine aminotransferase remained normal and plasma HCV RNA was repeatedly undetectable. The primary outcome measure was sustained alanine aminotransferase and HCV RNA response 6 months after treatment. RESULTS: Three hundred and thirty-six patients received treatment. The sustained response rate for patients receiving 3 MU tiw for 6 months was 14% (9-21%,) and for patients receiving double dose tiw for 8 weeks and thereafter titrated therapy 15% (10-21%) (p=0.8). Pretreatment factors associated with a sustained alanine aminotransferase plus HCV RNA response were the absence of cirrhosis, presence of genotype 2 or 3, a low viral load and, in addition, a low alanine aminotransferase/aspartate aminotransferase ratio; a model was developed to allow estimation of the chance of response for the individual patient. The most powerful predictor of sustained response, however, was plasma HCV RNA at week 4; a positive test virtually precluded a sustained response (1.7%, 0.4-5.0%). If week 4 HCV RNA was not detectable, the chance of a sustained response was 21% (12-34%) for genotype 1 versus 40% (28-54%) for the others (p=0.02). Six MU tiw led to a significantly higher week 4 HCV RNA response (47% not detectable) than 3 MU (37%) (p=0.02). During down-titration this difference in viral on-treatment response was lost. CONCLUSIONS: In the treatment of hepatitis C, an early HCV RNA response is a prerequisite for long-term efficacy. Doubling the initial interferon dose increases this early response, but subsequent downward titration negates this effect, especially in genotype 1.     

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.     

Interferon alfa-2b alone or in combination with ribavirin for the treatment of relapse of chronic hepatitis C. International Hepatitis Interventional Therapy Group

BACKGROUND: Interferon alfa is the only effective treatment for patients with chronic hepatitis C. Forty percent of patients have an initial response to this therapy, but most subsequently relapse. We compared the effect of interferon alone with that of interferon plus oral ribavirin for relapses of chronic hepatitis C. METHODS: We studied 345 patients with chronic hepatitis C who relapsed after interferon treatment. A total of 173 patients were randomly assigned to receive standard-dose recombinant interferon alfa-2b concurrently with ribavirin (1000 to 1200 mg orally per day, depending on body weight) for six months, and 172 patients were assigned to receive interferon and placebo. RESULTS: At the completion of treatment, serum levels of hepatitis C virus (HCV) RNA were undetectable in 141 of the 173 patients who were treated with interferon and ribavirin and in 80 of the 172 patients who were treated with interferon alone (82 percent vs. 47 percent, P<0.001). Serum HCV RNA levels remained undetectable 24 weeks after the end of treatment in 84 patients (49 percent) in the combination-therapy group, but in only 8 patients (5 percent) in the interferon group (P<0.001). Sustained normalization of serum alanine aminotransferase concentrations and histologic improvement were highly correlated with virologic response. Base-line serum HCV RNA levels of 2 x 10(6) copies per milliliter or less were associated with higher rates of response in both treatment groups. Viral genotypes other than type 1 were associated with sustained responses only in the combination-therapy group. Combined therapy caused a predictable fall in hemoglobin concentrations but otherwise had a safety profile similar to that of interferon alone. CONCLUSIONS: In patients with chronic hepatitis C who relapse after treatment with interferon, therapy with interferon and oral ribavirin results in higher rates of sustained virologic, biochemical, and histologic response than treatment with interferon alone.     

Re-treatment with interferon alfa of patients with chronic hepatitis C

Treatment of patients with chronic hepatitis C has had limited success because of relapses and nonresponse to interferon alfa therapy (currently the only established therapeutic agent). A retrospective study was done to determine the efficacy of re-treatment with interferon and the predictors of response in patients who failed to achieve sustained response after one standard course of interferon therapy (3 million units three times a week for 24 weeks). One hundred and eleven patients (47 relapsers and 64 nonresponders), mean age 45 years, were included in the study. Eighteen relapsers and 13 nonresponders received a higher dose (5 MU), and 11 relapsers and 6 nonresponders received a longer duration (48 weeks) of interferon therapy. The remaining patients received the same regimen as the first treatment. Eighty-one percent and 23% of relapsers and nonresponders, respectively, had an end-of-treatment response, and 19% and 3% of the corresponding patient groups had a sustained response to re-treatment. Two patients with breakthrough during their first treatment were the only nonresponders with sustained response after re-treatment. Sustained response was observed only in patients who received an increased dose or duration of interferon therapy. No predictor of sustained response was found. In conclusion, sustained response to re-treatment with interferon was only observed with augmentation of dose or duration of therapy in some relapsers and patients who had breakthrough. Established predictors of response to interferon in naive patients, in particular serum hepatitis C virus RNA and genotype, were not associated with sustained response to re-treatment.     

Treatment of chronic hepatitis C with interferon-alpha: a preliminary report

Interferon alpha (IFN-alpha) has been indicated to be dramatically effective in some but not all patients with chronic hepatitis C virus (HCV) infection. We investigated prospectively 27 patients of chronic hepatitis C, 12 females and 15 males, treated with IFN-alpha for a better regimen of the therapy and for any effective predictor of response to the treatment. All patients were treated with 3 to 6 million units (MU) of recombinant IFN-alpha 2b (n = 15) or lymphoblastoid IFN-alpha (n = 12) given 3 times weekly for 12 to 36 weeks. Patients with normal alanine aminotransferase (ALT) value during therapy, who sustained this response throughout 6 months follow-up after treatment was completed, were grouped into the complete responders. Patients with normal ALT value during therapy but who relapsed after treatment completed, were grouped as partial responders. Non-responders were defined as patients without normal ALT value during therapy. The rates of complete response, partial response, and non-response were 29.6%, 40.8%, and 29.6%, respectively. The degree of response to IFN-alpha therapy was not related to age, sex, type of IFN-alpha, history of blood transfusion, the state of liver pathology, or pretreatment level of ALT value. The complete responsive rate to IFN-alpha was higher in patients treated with total dose above 215 MU [38.1% (8/21) vs. 0% (0/6), p = 0.06], in patients treated for at least 24 weeks [40% (8/20) vs. 0% (0/7), p < 0.05], and in patients with non-genotype 1b/II HCV infection [40% (8/20) vs. 0% (0/7), p < 0.05]. We concluded that IFN-alpha was effective in the treatment of chronic HCV infection, particularly in those other than HCV genotype 1b/II. A high-dose, and long-duration regimen may be recommended for better response of chronic hepatitis C to IFN-alpha therapy.     

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.     

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.     

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.     

Chronic hepatitis C and interferon alfa therapy: predictors of long term response

OBJECTIVE: To identify independent patient, disease and viral characteristics that predict a sustained biochemical or viral response to interferon alfa therapy in patients with chronic hepatitis C. Design: Comparison of interferon responders and non-responders by univariate and multivariate analysis. SETTING: The hepatitis clinic of the Alfred Hospital, Melbourne (a tertiary referral hospital), between July 1989 and June 1994. SUBJECTS: All patients with chronic hepatitis C who were treated with interferon alfa (IFN-alpha; 3 million IU, three times a week or more) for at least 12 weeks. OUTCOME MEASURES: Patient demographic and epidemiologic characteristics, pretreatment serum alanine aminotransferase (ALT) and 2-gamma-glutamyl transpeptidase (GGT) levels, histological grading of hepatic steatosis, necroinflammatory activity and fibrosis, serum hepatitis C virus (HCV) RNA titres and genotype and post-treatment serum ALT levels and presence of HCV RNA. Results: Of 58 patients, 13 (22%) had a sustained (six months or longer) biochemical response to IFN-alpha therapy, including 12 (21%) with a sustained viral response. Univariate analysis showed that young patients with a normal serum GGT level, grade 0-1 steatosis and fibrosis, low viral titre and infection with genotypes 3a and 2a were more likely to have a sustained response. Infection with genotypes other than 1a and 1b was the only independent variable associated with both a sustained biochemical and viral response. After adjusting for genotype, a hepatic fibrosis grade of 0-1 was also independently associated with viral response. This logistic regression model accurately predicted the virological response in 80% of cases. Conclusion: In Australian patients with chronic hepatitis C, a sustained viral response to IFN-alpha therapy is most likely in those infected with a genotype other than 1a or 1b and with minimal hepatic fibrosis.