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Background and Aims: The population of patients chronically infected with hepatitis C virus (HCV) is aging, and the number of older patients with HCV-related hepatocellular carcinoma (HCC) is increasing. The purpose of this study was to elucidate the effects of peginterferon and ribavirin combination therapy on prevention of HCC in older patients with chronic hepatitis C (CH-C)., Methods: We compared the sustained virological response (SVR) and treatment discontinuation rates between older (≥ 65 years) and younger patients (< 65 years) among 1280 CH-C patients treated with peginterferon alfa-2b and ribavirin. Cumulative incidence of HCC was determined by Kaplan-Meier analysis, and factors associated with liver carcinogenesis were analyzed by Cox proportional hazards regression., Results: Older patients had a significantly lower SVR rate and a significantly higher discontinuation rate of treatment than younger patients. Fifty patients developed HCC during median follow-up period of 47 months. Cox proportional hazards regression analysis indicated that the following were independent risk factors associated with the development of HCC: older age, male, advanced fibrosis, non-SVR in all patients: higher gamma-glutamyltranspeptidase, and non-SVR in older patients. Older patients who achieved SVR had a significantly reduced rate of HCC compared with those who did not achieve SVR, especially those who had gamma-glutamyltranspeptidase over 44 IU/L., Conclusions: The SVR rate was lower and the combination therapy discontinuation rate was higher in older CH-C patients than in younger patients. However, older patients who achieved SVR had a markedly lower rate of HCC development compared with older patients who did not achieve SVR., (© 2014 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.)

Objective: Some patients with chronic hepatitis C virus (HCV) infection fail to achieve complete early virologic response (EVR) despite a marked decrease in HCV RNA at 4 weeks. We investigated the characteristics and final treatment outcomes of this patient subpopulation., Methods: A total of 516 patients with HCV genotype 1 were enrolled. Background characteristics and final outcomes were compared between patients who achieved complete EVR and those who did not among patients whose HCV RNA levels decreased 3.0 log10 or more at 4 weeks., Results: 78 of 334 patients (23.4%) with a ≥3.0 log10 reduction in HCV RNA levels at 4 weeks failed to achieve complete EVR. Female sex, higher pretreatment HCV RNA levels and lower baseline alanine aminotransferase (ALT) activity were independently associated with failure of complete EVR. The rate of sustained virologic response (SVR) in patients without complete EVR was 47.4%, significantly lower than that in patients with complete EVR (89.7%, p < 0.0001)., Conclusions: Female patients, patients with higher pretreatment HCV RNA levels and patients with lower baseline ALT have a high likelihood of failure of complete EVR even when they had a ≥3 log10 reduction of HCV RNA at 4 weeks, resulting in a significantly lower SVR rate., (© 2014 S. Karger AG, Basel)

Backgrounds/aims: We investigated the association between hepatic steatosis and hepatic expression of genes involved in innate immunity, both of which are reportedly associated with resistance to peginterferon (PEG-IFN) and ribavirin combination therapy for hepatitis C virus (HCV) infection., Methods: A total of 122 patients infected with HCV genotype 1b who underwent and completed PEG-IFN and ribavirin combination therapy were studied. Hepatic steatosis was evaluated on the basis of the liver specimen biopsied prior to antiviral therapy. The levels of mRNA of innate immunity genes (RIG-I, MDA5, LGP2, Cardif, RNF125, ISG15, and USP18) were measured by real-time polymerase chain reaction in RNA extracted from biopsied liver tissue and compared between patients with and without hepatic steatosis., Results: The proportion of patients with hepatic steatosis, the hepatic expression levels of RIG-I gene, and RIG-I/Cardif and RIG-I/RNF125 ratios were significantly higher in patients in whom serum HCV RNA did not disappear throughout the treatment period. Hepatic expression of RIG-I and the ratios of RIG-I/Cardif and RIG-I/RNF125 were significantly higher in patients with steatosis than those without., Conclusions: Changes in hepatic expression of some genes involved in innate immunity were observed along with hepatic steatosis, possibly playing a mechanistic role in resistance to IFN-based therapy in patients with hepatic steatosis., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Many patients with coagulation disorders are infected with hepatitis C virus (HCV) that advances to end stage liver disease, resulting in an increased number of deaths. The efficacy of ribavirin and peginterferon combination therapy for chronic HCV infection in patients with coagulation disorders has not been clarified fully. The aim of this study was to evaluate the efficacy and tolerability of combination therapy in this patient population compared with patients who are infected with HCV and do not have coagulation disorders. A total of 226 consecutive chronic hepatitis C patients were treated with combination therapy and divided into two groups: patients with (n = 23) and without coagulation disorders (n = 203). Clinical characteristics, sustained virological response rates obtained by an intention-to-treat analysis, and combination therapy discontinuation rates were compared between the two groups. The sustained virological response rates did not differ significantly between patients with and without coagulation disorders (65.2% vs. 47.8% by intention-to-treat analysis). According to a multivariate analysis, age, alanine aminotransferase, gamma-glutamyltransferase, and HCV genotype were associated significantly with a sustained virological response, whereas whether a patient had a coagulation disorder did not affect the sustained virological response. In conclusion, combination therapy for chronic hepatitis C was comparably effective between patients with and without coagulation disorders and did not result in adverse bleeding., (Copyright © 2012 Wiley Periodicals, Inc.)

Background: The importance of the reduction in hepatitis C virus (HCV) RNA levels 4 and 12 weeks after starting peginterferon (PEG-IFN) and ribavirin combination therapy has been reported to predict a sustained virologic response (SVR) in patients infected with HCV genotype 1. We conducted a multicenter study to validate this importance along with baseline predictive factors in this patient subpopulation., Methods: A total of 516 patients with HCV genotype 1 and pretreatment HCV RNA levels ≥5.0 log(10) IU/mL who completed response-guided therapy according to the AASLD guidelines were enrolled. The reduction in serum HCV RNA levels 4 and 12 weeks after starting therapy was measured using real-time PCR, and its value in predicting the likelihood of SVR was evaluated., Results: The area under the receiver operating characteristics (ROC) curve was 0.852 for 4-week reduction and 0.826 for 12-week reduction of HCV RNA levels, respectively. When the cut-off is fixed at a 2.8-log(10) reduction at 4 weeks and a 4.9-log(10) reduction at 12 weeks on the basis of ROC analysis, the sensitivity and specificity for SVR were 80.9% and 77.9% at 4 weeks and were 89.0% and 67.2% at 12 weeks, respectively. These variables were independent factors associated with SVR in multivariate analysis. Among 99 patients who showed a delayed virologic response and completed 72-week extended regimen, the area under ROC curve was low: 0.516 for 4-week reduction and 0.482 for 12-week reduction of HCV RNA levels, respectively., Conclusions: The reduction in HCV RNA levels 4 and 12 weeks after starting combination therapy is a strong independent predictor for SVR overall. These variables were not useful for predicting SVR in patients who showed a slow virologic response and experienced 72-week extended regimen.

Hepatitis C virus (HCV) genotype 1a is rare in Japanese patients and the clinical characteristics of this genotype remain unclear. The interferon (IFN) sensitivity-determining region (ISDR) and single-nucleotide polymorphisms (SNPs) of interleukin-28B (IL28B) among patients with HCV genotype 1b are associated with IFN response, but associations among patients with genotype 1a are largely unknown. This study investigated the clinical characteristics of genotype 1a and examined whether genomic heterogeneity of the ISDR and SNPs of IL28B among patients with HCV genotype 1a affects response to combination therapy with pegylated-IFN-α2b and ribavirin. Subjects comprised 977 patients infected with HCV genotype 1, including 574 men and 412 women (mean age, 55.2 ± 10.6 years). HCV was genotyped by direct sequencing of the 5'-untranslated region and/or core regions and confirmed by direct sequencing of the NS5A region. HCV genotypes 1a (n = 32) and 1b (n = 945) were detected. Twenty-three (71.9%) of the 32 patients with genotype 1a were patients with hemophilia who had received imported clotting factors. Prevalence of genotype 1a after excluding patients with hemophilia was thus 0.9%. Of the 23 patients with genotype 1a who completed IFN therapy, 11 (47.8%) were defined as achieving sustained virological response. Factors related to sustained virological response by univariate analysis were IL28B and ISDR. In conclusion, HCV genotype 1a is rare in Japan. The presence of IL28B genotype TT, and more than two mutations, in the ISDR are associated with a good response to IFN therapy in patients with HCV genotype 1a., (Copyright © 2012 Wiley Periodicals, Inc.)

Background and Aims: Mutations in the core and NS5A region of hepatitis C virus (HCV) genotype 1b have been associated with response to interferon (IFN) therapy. Genome-wide association studies have revealed that the single-nucleotide polymorphism (SNP) of interleukin 28B (IL28B) contributes to IFN response. The aim of this study was to investigate whether the SNP of IL28B (rs8099917) and amino acid substitutions in the core and NS5A region affect the response to IFN therapy., Methods: A total of 299 patients (157 men, 142 women; mean age, 55.9 ± 10.3 years) infected with HCV genotype 1b were studied. The fibrosis stage was diagnosed as F0 (n=23), F1 (n=121), F2 (n=62), F3 (n=32) and F4 (n=7) by liver biopsy., Results: Of the 299 patients, 138 achieved sustained virological response (SVR). On univariate analysis, predictors of SVR were age <60 years, male gender, higher platelet count, lack of fibrosis, non-Q at core 70, mutant-type interferon sensitivity-determining region (ISDR) and IL28B genotype TT. The factors related to SVR on multivariate analysis were IL28B (P=0.0001), fibrosis (P=0.0111) and mutations in the core region70 (P=0.0267) and ISDR (P=0.0408). The best SVR was achieved in patients with non-Q70, mutant-type ISDR and T allele (74.5%), and the worst was achieved in patients with Q70, wild-type ISDR and G allele (8.1%)., Conclusions: The SNP of IL28B and mutations in the core region and NS5A are associated with IFN responsiveness. Both host and viral factors might be useful for predicting IFN response., (© 2011 John Wiley & Sons A/S.)

An association has been reported between genetic polymorphism near IL28B gene and the prevalence of mutation of hepatitis C virus (HCV) core region residue 70, both of which have been associated with a lack of virologic response to antiviral combination therapy with peginterferon (PEG-IFN) and ribavirin. This study investigated whether PEG-IFN/ribavirin combination therapy induces amino acid (AA) mutation at residue 70 of HCV and whether genetic polymorphism near IL28B gene affects it. AA substitutions at residue 70 of the HCV core region were measured and compared before and after combination therapy in 65 non-responders and 88 relapsers to the combination therapy. In three patients in whom both wild-type AA (arginine) and mutant-type AA (glutamine or histidine) were detected at residue 70 before treatment, only mutant-type AA was identified after treatment. In two patients who had wild-type AA solely before treatment, both wild-type and mutant-type AAs were identified at residue 70 after treatment. In five patients, in whom the AA had changed at residue 70 between before and after treatment, four patients carried the TT genotype at a polymorphic locus (rs8099917) near the IL28B gene and one carried the TG/GG genotype. No difference was found in the prevalence of this change of AA at residue 70 between the TT and the TG/GG genotype. Antiviral combination therapy with PEG-IFN and ribavirin does not appear to induce mutation of HCV core region residue 70 regardless of genetic polymorphism near the IL28B gene in Japanese patients infected with HCV genotype 1b., (Copyright © 2011 Wiley-Liss, Inc.)

Mutations in two regions of hepatitis C virus (HCV) have been implicated in influencing response to interferon (IFN) therapy. Substitutions in the NS5A region of HCV have been associated with response to IFN therapy, and this region has been known as the IFN sensitivity-determining region (ISDR). The mutations in the core region of HCV have also been reported to predict IFN response. The aim of this study was to investigate whether amino acid substitutions in the core region and ISDR among patients with HCV genotype 1b affect the response to IFN therapy. A total of 213 patients who completed IFN treatment were randomly selected. All patients received pegylated-IFN-alpha 2b once each week, plus oral ribavirin daily for 48 weeks. Of the 213 patients, 117 (54.9%) showed early virologic response (EVR), with HCV-negativity, at 12 weeks. Factors related to EVR on multivariate analysis were non-Gln70 and Leu91 in the core region, and ISDR mutant-type. One hundred and two (47.9%) showed a sustained virologic response (SVR). SVR occurred more frequently in patients without Gln70 (55.4%) than in those with Gln70 (21.3%) (P < 0.0001). SVR was achieved in 43.6% of patients with wild-type ISDR and 62.5% of patients with mutant-type (P = 0.0227). Of the 34 patients who simultaneously had non-Gln70 and mutant-type ISDR, 26 (76.5%) achieved SVR. Factors related to SVR on multivariate analysis were non-Gln70 and ISDR mutant-type. In conclusion, amino acid substitutions in the core region and ISDR were useful for predicting the response to IFN in patients with HCV genotype 1b., (© 2010 Blackwell Publishing Ltd.)

Background: Despite being expensive, the standard combination of pegylated interferon (Peg-IFN)-α and ribavirin used to treat chronic hepatitis C (CH) results in a moderate clearance rate and a plethora of side effects. This makes it necessary to predict patient outcome so as to improve the accuracy of treatment. Although the antiviral mechanism of genetically altered IL28B is unknown, IL28B polymorphism is considered a good predictor of IFN combination treatment outcome., Methodology: Using microarray, we quantified the expression profile of 237 IFN related genes in 87 CH liver biopsy specimens to clarify the relationship between IFN pathway and viral elimination, and to predict patients' clinical outcome. In 72 out of 87 patients we also analyzed IL28B polymorphism (rs8099917)., Principal Findings: Five IFN related-genes (IFI27, IFI 44, ISG15, MX1, and OAS1) had expression levels significantly higher in nonresponders (NR) than in normal liver (NL) and sustained virological responders (SVR); this high expression was also frequently seen in cases with the minor (TG or GG) IL28B genotype. The expression pattern of 31 IFN related-genes also differed significantly between NR and NL. We predicted drug response in NR with 86.1% accuracy by diagonal linear discriminant analysis (DLDA)., Conclusion: IFN system dysregulation before treatment was associated with poor IFN therapy response. Determining IFN related-gene expression pattern based on patients' response to combination therapy, allowed us to predict drug response with high accuracy. This method can be applied to establishing novel antiviral therapies and strategies for patients using a more individual approach.

The course and outcome in patients infected with hepatitis C virus (HCV) genotype 1b with partial early virologic response during combination therapy with peginterferon and ribavirin, in whom serum HCV RNA is detectable but has decreased by more than 2 log(10) 12 weeks after the start of the therapy, has not been elucidated sufficiently. The outcome in this group of patients was investigated. Serum HCV RNA levels was measured every 4 weeks in 149 patients with HCV genotype 1b infection who underwent combination therapy for 48 weeks. In patients with partial early virologic response, the time point when serum HCV RNA became undetectable as well as the final virologic response to treatment was determined. Sixty-three patients (42.3%) had partial early virologic response. The time when serum HCV RNA became undetectable ranged from 16 to 48 weeks after the start of therapy. Serum HCV RNA remained detectable in 17 patients. The rates of sustained virologic response decreased with the delay of the time when serum HCV RNA became undetectable; sustained virologic responder was not found in patients in whom HCV RNA was still detectable at 24 weeks after the start of treatment. The degree of decrease in serum HCV RNA levels at 12 weeks corresponded to the rate of sustained virologic response in partial early virologic responders. The outcome of partial early virologic responders varied greatly, and close monitoring of serum HCV RNA is required for predicting the outcome of treatment in these patients., (© 2010 Wiley-Liss, Inc.)

As combination therapy with peginterferon (PEG-IFN) and ribavirin has a high morbidity, identifying individuals with hepatitis C virus (HCV) who will not respond to the treatment would be beneficial. The early responses of serum HCV RNA levels to standard interferon (IFN) and PEG-IFN were examined to determine if it was possible to identify resistance to combination therapy. One hundred thirty-one patients infected with HCV genotype 1b were enrolled. Patients were given 6 MU of standard IFN alpha-2b at least 2 weeks before initiating combination therapy. Serum HCV RNA levels were measured before, 24 hr after the administration of standard IFN, and 24 hr after the administration of PEG-IFN (at the start of the combination therapy). The association between reductions in HCV RNA levels at 24 hr after the administration of standard IFN and PEG-IFN and the outcome of combination therapy were analyzed. Reductions in HCV RNA levels were poorer in patients who did not respond than in those with a sustained virologic responses or relapses (P < 0.0001), both 24 hr after the administration of standard IFN and 24 hr after the administration of PEG-IFN. Reductions in HCV RNA levels 24 hr after the administration of standard IFN were an independent factor associated with non-response by multivariate analysis. An early reduction in viral load to a single administration of standard IFN is a useful predictor of non-response in patients with HCV genotype 1, allowing for pretreatment identification of patients who will not benefit from combination therapy.

Background and Aim: We prospectively compared the sensitivity to interferon (IFN) and the efficacy of antiviral combination therapy with peginterferon (PEG-IFN) and ribavirin for chronic hepatitis C virus (HCV) genotype 1b infection according to the amino acid sequences of the HCV core, E1, and NS5A regions reported to be associated with the outcome of antiviral therapy., Methods: A total of 107 patients with HCV genotype 1b were investigated. All patients received combination therapy with PEG-IFN alpha-2b and ribavirin. Amino acids 70 and 91 (core), 139 (E1), and 2209-2248 (NS5A) of HCV were analyzed by direct nucleotide sequencing., Results: The reduction in HCV RNA concentration at 24 h after a single administration of conventional IFN-alpha and after the start of combination therapy was significantly less marked, and rates of complete early virologic response, end-of-treatment response, and sustained virologic response (SVR) were significantly lower (all P < 0.0001) in patients with glutamine at amino acid 70 (n = 29) than in those with arginine at that position (n = 70). We found no differences associated with the other amino acid positions. Amino acid 70 was an independent factor for the responses to the therapy in multivariate analysis., Conclusion: The identity of amino acid 70 of the HCV core region affected the sensitivity to IFN; patients with glutamine at amino acid 70 of HCV showed resistance to IFN. Consequently, it strongly affected the outcome of combination therapy with PEG-IFN and ribavirin in Japanese patients with HCV genotype 1b.

Objectives: The aim of this study was to evaluate the efficacy and indication of combination therapy with ribavirin plus peginterferon-alpha-2b in chronic hepatitis C virus (HCV) patients aged 65 years and older., Methods: Five hundred and ninety-one consecutive HCV patients were treated with combination therapy. These patients were divided into elder patients (> or = 65 years) (n=115) and younger patients (< 65 years) (n=476). The clinical characteristics, sustained virological response (SVR) rates and discontinuation rates were compared between the two groups., Results: Compared with younger patients, baseline haemoglobin levels and baseline platelet counts were significantly lower (P<0.0001, P=0.013 respectively) and fibrosis was more advanced in elderly patients (P=0.0310). Moreover, the SVR rate was significantly lower (37.4 vs. 51.5%; P=0.0067) while the combination therapy discontinuation rate was significantly higher (32.2 vs. 17.0%; P=0.0003) in elderly patients. A multivariate analysis revealed that HCV load and genotype were significantly associated with an SVR in elderly patients. An SVR was achieved in over 50% of elderly male patients with genotype 1 and HCV RNA concentrations under 2,000,000 IU/ml. In contrast, the SVR rate was under 30% in elderly male patients with genotype 1 and with HCV RNA concentrations over 2,000,000 IU/ml and in all elderly female patients with genotype 1., Conclusions: The SVR rate was lower in elderly patients than in younger patients. However, in elderly patients combination therapy was most beneficial for genotype 1 patients, male patients with HCV RNA concentrations < 2,000,000 IU/ml and patients with genotype 2.

Background: The "response-guided therapy" based on response of hepatitis C virus (HCV) during antiviral combination therapy with peginterferon and ribavirin is important for patients with HCV genotype 1. However, the sensitivity of previous assays for serum HCV RNA is limited., Objectives: We evaluated the changes in serum HCV RNA during the combination therapy using a novel method for measurement based on real-time PCR., Study Design: Changes in serum HCV RNA during the combination therapy were reanalyzed using TaqMan PCR assay in 144 patients with chronic HCV genotype 1b infection who underwent the therapy under HCV RNA monitoring with the Amplicor Monitor assay. Treatment duration was elongated from 48 weeks to 72 weeks in 17 patients based on the time when serum HCV RNA became negative., Results: In 9 of 144 (6.3%) patients, serum HCV RNA transiently appeared again on the TaqMan PCR assay after having previously become negative. At the point of reappearance, the Amplicor Monitor assay gave a negative result in all patients, and no flare of alanine aminotransferase activity was observed. Each of the 9 patients achieved an end-of-treatment response but relapsed after the end of treatment, including 3 patients in whom the treatment duration was elongated to 72 weeks., Conclusions: Attention should be paid to this phenomenon in the antiviral treatment for patients with HCV infection. The transient reappearance of HCV RNA in the serum indicates a high likelihood of relapse, and is likely to be missed without frequent measurements by a sensitive detection method.

Background: There has been no direct comparison of the antiviral efficacy and the adverse effects of peginterferon (PEG-IFN) alfa-2a and PEG-IFN alfa-2b when used in combination therapy with ribavirin for chronic hepatitis C virus (HCV) infection., Objective: A head-to-head comparison of the antiviral efficacy and the adverse effects of PEG-IFN alfa-2a and PEG-IFN alfa-2b was made based on the results from the IDEAL trial, a large, multicenter, prospective, randomized, controlled study performed in the United States to provide guidance for the selection of the right PEG-IFN in clinical settings., Methods: The results of the IDEAL trial were analyzed., Results/conclusion: The antiviral efficacy, as well as the adverse effects, of PEG-IFN alfa-2a and PEG-IFN alfa-2b are similar in US patients with HCV genotype 1 when used in a standard dosing regimen in combination with ribavirin.

Hepatitis C virus (HCV) kinetics were determined after a single administration of standard interferon (IFN) according to the HCV genotype that affects the response to antiviral therapy with IFN/peginterferon. A total of 208 patients were investigated. All patients received a single administration of 6 megaunits of standard IFN-alpha. HCV RNA concentration was measured before, and at 24, 48, 72, and 120 hr after administration. Changes in HCV RNA concentration were compared between genotypes. The patient group consisted of 132 patients with genotype 1B, 58 with genotype 2A, and 18 with genotype 2B. In the comparison between genotypes 1 and 2, the reduction in HCV RNA concentration after a single IFN administration was less marked in patients with genotype 1B at both 24 and 48 hr after administration (P < 0.0001). In contrast, an increase in HCV RNA concentration during 24-48 or 24-72 hr after a single administration was comparable between genotypes 1 and 2. In the comparison between genotypes 2A and 2B, the reduction in HCV RNA concentration after a single administration was more marked in patients with genotype 2A, despite the similar rate of sustained virologic response to peginterferon and ribavirin combination therapy. The results of the study indicate that the rapid decrease in HCV RNA concentration observed during IFN or peginterferon therapy in patients with genotype 2 appeared to be due to the difference in sensitivity to IFN. Within genotype 2, HCV genotype 2A was more sensitive to IFN than genotype 2B., (2009 Wiley-Liss, Inc.)

Background/aims: Although the efficacy and safety of pegylated-interferon (PEG-IFN) alpha-2a and PEG-IFN alpha-2b have been comparatively studied, there are few study results available in which the two PEG-IFN products were strictly compared. To compare the effects of two PEG-IFN products on blood cell profile., Methodology: The time-course change in blood cell counts was compared between chronic hepatitis C patients with genotype 1b receiving PEG-IFN alpha-2a/ribavirin and PEG-IFN alpha-2b/ribavirin combination therapy. The comparison was made after matching patients from the two groups based on ribavirin apparent clearance (CL/F), a surrogate marker of the steady state blood ribavirin level, in order to eliminate the effect of ribavirin. Fifteen pairs of matched patients were selected., Results: The time-course change in hemoglobin did not differ significantly between the two groups. However, significantly greater reductions in both neutrophil and platelet counts were observed with PEG-IFN alpha-2a compared to PEG-IFN alpha-2b. A slightly longer period was required with PEG-IFN alpha-2a than with PEG-IFN alpha-2b for a reduction in neutrophil or platelet count large enough to necessitate dose reduction., Conclusions: Two types of PEG-IFN products affected the blood cell profile in different manners. Long-term monitoring of laboratory test values is necessary with PEG-IFN alpha-2a.

The interferon sensitivity-determining region (ISDR) is thought to be inhibited by the double-stranded RNA-dependent protein kinase (PKR). Several studies have reported a relationship between the ISDR and interferon (IFN) responsiveness. However, this relationship is controversial. The aim of this study was to investigate whether genomic heterogeneity of the ISDR among patients with hepatitis C virus (HCV) genotype 2a affects the response to pegylated-IFN-alpha 2a monotherapy. Eighty patients (47 men, 33 women; mean age: 54.2 +/- 12.9 years) infected with HCV genotype 2a were evaluated. HCV viral loads were determined by real-time PCR. The ISDR (amino acids 2193-2228) was examined by direct sequencing. Thirty-one patients received subcutaneous injections of pegylated-IFN-alpha 2a (180 microg) once weekly for 24 weeks, and 35 patients received injections for 48 weeks. Fourteen patients withdrew from treatment. Of the remaining 66 patients, 51 (77.3%) showed a sustained virologic response. Factors related to sustained virologic response on multivariate analysis were rapid virologic response (negative HCV at 4 weeks; odds ratio: 0.033; 95% confidence interval (95% CI) 0.003-0.363; P = 0.0052) and the number of mutations in the ISDR (odds ratio: 0.025; 95% CI 0.001-0.476; P = 0.0141). There were no significant differences in other factors, including sex, age, aspartate aminotransferase, alanine aminotransferase, platelet count, duration of treatment, and HCV viral load. Rapid virologic response and the ISDR sequence variations are significantly associated with response to pegylated-IFN-alpha 2a monotherapy in Japanese patients with HCV genotype 2a., (Copyright 2009 Wiley-Liss, Inc.)

Background: It remains unclear how we can shorten the treatment duration of antiviral combination therapy with peginterferon and ribavirin for patients with chronic hepatitis C virus (HCV) genotype 2 infection who achieved a rapid virological response (RVR)., Aim: We compared the efficacy of antiviral combination therapy with peginterferon and ribavirin for 8 vs. 24 weeks for the treatment of patients with HCV genotype 2 infection and with RVR., Methods: Sixty-one patients were enrolled. Serum HCV RNA was not detected at 4 weeks after the start of treatment in 32 patients with an RVR. These 32 patients were randomly assigned to 8-week (n=15) or 24-week (n=17) treatment regimens. Patients in the 8-week group who relapsed underwent a 24-week retreatment., Results: No significant difference in patient characteristics was observed between the 8- and the 24-week treatment groups. A sustained virological response (SVR) was seen in five of 15 patients (33.3%) in the 8-week treatment group and 14 of 17 (82.4%) in the 24-week treatment group; the rate was significantly higher in the 24-week treatment group (P=0.0140). Nine of 10 relapsed patients in the 8-week treatment group underwent a 24-week retreatment, and seven achieved an SVR., Conclusion: An 8-week regimen of combination antiviral therapy with peginterferon and ribavirin yielded an increase in the relapse rate, indicating the limitation of a reduction of treatment below 12 weeks in patients with genotype 2, after RVR.

Background: In Japan, patients with hepatitis C virus (HCV)-associated liver disease are getting older, and thus the number of deaths due to such disease is increasing. The efficacy of combination therapy with ribavirin and interferon for chronic HCV infection in elderly patients has not been fully clarified. The aim of the present study was to evaluate the efficacy and tolerability of combination therapy in such patients., Methods: Two hundred and twenty consecutive patients with chronic hepatitis C were treated with combination therapy. These patients were divided into two groups according to age: patients >or= 60 years (n = 66) and patients < 60 years (n = 154). Clinical characteristics, the sustained virologic response (SVR) rate obtained by intention-to-treat analysis, and the rate of reduction or discontinuation of ribavirin were compared between the two groups., Results: The ribavirin discontinuation rate was significantly higher in the patients aged >or=60 years than in the patients aged <60 years. However, the SVR rates did not differ significantly between patients aged >or=60 years and those aged <60 years (31.8% vs 38.3% by intention-to-treat analysis). According to multivariate analysis, genotype and HCV viral load were significantly associated with SVR while patient age did not affect SVR., Conclusions: Treatment of chronic hepatitis C with combination therapy was comparably effective between patients aged >or=60 years and those aged <60 years, although the ribavirin discontinuation rate was higher among the older patients than the younger patients.

Background: We carried out this study to assess the risk of hepatitis C virus (HCV) transmission after needlestick injuries in medical personnel, and to evaluate the efficacy of short-duration interferon administration to prevent HCV transmission., Methods: A total of 684 personnel who had been occupationally exposed to an anti-HCV-positive source and followed for more than 3 months were retrospectively examined., Results: Of the 684 subjects, 279 (41%) were treated with 1 to 3 days of interferon either just after or 1 to 12 days after the injury. One case of HCV infection was found in each of the treated (1/279; 0.4%) and nontreated (1/405; 0.2%) groups. There was no significant difference in the transmission of HCV between the two groups. Both infected patients were treated with interferon after developing acute hepatitis, and HCV was subsequently cleared., Conclusions: There is a lower risk of HCV transmission after needlestick accident than previously reported, and short-duration interferon administration at an early stage after the needlestick injury, to prevent HCV transmission, is unnecessary.

Background/aims: To evaluate efficacy of high-intensity interferon administration for patients chronically infected with hepatitis C virus genotype 1b, we administered interferon-alpha with different regimens according to viral load., Methodology: Eighty-eight patients with hepatitis C virus genotype 1b were treated with recombinant interferon alpha-2b. The 70 patients with pretreatment hepatitis C virus RNA concentration > or = 10(6) copies/mL were given 10(7) units of interferon daily for the first 8 weeks and then three times weekly for 16 weeks (group A). The 18 patients with smaller pretreatment hepatitis C virus RNA concentration received the same dose daily for the first 2 weeks and then three times weekly for 14 weeks (group B). We analyzed tolerance of therapy, responses, and long-term outcome in the two groups., Results: Fifteen of 70 patients (21.4%) in group A could not continue treatment and dropped out, while all patients in group B completed the entire course of therapy. The rate of sustained response in group A was 10.0%, being significantly less than in group B (72.2%; p < 0.0001). However, 12 patients in group A showed a biochemical sustained response despite presence of viremia. Long-term outcome did not differ between groups., Conclusions: Many patients could not tolerate high-intensity therapy, which showed the limitation of tolerance of patients receiving interferon monotherapy. High-intensity therapy could not improve eradication of hepatitis C virus in patients with high pretreatment hepatitis C virus RNA concentration. However, this therapy may increase the rate of sustained biochemical response, improving long-term outcome.

Background/aims: We investigated the rate of occurrence and the risk factors for hepatocellular carcinoma in chronic hepatitis C patients who received interferon therapy., Methodology: We followed 413 chronic hepatitis C patients for more than 6 years after interferon therapy and assessed the following patient characteristics: age, sex, platelet count, response to interferon, hepatitis C virus RNA level, hepatitis C virus genotype, liver histology, and changes in serum alanine aminotransferase levels., Results: Hepatocellular carcinoma was found in 21 patients after interferon therapy. The factor most related to the occurrence of hepatocellular carcinoma was changes in serum alanine aminotransferase levels (univariate analysis, P < 0.0001; multivariate analysis, P = 0.0013), followed by age (univariate analysis, P = 0.0003; multivariate analysis, P = 0.0029). A significant difference was observed in the platelet count and response to interferon based on univariate analysis alone (P = 0.0096, P = 0.0241, respectively), however no significant differences were noted in the other factors. The course of serum alanine aminotransferase levels following interferon therapy rather than the eradication of hepatitis C virus was found to be the factor most profoundly involved in liver carcinogenesis., Conclusions: Even if interferon therapy fails to eradicate the hepatitis C virus, maintaining low serum alanine aminotransferase levels post-interferon therapy would reduce the risk of hepatocellular carcinoma in chronic hepatitis C.

Background: Genotype 1b of hepatitis C virus (HCV) comprises mainly three subtypes, each named for its geographic prevalence (worldwide, W; Japan, J; and not in Japan, NJ)., Aim: To characterise the newly identified subtypes of genotype 1b and to review factors associated with response to interferon (IFN) for each subtype., Patients: Chronic hepatitis patients (80 men and 41 women; mean age 48.5 years, range 20.7--69.3) with HCV genotype 1b (W type, n=41; J type, n=38) or genotype 2a (n=42) were treated according to the same IFN protocol. Forty four patients (36.4%) negative for serum HCV RNA six months after cessation of treatment were considered complete responders., Methods: Factors associated with complete response were investigated., Results: Genotype 2a patients had lower viral loads (odds ratio 0.11 (95% confidence intervals (CI) 0.049--0.256)) and a better IFN response (odds ratio 0.25 (95% CI 0.117--0.552)) than genotype 1b patients whereas W type and J type patients had similar viral loads and responses to IFN. IFN response in W type patients was associated with female sex (odds ratio 0.23 (95% CI 0.055--0.983)) and low viral load (odds ratio 84.00 (95% CI 14.04--502.6)) whereas response in J type patients was related to transfusion history (odds ratio 7.20 (95% CI 1.443--35.91)), low viral load (odds ratio 117.0 (95% CI 17.82--768.3)), and genetic mutation in the interferon sensitivity determining region of the virus (odds ratio 0.08 (95% CI 0.013--0.553)). Multivariate analysis found low viral load (odds ratio 64.19 (95% CI 14.66--281.06)) to be the only significant independent factor associated with IFN response., Conclusions: Factors associated with IFN responsiveness in HCV infection differ with viral subtype.

Objective: We evaluated the effect of dose and duration of treatment with interferon (IFN)-alpha on the incidence of hepatocellular carcinoma (HCC) after IFN treatment in patients with chronic hepatitis C., Methods: A total of 291 noncirrhotic patients with chronic hepatitis C without hepatitis B virus coinfection in whom hepatitis C virus (HCV) was not eradicated by IFN-alpha therapy were retrospectively analyzed. The incidence of HCC after IFN therapy was compared according to the total dose or duration of treatment., Results: Patients were followed up for 6-117 months after the end of IFN treatment. The duration of IFN treatment (< or =24 vs. >24 weeks) had no effect on the incidence of HCC. However, the incidence of HCC was significantly lower in patients who received >500 million units of IFN as a total dose than in patients who received < or =500 million units of IFN (p = 0.0480), and the total dose of IFN (>500 million units) was an independent factor affecting the incidence of HCC (p = 0.0405). In addition, when focusing on patients whose histology was F2 or F3 before IFN treatment, the suppressive effect of the total dose of IFN (>500 million units) was emphasized (p = 0.0049 in generalized Wilcoxon test and p = 0.0178 in multivariate analysis)., Conclusions: Patients with chronic hepatitis C should receive more than 500 million units of IFN when IFN is used to decrease the incidence of subsequent HCC., (Copyright 2001 S. Karger AG, Basel)

Background: Interferon (IFN) has been reported to have beneficial long term effects that reduce the occurrence of hepatocellular carcinoma (HCC), even in patients who do not have complete responses to IFN. The authors evaluated the effect of retreatment with IFN-alpha on the long term prognoses of those with incomplete responses to their initial IFN-alpha treatment., Methods: Among 271 patients with incomplete responses to initial IFN-alpha treatment who had received sufficient dose and duration (a total dose of more than 350 megaunits administered over a period longer than 12 weeks) between October 1989 and September 1997, 63 patients received retreatment and 208 did not. The authors retrospectively compared the incidence of HCC between patients who received retreatment and those who did not., Results: There were no significant differences in the clinical characteristics between these two groups. The cumulative incidence of HCC was significantly lower among the patients who had retreatment, and retreatment with IFN-alpha was the only factor that correlated with the lower incidence of HCC in multivariate analysis. The results were similar when the 12 patients with complete responses to retreatment were excluded from the analysis., Conclusions: Retreatment with IFN-alpha appeared to have the additional effect of suppressing the development of HCC in patients who had incomplete responses to the initial treatment, even when the hepatitis C virus was not cleared (i.e., a complete response was not achieved) with retreatment. Further prospective study is required., (Copyright 2000 American Cancer Society.)

We studied 349 patients with chronic infection due to hepatitis C virus (HCV), including 83 with coagulopathy, 122 with community-acquired infection, 20 with chronic posttransfusion hepatitis C, and 124 for whom the transmission mode was unknown. The prevalence of mixed-subtype HCV infection was investigated in each group of patients. The serum HCV RNA concentration and the response to interferon (IFN) therapy were evaluated. HCV infection with mixed subtypes was more frequent in patients who had been at high risk for exposure to HCV, such as those with coagulopathy or community-acquired infection. HCV RNA concentrations were lower in patients infected with mixed subtypes, except for those with subtypes 1a and 1b. Ten of 11 patients with mixed subtypes (not including those with 1a and 1b) achieved complete clearance of HCV RNA with IFN therapy.

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.

Background/aims: The response to interferon-alpha (IFN) therapy of recently isolated GB virus C and hepatitis G virus (HGV) is still unclear. To investigate the biochemical and virological response to IFN therapy in patients with chronic hepatitis C virus (HCV) infection concomitantly infected with HGV, 196 patients with HCV who had received IFN therapy were retrospectively studied., Methods: HGV and HCV RNA were detected by reverse transcription nested polymerase chain reaction (RT-PCR). Serum HGV RNA levels were quantified by competitive RT-PCR. The HGV genotype was detected by restriction fragment length polymorphism analysis using the PCR products., Results: Of 196 patients, 16 (8.2%) were positive for both HCV and HGV RNA before IFN therapy. There were no significant clinical and virological differences between the patients with dual infection and those with only HCV infection. During the therapy, a decrease or loss of serum HGV RNA level was observed in these patients. Six months after cessation of the therapy, five of 16 patients became negative for HGV RNA by RT-PCR. The pretreatment HGV RNA level of the patients who lost HGV RNA after cessation of IFN was low (median=10(3) copies/ml), compared to the level (median=10(7) copies/ml, p<0.01) in the patients with positive HGV RNA after the therapy. The HGV genotype of these 16 patients was the same type., Conclusions: These data suggest that: 1) there is no significant difference in response to IFN therapy between patients with dual and single infection; 2) HGV shows sensitivity to IFN therapy; and 3) in the patients who show a low pretreatment HGV RNA level, serum HGV RNA becomes undetectable by RT-PCR after cessation of IFN therapy.

Background: Interferon can induce complete clearance of hepatitis C virus (HCV) in some patients with chronic hepatitis C. However, various side effects often require cessation of administration during the treatment period. Early prediction of response to interferon would be helpful. We evaluated measurement of serum HCV RNA 2 weeks after starting interferon as a predictor of response., Methods: The presence of HCV RNA was measured in serum 2 weeks after starting therapy in 85 patients receiving natural interferon a (total 480 MU)., Results: Twenty-seven of 38 patients (71.1%) in whom serum HCV RNA had disappeared at 2 weeks achieved a sustained response. Only two out of 47 patients (4.3%) in whom serum HCV RNA had not disappeared at 2 weeks achieved a sustained response. Of 42 patients with pre-treatment HCV RNA concentrations less than 1 x 10(6) eq/ml, 26 of 30 patients (86.7%) whose HCV RNA had disappeared at 2 weeks achieved a sustained response, while only one of 12 patients (8.3%) whose HCV RNA was still detectable at 2 weeks had a sustained response., Conclusion: Clearance of serum HCV RNA after 2 weeks of treatment with interferon was more likely in patients with lower pre-treatment HCV RNA concentrations and they had a high likelihood of achieving a sustained response. In patients in whom serum HCV RNA was still detectable after 2 weeks of interferon therapy, a sustained response was most unlikely.

Background/aims: We evaluated the significance of the quasispecies nature of HCV as a predictor of the response to alpha interferon therapy in patients with chronic hepatitis C., Methods: Natural alpha interferon was administered in 62 patients for 24 weeks (daily for 2 weeks, then three times weekly for 22 weeks) and factors were analyzed that could affect the response. HCV subtype, HCV RNA concentrations and the number of HCV quasispecies were evaluated before treatment. HCV RNA concentrations were measured by branched DNA probe assay. The number of HCV quasispecies was measured by fluorescence single-strand conformation polymorphism analysis., Results: The HCV RNA concentration (p < 0.0001), HCV subtype (p = 0.0076), and the number of HCV quasispecies (p = 0.0024) were significantly associated with a complete response. Multivariate analyses showed that the number of HCV quasispecies was an independent predictor of the disappearance of HCV RNA during the administration of alpha interferon, but did not predict a relapse after its completion. Pretreatment concentration of HCV RNA was the only factor that was related to a long-term disappearance of HCV RNA., Conclusions: The number of HCV quasispecies was significantly related to the response to alpha interferon early in its administration. The pretreatment concentration of HCV RNA was mainly related to a relapse following completion of treatment.

Objective: A randomized, controlled trial was performed to study the effect of the period of daily administration of interferon therapy in patients with chronic hepatitis C., Patients and Methods: Sixty-three patients were administered a total dose of 480 MU of natural alpha-interferon, 6 MU each day. In 32 cases, interferon was given daily for 2 wk, followed by intermittent administration (three times a week) for 22 wk. The other 31 patients received daily administration for 8 wk, followed by intermittent administration (twice a week) for 12 wk. The responses were based on the normalization of ALT and the clearance of hepatitis C virus., Results: Although ALT normalized in 37 patients during the administration of interferon, it relapsed after the end of interferon therapy in 20 patients. The other 17 patients achieved sustained normalization of ALT and clearance of hepatitis C virus RNA. Responses did not differ according to the administration period of interferon., Conclusions: Prolonged daily administration did not improve the responses to interferon therapy when the total dose was the same.

A study was carried out to assess the correlation between the serum concentration of hepatitis C virus RNA (HCV-RNA) in patients with chronic hepatitis, as measured by competitive reverse transcription polymerase chain reaction (cRT-PCR) and branched DNA probe assay (bDNA), and response to interferon-alpha (IFN alpha) therapy. The serum HCV-RNA concentration was evaluated by both cRT-PCR and bDNA in 54 patients who had received a total dose of 480 MU of IFN alpha. HCV subtypes were also identified in all patients. The measurement of serum HCV-RNA concentration by bDNA correlated significantly with that of cRT-PCR. The concentration of HCV-RNA in subtype 1 patients was significantly higher than that in subtype 2 patients when measured by bDNA, but not when measured by cRT-PCR. The correlation of HCV-RNA concentration between bDNA and cRT-PCR was associated with both subtypes 1 and 2. The difference in serum HCV-RNA concentration between complete and incomplete responders was more significant when measured by bDNA probe assay than by cRT-PCR. Moreover, only 1 of 26 patients with a HCV-RNA concentration of more than 1 x 10(6) eq/ml as measured by bDNA probe assay attained a complete response, while 19 of 28 patients with that of less than 1 x 10(6) eq/ml achieved it. Measurement of serum HCV-RNA concentration by bDNA probe assay was a better predictor of clinical response of IFN alpha therapy than measurement by cRT-PCR.

To virologically assess the efficacy of interferon therapy in chronic hepatitis C, either 5 or 10 MU/day natural interferon-alpha (IFN alpha) was administered to 57 patients with chronic hepatitis C for 38 weeks. A complete and sustained response (CR-SR), as evidenced by the absence of serum hepatitis C virus (HCV)-RNA during the administration period and at 6 months after the final administration of IFN alpha and normal GPT level at 6 months after final administration, occurred in 42.6% (23/54) of subjects. Liver tissue was histologically evaluated using the histological activity index (HAI) score before and after the administration period. In CR-SR cases, significant improvements (P < 0.01) occurred in periportal necrosis, intralobular necrosis, portal inflammation and total score. A comparison, by HCV genotypes, revealed that CR-SR occurred in 60% (9/15) of subjects with type 2a and 30.3% (10/33) of subjects with type 1b. A comparison by virus concentration revealed that CR-SR occurred in 71.4% (15/21) of those subjects having a virus concentration of < 10(5) copies/mL, but in only 24.2% (8/33) of those having a virus concentration of > 10(5) copies/mL. Analysis by a multiple logistic model revealed a strong correlation between the therapeutic effect of interferon therapy and the pre-administration virus concentration (P = 0.0061) and genotype (P = 0.0015). These results suggest that the pre-administration virus concentration and genotype are both key factors affecting the therapeutic effect of interferon therapy in chronic hepatitis C and that the therapeutic effect of interferon is satisfactorily high, irrespective of virus concentration, in subjects with type 2a HCV, but varies depending on virus concentration in subjects with type 1b.

Background: Serum levels of soluble interleukin-2 receptor (sIL-2R) seem to serve as a marker for the activation of T lymphocytes. The aim of this study was to evaluate the clinical significance of such levels in patients with chronic hepatitis C (CHC) treated with interferon., Methods: We measured serum levels of sIL-2R in 37 patients with CHC before and after treatment with recombinant interferon-alpha. Serum receptor levels were then compared with the response of the hepatitis C virus (HCV)-RNA level in serum after interferon., Results: Receptor levels were significantly higher in the patients with chronic persistent hepatitis and chronic active hepatitis than in normal controls (p < 0.01). There was a weak correlation between serum sIL-2R and alanine aminotransferase (ALAT) levels (r = 0.14, p = 0.010). Patients were then classified into three groups on the basis of the effect of interferon treatment on HCV-RNA levels in serum: sustained response (SR; n = 21), non-sustained response (NSR; n = 14), and nonresponse (NR; n = 2). Before and during interferon treatment the serum sIL-2R level remained increased in the SR group and in the combined groups with NSR or NR. However, after interferon was withdrawn, the serum sIL-2R decreased in the SR group but remained significantly increased in the combined response group (p < 0.01-0.05)., Conclusion: This finding seems to reflect the disappearance of HCV-RNA from the serum of the patients with an SR, and monitoring of sIL-2R levels may therefore be of value as an adjunct to the measurement of serum ALAT and HCV-RNA in evaluating the response to the interferon therapy for CHC.

The effect of recombinant interferon-alfa on serum HCV RNA levels in Japanese patients with chronic hepatitis C was investigated. At 24 weeks of treatment, 41 (32.5%) of 126 patients lost HCV RNA from serum, and aminotransferases were normalized in 31 (75.6%) of these 41 cases. HCV genotypes were categorized into four types (Type I, II, III, IV); the frequencies among the patients were: Type I: 0%, Type II: 70.6%, Type III: 20.6%, and Type IV: 6.3%. At the end of the 24-week treatment, HCV RNA levels were remarkably decreased in Type III patients and became undetectable in 18 (69.2%) of 26. In contrast, only 18 (20.2%) of 89 patients with Type II and two of eight with Type IV lost HCV RNA from sera. The relation between HCV genotype (Type III) and response to IFN therapy was also confirmed using a logistic regression model. HCV genotype seems to be an important factor in determining the response to IFN in patients with chronic hepatitis C.

A patient with chronic hepatitis type C, confirmed by the detection of hepatitis C virus RNA (HCV RNA) in the serum and by histological examination of the liver biopsy specimen, was treated with four courses of interferon-alpha (IFN-alpha). For the first three courses of IFN-alpha the patient's serum alanine aminotransferase (ALT) level normalized during the administration of IFN-alpha but rose again after its cessation; similarly, HCV RNA was absent from the serum by the end of each course of treatment but could be detected once again after treatment stopped. The fourth course of IFN-alpha therapy, however, produced a sustained normalization of the ALT level and sustained absence of HCV RNA from the serum for 20 months after the end of treatment. This case suggests that patients with the potential for an eventual complete response to IFN-alpha therapy may show a normalization of serum ALT levels during IFN-alpha administration and the absence of HCV RNA in the serum by the end of each course of treatment (even if that particular course of treatment does not produce a sustained response).

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.