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The interferon sensitivity determining region (ISDR) of the hepatitis C virus (HCV) and T-helper type 1 and type 2 (Th1/Th2) ratio were analyzed along with other host and viral factors for their ability to predict the response of patients with chronic hepatitis C to pegylated interferon alpha-2b (Peg-IFN) and ribavirin (RBV) combination therapy. A total of 120 chronic hepatitis C patients with genotype 1 HCV and high baseline viral loads who were to undergo combination therapy scheduled for 48 weeks were enrolled. Sustained virologic response (SVR) was achieved in 54 (45%) of the 120 patients. The pretreatment factors significantly associated with SVR by logistic regression analysis were ISDR mutant [odds ratio (OR) = 86.0, P = 0.0008], Th1/Th2 ratio

Persistent infection of hepatitis C virus (HCV) can lead to a high risk for hepatocellular carcinoma (HCC). HCV core protein plays important roles in HCV-related hepatocarcinogenesis, because mice carrying the core protein exhibit multicentric HCCs without hepatic inflammation and fibrosis. However, the precise mechanism of hepatocarcinogenesis in these transgenic mice remains unclear. To evaluate whether the core protein modulates hepatocyte proliferation and apoptosis in vivo, we examined these parameters in 9- and 22-month-old transgenic mice. Although the numbers of apoptotic hepatocytes and hepatic caspase 3 activities were similar between transgenic and nontransgenic mice, the numbers of proliferating hepatocytes and the levels of numerous proteins such as cyclin D1, cyclin-dependent kinase 4 and c-Myc, were markedly increased in an age-dependent manner in the transgenic mice. This increase was correlated with the activation of peroxisome proliferator-activated receptor alpha (PPARalpha). In these transgenic mice, spontaneous and persistent PPARalpha activation occurred heterogeneously, which was different from that observed in mice treated with clofibrate, a potent peroxisome proliferator. We further demonstrated that stabilization of PPARalpha through a possible interaction with HCV core protein and an increase in nonesterified fatty acids, which may serve as endogenous PPARalpha ligands, in hepatocyte nuclei contributed to the core protein-specific PPARalpha activation. In conclusion, these results offer the first suggestion that HCV core protein induces spontaneous, persistent, age-dependent and heterogeneous activation of PPARalpha in transgenic mice, which may contribute to the age-dependent and multicentric hepatocarcinogenesis mediated by the core protein., (Copyright 2007 Wiley-Liss, Inc.)

Background and Objective: In Japan the prevalence of the hepatitis C virus (HCV) antibody is highest in the elderly population. Therefore, it is important for elderly patients to undergo interferon (IFN) therapy. In patients with HCV genotype 1b and a high viral load, the sustained virological response (SVR) rate is lower in older compared with younger patients receiving combination antiviral therapy. In addition, inadequate adherence to combination therapy is often seen in elderly patients, and is associated with reduced response rates. The aim of this retrospective analysis was to evaluate the effects of host-related factors (i.e. sex, age, baseline HCV RNA level, bodyweight and fibrosis stage) and peginterferon (PEG IFN)-alpha-2a plus ribavirin dose reductions on SVR rates., Methods: A total of 192 treatment-naive patients with a HCV genotype 1b infection and a high viral load were included in the analysis. Patients had been enrolled into a phase III trial of 48 weeks of treatment with PEG IFN-alpha-2a plus ribavirin or PEG IFN-alpha-2a plus placebo. All patients were evaluated for effect of drug exposure on SVR. In addition, the impact of host-related factors or dose reductions on SVR was assessed., Results: Approximately 30% of patients were considered elderly (> or =60 years of age). The overall SVR rate was significantly higher in patients treated with combination therapy versus monotherapy (59.4% vs 24.0%, p < 0.001). Attainment of an SVR following combination therapy was not influenced by any factor evaluated in the analysis, although elderly males were associated with decreased SVR rates. Younger age (odds ratio [OR] 1.081; 95% CI 1.125, 1.034; p = 0.0009), lower baseline HCV RNA levels (OR 1.003; 95% CI 1.006, 1.001; p = 0.006) and a severe fibrosis stage (F3/4) [OR 6.194; 95% CI 1.037, 37.000; p = 0.0455] significantly increased the likelihood of achieving an SVR with monotherapy. In the combination therapy group, patients maintaining a full dosage schedule of PEG IFN-alpha-2a and ribavirin and those requiring dose reductions of either study drug had similar SVR rates (64.5% vs 61.9%). However, the SVR rate was reduced to 33.3% among patients who discontinued combination therapy. Three out of the 31 patients who received the full dosage schedule were elderly patients. In addition, of the 15 patients who discontinued combination therapy, three were <50 years of age and six were > or =60 years of age. The SVR rate was reduced in patients with cumulative PEG IFN-alpha-2a and ribavirin doses of <60%; the majority of these patients were elderly., Conclusion: The attainment of an SVR following PEG IFN-alpha-2a plus ribavirin combination therapy was not influenced by any of the host-related factors evaluated in this analysis, although elderly males were associated with a decreased SVR rate. Younger age, male sex and lower baseline HCV RNA levels significantly increased the likelihood of achieving an SVR with monotherapy. In addition, dose reductions appeared to have a negative impact on SVR in elderly patients. Therefore, it is important to minimize PEG IFN-alpha-2a and ribavirin dose reductions by effectively managing treatment-related adverse events in elderly patients.

Background: The efficacy and safety of peginterferon alpha-2a (40 KD) (peg-IFNalpha-2a) plus ribavirin has not been reported for Japanese patients with chronic hepatitis C. The aim of this study was to evaluate this combination in treatment-naïve patients and in non-responders or relapsers to interferon monotherapy., Methods: Overall, 201 treatment-naïve patients with hepatitis C virus (HCV) genotype-1b were randomly assigned to 180 microg peg-IFNalpha-2a once-weekly plus ribavirin 600-1000 mg/day or peg-IFNalpha-2a plus placebo for 48 weeks. Additionally, peg-IFNalpha-2a plus ribavirin was administered for 48 weeks to 100 non-responders or relapsers (85% genotype-1) to previous interferon monotherapy., Results: A sustained virological response (SVR) was attained among significantly more treatment-naïve patients receiving combination therapy than monotherapy (61% vs 26%, P < 0.001). For patients with high baseline HCV RNA, the SVR rate was 59% with peg-IFNalpha-2a plus ribavirin versus 24% with peg-IFNalpha-2a monotherapy. Among non-responders or relapsers to previous interferon monotherapy, 54% attained an SVR. Adverse events were generally mild, and discontinuations rates due to adverse events or laboratory abnormalities were low., Conclusion: In Japanese patients, peg-IFNalpha-2a plus ribavirin provided significant improvement in SVR rates compared with peg-IFNalpha-2a alone in treatment-naïve patients, and was effective as re-treatment for non-responders or relapsers to previous treatment with interferon monotherapy.

We sought to clarify the incidence and role of Helicobacter pylori (H. pylori) seropositivity in patients with hepatitis C virus (HCV) infection and the effect of coinfection on interferon-alpha and ribavirin therapy. The presence of H. pylori was tested using a commercially available enzyme immunoassay in serum samples from 93 patients with chronic hepatitis C. Clinical features, HCV markers and response of HCV to interferon-alpha and ribavirin were compared between H. pylori-positive and H. pylori-negative patients. Anti-H. pylori antibody was detected in 45 (48%) of the 93 patients, whose median HCV-RNA level (495 vs 760 kIU/mL; P = 0.013) and platelet count (128 vs 158 x 10(3)/microL; P = 0.009) were significantly lower than in patients with HCV infection alone. Anti-H. pylori antibody levels were found to be significantly correlated with fibrosis score (P = 0.0083, r = 0.33) but inversely related to platelet count (P = 0.0037, r = -0.34). The sustained response rate for HCV clearance following interferon-alpha and ribavirin treatment did not differ between patients with and without anti-H. pylori seropositivity. The presence of H. pylori [odds ratio (OR) 8.61; 95% confidence interval (CI) 1.59-46.70] and fibrosis score (OR 30.13; 95% CI 5.44-166.78) were found by multivariate analysis to be associated with the decrease of platelet count during therapy. Coexistent H. pylori infection does not demonstrably influence the clinical course of chronic hepatitis C. A possible connection between H. pylori coinfection and thrombocytopenia was found during the treatment course, suggesting that preemptive eradication of H. pylori may facilitate completion of treatment and increased sustained virological response.

In an effort to clarify the life cycle of HCV, the HCV genome in liver biopsies taken from chronic active hepatitis C patients undergoing interferon treatment was investigated. Molecular cloning by long distance reverse-transcription polymerase chain reaction (RT-PCR) revealed that the HCV genome in two patients with high viral loads in the liver had in-frame deletions of approximately 2 kb between E1 and NS2, which encode the E1-NS2 fusion protein and six other HCV proteins: core, NS3, NS4A, NS4B, NS5A, and NS5B. Among the remaining 21 chronic active hepatitis C patients, these types of deletion were found in another two patients and in two hepatocellular carcinoma patients. Out-of-frame deletions in the structural region were isolated from the other five patients, but the dominant RT-PCR products were non-truncated genomes. Retrospective analysis of a series of serum samples taken from a patient carrying the subgenome with the in-frame deletion revealed that both the subgenome and the full genome persisted through the 2-year period of investigation, with the subgenome being predominant during this period. Sequence analysis of the isolated cDNA suggested that both the subgenome and the full genome evolved independently. Western blotting analysis of HCV proteins from the HCV subgenome indicated that they were processed in the same way as those from the full genome. HCV subgenomes thus appear to be involved in the HCV life cycle.

Hepatitis C virus (HCV) causes persistent infection in most patients. To clarify the mechanisms underlying establishment of this persistent infection, nucleotide sequences of the E1/E2 region were characterized in 5 patients with acute and chronic HCV infection. We used direct DNA sequencing methods to identify the major sequence of HCV in each patient. Each HCV genome displayed a high frequency of nucleotide sequence variation in the hypervariable region (HVR) of E2. However, patient-specific conserved nucleotide sequences were identified in the E1/E2 region during the course of infection and conserved the higher-order protein structure. In the acute phase HCV infection, amino acid substitution in HVR-1 as the monthly rate of amino acids substitution per site (%) between each point exceeded 10.2%. In the chronic phase HCV infection, a significantly lower rate of amino acid substitution was observed in patients. The host immune responses to HVR-1 of each HCV isolates from all clinical courses were characterized using synthetic peptides and ELISA. One chronic patient serum (genotype 1b) did not react at all to its own HVR-1 peptides, however another patient (genotype 2b) reacted to all clinical course. These results indicated that HVR-1 might not always exhibit neutralizing epitopes of HCV infection. The sequence variation in HVR-1 may instead indicate the existence of various clones in acute phase infection and the adaption of these clones is thought to have caused persistent and chronic infection in each patient.

The association between cryoglobulinemia and hepatitis C virus (HCV) infection has been reported. However, the factors underlying its wide variation of occurrence have not yet been well identified. To investigate this, cryoglobulinemia was studied in four cohorts of Egyptian and Japanese patients. Fifty Egyptian patients with chronic hepatitis C, infected with genotype 4 (the predominant HCV genotype in Egypt), were compared with 50 age- and sex-matched Japanese patients, infected with HCV genotype 1b (the predominant HCV genotype in Japan). Thirty-two Egyptian and 30 age- and sex-matched Japanese patients with chronic hepatitis B were included as controls. All patients were noncirrhotic. Antinuclear antibody (ANA), immunoglobulins (Ig), and cryoglubulins were assessed. Results showed a significantly higher prevalence of cryoglobulinemia in chronic hepatitis C Japanese genotype 1b (40%) as compared with Egyptian genotype 4 (14%), P = 0.003, while no difference was found between Japanese (17%) and Egyptian chronic hepatitis B controls (13%). Symptomatic cryoglobulinemia was more prevalent in the Japanese than in the Egyptian chronic hepatitis C group (10% vs. 4%), but the difference was not statistically significant. Univariate analysis showed no association between cryoglobulinemia and either age, sex, alanine aminotransferase level, or HCV viral load in Japanese or Egyptian patients, while the mean IgM level was significantly higher in the cryoglobulin-positive than in the cryoglobulin-negative chronic hepatitis C patients in each group (P = 0.003 and 0.017, respectively). Cryoglobulinemia was found to be significantly associated with both high IgG level (P = 0.020), and positive ANA (P < 0.001) in Japanese patients with chronic hepatitis C, genotype 1b but not in Egyptians with genotype 4. Multivariate analysis showed that the only factors predisposing to cryoglobulinemia were Japanese ethnicity with HCV genotype1b (P = 0.002, OR = 2.56), high IgM level of >245 mg/dl (P = 0.018, OR = 2.05) and female gender (P = 0.040, OR = 1/0.66). In conclusion, cryoglobulinemia is prevalent in Japanese patients with chronic hepatitis C infected with genotype 1b, but cryoglobulinemia is not common in Egyptians with HCV genotype 4. Although it was not possible to evaluate ethnicity and HCV genotype separately in this study, HCV genotype 1b appears to predispose more to cryoglobulinemia than does genotype 4. Female gender and high serum IgM level were also related., (Copyright 2003 Wiley-Liss, Inc.)

Malignant neoplasias are the leading cause of death in Japan at present, of which hepatocellular carcinoma (HCC) ranks the third most frequent in men and the fourth most frequent in women. Annual deaths due to HCC are rising sharply and amounted to 33,000 in 1999. Chronic hepatitis C is the most frequent etiology of HCC in Japan and accounts for nearly 90% of cases. The recent rapid increase of HCC in Japan is a long-term sequel of hepatitis C virus infection that affected many individuals in the past, and manifests itself currently as HCC. Infection with the hepatitis C virus has prevailed since the end of World War II for reasons inherent in the socioeconomic background in Japan.

During long-term follow-up of patients chronically infected with the hepatitis C virus (HCV) and treated with interferon (IFN), we identified some who had persistent normalization of serum alanine aminotransferase (ALT) but remained positive for HCV RNA. The aims of this study were to clarify the characteristics of these patients and to examine their clinical outcome after treatment. Nine hundred and ninety-eight patients treated with IFN were followed-up biochemically and virologically, and by liver ultrasound, for 13-95 months. A short-term biochemical sustained response, where ALT remained within the normal range for 6 months after the completion of IFN therapy, was found in 296 patients; in 240 of these patients serum HCV RNA remained undetectable during long-term follow-up. The rate of HCV RNA persistence was 7.09 times greater in short-term biochemical sustained responders with a high viral load than in those with a low viral load (P=0.0001, odds ratio [OR]=7.09), and 3. 70-fold lower in those treated with a large dose of IFN than in those treated with a small dose (P=0.02, OR=0.27). Thirty-three (59%) of 56 patients without HCV eradication showed continuous ALT normalization for 26-80 months after cessation of IFN therapy. Short-term biochemical sustained responders who were older (P=0.009, OR=10.43) and who were male (P=0.03, OR=6.98) had a significantly greater probability of maintaining a normal ALT level, even when serum HCV RNA was positive. When the incidence of HCC was investigated during long-term follow-up in patients without HCV eradication, it was found to be significantly lower in patients with persistently normal ALT levels than in those with abnormal ALT levels (P=0.03). Hence, when HCV is not eradicated as a result of IFN therapy, it may induce a long-term carrier state of HCV infection with normal ALT levels in older or male patients, in whom the cumulative incidence of HCC is markedly decreased.

The aim of this study was to analyze the clinical performance of a new enzyme immunoassay (EIA) for hepatitis C virus (HCV) core antigen in comparison with the reverse transcription polymerase chain reaction (RT-PCR). A total of 310 patients with acute or chronic hepatitis C, and 132 HCV-negative controls were studied. Chemiluminescence EIA with monoclonal anti-HCV core antigen was used, and qualitative and quantitative commercial RT-PCRs and an in-house nested RT-PCR were performed. Compared with nested RT-PCR, the core antigen assay showed 97% sensitivity and 100% specificity in 75 patients with chronic hepatitis C and 132 controls. HCV core antigen was positive in 16 (94%) of 17 patients with acute hepatitis C at initial consultation. In 3 persons prospectively followed, core antigen was detected in the first available (1-3 weeks) post-transfusion sample. In 167 anti-HCV-positive individuals, 129 (77%) were viremic; core antigen was detected in 126 (98%) compared with 129 (100%) for nested RT-PCR and 121 (94%) for the commercial RT-PCR. In 48 patients with chronic hepatitis C treated with interferon alfa, the concentration of core antigen before treatment was significantly (P <.002) lower in patients with sustained response than in nonresponders. All responders had a sustained loss of core antigen, whereas all nonresponders remained core antigen positive. The concentrations of HCV core antigen and HCV RNA correlated significantly (n = 48, r =.627, P <.001). In conclusion, the HCV core antigen assay is useful for the diagnosis of acute and chronic hepatitis C, and for predicting and monitoring the effect of interferon alfa treatment.

Background: Hepatitis C virus (HCV) viraemia is one of the factors for histological prognosis of chronic hepatitis C., Methods: One hundred and thirty-five patients who received hepatic biopsies twice at intervals of 5 years or longer were followed up for a mean of 9.7 +/- 4.0 years were studied retrospectively. The amount of HCV viraemia present was measured as the concentration of HCV core protein by using the fluorescence enzyme immunoassay method., Results: Multiple-regression analysis, using deterioration of the histological stage as a dependent variable, showed that greater age (P = 0.041), higher stage of hepatic histology at the start of follow up (P = 0.029), and higher serum concentration of core protein (P < 0.001) were independent factors affecting the deterioration of the liver's histological stage. At follow up, no significant difference in histological stage was seen between patients with serum HCV core protein > or = 100 pg/mL (n = 60) and those with serum core protein < 100 pg/mL (n = 75). The histological grade in patients with high serum core-protein levels tended to be significantly worse and the deterioration rate of the histological stage was significantly higher than in those with low HCV core protein levels (68 vs 35%, P < 0.001). The mutation rate of the HCV envelope-2/non-structural 1 (E2/NS1) nucleotide region was compared in two patients who had high serum concentrations of HCV core protein and whose histological stage had deteriorated with two patients who had low serum concentrations of the core protein and whose histological stages remained unchanged. No significant difference in E2/NS1 mutation was found., Conclusions: The amount of HCV viraemia was suggested to be a significant factor for determining histological outcome in patients with chronic hepatitis C. The mutation rate in the E2/NS1 region did not seem to be associated with the prognosis of chronic hepatitis C.

Objective: Changes in the deduced amino acid sequence of the envelope 2 (E2) region of the GB virus C/hepatitis G virus (GBV-C/HGV) were analyzed to investigate whether or not the region contributes to persistent infection with the virus., Methods: Eight patients with acute hepatitis C and 1 patient with acute hepatitis of unknown etiology were included in the study. GBV-C/HGV RNA was detected in 6 patients, including the patient with hepatitis of unknown origin. The nucleotide sequence of the E2 region of hepatitis C virus (HCV) and GBV-C/HGV was determined by direct sequencing of polymerase chain reaction products in 5 patients with HCV infection and in 6 patients with GBV-C/HGV infection twice during the period of early infection and several months or years later in each patient., Results: The mean substitution rate of the deduced amino acid sequence in the E2 region was over 100 times lower (p < 0.001) in GBV-C/HGV (0.01 +/- 0.04/month/100 sites) than in HCV (2.4 +/- 1.7/month/100 sites). The amino acid sequence of the loop domain of GBV-C/HGV-E2 did not change in any of the 6 patients. On the other hand, the sequence of the hypervariable region of HCV-E2 changed remarkably (5.9 +/- 4.3/month/100 sites). No amino acid substitution in the loop domain was observed in 7 additional patients who showed persistent GBV-C/HGV viremia for more than 2 years., Conclusion: These results indicate that changes in the amino acid sequence of the E2 region are not involved in the mechanism of persistent GBV-C/HGV infection.

Primary human hepatocytes were used to develop a culture model for in vitro propagation of hepatitis C virus (HCV). Production of positive- strand full-length viral RNA in cells and culture supernatants was monitored by PCR methods targeting three regions of the viral genome: the 5' NCR, the 3' X-tail and the envelope glycoprotein E2. De novo synthesis of negative-strand RNA was also demonstrated. Evidence for a gradual increase in viral components over a 3 month period was obtained by two quantitative assays: one for evaluation of genomic titre (quantitative PCR) and one for detection of the core antigen. Production of infectious viral particles was indicated by passage of infection to naive hepatocyte cultures. Reproducibility of the experiments was assessed using cultures from three liver donors and eleven sera. Neither the genotype, nor the genomic titre, nor the anti-HCV antibody content, were reliable predictive factors of serum infectivity, while the liver donor appeared to play a role in the establishment of HCV replication. Quasispecies present in hepatocyte cultures established from three different liver donors were analysed by sequencing hypervariable region 1 of the E2 protein. In all three cases, the complexity of viral quasispecies decreased after in vitro infection, but the major sequences recovered were different. These data strongly suggest that human primary hepatocytes are a valuable model for study of persistent and complete HCV replication in vitro and for identification of the factors (viral and/or cellular) associated with successful infection.

A fluorescence enzyme immunoassay (FEIA) for the quantitative measurement of hepatitis C virus (HCV) core protein has recently been developed. In this study, we studied the clinical usefulness of this measurement in patients with acute hepatitis C. Eighteen patients with post-transfusion acute hepatitis C were enrolled in the study; 5 patients showed resolution of hepatitis with disappearance of HCV viremia, while the remaining 13 patients did not. A second generation HCV antibody, HCV RNA, and HCV core protein were measured in serial serum samples taken within 1 month of the onset of acute hepatitis and 3, 6, 12, 24, and 36 months after onset. Within the first month after disease onset, the positivity rates of HCV RNA (100%; P = 0.0014) and HCV core protein (89%; P = 0.0300) were both significantly higher than that of HCV antibody (56%). Six months after disease onset, the positivity rate of HCV antibody had increased, to 100%, and the positivity rates of HCV RNA and HCV core protein began to decrease. HCV core protein levels did not differ between patients with resolved and unresolved disease in the first month after disease onset. These findings indicate that FEIA, a simple assay, for the measurement of HCV core protein was useful for the early diagnosis of acute hepatitis C.

Detection of the viral genome in serum is the most reliable way to analyze HCV viremia. In the present study, we evaluated the availability of a new detection kit for HCV-RNA, Amplicor HCV, which is based on the RT-PCR microplate hybridization protocol. The procedure of Amplicor HCV is simple, unlike the conventional RT-nested-PCR method. Although Amplicor HCV assay exhibited the lower sensitivity than the the conventional RT-nested-PCR method (10 x for HCV type 1a, 1b and 2b; 10(3) x for type 2a), Amplicor HCV assay could detect the HCV-RNA in all HCV-RNA positive cases by conventional RT-nested PCR method, except for one case who contained low concentration of HCV-RNA (10 copies/ml). The coincidence rate was 99.2% in 120 clinical samples between two assays. Amplicor HCV assay, moreover, could efficiently evaluate the viremia regardless of anti-HCV-2 antibody titer. This assay was useful for monitoring the effect of interferon therapy during and after administration. These results suggest that Amplicor HCV has an excellent availability for the clinical laboratories.

Antibody response to the E2/NS1 protein of the hepatitis C virus (HCV) was studied in 26 patients with post-transfusion acute hepatitis C. Second-generation HCV (HCV-2) antibody, E2/NS1 antibody and HCV-RNA were measured in serial serum samples taken within 1 month and 3, 6 and 12 months after the onset of acute hepatitis C. The HCV genotype was also tested to study its clinical significance. Of 26 patients, eight showed normalization of alanine aminotransferase (ALT) and clearance of HCV-RNA (resolved group). In the remaining 18 patients, HCV viraemia and ALT abnormality (except one patient) continued for more than 3 years (unresolved group). Both HCV-2 and E2/NS1 antibodies were positive at least once in all patients. The prevalence of E2/NS1 antibody was significantly (P < 0.05) higher in the resolved group (88%) than in the unresolved group (39%) in the period within 1 month of onset; the prevalence was similar between the two groups thereafter. The prevalence of HCV-2 antibody did not differ between the two groups at any point. The HCV genotype was not related to the chronicity of acute hepatitis C. In conclusion, the E2/NS1 antibody appeared in all patients with acute hepatitis C and was associated with the clearance of HCV.

The quantitation of hepatitis C virus (HCV) viremia can be helpful in the diagnosis, therapy, and monitoring of patients with chronic hepatitis C. A sensitive and quantitative fluorescence enzyme immunoassay (FEIA) has recently been developed for assaying HCV core protein in serum. To assess the utility of measurements of serum HCV core protein during the course of treatment of chronic hepatitis C, we studied 27 patients who were treated with a single schedule of interferon alfa (IFN-alpha) (9 million units per dose for 24 weeks; total dose, 720 million units). Eleven of the 27 patients responded with clearance of HCV RNA and fall of aminotransferase to normal; 16 patients did not respond to treatment. Before therapy, HCV core antigen was detectable in 25 of the 27 patients (93%). The initial serum concentration of HCV core protein was significantly (P < .01) higher in the nonresponders versus the responders. Two weeks after initiating IFN-alpha therapy, HCV core protein was not detectable in any of the 11 responders, but was detected in 8 of 16 nonresponders (P < .01). All responders, but none of the nonresponders, remained negative for core protein after IFN-alpha therapy. The measurement of HCV core protein by FEIA may be useful for predicting the response to IFN-alpha and for monitoring its therapeutic efficacy.

This study was conducted to clarify if the long-term histological outcome among patients with chronic hepatitis C differs according to whether they are infected with genotype 1 or 2 hepatitis C virus (HCV). We examined 140 patients with chronic hepatitis C. The HCV genotype was determined by the enzyme-linked immunosorbent assay (ELISA) based on genotypes 1 and 2 specific recombinant proteins; genotype 1 was found in 100 patients (96 were 1b and 4 were indeterminate) and genotype 2 in 36. The two groups showed no significant difference for any clinical background features. Deterioration of the grade of liver histology during the follow-up period was seen in 68.0 percent of the patients with genotype 1 as compared with 41.7 percent of those with genotype 2 (P < .01). Similarly, the deterioration of the stage of liver histology was more common in the former group than in the latter (63.0 percent and 38.9 percent respectively; P < .05). The mean serum HCV-RNA titer was significantly higher in the patients with genotype 1 than in those with genotype 2 (P < .001), and multivariate analysis showed the titer was one of the independent factors of the deterioration of the stage (P = .0044). This phenomenon may be related in part to the difference in pathogenicity between the two HCV genotypes. In conclusion, our results suggest that more severe progression of chronic hepatitis C is seen in patients showing genotype 1b compared with those with genotype 2.

A protein-capture fluorescence enzyme immunoassay (FEIA) was developed using monoclonal antibodies (mAbs) against recombinant hepatitis C virus (HCV) core protein. Four hybridoma cell lines (5E3, 5F11, 515S, 1080S) were established and characterized. These monoclonal antibodies (mAbs) each had IgG1 and OgG2 isotypes, and recognized major B cell epitopes within the immunodominant nucleoprotein amino terminal subregion. Using mAb 5F11 as the first antibody to the solid phase and beta-D-galactosidase-conjugated mAb 5E3 as the second antibody to the protein, we established a specific HCV core protein capturing FEIA capable of detecting as little as 20 pg/ml of recombinant HCV core protein. HCV core protein in serum was detectable after treatment with 4.0% polyethyleneglycol, 0.5 NaOH, and 5% Triton X-100. The results of a peptide inhibition assay indicated that this FEIA is specific for HCV RNA positive sera. The quantity of HCV core protein detected in serum was significantly correlated to the level of HCV RNA. The detection limit for HCV core proteins was an HCV RNA per titer of approximately 10(4)/ml. Using this FEIA system, the detection ratio of HCV core protein in patients with chronic HCV infection was 92.3% (70/76).

Sixteen medical institutions in Japan collaborated in this study of the epidemiology of hepatitis C virus (HCV) genotypes. A total of 4176 patients with type C chronic liver disease, from the four main islands of Japan, were evaluated. Of those evaluated, 2794 had chronic hepatitis, 727 had liver cirrhosis and 655 had hepatocellular carcinoma. The HCV genotype of the patients was determined by an enzyme-linked immunosorbent assay based on serological genotype 1- and 2-specific recombinant peptides (SG-1 and SG-2, respectively) of the NS4 region. The prevalence of SG-1 and SG-2 HCV was similar in the four main islands of Japan. SG-1 HCV predominated in each disease category (69-76%). The percentage of patients with SG-1 HCV increased by 7%, while that of patients with SG-2 HCV decreased by 7%, as liver disease progressed in severity from chronic hepatitis to carcinoma (P < 0.001). Patients with either SG-1 or SG-2 had a similar mean age and history of blood transfusion. In conclusion, SG-1 HCV was found to predominate in Japan, and the HCV genotype was found to be related to the stage of hepatitis C disease.

To document the transmission of hepatitis C virus (HCV) through needlestick accidents, 3 health workers who acquired HCV through such accidents and their HCV donor patients were studied using molecular evolutionary analysis based on the HCV E2 region. At least six clones were sequenced from each subject. Nucleotide substitutions were estimated by the six-parameter method, and a phylogenetic tree was constructed by the neighbor-joining method. HCV isolates from the donor patient and the recipient were nested in one monophyletic cluster; this clustering was confirmed to be statistically significant by bootstrap analysis. The nucleotide divergence among the isolates from the recipient was always smaller than that from the donor, supporting the notion that the direction of transmission was from the donor to the recipient. These findings provide evidence, at a molecular evolutionary level, that HCV was transmitted through needlestick accidents.

Nucleotide sequencing was used to analyze amino acid substitutions in the putative envelope 1 (E1) and envelope 2/nonstructural 1 (E2/NS1) regions of hepatitis C virus (HCV) to clarify a viral mechanism of persistent infection in three patients with acute hepatitis C who developed chronic hepatitis and two patients with chronic hepatitis. The HCV RNA titer in serum decreased markedly after the onset of acute hepatitis and then re-elevated. During this period, the substitution rate in the E2/NS1 region (especially in the hypervariable region located in the N-terminus) was significantly higher in patients with acute hepatitis than in patients with chronic hepatitis (P < 0.05). When patients with acute hepatitis C became persistent HCV carriers, the substitution rate decreased to the level seen in patients with chronic hepatitis. The amino acid substitution rate in the E1 region in the acute phase was similar to that found in the chronic HCV carrier state. These observations suggest that rapid substitution of the amino acid sequence in the hypervariable region of the E2/NS1 region may be one of the mechanisms of persistent HCV infection.

Hepatitis C virus (HCV) genotypes (groups I and II) were determined by a newly developed C14 assay in which antibodies against group-specific recombinant proteins of the NS4 region were measured by ELISA (enzyme-linked immunosorbent assay). The genotypes determined by the C14 assay were compared to those determined by a polymerase chain reaction (PCR) in 50 patients. The HCV genotypes determined by both methods were consistent in 78% of the patients. The results of the assays were not contradictory in any patient. The sensitivity of the C14 assay was as high as over 90%. Frequency of HCV genotypes was studied in 300 patients with chronic liver diseases type C by using the C14 assay. The prevalence of groups I and that of II in patients with chronic hepatitis were 73% and 21%, the correspondence figures in those with liver cirrhosis 80% and 13%, and in those with hepatocellular carcinoma 81% and 13%, respectively. The clinical characteristics were similar between the patients with group I and II HCV infections in each disease category. In conclusion, the C14 assay is useful for epidemiological studies of HCV genotypes, and group I is a major HCV genotype of chronic liver diseases type C in Japan.

The localization of hepatitis C virus (HCV) in the liver has not been well clarified. We report successful indirect immunoperoxidase staining of the HCV core antigen using polyclonal antibodies raised in rabbits and conventional formalin-fixed, paraffin-embedded needle biopsy sections of liver. The core antigen was distributed in a fine granular pattern diffusely, perisinusoidally, or focally within the hepatocellular cytoplasm of livers from patients with HCV infection. The staining tended to show a more heterogeneous pattern in terms of intensity and distribution in cases of more advanced disease. Hepatocellular carcinoma cells were also frequently stained. HCV immunostaining will provide important information on the pathogenesis and treatment of HCV-related liver diseases.

Background: Needlestick accidents are a problem among health care workers. Using sensitive new assays, we evaluated the prevalence and features of hepatitis C virus (HCV) infection following a needlestick accident., Method: The clinical outcome and evolution of serum HCV markers were assessed in 90 hospital employees (recipients) who sustained needlestick injuries (selected from 146 episodes) involving 92 patients with clinical non-A, non-B hepatitis (donors)., Results: Of the 92 patient donors, 62 (67%) and 88 (96%) were anti-C100-3 and second-generation anti-HCV positive, respectively, at the time of the needlestick accident. During the follow-up period (> or = 6 months), acute non-A, non-B hepatitis developed in three of 90 recipients about 1 month after the accident. The three respective donors were positive for serum HCV-RNA at the time of the accident. Two of the three recipients became HCV-RNA positive just after the onset of hepatitis, and subsequently, HCV antibodies developed. None of the remaining 87 recipients had any clinical or laboratory evidence of hepatitis during follow-up, or experienced seroconversion for anti-C100-3 or second-generation anti-HCV. We measured additional HCV markers in 20 of the 89 donors; 16 had evidence of HCV infection (HCV-RNA). However, none of the respective recipients of any of these 20 became positive for HCV markers during follow-up., Conclusion: Although transmission of HCV infection by needlestick injury may be infrequent, such transmission does occur. Appropriate precautions should be taken to protect health care workers.

To compare the seroepidemiology of hepatitis C and hepatitis B between Bangladesh and Japan, we tested the second generation antibody to hepatitis C virus (anti-HCV-2) and hepatitis B surface antigen (HBsAg) in serum samples from 163 professional blood donors (161 males and 2 females, mean age 28.6 yr.) and 83 voluntary blood donors from Bangladesh, and 7479 Japanese voluntary blood donors (5036 males and 2443 females; mean age 37.1 yr.). In Bangladesh, anti-HCV-2 is detected in 2.4% of professional blood donors and 0% of voluntary blood donors, furthermore, HBsAg is detected in 29% and in 2.4% of professional and voluntary blood donors, respectively. In Japan, anti-HCV-2 is detected in 0.6% in voluntary blood donors, and HBsAg also in 0.6%. These results indicate that professional blood donors in Bangladesh are highly contaminated by hepatitis B virus and moderately by hepatitis C virus, while voluntary blood donors in both countries are not so highly contaminated by either hepatitis viruses.

To clarify the long-term clinical significance, antibody to hepatitis C virus (HCV) was examined using core (p22) and nonstructural (C100-3) protein assays in sera of 18 patients with non-A,non-B posttransfusion hepatitis (PTH-NANB) who were selected retrospectively. Each patient had been followed for more than 5 years after the development of the disease. They were divided into three groups according to clinical outcome: acute hepatitis that resolved within 1 year, group 1 (n = 3); chronic hepatitis that resolved within 1-4 years, group 2 (n = 4); and chronic hepatitis that persisted for 5 years or longer, group 3 (n = 11). Sixteen of the 18 were positive for anti-C100-3 and anti-p22, one was positive for anti-p22 alone, and one was negative for both. In ten of the 16 (62.5%), anti-p22 appeared before anti-C100-3. The anti-C100-3 titer peaked about 12 months after disease onset in all cases and thereafter declined gradually, finally becoming negative in groups 1 and 2, while the titer fluctuated in group 3. The mean titer in group 3 at 12 months (69.2 units) significantly exceeded that of groups 1 (4 units) and 2 (8.2 units). Group 1 was seronegative for HCV antibodies and HCV RNA at the last examination, suggesting the cessation of HCV replication. Group 3 remained positive for those markers, indicating the continued replication of HCV.(ABSTRACT TRUNCATED AT 250 WORDS)

To clarify the clinical usefulness of a second generation antibody to hepatitis C virus (anti-HCV-2), we tested the anti-HCV-2 by enzyme immunosorbent assay (Imucheck HCV Ab) in comparison to the first generation antibody (anti-HCV-1). Serum samples were obtained from the patients with acute hepatitis, chronic liver diseases, alcoholic liver disease and autoimmune liver diseases. Furthermore, both antibodies were tested in serum samples from individuals in a hyperendemic area of non-A, non-B hepatitis. Anti-HCV-2 was detected earlier than anti-HCV-1 in acute type C hepatitis. The prevalence of anti-HCV-2 was higher than that of anti-HCV-1 in acute and chronic non-A, non-B liver diseases. However, prevalence of anti-HCV-2 was not increased in patients with non-viral liver disease such as pure alcoholic liver disease and autoimmune liver diseases. The HCV-infection rate was increased to about 40% by detection of anti-HCV-2 in individuals in hyperendemic area of non-A, non-B hepatitis. Thus, the assay of anti-HCV-2 is very useful to detect actual HCV infection. The accuracy and sensitivity of anti-HCV-2 were higher than those of anti-HCV-1.

A new human hepatocellular carcinoma cell (HCC) line, designated SUHC-1, was derived from a Japanese patient with hepatocellular carcinoma having antibody to hepatitis C virus (HCV) and HCV-RNA in his serum, and established in tissue culture. This cell line exhibited typical epithelial cell morphology in culture as observed by phase-contrast and electron microscopy. The SUHC-1 cells produced albumin and alpha 2-macroglobulin. Chromosomal analysis showed several rearrangements at short and long arms of chromosome 1, 17 and 20 (1p-, 1q-, i(1q), i(17q) and 20q+) with a modal number of 91. HCV-RNA was not detected in the supernatant of SUHC-1 cells by nested polymerase chain reaction assay or in the SUHC-1 cells by the in situ hybridization method. We concluded that complete HCV does not exist in the SUHC-1 cell line. The SUHC-1 cell line is the first line of HCC to have been derived from a patient with persistent HCV infection, and may provide a suitable model for studies of hepatocarcinogenesis related to HCV.

To clarify the effect of hepatitis C virus (HCV) infection in patients with chronic schistosomiasis, 96 patients with schistosomiasis and 137 patients with chronic liver disease without schistosomal infection were analysed by domination of antibody to HCV (anti-HCV). In 45 of 96 schistosomiasis patients, the serum alanine aminotransferase (ALT) level was continuously elevated, and the positive rate of anti-HCV was 52.9%, which is almost the same prevalence rate as in patients with chronic liver disease (48.9%). In contrast, in the remaining 51 schistosomiasis patients, serum ALT level was continuously within the normal range and the positive rate of anti-HCV was 0%. Histological investigation showed that the positive rate of anti-HCV in HBsAg-negative schistosomiasis patients was 14% for hepatic fibrosis, 71% for chronic hepatitis, 80% for liver cirrhosis and 56% for hepatocellular carcinoma. In all anti-HCV-positive patients, serum ALT level was continuously elevated. The serum transaminase levels in anti-HCV-positive patients were higher than those in anti-HCV-negative patients. These data suggest that in patients with chronic schistosomiasis, HCV infection accelerates the derangement of liver function, and may be a major aetiological factor in the development of chronic hepatitis and liver cirrhosis, supporting a causative association between HCV infection and hepatocellular carcinoma.

A total of 1,442 schoolchildren in the Matsumoto City area were investigated for the prevalence of hepatitis virus-related serum markers, including antibody to hepatitis C virus (anti-HCV) and an abnormal serum transaminase level. Despite the large number of children tested, none was positive for anti-HCV antibodies or had been diagnosed as having viral hepatitis. The prevalence of anti-HCV antibodies in children and adult blood donors in the same area increased significantly with age from 0% in the 6-15-year-old group to 1.14% in the 50-65-year-old group (P less than 0.001). Our results indicate that even if only the enzyme-linked immunosorbent assay results confirmed by the recombinant immunoblot assay are considered positive, the prevalence in children is significantly lower than that in blood donors (P less than 0.05). Six children were healthy carriers of hepatitis B virus (HBV); all had been born to carrier mothers. These results indicate that apparently healthy schoolchildren in Japan have a low exposure to HCV infection.

To investigate the prevalence of antibody to hepatitis C virus (anti-HCV) in heavy drinkers with liver disease in Japan, we tested serum samples from 113 heavy drinkers with liver disease and 121 without liver disease. All were negative for HBsAg with no history of blood transfusion. These subjects had consumed more than 80 g of ethanol daily for 5 years or more. Findings for anti-HCV determined by recombinant immunoblot assay testing were positive in 14 (35.9%) of the 39 patients with liver cirrhosis, 14 (58.3%) of the 24 patients with hepatocellular carcinoma and in 8 (53.3%) of the 15 patients with chronic hepatitis. The anti-HCV positive rate in the drinkers with these liver diseases was significantly higher than in those with such disorders as fatty liver (0/10), hepatic fibrosis (0/22), and alcoholic hepatitis (0/3), as well as in the alcoholics without liver disease (5/121, 4.2%). Considering histologic findings in the anti-HCV positive cirrhotics, the occurrence of lymph follicle formation (71.4%), piecemeal necrosis (78.6%) and loose fibrosis (64.3%) were observed to a significantly higher extent than in cirrhotics who were negative for anti-HCV. These findings suggest that advanced chronic liver disease among heavy drinkers in Japan, especially of hepatocellular carcinoma, is closely associated with HCV infection. In the livers of heavy drinkers who were positive for anti-HCV, histologic findings indicated the possibility of viral infection.

Localization of hepatitis C virus (HCV) RNA was investigated by non-radioactive in situ hybridization in human liver specimens of chronic non-A, non-B (NANB) hepatitis patients who were seropositive for antibodies to HCV (anti-HCV). For in situ hybridization, T-T dimerized synthetic oligodeoxynucleotide probes were used and DNAs hybridized in situ were detected immunohistochemically using specific antibodies against T-T dimer. The data demonstrates that HCV-RNA was localized in the cytoplasm of hepatocytes in human liver biopsies obtained from the patients with chronic NANB hepatitis seropositive for anti-HCV.

In a retrospective study, antibody to hepatitis C virus (anti-HCV antibody) was measured in 80 patients with acute viral hepatitis (type A, 18; type B, 21; type non-A,non-B, 41). Anti-HCV antibody was found in 12 of 20 patients (60%) with non-A,non-B post-transfusion hepatitis (NANB-PTH) and in 9 of 21 patients (43%) with sporadic NANB hepatitis (NANB-SPO). Patients with acute hepatitis type A or type B did not have anti-HCV antibody. The number of patients who developed chronic hepatitis was greater in the group with anti-HCV antibody than in the anti-HCV negative group in both NANB-PTH and NANB-SPO. The difference was significant in those with NANB-PTH (P less than 0.05). To investigate the relationship between the long-term prognosis of NANB-PTH and the course of anti-HCV, we studied anti-HCV antibody in 12 patients who developed chronic type C hepatitis (C-CH) after PTH and followed them for more than 5 years after the development of PTH. One year after the development of PTH, all 12 had anti-HCV antibody. Five lost anti-HCV antibody (group 1) while 7 remained positive (group 2) at the final examination. Four of the 5 patients in group 1 had normal serum transaminases; however, abnormal transaminase persisted in all 7 patients in group 2 until the end of follow-up (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

To clarify the intrafamilial transmission of hepatitis C virus (HCV), the prevalence of antibody to HCV (anti-HCV) in 107 index patients with type C chronic liver disease was studied and compared with the prevalence of anti-HCV antibody in their 296 family members. Of the 85 index patients who were positive for anti-HCV, 15 (8%) of 196 of their family members were also HCV antibody positive, whereas of the 22 index patients who were anti-HCV antibody negative, none of the family members of the 100 evaluated was positive for anti-HCV antibody, a statistically significant difference between groups (P less than 0.02). No specific relative (spouse, child, parent, and sibling) was linked to HCV positivity in the index cases making it difficult to identify the route of infection that is believed to occur via the parenteral route in the home or community.

Fifty-eight patients with chronic hepatitis C were followed for more than 7 years. Of them, 10 patients were found to develop hepatocellular carcinoma, 14 to develop liver cirrhosis, 30 to sustain chronic hepatitis, and 4 to show subsidence of hepatitis. Antibody to hepatitis C virus (anti-HCV) disappeared from the 4 patients whose hepatitis subsided, but it persisted in the remaining 54 patients. The mean titer of anti-HCV was almost the same at the stages of chronic hepatitis and of cancer in the 10 patients who developed hepatocellular carcinoma. These results indicate that chronic infection of hepatitis C virus may lead to hepatocellular carcinoma.

To clarify the relationship between hepatitis C virus infection and the development of hepatocellular carcinoma as sequelae of non-A, non-B posttransfusion hepatitis, 231 patients with chronic non-A, non-B hepatitis (96 with chronic hepatitis, 81 with cirrhosis and 54 with hepatocellular carcinoma) were analyzed for antibody to hepatitis C virus and were compared with 125 patients with chronic hepatitis B (50 with chronic hepatitis, 46 with cirrhosis and 29 with hepatocellular carcinoma). Antibody to hepatitis C virus was detected in 89.6%, 86.4% and 94.4% of patients with non-A, non-B hepatitis-related chronic hepatitis, cirrhosis and hepatocellular carcinoma, respectively, compared with 6%, 17.4% and 34.5% with similar diseases related to hepatitis B. A history of transfusion was documented in 52%, 33% and 42% of anti-hepatitis C virus-positive cases of chronic hepatitis, cirrhosis and hepatocellular carcinoma. The mean intervals between the date of transfusion and the date of diagnosis of anti-hepatitis C virus-positive chronic hepatitis, cirrhosis and hepatocellular carcinoma were 10, 21.2 and 29 yr, respectively. In 21 patients with transfusion-associated hepatocellular carcinoma, anti-hepatitis C virus was present in each serial sample available for testing, including samples obtained up to 14 yr before the diagnosis of hepatocellular carcinoma. These data suggest the slow, sequential progression from acute hepatitis C virus-related non-A, non-B hepatitis through chronic hepatitis and cirrhosis to hepatocellular carcinoma and support a causal association between hepatitis C virus and hepatocellular carcinoma.

Prospective studies of posttransfusion hepatitis carried out in the past decade showed that 18.1% of the blood transfusions resulted in non-A non-B hepatitis in Japan. As an approach to the prevention of posttransfusion non-A non-B hepatitis (PTNANB), anti-hepatitis C virus (HCV) positivity was measured in 2,970 blood donations in the Tokyo area, and in 200 children aged between 6 and 15 years. Thirty-four cases were anti-HCV-positive, showing an overall positivity of 1.14%. None of the 200 children younger than 15 years old were positive. Correlation of anti-HCV positivity with the serum ALT levels was observed, but by reducing the accepted ALT levels from 35 Karmen Units (KU) down to 25 KU, it is estimated that 62.5% of the observed PTNANB would still have occurred, and 5.1% of the donated blood could not be used for transfusion. On the other hand, it is estimated that the majority of PTNANB could be prevented, with the loss of 1.14% of donated blood units, using the anti-HCV screening test.