To evaluate the clinical feasibility of the antibody titer against a chimeric polypeptide (named Core 518), in which a domain of Core and NS3 of hepatitis C virus (HCV) was fused, ELISA was performed in a total of 76 serum samples. Each serum was serially diluted using two-fold dilution method with distilled water into 10 concentrations. They were all positive for second generation anti-HCV assay (HCV EIA II; Abbott Laboratories). Genotyping RT-PCR, quantitative competitive RT-PCR, and RIBA (Lucky Confirm; LG Biotech) were also assayed. Anti-Core 518 antibody was detected in x 12800 or higher dilutions of sera from 35 of 43 chronic hepatitis C (81.4%) and nine of 16 hepatocellular carcinoma sera (56.3%), one of four cirrhosis (25%), 0 of four acute hepatitis C, and one of nine healthy isolated anti-HCV-positive subjects (p=0.0000). The anti-Core 518 antibody titers were well correlated with the presence of HCV RNA in serum (p=0.002). The anti-Core 518 antibody titers decreased significantly in nine of ten responders to IFN-alpha treatment. Monitoring anti-Core 518 titers may be helpful not only for differentiating the status of HCV infection among patients with various type C viral liver diseases, but also for predicting responses to IFN-alpha treatment.
Adult ; Aged ; Female ; Genotype ; Hepatitis C/immunology* ; Hepatitis C/drug therapy* ; Hepatitis C/diagnosis ; Hepatitis C/blood ; Hepatitis C Antibodies/immunology* ; Hepatitis C Antibodies/blood ; Hepatitis C Antigens/immunology* ; Hepatitis C-Like Viruses/immunology* ; Hepatitis C-Like Viruses/genetics ; Human ; Immunoblotting ; Interferon Alfa-2a/therapeutic use* ; Male ; Middle Age ; RNA, Viral/blood ; Recombinant Fusion Proteins/immunology ; Viral Core Proteins/immunology* ; Viral Nonstructural Proteins/immunology*

BACKGROUND: Although the polyproteins of hepatitis C virus(HCV) are processed and formed in nearly equimolar amounts, individual functional proteins have a discrepancy in their time of appearance following HCV infection and eliciting immune response. This study was conducted to compare the reactivity toward regional specific HCV protein in relation to virological characteristics, including HCV genotype and HCV replication. METHODS: Sera from forty-five patients with chronic HCV infection were analyzed through the experiments of the recombinant immunoblot assay(RIBA-2), HCV genotyping and HCV RNA quantitation. RESULTS: The frequencies of seropositivity to C22-3, C33C, C100-3 and 5-1-1 proteins were 91.1+ACU-, 91.1+ACU-, 64.4+ACU- and 53.3+ACU-, respectively, of all the patients, and thus the antibodies to C22-3 and C33C proteins were found more frequently (p +ADw- 0.05). The antibody responses between core or NS3 proteins and NS4 proteins showed more discrepancy in the HCC group than that in the CH group, implying a possibility of oncogenic potential of core or NS3 gene in hepatocarcinogenesis. The detection rate of antibodies to C22-3 and C33C, in accordance with serum HCV RNA levels, was significantly higher in highly viremic patients than that in low viremic patients (p +ADw- 0.05). Antibodies to C22-3, C33C, C100-3 and 5-1-1 were also found more frequently in patients with HCV genotype 1b, compared to those with HCV genotype 2a (p +ADw- 0.05). CONCLUSION: These results suggest that antibody detection of HCV may depend on the virological characteristics of HCV, the levels of HCV replication and HCV genotype and, therefore, HCV RNA detection using RT-PCR technique is essential for confirmatory diagnosis for HCV infection. Furthermore, the HCV core or NS3 Protein may play important role in hepatocarcinogenesis.
Adult ; Aged ; Female ; Genotype ; Hepatitis C Antibodies/blood+ACo- ; Hepatitis C, Chronic/virology ; Hepatitis C, Chronic/immunology+ACo- ; Hepatitis C-Like Viruses/physiology ; Hepatitis C-Like Viruses/genetics ; Human ; Male ; Middle Age ; RNA, Viral/blood ; Viral Core Proteins/immunology+ACo- ; Viral Nonstructural Proteins/immunology+ACo- ; Virus Replication