Comparison of Serological and Nucleic Acid Based Assays Used to Diagnose Hepatitis C Virus (HCV) Infection in Acute and Chronic Liver Diseases

Background: This study reports a comparative diagnostic potential of three different assay systems used to detect HCV infection in acute and chronic liver diseases. Methods: A total number of 364 patients with various types of liver diseases were analyzed for hepatitis C virus (HCV) core antigen using Enzyme Immuno Assay (EIA), HCV-RNA by RT-PCR and anti-HCV antibodies by third generation EIA system. Simultaneously these patients were also tested for markers of other hepatitis viruses, notably, hepatitis A, B, C, D and E. In some cases, even transfusion transmitted virus (TTV) was tested using TTV-DNA as the marker of TTV infection. Results: Analysis of results demonstrated the presence of hepatitis B, C and E in different proportions of patients belonging to these liver diseases. Hepatitis A and D infections could not be detected in these cases TTV infection was prevalent in different liver diseases in different proportions. Though none of control sera demonstrated hepatitis A E infection, however, TTV infection was noted in control group also. When we analysed all the sera for HCV infection using these different assay systems, we found HCV core, HCV-RNA and anti-HCV antibodies in 18.3%, 18.3% and 5.83% cases of acute viral hepatitis (AVH), 13.3 %, 13.3% and 46.6% cases of chronic viral hepatitis (CVH), 23.8%, 23.8% and 23.8% cases with cirrhosis of liver and 20%, 17.5% and 10% cases respectively, of fulminant hepatic failure (FHF) patients. Whereas HCV core and HCV RNA assays were comparable and predominantly positive in acute cases (AVH and FHF), anti-HCV antibodies were detected in high proportions in chronic liver diseases. Cirrhosis patients showed all the markers in equal proportions. This pattern of HCV markers remains unaffected by co-infection of HCV with other hepatitis viral infections. Conclusion: In conclusion, where HCV core and HCV-RNA are best diagnostic markers in acute liver diseases, anti-HCV diagnoses high proportion of HCV cases in chronic liver diseases. This diagnostic pattern is not changed on co-infection of HCV with other viral infections.