Profiling the HCV Immune Response in Patients with Chronic Liver Diseases and Hepatocellular Carcinoma by Peptide Microarray Analysis

Background: Chronic infection with hepatitis C virus (HCV) is among the major causes of hepatic fibrosis, cirrhosis, as well as hepatocellular carcinoma (HCC), and it is associated with a significant risk of developing lymphoproliferative disorders. The rate of clinical disease progression is variable depending on multiple host and viral factors, including immune response. Methods: To perform a comprehensive epitope mapping of anti-HCV antibodies in patients suffering from HCV-related liver or lymphoproliferative diseases, we analyzed clinical samples on a peptide microarray platform made of 5952 overlapping 15-mer synthetic peptides derived from the whole HCV proteome. We evaluated the antibody profile of 71 HCV-positive patients diagnosed with HCC, mixed cryoglobulinemia (MC), and HCV chronic infection. Antibody reactivity against virus peptides was detected in all HCV-positive patients. Importantly, the signal amplitude varied significantly within and between diverse patient groups. Results: Antibody reactivity against C peptides were found generally low in HCV chronically infected asymptomatic subjects and increasingly high in HCC and MC patients. Moreover, we found a statistically significant higher IgG response in HCC and MC patients against specific domains of HCV C, E2, NS3, NS4A, NS4B, NS5A, and p7 compared to HCV-positive subjects. Conclusion: In conclusion, our data suggest that immune response against specific HCV protein domains may represent useful biomarkers of disease progression among HCV-positive patients and suggest that peptide microarrays are good tools for the screening of immunotherapy targets in preclinical HCV research.