Magnitude of CD8+ T-cell responses against hepatitis C virus and severity of hepatitis do not necessarily determine outcomes in acute hepatitis C virus infection

Aim:  We investigated the relationship between the magnitude of comprehensive hepatitis C virus (HCV)-specific CD8⁺ T-cell responses and the clinical course of acute HCV infection.
Methods:  Six consecutive patients with acute HCV infection were studied. Analysis of HCV-specific CD8⁺ T-cell responses was performed using an interferon-γ-based enzyme-linked immunospot assay using peripheral CD8⁺ T-cells, monocytes and 297 20-mer synthetic peptides overlapping by 10 residues and spanning the entire HCV sequence of genotype 1b.
Results:  Five patients presented detectable HCV-specific CD8⁺ T-cell responses against a single and different peptide, whereas 1 patient showed responses against three different peptides. Neither the magnitude of HCV-specific CD8⁺ T-cell responses nor the severity of hepatitis predicts the outcome of acute hepatitis. The maximum number of HCV-specific CD8⁺ T-cells correlated with maximum serum alanine aminotransferase level during the course ( r  = 0.841, P  = 0.036).
Conclusions:  HCV-specific CD8⁺ T-cell responses were detectable in all 6 patients with acute HCV infection, and 6 novel HCV-specific CTL epitopes were identified. Acute HCV infection can resolve with detectable HCV-specific CD8⁺ T-cell responses, but without development of antibody against HCV.