Hepatitis
C virus (HCV) infection becomes chronic in the most patients, although the immunological
factors associated with spontaneous clearance versus acute infection are not well
understood.
As described in the February 2007 issue of Gastroenterology,
investigators studied HCV-specific CD4, CD8, and HCV pseudoparticle neutralizing
antibody responses in patients with HCV infection.
Results
•
The outcome of acute
HCV infection was associated with a functional hierarchy of HCV-specific CD4 T-cell
responses and the scope of virus-specific total T-cell interferon-gamma response.
•
HCV-specific CD8 T-cell
responses were readily detectable in acutely infected patients, regardless of
virological outcome or virus-specific CD4 T-cell responses.
•
In contrast, HCV pseudoparticle-specific
neutralizing antibodies were readily detected in patients with chronic infection
and impaired HCV-specific CD4 T-cell responses, but not in those who spontaneously
cleared the infection and had robust virus-specific CD4 T-cell responses.
Conclusion
In
conclusion, the authors wrote, "The outcome of acute hepatitis C is associated
with efficient virus-specific CD4 T-cell response(s) without which HCV-specific
CD8 T-cell and heterologous neutralizing antibody responses may develop but fail
to clear viremia." Furthermore, they added, "HCV-specific neutralizing
antibody responses may not be induced despite robust virus-specific CD4 T-cell
response."
Gastroenterology Division, University of Pennsylvania
School of Medicine, Philadelphia, PA; Philadelphia Veterans Affairs Medical Center,
Philadelphia, PA.
03/20/07
Reference DE
Kaplan, K Sugimoto, K Newton, and others. Discordant Role of CD4 T-Cell Response
Relative to Neutralizing Antibody and CD8 T-Cell Responses in Acute Hepatitis
C. Gastroenterology 132(2): 654-666. February 2007.
