icon-folder.gif   Conference Reports for NATAP  
  38th Annual Meeting of the European Association for the Study of the Liver
Istanbul, Turkey. March 28-April 1, 2003
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  C. Boni*, B. Amadei, S. Urbani, G. Elia, A. Cavalli, S. Cerioni, M. Malpeli, G. Missale, C. Ferrari, *Presenting Author Department Of Infectious Diseases And Hepatology, Azienda Ospedaliera Universitaria Di Parma, Parma, Italy
In HCV infection, HCV-specific CD8+ lymphocytes show various degrees of impairment of antiviral function. To assess if this HCV-related impairment is limited to HCV-specific T cells or can affect also cell-mediated immune responses to other pathogens, we analyzed virus-specific T cell responses of 3 patients infected simultaneously with HCV and HBV (2 with chronic hepatitis C and acute HBV infection who cleared successfully HBV but remained HCV-RNA positive; one with simultaneous acute HBV and HCV infections who cleared HCV but developed chronic hepatitis B) and 5 patients with acute HBV infection alone, as controls. The cell-mediated immune response was studied with four HLA A2/HCV-specific and six HLA-A2/HBV-specific tetramers. Frequencies and perforin content of HBV- and HCV-specific T cells were analyzed ex-vivo, while IFN-_ production, proliferation and cytolytic activity were analyzed upon peptide stimulation.
The two patients with acute hepatitis B associated with chronic HCV infection showed multispecific and strong HBV-specific cytotoxic T lymphocyte (CTL) responses. The HCV-specific CTL response was only transient and weak although HCV RNA dropped at low or undetectable levels at the time of HBV coinfection. The third patient did not develop HBV-specific CTL responses but displayed a strong and sustained HCV-specific CTL response.
In conclusion, the lack of effect of chronic HCV infection on the T cell-response to another virus with tropism for the same organ suggests that the HCV inhibitory effect is selective for HCV-specific T cell responses; moreover, the immune response primed by HBV infection can only partially and transiently control HCV infection.