CD4 and hepatitis C virus infection: These data suggest that continued antigen re-encounter alone is insufficient to explain the loss of HCV specific CD4+ T cells during acute hepatitis C. Addressing compartmentalization of HCV specific CD4+ T cells to the liver is very difficult due to the lack of availability of liver biopsies from patients with acute hepatitis C. When we stained liver derived T cell lines from six HLA-DR1 positive patients with chronic hepatitis C we could not detect HCV specific CD4+ T cells although this issue certainly needs further study.