The frequency and quantity of CD8 T cells expressing CD38/HLA-DR and Ki-67/Bcl-2 phenotypic markers was analyzed in 20 patients with acute hepatitis B. Samples were collected at multiple time points from onset of disease (HBsAg+, ALT>1000 U/L) to full recovery (HBsAg- at least 1 month after onset). This evidence concerns the gene CD8A and hepatitis B virus infection.