APOPTOSIS OBSERVED IN PERIPHERAL T-LYMPHOCYTES FROM PATIENTS WITH CHRONIC HEPATITIS-B

Background & Aims: Activation-induced cell death is involved in regula ting peripheral T-cell function. Understanding the kinetics of these T cells is important to elucidate the pathogenesis of chronic hepatitis B, which is mediated by cellular immune mechanisms. Methods: Subtle a poptotic cells in CD3(+) cells were discriminated by flow-cytometric a ssay using freshly obtained and in vitro recombinant hepatitis B core antigen-stimulated peripheral lymphocytes from patients with chronic h epatitis B. Results: The ratio of apoptotic cells in freshly obtained CD3(+) cells was significantly higher during the decreasing phase than increasing phase of serum alanine aminotransferase activity in each p atient, and apoptosis of CD3(+) cells was induced by stimulation with recombinant hepatitis B core antigen. Conclusions: Activation-induced cell death in peripheral T cells was found in chronic hepatitis B viru s infection, similar to some other viral infections. The apoptosis in T cells during the decreasing phase of serum alanine aminotransferase activity results in a vast amount of T-cell deletion that may weaken T -cell function of cytotoxicity over hepatitis B virus-infected hepatoc ytes. Thus, activation-induced cell death is considered an important m odulator in down-regulating the ''burst'' of responding T cells in pat ients with chronic hepatitis B.