Fas ligand-induced apoptosis of hepatocytes in natural killer cell leukaemia

Neoplastic natural killer (NK) cells overexpress Pas ligand (FasL), which may cause damage of Pas-bearing tissues. We report a patient with NK cell leukaemia who developed liver injury after pharyngitis. The NK leukaemic cells expressed functional Fast. In addition to soluble Fast, serum levels of interleukin-6 and interferon-gamma were increased dramatically when liver injury was aggravated. Moreover, hepatocytes expressed Fas and apoptotic hepatocytes were detected in the portal areas. These findings are consistent with the notion that inflammatory cytokines enhance the sensitivity to Fast and trigger apoptosis of hepatocytes in NK cell malignancies.