State-of-the-Art Review : Elevated Tissue Factor Levels in Leukemic Cell Homogenate

Tissue factor (TF) antigen and activity were mea sured in leukemic cell homogenates. In leukemic cell homog enate, especially that of acute promyelocytic leuekmia (APL), both TF antigen and activity were significantly higher than these levels in the mononuclear cells obtained from healthy volunteers. Both TF antigen and activity were significantly higher in myelocytic leukemia than in lymphocytic leukemia cells. In leukemic cell homogenates, there was a close corre lation between TF antigen and TF activity. The TF activity/TF antigen ratio was significantly higher in myelocytic leukemia than in lymphocytic leukemia cells. As the TF activity was not increased in lymphocytic leukemia cell homogenates to which were added phospholipids, the decrease in TF activity in lym phocytic leukemia might not be due to phospholipid in the leukemic cell membrane. Values for TF activity, TF antigen, and the TF activity/TF antigen ratio in leukemic cell homog enate from patients with disseminated intravascular coagulation (DIC) were significantly higher than those in patients without DIC. Therefore, the measurement of TF antigen and activity in leukemic cells could be useful for the prediction of DIC.