Application of bromodeoxyuridine (BrdU) and anti-BrdU monoclonal antibody for the in vivo analysis of proliferative characteristics of human leukemia cells in bone marrows.

To investigate the proliferative characteristics of human bone marrow leukemic cells in vivo, we developed a new method using bromodeoxyuridine (BrdU) and its monoclonal antibody. Thirty minutes after a bolus BrdU infusion, a lst bone marrow aspiration (BMP) was performed to calculate the BrdU labeling index (BrdU-LI). Then, a 150-min continuous infusion of BrdU was started. Immediately after the infusion, a 2nd BMP was done to analyze the increasing rate of the BrdU-LI for 3 h. Each smear was stained by an immunohistochemical method. The BrdU-LI, the duration of S phase (Ts) and the cell cycle time (Tc) of leukemic cells from 13 previously untreated patients with acute leukemias were estimated. A mean value of 7.2% for BrdU-LI was obtained. Furthermore, mean values of 9.7 h and 152.5 h for Ts and Tc respectively were calculated. This method may prove to be useful in the in vivo cell cycle analysis of leukemias and other malignancies.