Flow cytometric analysis of deoxyribonucleic acid (DNA) content in adult leukemia

Flow cytometric analysis of the bone marrow cellular DNA content was performed in 40 adult patients with acute leukemia. Twenty-eight had AML (29 previously untreated and 9 relapse) and 12 ALL (8 previously untreated and 4 relapse). For the whole series, the mean G1/0-phase compartment was 82 +/- 1.3%, the mean S-phase compartment 14 +/- 1%, and the mean G2 +M-phase compartment 4 +/- 0.7%. The percentage of cells in the S-phase had a positive correlation with the LDH level, but not with other parameters. Patients at relapse had significantly lower percentages of cells in the S-phase in AML and significantly higher in ALL. The changes of the S-phase size of the same patients at the first and relapse phases varied. Patients who obtained complete remission had significantly higher percent S phase than patients who did not. This difference was more significant in ALL. Percent cytoreduction had no correlation with the remission rate or S-phase size. Therefore, we analyzed changes of cells in the S-phase of patients with untreated AML during chemotherapy. The reduction rate of cells in the S-phase of patients who obtained complete remission was significantly higher than that of patients who did not.