抄録
The in vivo cell cycle effects of cytosine arabinoside (Ara-C), Vincristine (VCR), and massive leukapheresis on human leukemic blast cells in bone-marrow have been studied in 15 patients with acute leukemia.
Mitotic index (MI) and 3H-thymidine labeling index (LI) were determined in the repeated marrow samples before the study and at intervals thereafter for the duration of study. Eight patients were given intravenous injection of Ara-C over 19 courses in a dose of 70 mg/m2 for 2 consecutive days. Computor analysis indicated that statistically significant increase in LI was seen 48 hours after the injection, implying partial S-phase synchronization of leukemic cells. Five patients were given intravenous injection of VCR in a dose of 0.6 mg/m2 and no significant change in LI was seen until 48 hours after the injection. No significant change in MI was observed either by Ara-C or VCR.
Massive leukapheresis by means of Celltrifuge was done in three patients with acute leukemia and two patients with chronic myelogenous leukemia. In one patient with acute myelogenous leukemia, peripheral leukocyte counts were reduced from the level of 10.2×104/cmm down to 6.9×104/cmm., and the nucleated marrow cell counts were reduced from 112.2×104/cmm. to 18.6×104/cmm., through the extraction of 26.6×1010 leukocytes. LI was significantly increased after leukapheresis, whereas MI was significantly reduced inversely. The result was reproduced by the second leukapheresis in the same patient.
A new quadruple combination chemotherapy (Neo-DCMP) was designed, applying the said results of partial synchronization with Ara-C, and 9 patients with acute leukemia were treated, of whom 6 developed complete remission.
Sequential changes in LI of both leukemic blast cells and normal myeloid precursors were determined during the course of therapy and the results were discussed in view of cell cycle effects of chemotherpy.
