1. [Intracellular retention of cytarabine-triphosphate (Ara-CTP) in blasts of children with acute lymphoblastic leukemia. Correlation with clinical course parameters].
- Author
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Schiller M, Hohenlöchter B, Schulze-Westhoff P, Zimmermann M, Ritter J, Jürgens H, and Boos J
- Subjects
- Adolescent, Adult, Blast Crisis drug therapy, Blast Crisis mortality, Bone Marrow drug effects, Bone Marrow metabolism, Child, Child, Preschool, Cytarabine administration & dosage, Dose-Response Relationship, Drug, Drug Administration Schedule, Female, Humans, Infant, Leukemia, Myeloid, Acute blood, Leukemia, Myeloid, Acute drug therapy, Leukemia, Myeloid, Acute mortality, Male, Precursor B-Cell Lymphoblastic Leukemia-Lymphoma blood, Precursor B-Cell Lymphoblastic Leukemia-Lymphoma drug therapy, Precursor B-Cell Lymphoblastic Leukemia-Lymphoma mortality, Precursor Cell Lymphoblastic Leukemia-Lymphoma drug therapy, Precursor Cell Lymphoblastic Leukemia-Lymphoma mortality, Prognosis, Remission Induction, Arabinofuranosylcytosine Triphosphate pharmacokinetics, Blast Crisis blood, Cytarabine pharmacokinetics, Precursor Cell Lymphoblastic Leukemia-Lymphoma blood
- Abstract
Background: Cellular uptake and intracellular phosphorylation to the nucleotide cytosine arabinoside-triphosphate (Ara-CTP) is the precondition for the cytostatic effect of cytarabine. The pharmacokinetics of Ara-CTP in leukemic cells was reported to be of clinical importance in adult nonlymphoblastic leukemia. Therefore, the role of intracellular Ara-CTP formation and retention was investigated in blast cells from children with acute lymphoblastic leukemia (ALL)., Patients and Methods: At the time of diagnosis, peripheral or bone marrow blast cells from 41 children with ALL and 13 with relapsed ALL were incubated in Ara-C containing medium (1 hour, 1 or 3 micrograms/ml) followed by reincubation in Ara-C free medium (3 h). Intracellular Ara CTP formation and Ara-CTP retention were determined., Main Results: Ara-CTP formation did not show marked differences between the different immunological subtypes. Ara-CTP retention, however, was significantly lower in T-ALL (37 +/- 15%, n = 8) compared to non-T-ALL (67 +/- 25%, n = 33; p < 0.003). Ara-CTP retention was also significantly different in children with and without persistence of peripheral blast cells after one week of prednison treatment (71 +/- 30%, n = 9 and 53 +/- 19%, n = 21; p = 0.031) as well as in children with and without complete bone marrow remission on day 15 of the ALL-BFM treatment protocol (66 +/- 17%, n = 19 and 43 +/- 18%, n = 11; p = 0.018). Ara-CTP retention was inversely correlated with the risk groups defined by the ALL-BFM treatment protocols (standard 79 +/- 29, intermediate 59 +/- 25, high risk 47 +/- 21%). A trend towards lower Ara-CTP retention was observed in relapsed leukemias (relapsed non-T-ALL 51 +/- 17%, p = 0.061). The difference in the probability of event free survival (following risk group adapted treatment according to ALL-BFM trials) between children with high (> or = 72%; 0.92 +/- 0.08) and low (< 72%: 0.58 +/- 0.15) Ara-CTP retention up to now did not reach statistical significance (p = 0.12)., Conclusions: The more rapid decrease of cellular Ara-CTP in T-cell leukemia and children at higher clinical risk groups provide a pharmacokinetic rationale for prolonged infusion duration as an alternative to the intensification by dose escalation alone.
- Published
- 1996
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