The recovery of circulating progenitor cells after chemotherapy in AML and ALL and its relation to the rate of bone marrow regeneration after aplasia

Abstract

Peripheral blood levels of BFU-e, CFU-GM and CFU-mix were studied serially in nine patients with acute leukaemia in remission during the period of recovery that followed induction or consolidation chemotherapy. Following 23 courses of treatment in the nine patients, the values for all three classes of progenitor were found to be higher in ALL than in AML (mean peak CFU-GM levels 5.8 .times. 103/ml and 0.8 .times. 103/ml respectively) and the highest levels were observed in patients recovering the most rapidly from bone marrow aplasia. Peak levels of these progenitors correlated best with the rate and extent of platelet recovery and all patients achieving blood levels of > 1.0 .times. 103 CFU-GM/ml had recovered > 100 .times. 109/l within 40 d following chemotherapy. The peak values for circulating progenitors fell markedly after repeated courses of treatment in three of the five AML patients studied and this is likely to limit useful harvesting of such cells during later consolidation courses in this disease.