Prediction of relapse and remission in AML by marrow culture criteria.

Bone marrow culture studies in semi-solid agar have been performed on 250 patients presenting with acute myeloid leukemia. The detection of a spectrum of qualitative defects in the proliferation, differentiation and biophysical characteristics of leukemic colony forming cells (CFU-c) has permitted a detailed analysis of the relapse-remission status based on transition from qualitatively abnormal cell growth in vitro to a normal pattern of proliferation and differentiation. Changes in vitro generally preceded clinical or morphological evidence of the onset of relapse or remission and serve as a valuable additional parameter in monitoring clinical status. Marked cyclic changes in CFU-c incidence appeared to characterize the remission phase of AML and were frequently associated with fluctuations in marrow blast cell count which can lead to mis-diagnosis of incipient relapse. Detection of qualitative defect in marrow culture serves to distinguish patients with preleukemic disorders at high risk of termination in acute myeloid leukemia from patients with clinically similar disease who have not undergone further progression over a 2-4 year period of observation.