Acute nonlymphocytic leukemia: evidence of clonogenic cells in peripheral blood in early complete remission.

We describe a patient with acute nonlymphocytic leukemia in whom chromosomal analysis showed a 8,21(q22;q22) translocation and who entered complete remission after one course of chemotherapy. During the post-chemotherapy aplastic phase blood-derived hemopoietic circulating stem cells were collected by continuous flow aphereses. Chromosomal analysis on the collected cells and on colonies (CFU-GM grown in agar) showed the same anomaly as was present at diagnosis in about 30% of those analyzed. This confirms the persistence of the malignant clone in the early phase of the clinical remission in acute nonlymphocytic leukemia.