Maturation changes in relapsing acute myeloid leukaemia

Smears of peripheral blood and bone marrow from 17 patients with acute myeloid leukaemia in relapse were compared with smears made at presentation. We found a change of more than 10 in Maturation Index (MI) in the bone marrow smears of 14 out of 17 patients (82%). Decreases and increases were equally represented. In 5 cases the changes caused assignment to another FAB-group.