Comparison of 7 and 12 day bone marrow CFUc culture in adult acute non lymphoblastic leukaemia.

Bone marrows from 17 patients with acute nonlymphoblastic leukaemia (ANLL) were serially cultured on semisolid agar during periods of intensive remission induction chemotherapy and during remission. Of 12 patients achieving remission, six showed recovery of 7 and 12 day colony forming units (CFUc) culture to normal. However, in four of the six patients, recovery was short-lived with reappearance of typically leukaemic culture patterns while still in remission by bone marrow and peripheral blood criteria. In individual patients, serial 7 day cultures frequently showed persisting or recurring leukaemia-associated patterns while 12 day cultures were normal. This study confirms the heterogeneity observed in the cultural characteristics of the CFUc in acute non lymphoblastic leukaemia. Bone marrow cultures in patients with ANLL following intensive remission induction chemotherapy appear to provide a more reliable indication of persisting leukaemia or early relapse if they are interpreted earlier at 7 days.