Importance of the detection of minimal residual disease in the management of acute leukemia

Between 1984-1988, 57 adult acute leukemic patients were treated with intensive combined chemotherapy in the National Institute of Haematology and Blood Transfusion. For the evaluation of response to therapy, 4 investigations were performed in parallel: bone marrow aspirate, bone marrow biopsy, cytogenetic analysis and bone marrow culture. Nonparametric test for samples taken for the evaluation of remission status showed that bone marrow biopsy was significantly the most sensitive method for the detection of residual disease. The bone marrow culture was also on the borderline of significance, but the low CFU-GM level did not always correlate with the further clinical course. Occasionally, karyotypic abnormality was the only sign of the residual disease. It would be of great importance to quantitate the minimal residual disease in order to evaluate and compare the various intensive postinduction therapeutic strategies.