Flow cytometry for the detection of minimal residual disease in acute myeloid leukaemia

Abstract

The recognition of specific aberrant patterns of leucocyte differentiation antigens on leukemic cells now allows flow cytometry to be used as a tool for assessing treatment response in acute myeloid leukaemia (AML), based on detection of small numbers of abnormal cells surviving therapy, therefore allowing individualisation of patient management. The availability of flow cytometers with eight or more fluorescence detectors, together with a wide range of antibodies conjugated with appropriate fluoro-chromes, has greatly improved the efficiency of identifying leukaemia aberrant phenotypes (LAP), which can be found in more than 90% of AML cases at diagnosis. Knowledge of the LAP profile of a case can then be used to detect abnormal cells in the marrow after chemotherapy, at sensitivities of 10^–4 and lower. Recent data¹ have shown that detection of minimal residual disease (MRD) in AML provides strong independent prognostic information, and can be used to identify patients with good and poor outcomes within standard and intermediate cytogenetic risk groups. A national consortium sponsored by the Australasian Leukaemia and Lymphoma Group (ALLG) is establishing a network to standardise methods, analysis and reporting of flow MRD in AML in Australia.