The classification of acute leukaemia

The standard methods for classifying acute leukaemias now include morphology, cytochemistry and membrane markers. Major advances in immulogy, in particular the development of monoclonal antibodies (MCAb) with lineage specificity, have provided objective positive criteria for the diagnosis of acute lymphoblastic leukaemia (ALL). The FAB group has recognised the importance of MCAb for the classification of some forms of acute myeloid leukaemia (AML), such as megakaryoblastic leukaemia, AML-M7, in which reactivity with MCAb against platelet glycoproteins is a requirement for diagnosis. More recently the group has defined a type of myeloblastic leukaemia with minimal differentiation, AML-M0, in which myeloid cytochemistry is negative and the diagnosis is made by the expression of myeloid antigens and negative lymphoid markers in the blast cells