Use of flow cytometry in the diagnosis of acute leukemias in childhood

: The authors examined, using the method of flow cytometry, 56 children with acute lymphoblastic leukaemia. Leukaemic cells of the bone marrow aspirate and peripheral blood were examined on a FACS 440 apparatus for establishment of the diagnosis before treatment was initiated. Individual immunological subtypes were differentiated by means of a panel of monoclonal antibodies. 80.5% of acute lymphoblastic leukaemias originated from different developmental stages of B cells, 12.5% were formed by leukaemias from T cells and 7% were non-differentiated leukaemias. The mean follow-up period in the group was 33 months. According to the therapeutic results children with leukaemia ensuing from precursors of B cells had a more favourable prognosis than children with T leukaemia and children with non-differentiated leukaemia. Quantitative examination of nuclear DNA of leukaemic cells revealed in 55% of the patients of the group aneuploidy with clear predominance of hyperdiploidy, 45% of the patients suffered from diploidy. The least number of relapses was recorded in the investigation period in children with hyperploid acute lymphoblastic leukaemia. The proliferating activity of leukaemic blasts was expressed by the number of cells in the S + G2M stage of the cellular cycle and was higher in the bone marrow than in peripheral blood but did not differ in individual immunological subtypes or in diploid leukaemias. The authors were not able to prove its prognostic importance. Flow cytometry is a rapid and sensitive diagnostic method which makes it possible to characterize more satisfactorily the heterogeneous group of acute lymphoblastic leukaemias.