Characterization of hematologic malignancies by flow cytometry

The quantitative assessment of cellular DNA and RNA content by flow cytometry to provide useful information for both diagnosis and prognosis of patients with hematologic malignancies is reviewed. While the characterization of cell surface antigens seems to be more germane to questions of the normal cell counterpart (stage) of malignant transformation and the biology of regulation of proliferation and differentiation by cell-cell contact and humoral factors, DNA-derived and RNA-derived parameters were surprisingly sensitive in the distinction of major morphologic groups, drug sensitivity and long-term prognosis. Our findings to date in the study of leukemias, lymphomas and myelomas are summarized. Our laboratory has been engaged in the flow cytometric (FCM) analysis of a variety of human tumors in an effort to relate the heterogeneity in the clinical course of malignant disease to quantitative measurements, particularly of nucleic acids. These constituents can be conveniently probed by DNA-specific and RNA-specific dyes and related to important aspects of cellular diversity in terms of ploidy, proliferative activity and differentiation. This paper summarizes our experience with DNA-RNA FCM using the metachromatic dye acridine orange (AO) for the diagnosis and assessment of prognosis in leukemia, lymphoma and myeloma.