EuroFlow: Resetting leukemia and lymphoma immunophenotyping. Basis for companion diagnostics and personalized medicine

Laboratory diagnostics in patients with a hematological malignancy has three major applications: establishing the diagnosis, prognostic classification and evaluation of treatment effectiveness. Immunophenotyping is currently recognized to provide essential information for all three applications. 2-9 Expression of individual immunophenotypic markers was initially assessed by microscopic techniques, but since the 90's multiparameter flow cytometric immunophenotyping has become the technique of choice, as it is the sole technique that fulfills the requirements for high speed, broad applicability at diagnosis and during follow-up, and accurate focusing on the malignant cell population using membrane-bound and intracellular proteins as targets. 9-14 6] In this regard, the weakest points of multiparameter flow cytometry relate to: (i) the design of the panels of markers to be applied, (ii) the evaluation of new versus 'classical' markers, (iii) the analysis of the data obtained from the flow cytometric measurements and (iv) interpretation of the results. In addition, it is a technological field that is continuously evolving, but where many traditional procedures are still in use, for example, for data analysis. Whereas industry invested significantly in developing and implementing further innovation of the flow cytometry instruments, the innovation in immunophenotyping reagents and in software for analysis of the progressively larger and complex data sets was much more limited or virtually absent, particularly in the area of leukemia and lymphoma typing.