Flow cytometry in the diagnosis of myelodysplastic syndromes

In hematologic neoplasms, the identification of recurrent disease-associated phenotypic features in general is followed after a prolonged period by the identification of disease-associated and even disease-defining genetic changes based on which specific treatment will be developed. As an example, for chronic myelogenous leukemia (CML) this has taken one and a half century from the first publication on morphology (Virchow, 1845) to the first report on a tyrosin-kinase inhibitor (Druker et al., 2001). For myelodysplastic syndromes (MDS) the interval between publication of morphologic classification system (Bennett et al., 1982) and the most recent WHO classification applying genetic criteria for diagnostics (Khoury et al., 2022) the interval has been significantly shorter. For various reasons, the role of immunophenotypic features of MDS and their flow cytometric identification had been neglected for a long time.

Following pivotal publication on the topic by Denise Wells and Mike Loken (Wells et al., 2003) flow cytometrists became increasingly interested and gathered together in 2007 at the MDS Foundation Conference in Florence, Italy, which proved to be the founding hour of the “ELN iMDS flow working group.” Each member of the group has focused their research on assessing the diagnostic application of flow cytometry in MDS. Since 2007, the ELN iMDS flow working group has held yearly meetings to discuss progress in research activities as well as to divise consensus guideline publications aiming to apply flow cytometry in a valid manner for in the diagnostic setting of MDS (Porwit, 2014; van de Loosdrecht et al., 2009; van de Loosdrecht et al., 2013; Westers et al., 2012; Westers et al., 2017). These meetings allowed not only for continuous scientific discussion between experts from worldwide (i.e., although formed under the roof of the European LeukemiaNet members came from North America, Europe, Asia and Australia) but also for friendships reaching beyond any scientific scope.

This Special Issue of Clinical Cytometry on the application of flow cytometry in the diagnostic setting of MDS comprises a variety of different papers from the ELN iMDS flow working group reaching from updated consensus guidelines over multi center studies to research results generated by the members of the group. It has been our pleasure to coordinate this group for one and a half decades and we hope the readers of the Special Issue enjoy reading the articles and get stimulated to add their research to the topic.

Wolfgang Kern declares part ownership of MLL Munich Leukemia Laboratory.