1 Department of Hematology, VU University Medical Center, Amsterdam, The Netherlands 2 Faculty of Medicine & CHU, Nancy Université, France 3 Department of Hematology and Oncology, Fondazione IRCCS Policlinico San Matteo, Pavia, and University of Pavia, Italy 4 Laboratoire d’Hématologie, CHU Dupuytren, Limoges, France 5 Department of Hematology, Hospital General Universitario Gregorio Marañón, Madrid, Spain 6 Department of Hematology Oncology and Clinical Immunology, Heinrich-Heine-University, Düsseldorf, Germany 7 Department of Hematology and Oncology, Georg-August-University, Göttingen, Germany 8 Sanquin Research at CLB, Amsterdam, The Netherlands 9 King’s College Hospital, London, United Kingdom 10 Department of Hematology, St Radboud University Medical Center, Nijmegen, The Netherlands 11 MLL Munich Leukemia Laboratory, Munich, Germany 12 Department of Immunology, Erasmus MC, Rotterdam, The Netherlands 13 Division of Hematology, Department of Medicine, Nippon Medical School, Tokyo, Japan 14 Servicio Central de Citometría, Centro de Investigación del Cáncer, Instituto de Biologia Celular y Molecular del Cáncer (CSIC/USAL) and Department of Medicine, Universidad de Salamanca, Spain 15 Department of Pathology, Karolinska University Hospital, Stockholm, Sweden 16 HMDS, St. James’s University Hospital, Leeds, United Kingdom 17 Department of Hematology, Fundación Jiménez Díaz, Madrid, Spain 18 Department of Internal Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna, Austria 19 Department of Hematology, Weatherall Institute of Molecular Medicine University of Oxford and John Radcliffe Hospital, Oxford, United Kingdom 20 Hematologics, Inc., Seattle, WA, USA Correspondence: Arjan A. van de Loosdrecht, MD, PhD, Department of Hematology, VU-Institute of Cancer and Immunology, Cancer Center Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands. E-mail: a.vandeloosdrecht{at}vumc.nl The myelodysplastic syndromes are a group of clonal hematopoietic stem cell diseases characterized by cytopenia(s), dysplasia in one or more cell lineages and increased risk of evolution to acute myeloid leukemia (AML). Recent advances in immunophenotyping of hematopoietic progenitor and maturing cells in dysplastic bone marrow point to a useful role for multiparameter flow cytometry (FCM) in the diagnosis and prognostication of myelodysplastic syndromes. In March 2008, representatives from 18 European institutes participated in a European LeukemiaNet (ELN) workshop held in Amsterdam as a first step towards standardization of FCM in myelodysplastic syndromes. Consensus was reached regarding standard methods for cell sampling, handling and processing. The group also defined minimal combinations of antibodies to analyze aberrant immunophenotypes and thus dysplasia. Examples are altered numbers of CD34 + precursors, aberrant expression of markers on myeloblasts, maturing myeloid cells, monocytes or erythroid precursors and the expression of lineage infidelity markers. When applied in practice, aberrant FCM patterns correlate well with morphology, the subclassification of myelodysplastic syndromes, and prognostic scoring systems. However, the group also concluded that despite strong evidence for an impact of FCM in myelodysplastic syndromes, further (prospective) validation of markers and immunophenotypic patterns are required against control patient groups as well as further standardization in multi-center studies. Standardization of FCM in myelodysplastic syndromes may thus contribute to improved diagnosis and prognostication of myelodysplastic syndromes in the future. Key words: myelodysplastic syndromes, flow cytometry, standardization, ELN, consensus. Related Article Flow cytometry immunophenotyping for diagnosis of myelodysplastic syndrome Mario Cazzola Haematologica 2009 94: 1041-1043. Full Text PDF