Translating the MDS flow cytometric score into clinical practice

Myelodysplastic syndromes (MDS) are classified by the WHO as myeloid neoplasms, and are characterized by cytopenia and dysplasia in one or more myeloid cell lines. Recently, a flow cytometric score (FCM-score) was published capable of discriminating low-grade MDS from non-clonal cytopenias (Della Porta et al., 2012). We tested the applicability of the FCM-score in a patient population from a large peripheral teaching hospital in The Netherlands. The evaluation of the proposed FCM score in low-grade MDS showed a high sensitivity and specificity, and clinically significant positive and negative likelihood ratios. The use of CD10 and CD19 positivity to identify progenitor B-cell blasts provided a specific and precize method to separate progenitor B-cell blasts from myeloid blasts within the CD34+/low CD45+ population and may be more convenient compared to the published method using low SSC and CD45 expression. This study confirms the value of utilizing the FCM-score in our patient population.