Value of Quantitative assessment of Myeloid Nuclear Differentiation Antigen expression and other flow cytometric parameters in the diagnosis of Myelodysplastic syndrome.

INTRODUCTION: The diagnosis of myelodysplastic syndrome (MDS) based on morphology is particularly difficult in low-grade MDS. Thus, the role of myeloid nuclear differentiation antigen (MNDA) and other flow cytometric (FCM) parameters in MDS was evaluated.

METHODS: Bone marrow aspirates (BMA) collected from 52 patients with unexplained persistent cytopenias were divided into three groups: (i) proven MDS (n = 12) based on morphology and/or cytogenetics; (ii) suspected MDS (n = 6), noncontributory morphology, and cytogenetics; and (iii) non-MDS (n = 34). Sixteen control BMA were studied. Cases were analyzed for MNDA expression (on granulocytes, blasts, monocytes, and lymphocytes) and for seven quantitative parameters: CD34(+) myeloblasts % in nucleated cells, CD34(+) B-cell progenitor% in CD34(+) cells, lymphocyte/myeloblast CD45 MFI ratio, granulocyte/lymphocyte SSC peak channel ratio and the proportion of CD34(+) myeloblasts expressing CD15, CD11b, and CD56. A score of 1 was given to each parameter beyond the cutoff, and score ≥3 was considered FCM positive.

RESULTS: MNDA expression on granulocytes and blasts was significantly lower in proven MDS and suspected MDS vs. non-MDS. Quantitative FCM parameters successfully distinguished MDS and suspected MDS from non-MDS.

CONCLUSION: MNDA expression is an independent marker for the evaluation of dyspoiesis and may be added to the standard panel for quantitative assessment by FCM.