The use of Flow Cytometry in the Diagnosis of Low Grade Myelodysplasia — Australasian Cytometry Society
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  3. The use of Flow Cytometry in the Diagnosis of Low Grade Myelodysplasia

The use of Flow Cytometry in the Diagnosis of Low Grade Myelodysplasia (24059)

Ashlea Campbell 1 , Matthew Powell 2 , Robin Gasiorowski 1 3
  1. Haematology, NSW Health Pathology - Concord Repatriation General Hospital, Sydney, NSW, Australia
  2. Flow Cytometry, NSW Health Pathology - Concord Repatriation General Hospital, Sydney, NSW, Australia
  3. ANZAC Research Institute, University of Sydney, Sydney, NSW, Australia

Aim:

The diagnosis of low grade Myelodysplastic Syndrome (MDS) can be challenging. By definition these patients do not have increased numbers of blasts, morphological changes can be subjective and confirmatory cytogenetic changes are often absent. Whilst flow cytometry may assist in the diagnosis, established guidelines are extremely complex requiring both expert interpretation and at least 20 markers in 5 separate tubes (1).  Other studies have shown that just 4 key parameters can be used to help diagnose low-grade MDS (P<0.001) (2). We aimed to validate the utility of these characteristics in our patient cohort.

 

Methods:

We  used  flow cytometry to assess side scatter, CD34 and CD45 expression in the bone marrow of 48 patients being investigated for cytopenias. These characteristics were used to establish 4 parameters:  myeloblast-related cluster size, B-progenitor-related cluster size, myeloblast CD45 expression and granulocyte side scatter. Abnormalities in at least 2 of these parameters were considered supportive of the diagnosis of MDS, whilst a score of <2 meant MDS was unlikely.  The final diagnosis of MDS was confirmed after 2-36 months of follow-up by the treating haematologist. We compared the initial flow assessment of the patient with their final diagnosis.

 

Results:

Of the 48 patients, the final diagnosis remains unclear in 6 and they were excluded from the analysis. There were 29 patients who were found to have probable or definite MDS and 12 patients in whom MDS was deemed unlikely. The sensitivity of the flow score was 72%, specificity 83% with a positive predictive value of 91% and negative predictive value of 56%.

 

Conclusion:

There appears to be a role for flow cytometry in the diagnosis of low grade MDS. This relatively simple assay may help guide which patients without blasts or cytogenetic changes are more likely to have true clonal MDS. 

  1. 1. Westers TM, Ireland R, Kern W, Alhan C, Balleisen JS, Bettelheim P, et al. Standardization of flow cytometry in myelodysplastic syndromes: a report from an international consortium and the European LeukemiaNet Working Group. Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, UK. 2012;26(7):1730-41.
  2. 2. Della Porta MG, Picone C, Pascutto C, Malcovati L, Tamura H, Handa H, et al. Multicenter validation of a reproducible flow cytometric score for the diagnosis of low-grade myelodysplastic syndromes: results of a European LeukemiaNET study. Haematologica. 2012;97(8):1209-17.
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