Researchers from Denmark have developed a novel scoring system named ProGraME that holds promise for evaluating bone marrow dysplasia in patients with myelodysplastic syndromes (MDS).
In a training cohort comprising 209 patients, the ProGraME score demonstrated high sensitivity (91%) and specificity (81%), using a cutoff of 2 or higher, for dysplasia indication. The researchers further validated the ProGraME score in an independent cohort of 159 patients, achieving sensitivity and specificity rates of 95% and 75%, respectively.
In addition, the ProGraME score displayed a negative predictive value of 97.1% in the training cohort and 97.8% in the validation cohort.
“ProGraME has higher sensitivity and specificity than other established algorithms, such as the Ogata and RED scores, but its main advantage is a particularly high negative predictive value, making it a very useful parameter for excluding bone marrow dysplasia using FC [flow cytometry]. Finally, a major advantage of our suggested algorithm, is its simplicity and potential for a more standardized FC analysis of dysplasia,” the researchers wrote in the European Journal of Haematology.
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Within the subgroup of patients positively identified for dysplasia by ProGraME, most (69%) carried high-risk mutations.
The ProGraME score combines flow cytometry parameters with morphological and cytogenetic/molecular analyses. The score includes 4 parameters from distinct hematopoietic cell lineages—progenitor cells, and granulocytes, monocytes, and erythroid precursors—defined by specific population gates.
As a result, calculating flow cytometry parameters for the ProGraME score requires minimal experience as flow analyzers, as it only requires setting a gate for the relevant populations and allows using any available flow cytometry analysis software to compute the corresponding parameters.
ProGraME points are assigned for specific criteria: lymphoid precursors accounting for 5% or less of CD34+ cells (1.5 points); a granulocyte-to-lymphocyte side-scatter ratio of 6 or lower (1 point); a monocyte coefficient of variation of CD33 equal to or exceeding 63 (2 points); and an erythroid precursor coefficient of variation of CD36 equal to or exceeding (2 points).
Reference
Therkelsen J, Træden DW, Schjødt I, et al. ProGraME: a novel flow cytometry algorithm for the diagnosis of low-risk myelodysplastic syndromes in patients with cytopenia. Eur J Haematol. Published online August 23, 2023. doi:10.1111/ejh.14086
