A simple score derived from bone marrow immunophenotyping is important for prognostic evaluation in myelodysplastic syndromes.

Immunophenotyping of bone marrow (BM) precursors has been used as an ancillary diagnostic tool in myelodysplastic syndromes (MDS), but there is no general agreement about which variables are the most relevant for prognosis. We developed a parsimonious prognostic model based on BM cell populations well-defined by phenotype. We analyzed 95 consecutive patients with primary MDS diagnosed at our Institution between 2005 and 2012 where BM immunophenotyping had been performed at diagnosis. Median follow-up: 42 months (4-199). Median age: 67 years (33-79). According to IPSS-R, 71 cases were low or intermediate risk. Flow variables significant in the univariate Cox analysis: "%monocytes/TNCs", "% CD16 monocytes/TNCs", "total alterations in monocytes", "% myeloid CD34 cells", "number of abnormal expressions in myeloblasts" and "% of B-cell progenitors". In the multivariate model remained independent: "% myeloid CD34 cells", B-cell progenitors" and "% CD16 monocytes/TNCs". These variables were categorized by the extreme quartile risk ratio strategy in order to build the score: % myeloid CD34 cells" (≥ 2.0% = 1 point), B-cell progenitors" (< 0.05% 1 point) and "CD16 monocytes/TNCs" (≥ 1.0% 1 point). This score could separate patients with a different survival. There was a weak correlation between the score and IPSS-R. Both had independent prognostic values and so, the flow score adds value for the prognostic evaluation in MDS.