A simple prognostic score based on a few, well-defined bone marrow cell populations characterized using multiparametric flow cytometry (FCM)–based immunophenotyping was developed for patients with myelodysplastic syndromes (MDS), according to findings published in Scientific Reports.
Although other FCM-based prognostic scores have been proposed in the setting of MDS, their use in clinical practice has been limited.
In providing a rationale for the limited use of these previously developed flow-based prognostic scores, the study authors noted that these other scores “are based on a large number of markers, which are difficult to standardize and depend on highly trained operators with good expertise.”
This prospective patient cohort study conducted at a single institution in Campinas, Brazil, included 95 consecutive patients who were newly diagnosed with primary MDS between 2005 and 2012 and were followed for at least 1 month.
Using FCM, bone marrow biopsy specimens performed at diagnosis were characterized according to the percentages of total monocytes, classical monocytes, and CD16 monocytes to total nucleated cells, total number of antigen alterations in monocytes, the percentages of B-cell progenitors and CD34 myeloblasts, the number of abnormal antigen alterations in myeloblasts, the side-scattered light (SSC) granulocyte-to-lymphocyte ratio, as well as other parameters.
The numbers of abnormal antigen alterations in monocytes and myeloblasts were determined through a comparison with results of similar analyses of bone marrow biopsy specimens from 15 healthy donors. For the patients with MDS, disease risk was also assessed using the Revised International Prognostic Scoring System (IPSS-R).
The median age of patients with MDS was 67 years, and 71 and 24 patients were classified as having low-/intermediate-risk and high-/very high–risk disease, respectively, based on the IPSS-R.
On multivariate analysis at a median follow-up time of 42 months, 3 FCM-based parameters — the percentages of CD34 myeloblasts and B-cell progenitor cells, as well as the ratio of CD16-positive monocytes to total nucleated cells — were found to be independently predictive of survival.
Specifically, 1 point was assigned for 2% CD34 myeloblasts or higher, B-cell progenitor cells less than 0.05%, and the presence of at least 1% CD16-positive monocytes to total nucleated cells. Hence, possible patient flow scores ranged from 0 to 3, with a higher score associated with a worse prognosis.
Although this simple FCM-based score was found to weakly correlate with the IPSS-R, the study investigators noted that “both had independent prognostic values and so, the flow score adds value for the prognostic evaluation in MDS.”
Nevertheless, in their concluding remarks, they cautioned that “a test of external stability is however still missing and therefore reproducibility should be tested with a new cohort of patients, preferentially in another institution and population.”
Vido-Marques JR, Reis-Alves SC, Saad STO, et al. A simple score derived from bone marrow immunophenotyping is important for prognostic evaluation in myelodysplastic syndromes. Sci Rep. Published online November 20, 2020. doi:10.1038/s41598-020-77158-z