Side scatter ratio of the CD105-positive and CD105-negative red blood cell fractions is useful for the detection of low-grade myelodysplastic neoplasms by flow cytometry

Abstract

Abstract Objectives We assessed the utility of red blood cell (RBC) CD105 and side scatter (SSC) parameters by flow cytometry for the detection of low-grade myelodysplastic neoplasms (MDS) in bone marrow specimens. Methods Ten RBC parameters incorporating CD105 or SSC combined with the Meyerson-Alayed scoring system (MASS) metrics were retrospectively evaluated by flow cytometry for utility in detecting low-grade MDS (n = 56) compared with cytopenic controls (n = 86). Results Myelodysplastic neoplasms were associated with 7 of the RBC parameters in univariate analysis. Multivariate analysis using cutoff values based on optimal and 95% specificity levels of the RBC metrics and the MASS parameters revealed the SSC ratio of CD105-positive and CD105-negative RBC fractions (CD105+/− SSC); the percentage and coefficient of variation of the CD105-positive fraction of RBCs (CD105%, CD105+CV) emerged as significant RBC variables. Two simple scoring schemes using these RBC values along with MASS parameters were identified: 1 using CD105+/− SSC, CD105%, and CD105+CV combined with the percentage of CD177-positive granulocytes (CD177%), myeloblast percentage (CD34%), and granulocyte SSC (GranSSC), and the other incorporating CD105+/− SSC, CD105+CV, CD177%, CD34%, GranSSC, and B-cell progenitor percentage. Both demonstrated a sensitivity of approximately 80%, with a specificity of roughly 90% for the detection of MDS compared with cytopenic controls. Conclusions The red blood cell parameter, CD105+/− SSC, appears to be beneficial in the evaluation of low-grade MDS by flow cytometry.