Evaluation of CD319 (SLAMF7) as a Novel Gating Marker for Plasma Cells in Flow Cytometric Immunophenotyping of Multiple Myeloma

Abstract

Traditionally, plasma cells (PCs) are identified using strong CD38 and CD138 expression in flowcytometric Immunophenotyping (FCI). However, variable loss of CD138 and decreased-expression of CD38 is well-known in clonal-PCs. Furthermore, anti-CD38-monoclonal antibody (Daratumumab) therapy causes down-regulation of CD38 expression. In these scenario, traditional markers are not adequate for FCI of PCs, especially for monitoring of minimal residual disease (MRD). Recently, CD319 (SLAMF7) has been demonstrated to be useful for FCI-PC gating, but in a small cohort of samples and clinical-trial settings.