Multiparameter flow cytometry (MFC) identification and characterization of plasma cells (PC) is a useful tool to support diagnosis, prognostication and monitoring of PC diseases (PCD). Currently, the number of MFC markers suited for the identification of PC remains limited. Moreover, antibody therapies against PC-associated markers further compromise the utility of the most widely used reagents (e.g. CD38). Despite markers other than CD38 and CD138 are recognized as potentially useful PC-identification markers, no study has comparatively evaluated their performance in combination with CD38 and CD138. Here we compared the utility of CD229, CD54 and CD319 for the identification of normal and aberrant PC.
Bone marrow samples from 5 healthy controls, two non-infiltrated non-Hodgkin lymphoma cases and 46 PCD patients plus 3 extraosseous plasmocytomas, plus normal PB specimens, were studied.
Our results showed adequate performance of all three markers once combined with CD38. In contrast, when combined with CD138 for the identification of PC, only CD229 provided a good discrimination between PC and all other cells in the sample for all BM and PB samples analyzed; in contrast, CD54 and CD319 showed limited utility for the identification of PC, mainly because of significant overlap of the staining for these two markers on PC and other myeloid cells in the sample.
From the three markers evaluated, CD229 may be considered as the most reliable marker to replace CD38 or CD138 for the identification of PCs in patients undergoing anti-CD38 or anti-CD138 therapy, until a better alternative is available. This article is protected by copyright. All rights reserved.