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Evaluation of CD229 as a new alternative plasma cell gating marker in the flow cytometric immunophenotyping of monoclonal gammopathies
Author(s) -
Tembhare Prashant R.,
Ghogale Sitaram,
Tauro Wilma,
Badrinath Yajamanam,
Deshpande Nilesh,
Kedia Shweta,
Cherian Keziah,
Patkar Nikhil V.,
Chatterjee Gaurav,
Gujral Sumeet,
Subramanian Papagudi G.
Publication year - 2018
Publication title -
cytometry part b: clinical cytometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 61
eISSN - 1552-4957
pISSN - 1552-4949
DOI - 10.1002/cyto.b.21619
Subject(s) - flow cytometry , immunophenotyping , plasma cell , gating , staining , cd38 , monoclonal antibody , microbiology and biotechnology , antibody , bone marrow , chemistry , pathology , medicine , immunology , biology , stem cell , biophysics , cd34
Background Current flow‐cytometric plasma cell (PC) gating is based on CD138, CD38, and CD45 expression. CD138 is known for variable expression and loss during storage and processing. Introduction of anti‐CD38 and anti‐CD138 monoclonal‐antibody therapies has limited the use of these markers during follow‐up. Hence, additional reliable PC‐gating markers are required. Recently, CD229 has been claimed as an alternative PC‐gating marker. However, these studies are limited to a small cohort of samples. We evaluated the utility of CD229 as a new PC‐gating marker in routine laboratory practice. Methods Expression of CD229 was studied in 310 bone marrow (BM) samples (251 plasma‐cell disorders and 59 controls) and compared with CD138 and CD38 expression. We also evaluated the effect of additional processing for cytoplasmic immunoglobulin‐light‐chains (CyIgL) staining on the quantitation of PC. Results Expression of CD229 was consistently stronger on PC than other hematopoietic‐cells ( p < 0.001). PC‐percentages using CD229 in combination with CD38 or CD138 and CD45 revealed high correlation with a reference gating‐strategy using CD138, CD38 and CD45 ( r = 0.98, r = 0.99 r = 0.99 respectively) and r = 0.92 using CD229 and CD45 without CD38 or CD138. In contrast, CD138 expression showed significant variability (CV‐MFI, 97.5) and loss from PC in 53% of samples. Quantitation of PC was found to be lower in 69.3% and higher in 30.7% samples processed for CyIgL‐staining as compared to surface‐staining. Conclusions CD229 is a reliable new alternative PC‐gating marker in routine laboratory practice. Quantitation of PC based on CD138 expression or from samples processed for CyIgL‐staining should be used with caution. © 2018 International Clinical Cytometry Society