Phenotypic difference of normal plasma cells from mature myeloma cells

Abstract

We have recently shown that two-color analysis with fluorescein isothiocyanate (FITC)-anti-CD38 antibody could clearly distinguish myeloma cells (plasma cells) from other hematopoietic cells in the bone marrow. Myeloma cells (plasma cells) alone were located at CD38strong positive (++) fractions. To further distinguish normal plasma cells from mature myeloma cells phenotypically, we examined immunophenotypes of normal plasma cells and myeloma cells by two-color flow cytometry with FITC-anti-CD38 antibody and phycoerythrin staining with antibody to VLA-4, MPC-1, CD44, CD56, CD19, CD20, CD24, or CD10. Normal plasma cells were all VLA-4+VLA-5+MPC-1+CD44+ CD19+CD56- in the bone marrows from seven healthy donors, tonsils from four patients with chronic tonsillitis, a spleen from one patient with idiopathic thrombocytopenic purpura, and lymph nodes from two patients with chronic lymphadenitis, respectively. On the other hand, mature myeloma cells (12 of 20 cases), VLA-4+VLA-5+MPC-1+, were all CD19- and most of them CD56+, and there were no myeloma cells with the CD19+CD56- phenotype in the 20 cases of myelomas we tested. Thus, as for the expression of CD19 and CD56, normal plasma cells from various tissues are all CD19+CD56-, whereas no myeloma cells have the CD19+CD56- phenotype. According to this finding, we investigated the expression of CD19 and CD56 on plasma cells (CD38++ fractions) in monoclonal gammopathy of undetermined significance (MGUS). Both CD19+CD56- and CD19-DC56+ plasma cells were found in all five cases of MGUS we tested, suggesting that MGUS consists of phenotypically normal plasma cells and myeloma cells. Therefore, it is reasoned that phenotypic analysis of plasma cells with anti-CD19 and anti-CD56 antibodies can distinguish normal plasma cells from malignant plasma cells (myeloma cells), and can detect malignant plasma cells even in MGUS or premyeloma states.

Loss of CD19 expression in B‐cell neoplasms

“…3 CD19 has also been detected by flow cytometry in plasma cells isolated from human tissues. 6 Previous studies of CD19 in B-cell neoplasia have been limited to flow cytometric analysis of living cells 2,7-10 and its expression in B-cell neoplasia in routine tissue biopsy specimens has not been previously investigated. In this paper, we describe a polyclonal antibody against CD19 that is reactive on paraffin sections.…”

Neural cell adhesion molecule expression in plasma cells in bone marrow biopsies and aspirates allows discrimination between multiple myeloma, monoclonal gammopathy of uncertain significance and polyclonal plasmacytosis

“…Subsequently, anti-CD56 began to be used for characterization and differentiation of normal and neoplastic plasma cells using phenotypic analysis. [10][11][12] A recent study 13 found that expression of NCAM in myeloma cells is as strong as in the osteoblast layer and is associated with lytic bone lesions.…”

Constitutively lower expressions of CD54 on primary myeloma cells and their different localizations in bone marrow

“…Bone marrow monoclonal cells (BMMNC) from BM aspirates were separated by Ficoll-Hypaque centrifugation, suspended at a concentration of 0.5 · 10 6 cells ⁄ mL, and cultured in RPMI-1640 medium supplemented with 10% FBS (M.A. Bioproducts, Walkersville, MD, USA) as reported previously (20).…”

“…Cells were stained with fluorescein isothiocyanate (FITC)-labeled anti-CD38 (A07778, Beckman Coulter, Tokyo, Japan), phycoerythrin (PE)-labeled anti-mature plasma cell-1 (MPC-1) [Japan Immunoresearch Laboratories (JIMRO), Takasaki, Japan], PE-labeled anti-CD19 (A07769, Beckman Coulter) antibody, PE-anti-CD54 antibody (IM1239U; Beckman Coulter, Hialeah, FL, USA), or PE-labeled anti-human CXCR4 (FAB170P; R&D Systems, Minneapolis, MN, USA). Cells were washed twice with phosphate-buffered saline containing 1% FBS, incubated at 4°C for 30 min with the above antibodies, and analyzed by a flow cytometer (Epics Elite ESP; Beckman Coulter) (20). The cells were also sorted by the cell sorter (Epics Elite ESP) as reported previously (20).…”

“…Cells were washed twice with phosphate-buffered saline containing 1% FBS, incubated at 4°C for 30 min with the above antibodies, and analyzed by a flow cytometer (Epics Elite ESP; Beckman Coulter) (20). The cells were also sorted by the cell sorter (Epics Elite ESP) as reported previously (20).…”