title: CD45 expression by bone marrow plasma cells in multiple myeloma: clinical and biological correlations.
abstract: Multiple myeloma (MM) is characterized by accumulation of clonal plasma cells (PCs). CD45, a key regulator of antigen-mediated signaling and activation in lymphocytes, is present in early stages of PCs development. We studied CD45 expression on MM PCs by flow cytometry, correlating it to important biological disease characteristics. Additionally, we examined the expression of various adhesion molecules on PCs. A total of 75 patients with untreated MM (29), relapsed MM (17), smoldering MM (12), and monoclonal gammopathy of undetermined significance (MGUS) (17) were studied. The proportion of PCs expressing CD45 was higher among those with early disease (MGUS or smoldering MM) compared to those with advanced disease (new or relapsed MM) (43 vs 22%; P=0.005). Among those with advanced disease, patients with bone lesions had a lower percentage of CD45-positive (CD45+) PCs; 14 vs 34% (P=0.02). Patients with high-grade angiogenesis had a lower percentage of CD45+ PCs; 13 vs 31% (P=0.03). The median overall survival for the CD45+ group (>20% PCs positive) was 39 vs 18 months for the CD45-negative (CD45-) group (P=0.07). The expression of CD138, CD56 and CD54 were higher among the CD45- PCs. This study demonstrates important biological correlates of CD45 expression on myeloma cells.
authors.affiliation: Division of Hematology, Department of Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.forename: S V
authors.initials: SV
authors.lastname: Rajkumar
authors.forename: T
authors.initials: T
authors.lastname: Kimlinger
authors.forename: P R
authors.initials: PR
authors.lastname: Greipp
authors.forename: T E
authors.initials: TE
authors.lastname: Witzig
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D000951:Antigens, Neoplasm / Q000032:analysis; D001854:Bone Marrow Cells; D001859:Bone Neoplasms / Q000737:chemistry; D015815:Cell Adhesion Molecules / Q000032:analysis; D002452:Cell Count; D018450:Disease Progression; D005434:Flow Cytometry; D006801:Humans; D017493:Leukocyte Common Antigens / Q000032:analysis*; D009101:Multiple Myeloma / Q000401:mortality / Q000473:pathology*; D009389:Neovascularization, Pathologic; D010950:Plasma Cells / Q000737:chemistry* / Q000473:pathology; D016019:Survival Analysis
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D017493:Leukocyte Common Antigens