title: Quantification of circulating clonal plasma cells via multiparametric flow cytometry identifies patients with smoldering multiple myeloma at high risk of progression.
abstract: The presence of high numbers of circulating clonal plasma cells (cPCs) in patients with smoldering multiple myeloma (SMM), detected by a slide-based immunofluorescence assay, has been associated with a shorter time to progression (TTP) to MM. The significance of quantifying cPCs via multiparameter flow cytometry, a much more readily available diagnostic modality, in patients with SMM has not been evaluated. This study evaluated 100 patients with a known or new diagnosis of SMM who were seen at the Mayo Clinic, Rochester from January 2008 until December 2013. Patients with ⩾150 cPCs (N=9) were considered to have high number of cPCs based on the 97% specificity and 78% PPV of progression to MM within 2 years of cPC assessment. The median TTP of patients with ⩾150 cPCs was 9 months compared with not reached for patients with <150 cPCs (P<0.001). Thus, quantification of cPCs via multiparametric flow cytometry identifies patients with SMM at very high risk of progression to MM within 2 years and warrants confirmation in larger studies. In the future, this may allow reclassification of such patients as having MM requiring therapy prior to them enduring end-organ damage.
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: W I
authors.initials: WI
authors.lastname: Gonsalves
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: S V
authors.initials: SV
authors.lastname: Rajkumar
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: A
authors.initials: A
authors.lastname: Dispenzieri
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: D
authors.initials: D
authors.lastname: Dingli
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Timm
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: W G
authors.initials: WG
authors.lastname: Morice
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: M Q
authors.initials: MQ
authors.lastname: Lacy
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: F K
authors.initials: FK
authors.lastname: Buadi
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Go
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: N
authors.initials: N
authors.lastname: Leung
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: P
authors.initials: P
authors.lastname: Kapoor
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Hayman
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Lust
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Russell
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Zeldenrust
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: L
authors.initials: L
authors.lastname: Hwa
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: T V
authors.initials: TV
authors.lastname: Kourelis
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Kyle
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Gertz
authors.affiliation: The Divisions of Hematology and Blood and Marrow Transplantation, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Kumar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002452:Cell Count; D002999:Clone Cells / Q000473:pathology; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis* / Q000473:pathology; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D010950:Plasma Cells / Q000473:pathology*