Multiparametric flow cytometry profiling of neoplastic plasma cells in multiple myeloma.
OBJECTIVE
The clinical impact of multiparametric flow cytometry (MFC) in multiple myeloma (MM) is still unclear and under evaluation. Further progress relies on multiparametric profiling of the neoplastic plasma cell (PC) compartment to provide an accurate image of the stage of differentiation. The primary aim of this study was to perform global analysis of CD expression on the PC compartment and subsequently to evaluate the prognostic impact. Secondary aims were to study the diagnostic and predictive impact.


METHODS
The design included a retrospective analysis of MFC data generated from diagnostic bone marrow (BM) samples of 109 Nordic patients included in clinical trials within NMSG. Whole marrow were analyzed by MFC for identification of end-stage CD45(-) /CD38(++) neoplastic PC and registered the relative numbers of events and mean fluorescence intensity (MFI) staining for CD19, CD20, CD27, CD28, CD38, CD44, CD45, CD56, and isotypes for cluster analysis.


RESULTS
The median MFC-PC number was 15%, and the median light microscopy (LM)-PC number was 35%. However, the numbers were significant correlated and the prognostic value with an increased relative risk (95% CI) of 3.1 (1.7-5.5) and 2.9 (1.4-6.2), P < 0.0003 and P < 0.004 of MFC-PC and LM-PC counts, respectively. Unsupervised clustering based on global MFI assessment on PC revealed two clusters based on CD expression profiling. Cluster I with high intensity for CD56, CD38, CD45, right-angle light-scatter signal (SSC), forward-angle light-scatter signal (FSC), and low for CD28, CD19, and a Cluster II, with low intensity of CD56, CD38, CD45, SSC, FSC, and high for CD28, CD19 with a median survival of 39 months and 19 months, respectively (P = 0.02).


CONCLUSIONS
The MFC analysis of MM BM samples produces diagnostic, prognostic, and predictive information useful in clinical practice, which will be prospectively validated within the European Myeloma Network (EMN). © 2010 International Clinical Cytometry Society.
Department of Haematology, Medical Center and Aalborg Hospital Science and Innovation Center (AHSIC), Aarhus University Hospital, Aalborg, Denmark. haej@rn.dk
Hans E
HE
Johnsen
Martin
M
Bøgsted
Tobias W
TW
Klausen
Peter
P
Gimsing
Alexander
A
Schmitz
Erik
E
Kjaersgaard
Tina
T
Damgaard
Pia
P
Voss
Lene M
LM
Knudsen
Anne K
AK
Mylin
Johan Lanng
JL
Nielsen
Bo
B
Björkstrand
Astrid
A
Gruber
Stig
S
Lenhoff
Kari
K
Remes
Inger Marie
IM
Dahl
Kirsten
K
Fogd
Karen
K
Dybkaer
D051997:ADP-ribosyl Cyclase 1 / Q000032:analysis / Q000276:immunology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002986:Clinical Trials as Topic; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D017493:Leukocyte Common Antigens / Q000032:analysis / Q000276:immunology; D008558:Melphalan / Q000627:therapeutic use; D008562:Membrane Glycoproteins / Q000032:analysis / Q000276:immunology; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology; D054219:Neoplasms, Plasma Cell / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology; D011379:Prognosis; D012189:Retrospective Studies; D033581:Stem Cell Transplantation; D055815:Young Adult
D008562:Membrane Glycoproteins; D017493:Leukocyte Common Antigens; C516769:PTPRC protein, human; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1; D008558:Melphalan