Prognostic Value of Immunophenotyping in Multiple Myeloma: A Study by the PETHEMA/GEM Cooperative Study Groups on Patients Uniformly Treated With High-Dose Therapy

Abstract

To the best of our knowledge, this is the first prospective analysis in which the prognostic impact of a relatively high number of antigenic markers has been simultaneously analyzed in a large series of uniformly treated patients, showing that the expression of several antigens (particularly CD28 and CD117) on bone marrow plasma cells from patients with MM can help to identify patients at high risk of progression.

Utility of flow cytometry immunophenotyping in multiple myeloma and other clonal plasma cell‐related disorders

“…Adverse prognostic factor in MM (17). lower PC counts with a median difference of 23%, we found a significant positive correlation between the two techniques and multivariate analysis selected the BMPC counts specifically obtained by MFC, as an independent prognostic factor for overall survival.…”

“…Immunophenotypic panels containing simultaneous stainings for at least four markers in multicolor combinations are typically required for the identification and characterization of PC (50). On the basis of this strategy, the usage of antibody panels, which include the aberrantly expressed markers described earlier, allows identification of phenotypic abnormalities in virtually all (>90%) MGUS (20,22), MM (17), and PCL (28) cases. In particular, 4-color MFC, specifically based on combined assessment of the expression of CD38, CD56, CD19, and CD45 provides a reliable tool for the specific identification of clonal PC in >90% of all patients with MM, both at diagnosis ( Fig.…”

“…In particular, 4-color MFC, specifically based on combined assessment of the expression of CD38, CD56, CD19, and CD45 provides a reliable tool for the specific identification of clonal PC in >90% of all patients with MM, both at diagnosis ( Fig. 2) (17,20) and after therapy ( Fig. 3) (23,(51)(52)(53).…”

“…Despite this, immunophenotyping has also shown to provide accurate assessment of the expression of multiple markers and their fluorescence intensity in thousands of PC/tube, specific information being provided on individual PC, and to allow clear discrimination between aberrant and both normal and reactive PC, even when they are present at low or very low frequencies in a sample (17)(18)(19)(20)(21)(22). This is a unique feature of MFC since conventional morphological approaches fail to distinguish clonal from normal PC and molecular approaches mainly focus on the detection of specific genetic markers in whole BM and not in single cells.…”

“…Such heterogeneous results could be explained at least to a certain extent, on methodological grounds because of different staining profiles obtained with the use of distinct monoclonal antibody (MoAb) reagents (e.g. MoAb clones and/or fluorochrome conjugates) (14,16), the relatively high and variable baseline autofluorescense levels of clonal PC, inappropriate study designs and lack of standardization (17,18).…”