Circulating Plasma Cells in Monoclonal Gammopathies

Abstract

Multiparametric flow cytometry is a very sensitive method for detection of circulating plasma cells, so using a standardized approach can lead to determination and implementation of the flow cytometry diagnostic threshold in plasma cell leukemia suspicious cases as well as in prognostication of monoclonal gammopathies patients. Moreover, analysis of plasma cells phenotypic profile could probably clarify their future behaviour.Key words: monoclonal gammopathies - circulating plasma cells - plasma cell leukemia - flow cytometry.

Plasma Cell Leukemia: Definition, Presentation, and Treatment

“…Some studies use only one of the original two requirements to define PCL, and several recent studies question whether a lower threshold of total plasma cells might better risk classify a subgroup of MM patients. Moreover, advances in flow cytometry allow better characterization and clonality assessment of plasma cell populations [ 1 , 11 – 16 ]. The morphology and immunophenotype of the malignant PCs in PCL, MM, and sPCL are not distinguishable.…”

“…Identifying the most relevant threshold for circulating plasma cells to define PCL remains an interesting topic in PCL. The traditional cutoff set by Kyle et al [ 10 ] was arbitrary, and several studies have questioned this cutoff [ 11 , 12 •, 13 •]. In 2013, it was suggested by the IMWG that thresholds for diagnosis should be reevaluated [ 25 ].…”

Minimal Residual Disease Assessment in Multiple Myeloma by Multiparametric Flow Cytometry

“…1) [22][23][24]. Peripheral blood circulating clonal PCs are not detectable by routine analy sis in all MM in time of dia gnosis or are present in very low number, so their fur ther monitoring during treatment needs a highly sensitive approach [25].…”

LncRNAs LY86-AS1 and VIM-AS1 Distinguish Plasma Cell Leukemia Patients from Multiple Myeloma Patients

“…Suggestions for updated diagnostic, response, and progression criteria with an adjusted clonality assessment by flow cytometry for the diagnosis of PCL were discussed by the IMWG in 2013, especially in relation to the minimalization of risk of early death with onset therapy induction [ 14 ]. Bezdekova et al [ 63 ] discussed a need to determine the flow cytometry criteria, which reduces the original cut-off to at least 10%, as the number of cPCs is correlated with a shorter OS. Similarly, Granell et al [ 18 ] described the impact of cPCs on the survival of patients with MM and stated that the presence of ≥ 5% cPCs in these patients has a similar prognostic impact as PCL.…”