Multiparametric flow cytometry profiling of neoplastic plasma cells in multiple myeloma

The myeloma stem cell concept, revisited: from phenomenology to operational terms

“…[14][15][16] Lagging slightly behind this approach is the rapidly developing technology for examining the protein compartment of the cell. [17][18][19] In the present review, we have updated the latest scientific reports and propose a revision of the MMSC concept to include operational terms (Table 1), in accordance with recent (2012) consensus statements on the definitions, assays, and nomenclature of cancer stem cells, which is technically precise without completely abolishing established terminology. 20 We expect this will empower the design of translational research activities based on prospectively sampled biomaterial which reflects the spectrum of clinical disease.…”

Utility of Flow Cytometry to Classify Abnormal Plasma Cell Populations in Marrow Samples Collected from Patients with Putative Plasma Cell Neoplasms

“…Additionally, this reduction of CD27 expression correlates with loss of CD19 and progression of MGUS to MM [8]. Conversely, only very few cases of MGUS express CD28 [4], while this marker is expressed brightly in MM. Similarly, CD81 is brightly expressed by myeloma cells in a subset of patients, where it may be associated with CD19 co-expression, and poor clinical outcome [9].…”

“…Compared to lymphocytes, non-neoplastic plasma cells have low forward/side scatter, variable to absent expression of CD45, and lack CD20, CD22, and surface immunoglobulins. They are brightly positive for CD38, CD138, and CD19 [4,5] and have polyclonal cytoplasmic immunoglobulins. In contrast, myeloma cells demonstrate monoclonal cytoplasmic immunoglobulin and almost always lack CD19 (95%) and surface immunoglobulin [5].…”

“…CD117 is expressed with equal intensity in both MGUS and MM and is associated with better progression-free and overall survival in MM [17]. Conversely, CD28, when expressed, is bright in MM compared to MGUS and its expression correlates with the presence of t (11;14), t(4;14), deletion of 17p and 13q, non-hyperdiploid karyotype, and is considered an aggressive phenotype [4]. Cases with expression of both CD28 and CD117 on multivariate analysis have prognosis comparable to CD28+ cases and do not show favorable prognosis associated with CD28-CD117+ cases [17].…”

Issue Highlights—January 2013

“…MULTIPLE MYELOMA PATIENTS There is accumulating evidence in the literature indicating that multicolor flow cytometry is increasingly important for the diagnosis of minimal residual disease (MRD) assessment of patients with multiple myeloma (MM), although only sporadic reports have proposed consensus techniques for their detection (9)(10)(11)(12). However, the literature contains discrepancies in results regarding the exact immunophenotype of normal and neoplastic plasma cells (PCs) and their associated clinical significance.…”