{Reference Type}: Journal Article
{Title}: Immunophenotypic assessment of clonal plasma cells and B-cells in bone marrow and blood in the diagnostic classification of early stage monoclonal gammopathies: an iSTOPMM study.
{Author}: Pérez-Escurza O;Flores-Montero J;Óskarsson JÞ;Sanoja-Flores L;Del Pozo J;Lecrevisse Q;Martín S;Reed ER;Hákonardóttir GK;Harding S;Þorsteinsdóttir S;Rögnvaldsson S;Love TJ;Durie B;Kristinsson SY;Orfao A;
{Journal}: Blood Cancer J
{Volume}: 13
{Issue}: 1
{Year}: 2023 12 11
{Factor}: 9.812
{DOI}: 10.1038/s41408-023-00944-1
{Abstract}: Monoclonal gammopathy of undetermined significance (MGUS) is the earliest discernible stage of multiple myeloma (MM) and Waldenström's macroglobulinemia (WM). Early diagnosis of MG may be compromised by the low-level infiltration, undetectable to low-sensitive methodologies. Here, we investigated the prevalence and immunophenotypic profile of clonal (c) plasma cells (PC) and/or cB-lymphocytes in bone marrow (BM) and blood of subjects with a serum M-component from the iSTOPMM program, using high-sensitive next-generation flow cytometry (NGF), and its utility in the diagnostic classification of early-stage MG. We studied 164 paired BM and blood samples from 82 subjects, focusing the analysis on: 55 MGUS, 12 smoldering MM (SMM) and 8 smoldering WM (SWM). cPC were detected in 84% of the BM samples and cB-lymphocytes in 45%, coexisting in 39% of cases. In 29% of patients, the phenotypic features of cPC and/or cB-lymphocytes allowed a more accurate disease classification, including: 19/55 (35%) MGUS, 1/12 (8%) SMM and 2/8 (25%) SWM. Blood samples were informative in 49% of the BM-positive cases. We demonstrated the utility of NGF for a more accurate diagnostic classification of early-stage MG.