Multiparameter flow cytometry for the identification of the Waldenstrom%26apos;s clone in IgM-MGUS and Waldenstrom%26apos;s Macroglobulinemia: new criteria for differential diagnosis and risk stratification

作者：Paiva B; Montes M C; Garcia Sanz R; Ocio E M; Alonso J; de las Heras N; Escalante F; Cuello R; de Coca A G; Galende J; Hernandez J; Sierra M; Martin A; Pardal E; Barez A; Alonso J; Suarez L; Gonzalez Lopez T J; Perez J J; Orfao A; Vidriales M B; San Miguel J F^*

来源：Leukemia, 2014, 28(1): 166-173.

DOI：10.1038/leu.2013.124

• Waldenstrom%26apos
• s Macroglobulinemia
• MGUS
• flow cytometry
• phenotype
• plasma cells
• survival

Although multiparameter flow cytometry (MFC) has demonstrated clinical relevance in monoclonal gammopathy of undetermined significance (MGUS)/myeloma, immunophenotypic studies on the full spectrum of Waldenstrom%26apos;s Macroglobulinemia (WM) remain scanty. Herein, a comprehensive MFC analysis on bone marrow samples from 244 newly diagnosed patients with an immunoglobulin M (IgM) monoclonal protein was performed, including 67 IgM-MGUS, 77 smoldering and 100 symptomatic WM. Our results show a progressive increase on the number and light-chain-isotype-positive B-cells from IgM-MGUS to smoldering and symptomatic WM (P%26lt;.001), with only 1% of IgM-MGUS patients showing %26gt; 10% B cells or 100% light-chain-isotype-positive B-cells (P%26lt;.001). Complete light-chain restriction of the B-cell compartment was an independent prognostic factor for time-to progression in smoldering WM (median 26 months; HR: 19.8, P = 0.001) and overall survival in symptomatic WM (median 44 months; HR: 2.6, P = 0.004). The progressive accumulation of light-chain-isotype-positive B-cells accompanied the emergence of a characteristic Waldenstrom%26apos;s phenotype (CD22(+dim)/CD25(+)/CD27(+)/IgM(+)) that differed from other B-NHL by negative expression of CD5, CD10, CD11c or CD103. In contrast to myeloma, light-chain-isotype-positive plasma cells in IgM monoclonal gammopathies show otherwise normal antigenic expression. Our results highlight the potential value of MFC immunophenotyping for the characterization of the Waldenstrom%26apos;s clone, as well as for the differential diagnosis, risk of progression and survival in WM.

• 出版日期2014-1