High levels of peripheral blood circulating plasma cells as a specific risk factor for progression of smoldering multiple myeloma

• Published in: Leukemia Vol. 27; no. 3; pp. 680 - 685
• Main Authors: Bianchi, G, Kyle, R A, Larson, D R, Witzig, T E, Kumar, S, Dispenzieri, A, Morice, W G, Rajkumar, S V
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.03.2013; Nature Publishing Group
• Subjects: 631/250/1619/40/1742; 692/499; 692/699/67/1990/804; Adult; Aged; Aged, 80 and over; Amyloidosis; Blood circulation; Bone marrow; Cancer Research; Chemotherapy; Cohort Studies; Critical Care Medicine; Development and progression; Diagnosis; Disease Progression; Electronic health records; Female; Hematology; Humans; Immunoglobulins; Intensive; Internal Medicine; Leukemia; Leukocytes (mononuclear); Male; Malignancy; Medical prognosis; Medical records; Medicine; Medicine & Public Health; Middle Aged; Multiple myeloma; Multiple Myeloma - blood; Multiple Myeloma - diagnosis; Multiple Myeloma - etiology; Multiple Myeloma - mortality; Neoplastic Cells, Circulating - pathology; Oncology; original-article; Peripheral blood mononuclear cells; Physiological aspects; Plasma; Plasma cells; Plasma Cells - pathology; Prognosis; Risk analysis; Risk Factors; Smoldering; Survival Rate; United States > US; Eire, Connaught, Mayo; progression; multiple myeloma; smoldering multiple myeloma; circulating plasma cells; predictive factor
• ISSN: 0887-6924; 1476-5551
• DOI: 10.1038/leu.2012.237

Smoldering multiple myeloma (SMM) carries a 50% risk of progression to multiple myeloma (MM) or related malignancy within the first 5 years following diagnosis. The goal of this study was to determine if high levels of circulating plasma cells (PCs) are predictive of SMM transformation within the first 2–3 years from diagnosis. Ninety-one patients diagnosed with SMM at Mayo Clinic from January 1994 through January 2007, who had testing for circulating PCs using an immunofluorescent assay and adequate follow-up to ascertain disease progression, were studied. High level of circulating PCs was defined as absolute peripheral blood PCs >5 × 10 6 /l and/or >5% PCs per 100 cytoplasmic immunoglobulin (Ig)-positive peripheral blood mononuclear cells. Patients with high circulating PCs (14 of 91 patients, 15%) were significantly more likely to progress to active disease within 2 years compared with patients without high circulating PCs, 71% versus 24%, respectively, P =0.001. Corresponding rates for progression within 3 years were 86% versus 34%, respectively, P <0.001. Overall survival (OS) after both SMM diagnosis and MM diagnosis was also significantly different. High levels of circulating PCs identify SMM patients with an elevated risk of progression within the first 2–3 years following diagnosis.