Milani, Paolo

The detection and quantification of monoclonal‐proteins (M‐proteins) are necessary for the diagnosis and evaluation of response in plasma cell dyscrasias. Immunoglobulin enrichment‐coupled with matrix‐assisted laser desorption ionization time‐of‐flight mass‐spectrometry (MASS‐FIX) is a simple and inexpensive method to identify M‐proteins, but its clinical generalizability has not yet been elucidated. We compared MASS‐FIX to protein electrophoresis (PEL), serum/urine immunofixation‐electrophoresis (IFE), and quantitative serum free‐light chain (FLC) for the identification of M‐proteins in different clinical diagnoses. Paired serum and urine samples from 257 patients were tested. There were six patients for whom s‐IFE and FLC ratio were positive and serum MASS‐FIX was negative, but when serum and urine MASS‐FIX results were combined, only one patient with light chain‐MGUS was missed. Serum/urine‐MASS‐FIX detected M‐proteins in 18 patients with negative serum/urine‐PEL/IFE and serum‐FLC, 10 of whom had multiple myeloma or AL amyloidosis, who were mistakenly thought to have complete hematologic response by serum/urine‐PEL/IFE and serum‐FLC. Nearly half of the AL amyloidosis patients had atypical spectra, which may prove to be a clue to the diagnosis and pathogenesis of the disease. In conclusion, MASS‐FIX has a comparable sensitivity with PEL/IFE/FLC methods and can help inform the clinical diagnosis.

Multiple myeloma (MM) patient frailty has been delineated primarily by age and ECOG performance score (PS) and recently by the IMWG frailty score based on functional status [Activity of Daily Living (ADL) and Instrumental‐ADL scores], comorbidities [Charlson‐comorbidity‐index (CCI)] and age. It was hypothesized that N‐terminal natriuretic peptide type B (NT‐proBNP) might be both a more convenient measure of frailty and a predictor of overall survival (OS). Three‐hundred and fifty‐one consecutive symptomatic MM patients who were seen at Mayo Clinic within 30 days of diagnosis and who had blood stored were eligible. Data from the first visit was abstracted and used to calculate an ADL, CCI, and measure the NT‐proBNP level. The best cutoff of NT‐proBNP predicting OS was 300 ng/L. Variables predictive for OS were ECOG‐PS, age, CCI, ADL, ISS, revised‐ISS, and NT‐proBNP. On multivariate analysis age ≥70, PS ≥2, and NT‐proBNP ≥300 were independent predictors of survival. Patients were assigned a score of 1 for each of these variables, creating stages I–IV with scores of 0–3 points, respectively. The median OS from diagnosis was not reached, 58, 28, and 18 months (P < 0.0001), respectively. This frailty risk schema was independent of initial therapy and the revised‐ISS. NT‐proBNP is a useful predictor of survival independent of age and PS. It is a widely available biomarker that could be added to the panel of laboratory tests of newly diagnosed MM patients and serve as a simple and objective tool of determining frailty in clinical practice. Am. J. Hematol. 91:1129–1134, 2016. © 2016 Wiley Periodicals, Inc.