MALDI-TOF-MS Application in M-Protein Detection and Its Associations with Clinical Laboratory Findings in Geriatrics.

Currently, the methods used to detect M-protein such as SPEP (serum M-protein electrophoresis), IFE (immunofixation electrophoresis), and sFLC (serum free light chain) assay are hyposensitive, laborious, time-consuming, and expensive. In this study, the authors assessed the performance of MALDI-TOF-MS in the detection of M-protein in geriatrics. With IFE as the gold standard, the specificity, sensitivity, and consistency of MALDI-TOF-MS were 92.30, 89.68, and 90.06%, respectively. MALDI-TOF-MS achieved an agreement of 100.00, 100.00, 89.68, 88.89, and 87.50% in the detection of IgA, biclonal, negative, IgM, and IgG isotypes of M-protein, respectively. In addition, the results showed that the glycosylated haemoglobin level was increased in the MS-IFE+ group as compared to the MS+IFE- group. This study supports that the MALDI-TOF-MS is an alternative method for M-protein detection in aged subjects. The difference in glycosylated haemoglobin level may provide an explanation for the different detection results for M-protein between IFE and MALDI-TOF-MS. Key Words: M-protein, MALDI-TOF-MS, Immunofixation electrophoresis, Clinical laboratory findings, The aged.