Urine Bence Jones proteins as a novel source for De Novo light chain sequencing
This study shows the possibility of using urine samples for de novo sequencing of M-protein in patients with multiple myeloma. M-inSight was used to analyze paired urine and serum samples from 23 patients. Light chain sequences were successfully retrieved from 19 urine samples, with high similarity (over 90%) to those obtained from serum in 9 cases. Importantly, clonotypic peptides for monitoring M-protein levels were identified in all 19 urine samples, even when absent in serum from some patients. These findings suggest urine as a viable alternative for M-protein sequencing and monitoring, especially in cases with low serum M-protein concentrations.