Prognostic value of involved/uninvolved free light chain ratio determined by Freelite and N Latex FLC assays for identification of high-risk smoldering myeloma patients

Background Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell disorder with a high risk of progression to symptomatic multiple myeloma (MM). The serum free light chain (sFLC) ratio is a powerful prognostic factor for SMM: an sFLC ratio ≥8 has been reported to be associated with a high risk of progression to MM, and an sFLC ratio ≥100 has been described as a criterion for ultra-high-risk SMM, and has been integrated into the...