Serum FLC ratio can help assess risk in patients with Smouldering Multiple Myeloma
Immunoglobulin free light chain ratio is an independent risk factor for progression of smoldering (asymptomatic) multiple myeloma
Angela Dispenzieri et al. Blood 2008 111(2):785-789A large study of patients with Smouldering Multiple Myeloma (SMM), conducted by the Mayo Clinic, investigated whether an abnormal serum free light chain (FLC) ratio indicated an increased risk of progression to active Multiple Myeloma.
The results demonstrated that "an increasingly abnormal FLC ratio was associated with a higher risk of progression to active MM." 90% of the cohort study had an abnormal serum FLC ratio. The best cut-point for progression was found to be a ratio less than 0.125 or greater than 8 and the serum FLC ratio was independent of other known risk factors.
The authors conclude that the serum FLC ratio should be used as another variable to help define MGUS, SMM and active MM and how an abnormal serum FLC ratio also provides valuable prognostic information in each of these subsets of patients. "While genetic profiles or specific genetic markers may someday make these variables obsolete, that day has not arrived.
Until it does, the baseline serum immunoglobulin FLC ratio provides valuable prognostic information for each of these entities."