Extracorporeal Removal of Serum-Free Light Chains in Patients with Multiple Myeloma-Associated Acute Kidney Injury

Multiple myeloma (MM) is a clonal B-cell cancer of proliferating plasma cells. It represents nearly a tenth of all hematologic malignancies. Renal dysfunction is present in 25–50 % of newly diagnosed MM patients, about 9 % of which needs hemodialysis (HD). Cast nephropathy is determined by an overflow of filtered serum-free light chains (sFLC) in the proximal tubule that largely overwhelms its endocytic capacity. Bortezomib-based regimens, including high-dose dexamethasone, are recommended as first-choice therapy. In addition, kidney exposure to sFLC may be reduced with extracorporeal sFLC removal. Plasma exchange has been for long time the only extracorporeal technique used in cast nephropathy, but it is now not recommended for sFLC removal in patients with MM-associated AKI. In recent years, other techniques such as HD with new generation high cutoff dialyzers showed their efficacy in sFLC removal and should now be considered for a more rapid reduction of sFLC levels in combination with bortezomib-based therapies.