The Role of Extracorporeal Therapy in Light Chain Cast Nephropathy

Background: A comparison of the efficacy of different extracorporeal platforms in reducing free light chain levels in the setting of light chain cast nephropathy has not been discussed in detail. Summary: Recent advances in treating multiple myeloma have increased overall survival and brought a cure closer to reality. Kidney failure remains one of the most significant factors impacting survival, and the recovery of kidney function is crucial in this aspect. Light chain cast nephropathy is the most common subtype of kidney injury caused by toxic monoclonal proteins in myeloma patients and is closely related to the concentration of the involved serum-free light chain (sFLC). A fast decline in sFLC is associated with improved kidney recovery rates. Negative results in randomized controlled trials of extracorporeal therapies have not yet distracted clinicians from applying these options in light chain cast nephropathy due to the demonstrated efficiency of these modalities in sFLC removal compared to conventional dialytic therapies. This review summarizes the efficiency of sFLC reduction with available extracorporeal methods in patients with multiple myeloma and severe kidney failure when combined with anti-myeloma therapy. Key Messages: Since achieving a hematologic response is crucial in light chain cast nephropathy, it appears tough to demonstrate the possible benefit of extracorporeal FLC removal in cast nephropathy in this setting. High-cutoff hemodialysis reduces serum FLC by about 90% after several sessions when combined with anti-myeloma therapy, albeit with albumin loss. Other options, such as medium cutoff hemodialysis and adsorptive methods, may provide a less efficient removal with lower loss of plasma proteins. The contribution of extracorporeal therapy to renal recovery is still unclear.