Extracorporeal treatment of cast nephropathy.

Acute kidney injury (AKI) is common in patients with multiple myeloma (MM), most commonly caused by cast nephropathy resulting from precipitation of free light chains (FLC) in renal tubules. AKI may be irreversible and require dialysis and predicts a poor prognosis. Reduction in serum FLC concentration is thought to be associated with improved likelihood of kidney function recovery in MM patients with AKI. Plasma exchange (PE), by removing circulating FLC, has been used as a treatment modality to improve kidney function in MM, although its efficacy remains uncertain. Extracorporeal treatment with extended high cutoff hemodialysis (HCO-HD) has also recently been studied as a potentially more effective means of FLC removal. Both PE and HCO-HD may be beneficial in some patients, but only when used as adjuncts to successful chemotherapy. Further research is necessary to establish the specific efficacy of each of these extracorporeal methods in the treatment of cast nephropathy.