Objective: Cast nephropathy, due to free light chain (FLC) toxicity, is the main cause of acute kidney injury in multiple myeloma, with about 10% of patients requiring dialysis. In these patients, in addition to chemotherapy that prevents FLC production, daily hemodialysis using high cutoff or adsorptive membranes, showed promising results by decreasing quickly toxic serum FLC concentrations.
Case history: We report here the case of 2 patients presenting with acute kidney injury and high FLC serum concentration and M-components one with IgG Kappa and the other with IgD lambda. Both were treated with bortezomib and dexamethasone and received a 24-h continuous hemodialysis using a high and sharp cutoff (around 35,000 Daltons) polysulfone membrane (ultraflux® HD 1000, Fresenius Medical Care GmbH, Bad Homburg, Germany) with citrate regional anticoagulation using a safe and dedicated device (multi filtrate Ci-Ca®).
Conclusion: Despite similar range of depuration, serum plasma FLC decreased importantly in the patient with the kappa type who recovered but was unchanged in the lambda type patient who remained under maintenance dialysis. Further studies are needed to confirm this new approach therapy.