High cut-off haemodialysis for dialysis dependent myeloma cast nephropathy at first presentation: A case series

Light chain cast nephropathy, the most common cause of acute kidney injury (AKI) in multiple myeloma, is triggered by the overproduction of free light chains and the resultant generation of obstructing and pro-inflammatory casts in the renal tubules. Plasma cell-directed chemotherapies form the mainstay of management. At initial presentation some individuals have severe kidney injury requiring dialysis. High-cutoff haemodialysis (HCO-HD), which effectively filters circulating free light chains, has been posited as an adjunctive treatment for multiple myeloma patients with dialysis-dependent AKI. While standard haemodialysis, and indeed plasmapheresis, in the absence of a dialysis indication have shown no benefit in randomised trials, one randomised study using HCO-HD in patients requiring dialysis did suggest longer term benefit in terms of dialysis independence. Herein we describe three cases of multiple myeloma with severe AKIs treated with a shortened version of the MYRE study HCO-HD protocol and standard chemotherapy. All three cases demonstrated renal recovery; two within weeks and one within months of commencing HCO-HD. Treatment refractory multiple myeloma cases were excluded and cast nephropathy was not biopsy-confirmed. In cases of myeloma kidney requiring dialysis and receiving plasma cell-directed chemotherapy, use of HCO dialysis membranes should be considered over standard cut off membranes, to maximise potential for long term renal recovery.