Plasma exchange in rapidly progressive renal failure due to multiple myeloma : A retrospective case series

To evaluate the effect of plasma exchange on renal function in patients with rapidly progressive renal failure secondary to multiple myeloma. The study was done through a retrospective chart review using a standardized form at a tertiary care centre in southwestern Ontario. Patients were included in the study if they had a diagnosis of multiple myeloma and rapidly progressive renal failure. Multiple myeloma was defined by a bone marrow aspirate >15% plasma cells plus one of the following: serum monoclonal paraproteins, monoclonal light-chain excretion, or lytic lesions. Patients were excluded if they had evidence of chronic renal failure or failed to complete three plasma exchanges. Twenty-six patients were reviewed; of these 24 were followed up to 1 year. All patients received hydration, standard chemotherapy, and plasma exchange. The plasma exchange volume was 50 ml/kg of 50% normal saline and 50% human serum albumin. Primary outcome measures included (1) prevention of acute dialysis and (2) prevention of progression from acute to chronic dialysis; secondary end points included (1) a decrease in creatinine of 25% or more within 3 months of the last plasma exchange and (2) survival at 1 year. Sixteen of 24 patients, followed up to 1 year, did not require dialysis. Two patients required dialysis initially, but were able to come off dialysis after 3 months. Fourteen patients were alive at 1 year, 13 of whom were dialysis independent. Twelve of 13 dialysis-independent patients had a >25% reduction in creatinine at 3 months. Two patients were lost to follow-up after discharge and were not included in the analysis. This retrospective study suggests that plasma exchange may offer some benefit in preventing the initiation or continuation of dialysis in patients with rapidly progressive renal failure secondary to multiple myeloma. A randomized controlled prospective study is needed to determine whether plasma exchange should be recommended as a standard treatment for patients with rapidly progressive renal failure due to multiple myeloma.