101: High Renal Recovery Rate from Cast Nephropathy Following Free Light Chain Removal Hemodialysis

Abstract

HIGH RENAL RECOVERY RATE FROM CAST NEPHROPATHY FOLLOWING FREE LIGHT CHAIN REMOVAL HEMODIALYSIS Colin A Hutchison, Kolitha Basnayake, Mark Cook, Paul Cockwell, Arthur R. Bradwell. Departments of Renal Medicine and Hematology, Queen Elizabeth Hospital, QEMC, Birmingham, UK; Division of Immunity and Infection, Medical School, University of Birmingham, Birmingham, UK. This study assessed the efficacy of high cut-off hemodialysis (HCOHD), using the Gambro HCO 1100 dialyser, to result in sustained reductions in serum free light chain (FLC) concentrations in patients with cast nephropathy. Renal recovery rates and survival in 17 patients treated with HCO-HD were compared with a case matched control population treated with standard high flux dialysis (n=17). Standard induction chemotherapy regimens were initiated in all patients. HCO-HD was undertaken for 8 hours daily for the first 5 days and then 8 hours alternate days through to 21 days. Extended HCO-HD was supported by the replacement of human albumin solution, magnesium and calcium per protocol. HCO-HD resulted in sustained reductions in serum FLC concentrations in 12 of 17 patients (median 86% (range 50-93)). These 12 patients became independent of dialysis at a median of 27 days (range 13-50). With an estimated GFR three months following the commencement of treatment of 44mls/min/1.73m2 (range 29-60). Five patients had chemotherapy stopped because of early infective complications and did not achieve sustained reductions in serum FLCs. These patients did not recover renal function and had a significantly reduced survival (P<0.002). On an intention to treat basis FLC removal HD increased the rate of renal recovery from two of 18 (11%) patients in the control population to 12 of 17 (70%) in the study population (P<0.0001). In both groups, patients with cast nephropathy who recovered renal function had a significantly improved survival, P<0.012. In conclusion, extended HCO-HD resulted in sustained reductions in serum FLC concentrations in patients with cast nephropathy. This was associated with an increased rate of renal recovery compared with a historical control group and improved survival.