Incidence and outcome of acute renal failure complicating autologous stem cell transplantation for AL amyloidosis

Background. High-dose intravenous melphalan and autologous peripheral blood stem cell transplantation (HDM/SCT) is an effective treatment for AL amyloidosis but is associated with significant toxicity, including the development of acute renal failure (ARF). The incidence and outcome of ARF as a complication of such treatment is not known. Methods. All AL amyloidosis patients treated with HDM/SCT at a single institution between July 1, 1994 and May 31, 2000 were included in the analysis unless they were dialysis-dependent prior to treatment. Baseline data were collected prospectively. Treatment-related data were obtained from a prospectively maintained database and medical record review. ARF was defined as either a greater than or equal to1 mg/dL increase in serum creatinine or a doubling of serum creatinine to greater than or equal to1.5 mg/dL for at least 2 days. Recovery of renal function was defined as a return of serum creatinine to less than or within 0.5 mg/dL of the pretreatment value or the ability to discontinue dialysis initiated as a result of ARF. Results. ARF occurred in 37 of 173 patients (21%). Initiation of dialysis was required in nine patients (5%). Forty-six percent of patients with ARF, including four of nine who required dialysis, had recovery of renal function. Baseline clinical variables that were independent predictors of transplant-associated ARF included creatinine clearance, proteinuria, and cardiac amyloidosis. Treatment-related variables associated with ARF included melphalan dose and bacteremia. ARF was associated with reduced survival at 90 days but did not have an impact on overall survival at a median follow-up of 2.9 years. Conclusion. ARF is a frequent but often reversible complication of HDM/SCT for AL amyloidosis. Specific clinical and treatment-related factors are associated with the development of this complication.