Emergence of Dipstick Proteinuria Predicts Overt Nephropathy in Patients Following Stem Cell Transplantation

Background: Stem cell transplantation (SCT) places a heavy burden on the kidneys, often resulting in renal dysfunction or nephrotic syndrome. This study attempted to show that early-onset proteinuria predicts the development of overt nephropathy. Methods: A total of 831 patients who received allogeneic SCT were surveyed. Excluding those with prior kidney disease and those lacking in an observation period year after SCT, 251 patients were eligible for the study. Dipstick proteinuria >= 1+ within 1 year after SCT was defined as 'incident proteinuria', and subsequent persistence of an estimated glomerular filtration rate of <60 ml/min/1.73 m(2) at >= 1 year or longer after SCT was defined as 'incident chronic kidney disease (CKD)'. Between-group differences were analyzed using the chi-square or Mann-Whitney U test. Factors associated with the incidence of CKD were investigated by multivariate Cox proportional regression analysis. Kidney-biopsied tissue was examined in all nephrotic syndrome patients. Results: The mean duration of follow-up was 4 years. Thirty-four (13.5%) and 66 (26.3%) patients developed incident proteinuria and incident CKD, respectively. Nine (3.6%) patients developed nephrotic syndrome mainly due to membranous nephropathy. The incidence of CKD was significantly greater in patients with incident proteinuria than those without (61.8 vs. 20.7%, p < 0.0001), and incident dipstick proteinuria was a significant risk for incident CKD (hazard ratio 4.39, 95% CI 2.44-7.73, p < 0.0001). Conclusion: SCT patients who manifest dipstick proteinuria are predisposed to overt nephropathy. Routine monitoring of the urine dipstick test is strongly recommended, as it facilitates early nephrology care for post-SCT patients. (C) 2016 S. Karger AG, Basel