Urinary Biomarkers of Acute Kidney Injury in Pediatric Stem Cell Transplantation

Abstract

Novel Urinary Biomarkers of Early Acute Kidney Injury in Pediatric Stem Cell Transplantation Acute kidney injury (AKI) is a common complication in pediatric stem cell transplantation (SCT). Creatinine is a late biomarker of AKI. Several novel urinary biomarkers that predict AKI have been proposed. We evaluated the sequential patterns of biomarker elevation after SCT to determine their diagnostic accuracy. We measured urine neutrophil gelatinase associated lipocalin (NGAL), monocyte chemoattractant protein 1 (MCP1), kidney injury molecule 1 (KIM1), vitamin D binding protein (VDBP), and albumin using urine prospectively collected from consecutive pediatric allogeneic SCT patients at baseline and days 0, 14, and 28 using commercial ELISA assays validated for use with urine. Association of AKI (≥50% increase in serum creatinine from baseline) in the first 28 days of HSCT with patient, primary disease, and SCT characteristics was assessed (Table 1), for which only exposure to chemotherapy prior to SCT was significant. We then analyzed the association between each biomarker with the clinical outcome of AKI in the first 28 days of SCT. Of the 80 patients examined, AKI developed in 18 patients. Elevations of MCP1 and NGAL at day 14, and elevations in MCP1 and KIM1 at day 28 were significantly higher in patients who developed AKI (Figure 1). Albuminuria, the most traditional urinary biomarker, showed no discriminating ability. MCP1, KIM1, and NGAL are promising novel biomarkers of early AKI in SCT. Urinary biomarkers could improve renal outcomes in stem cell transplantation by enabling earlier identification of acute kidney injury.