Abstract 4574: Validation of Early Biomarkers of Acute Kidney Injury After Pediatric Cardiac Surgery
Body: Previous high-throughput proteomic analysis using SELDI-TOF-MS (JASN 17:49A, 2006) identified three urinary proteins, namely α1-microglobulin (A1M), α1-acid glycoprotein (AAG), and albumin (Alb), that were over-expressed at 2 hr after cardiac surgery in subjects who subsequently developed acute kidney injury (AKI). In order to validate the potential role of these biomarkers in clinical AKI, we prospectively collected serial urine samples at 0, 2, 6, 12, 24 and 48 hr after initiation of cardiopulmonary bypass from pediatric patients undergoing surgery for congenital heart disease. The biomarkers were measured by a standard clinical laboratory platform (Dade-Behring BN Prospec).
Results: 365 patients were enrolled with a mean age of 3.5 ± 4.5 years. 53% were males. 135 (37%) of patients developed AKI (50% increase in serum creatinine from baseline). In this group, 46% showed moderate AKI (100% increase in serum creatinine) and 5% displayed severe AKI (dialysis requirement). AKI based on serum creatinine was diagnosed at 2.2 ± 0.74 days after surgery. In contrast, the mean concentrations of all three biomarker proteins were significantly different at very early time points after surgery for various severities of AKI (Table 1⇓). The performance (area under ROC curve) of all three biomarkers peaked at 6 hr after surgery with accuracies of 86% (A1M), 90% (AAG), and 79% (Alb). The quartiles of biomarker values at 6 hr were also prognostic for peak serum creatinine, duration of AKI, and length of hospital stay (all p<0.001).
Conclusion: A1M, AAG, and Alb represent excellent early biomarkers for the diagnosis and prognosis of AKI after cardiac surgery.
This research has received full or partial funding support from the American Heart Association, AHA Great Rivers Affiliate (Delaware, Kentucky, Ohio, Pennsylvania & West Virginia).