CLEAVAGE OF IGFBP-1 BY AN ENZYME IN URINE PREDICTS THE FUTURE NEED FOR KIDNEY REPLACEMENT THERAPY IN ACUTE KIDNEY INJURY.

The only Food and Drug Administration (FDA)-approved biomarker for prediction of acute kidney injury (AKI) in adults has a false positive rate (FPR) of 50%. We identified insulin-like growth factor-binding protein 1 (IGFBP-1) as a good but not great predictor of severe AKI. IGFBP-1 was cleaved by an enzyme in the urine. We tested the ability of IGFBP-1 cleavage to predict progression to dialysis. Urine from all 12 patients with stage 1 AKI that progressed to require dialysis cleaved the protein (100% sensitivity). FPR was 0% among healthy controls. FPRs among patients with stage 1 AKI at the time of collection were 11% for patients who did not progress beyond stage 1, 15% for patients who progressed to stage 2, and 50% for patients who progressed to stage 3 but did not require dialysis. The sensitivity of a test with these characteristics would be 100% in a typical intensive care unit (ICU) population, and the FPR would be 6%.