Urine KIM-1 as a Potential Biomarker of Acute Renal Injury After Circulatory Collapse in Children

Objectives Serum creatinine (SCr) is a late marker of acute kidney injury (AKI) due to the lag time between initiating injury and loss of function. We assessed the ability of urinary interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) to predict AKI in critically ill children with circulatory collapse. Methods Serum creatinine, estimated creatinine clearance (eCrCL), urine IL-18, KIM-1, and NGAL values were measured in 86 children with circulatory collapse on the day of admission, and the results were compared with those obtained 6 days later. Acute kidney injury was defined as a decrease in eCrCL of greater than 25% within the first 48 hours of enrollment. Areas under the curve (AUC) for receiver operating characteristic curve were calculated for the early detection of AKI. Results Mean SCr concentration did not differ significantly during the first 6 days of hospital admission. In contrast, mean urine concentrations of IL-18, KIM-1, and NGAL rose significantly from day of admission to the sixth day of hospital stay (P < 0.001). Urinary KIM-1 emerged as having the strongest performance for the early detection of AKI, followed by NGAL, IL-18, and eCrCL. Urinary KIM-1 displayed the highest AUC of 0.81 (95% confidence interval [CI], 0.76-0.93; P < 0.001) for the early detection of AKI after circulatory collapse, followed by NGAL (0.77% CI, 0.70-0.84) and IL-18 (0.69% CI, 0.48-0.64). Conclusions Of a panel of 3 promising urinary biomarkers, KIM-1 demonstrated the best performance in predicting AKI in children with circulatory collapse before a change in SCr or eCrCL becomes apparent.