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.