Implication of combined urinary biomarkers in early diagnosis of acute kidney injury following percutaneous coronary intervention.

BACKGROUND: Kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL) and interleukin 18 (IL-18) are three of the most promising biomarkers for the early detection of acute kidney injury. In the present study, to determine whether a combination of the three biomarkers enhances their predictive value, representing an ideal indicator for the early detection of Acute Kidney Injury (AKI) we examined 118 adults undergoing elective percutaneous coronary intervention (PCI).

METHODS: We performed a single center, nested case-control study. Urinary KIM-1, NGAL and IL-18 were measured by enzyme-linked immunosorbent assay before and 6 h, 24 h, 48 h postcontrast. Serum creatinine was measured before and 24 h, 48 h postcontrast.

RESULTS: 12 patients (10.1%) were identified with AKI. 30 patients were selected as controls, matched with cases at an attempted 2.5 : 1 ratio. Compared to the non-AKI group, urinary NGAL were significantly higher at all the time-points. Urinary KIM-1 and IL-18 levels were significantly higher at 24 h and 48 h postcontrast. In the AKI group, Urinary NGAL peaked at 6 h postcontrast, and then decreased. Both KIM-1 and IL-18 peaked at 24 hours postcontrast, remained markedly elevated up to 48 h. By applying area under the receiver operator characteristic curve, the combination of KIM-1, NGAL and IL-18 had the most powerful diagnostic power (AUC = 0.99, (95%CI: 0.90 - 1.00), p = 0.0001) for diagnosis of AKI at 24 h postcontrast, superior to that for single detection and serum creatinine.

CONCLUSIONS: KIM-1, NGAL and IL-18 were increased in tandem after PCI. The combination of urinary biomarkers may allow for early detection of AKI following PCI, better than serum creatinine, and the individual biomarkers.