Diagnostic performance of urinary kidney injury molecule‐1 and neutrophil gelatinase‐associated lipocalin for acute kidney injury in an obstructive nephropathy patient

Abstract

We investigated the diagnostic performance of urinary kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) for acute kidney injury (AKI) in 90 obstructive nephropathy patients. Urine samples were obtained preoperatively and 4, 8, 12, 24, 48 and 72 h postoperatively, and urinary KIM-1 and NGAL contents were measured by enzyme linked immunosorbent assay and corrected against urine creatinine content. The receiver operating characteristic (ROC) curves were used to determine the area under the curve (AUCs) of urinary KIM-1 and NGAL for AKI. The baseline urinary KIM-1 contents were higher in AKI patients than non-AKI patients (P < 0.01). Urinary NGAL contents were also higher in AKI patients than non-AKI patients (P < 0.001). The area under the curve (AUC) of urinary KIM-1 was 0.900 (P = 0.004) and at a cutoff of 338.26 pg/mg Cr, the sensitivity was 90% and the specificity was 75%. The AUC of urinary NGAL was 0.900 (P = 0.004) and at a cutoff of 261.76 ng/mg Cr, the sensitivity was 90% and the specificity was 87.5%. The combined AUC of urinary KIM-1 and NGAL was 0.938 (P = 0.002) with a sensitivity of 90% and a specificity of 100%. Cox regression analysis revealed that urinary KIM-1content 72 h after operation correlated with the prognosis of AKI patients (P = 0.009). When kidney viability was stratified by urinary KIM-1 content 72 h postoperatively, Kaplan-Meier analysis showed that patients with a urinary content of KIM-1 < 138.20 pg/mg had a higher kidney viability rate than those with a urinary content of KIM-1 > 138.20 pg/mg. Urinary KIM-1 and NGAL had a good accuracy for detecting AKI. KIM-1 72 h postoperatively can predict the renal outcome of obstructive nephropathy.