Table 3.

Performance indices of kidney injury biomarkers to diagnose histological ATI

Biomarker	Median [IQR]	Cut-off from45*	Donors above cut-off	Severe ATI vs. No ATI			Any ATI vs. No ATI
				C statistic (95% CI)ˆ	P-value@	Sensitivity, Specificity	C statistic (95% CI)	P-value@	Sensitivity, Specificity
NGAL	54.2 [16.1–262.9] ng/mL	81	243 (44%)	0.67 (0.60–0.74)	0.03	53%, 61%	0.60 (0.55–0.66)	0.005	53%, 61%
L-FABP	16.4 [5.2–67.2] ng/mL	171	71 (13%)	0.61 (0.54–0.68)	0.6	16%, 88%	0.56 (0.50–0.61)	0.3	16%, 88%
IL-18	58.2 [24.1–127.5] pg/mL	133	131 (24%)	0.54 (0.45–0.62)	0.5	21%, 76%	0.51 (0.46–0.57)	0.9	21%, 76%
KIM-1	1.5 [0.7–3.5] ng/mL	12	31 (6%)	0.47 (0.39–0.56)	0.1	7%, 95%	0.50 (0.44–0.55)	0.6	7%, 95%

ATI, Acute Tubular Injury; AUROC, area under receiver operating characteristic curve; CI, confidence interval; Scr, serum creatinine; NGAL, neutrophil gelatinase-associated lipocalin; L-FABP, liver-fatty acid binding protein; IL-18, interleukin 18; KIM-1, kidney injury molecule 1. IQR, interquartile range

^*Injury biomarker cut-offs derived as highest tertile cut-off values from Coca et al JASN 2014²⁹.

^@De-long test comparing AUROC of each log-transformed ATI biomarker with AUROC of Scr for diagnosing severe and any ATI. AUROC of ΔScr for severe ATI was 0.58 (95% CI, 0.49–0.67) and for any ATI was 0.52 (95% CI, 0.45–0.58)

Note: Any ATI includes mild, moderate and severe ATI. Severe ATI includes moderate and severe ATI.