Table 5. The best cut-off values, AUC, sensitivity, and specificity of NGAL and CRP for predicting APN, VUR, and renal scarring.

Variables		Cut-off levels	AUC (95% CI)	Sensitivity, %	Specificity, %	P value
APN
	Pre-NGAL	105 ng/mL	0.888 (0.822–0.954)	89.8	82.5	< 0.001
	Pre-CRP	2.75 mg/dL	0.880 (0.818–0.943)	91.1	68.6	< 0.001
	Post-NGAL	78.5 ng/mL	0.834 (0.757–0.911)	72.2	82.9	< 0.001
	Post-CRP	0.56 mg/dL	0.736 (0.641–0.831)	63.3	82.9	< 0.001
VUR
	Pre-NGAL	123 ng/mL	0.680 (0.611–0.743)	76.7	56.6	< 0.001
	Pre-CRP	4.25 mg/dL	0.709 (0.645–0.767)a	70.8	64.1	< 0.001
	Post-NGAL	78 ng/mL	0.613 (0.526–0.695)	74.3	52.4	0.037
	Post-CRP	0.27 mg/dL	0.553 (0.477–0.627)	84.1	33.6	0.307
Renal scarring
	Pre-NGAL	150 ng/mL	0.723 (0.602–0.824)	92.3	46.5	< 0.001
	Pre-CRP	3.39 mg/dL	0.703 (0.590–0.801)	100.0	35.3	0.001
	Post-NGAL	80 ng/mL	0.730 (0.591–0.843)b	100.0	38.7	0.001
	Post-CRP	0.31 mg/dL	0.520 (0.395–0.643)	92.6	24.4	0.784

AUC = area under the curve, NGAL = neutrophil gelatinase-associated lipocalin, CRP = C-reactive protein, APN = acute pyelonephritis, VUR = vesicoureteral reflux, Pre- = pre-treatment, Post- = post-treatment, CI = confidence interval.

^aPairwise comparison test for VUR, Pre-CRP vs. Post-CRP, P = 0.03; ^bPairwise comparison test for renal scarring, Post-NGAL vs. Post-CRP, P = 0.035.