LCN2 and acute kidney injury: U-NGAL was significantly higher in patients that developed severe AKI, with a median of 210 (P25–75: 75–1580) ng/ml in non-severe AKI versus 1031 (P25–75: 915–3772) ng/ml in severe AKI group; AUC 0.62 (CI 0.50 − 0.74), p = 0.05 and remained markedly elevated in KRT patients’ group, with an AUC 0.80 (CI 0.72–0.89), p < 0.0001.