Early diagnosis of plasma neutrophil gelatinase-associated lipocalin for acute kidney injury after off-pump coronary artery bypass grafting surgery

He Jianxun; Yuan Hui

doi:10.3760/cma.j.issn.1673-4777.2014.06.008

Abstract：Objective To evaluate the neutrophil gelatinase-associated lipocalin (NGAL) for early diagnosis of acute kidney injury (AKI) after off-pump coronary artery bypass grafting (CABG) surgery.Methods Total 231 patients with coronary artery disease were continuously enrolled in our study from Jan.2010 to Jan.2011.All the patients had undergone off-pump CABG.AKI was defined as an absolute increase in serum creatinine of more than or equal to 0.3 mg/dl (≥ 26.4 μmol/L),or a percentage increase in serum creatinine of more than or equal to 50％ (1.5-fold from baseline) within 48 hours after surgery.Plasma NGAL at baseline and 2 hours after procedure were measured using ELISA kit.Receiver operation characteristic curve (ROC) was used to evaluate the diagnostic sensitivity and specificity.The Youden index was used to determine the Cut-off value for the biomarkers.Results Total of 231 patients were enrolled,among them 37 cases(16.0％) developed AKI.Among AKI patients,the plasma NGAL at baseline and 2 hours after procedure were (69 ± 25) μg/L and (112 ± 29) μg/L (P ＜0.01),respectively; while among non-AKI patients,the plasma NGAL was (66 ± 24)μg/L and (71 ± 21)μg/L (P =0.004),respectively.The plasma NGAL at baseline did not show any significant difference between AKI and non-AKI patients (P =0.501).But plasma NGAL at 2 hours after procedure among AKI patients was higher than that among non-AKI patients (P ＜0.01).The area under the ROC (AUC) of plasma NGAL at 2hours after surgery was 0.899 (95％ CI:0.843-0.954,P ＜ 0.01).The cut-off was 85.6 μg/L according to Youden index with 0.865 of sensitivity and 0.851 of specificity.Conclusion Plasma NGAL might be useful biomarker for early diagonosis of AKI after off-pump CABG.