Diagnostic value of joint marker detection in the early acute kidney injury after adult cardiac surgery

Objective To explore the sensitivity and clinical value of combined detection of urine NGAL,Urine Kim-1,Urine NAG,urine Cystatin C in early acute kidney injury after adult cardiac surgery.Methods A hundred-five patients who underwent cardiac surgery in the department of heart surgery in the People's Hospital of the Xinjiang Uygur Autonomous Region from January 2010 to June 2011 were collected as subjects.Blood and urine specimens before operation and 24,48 and 72 hours after the operation were collected,urine NGAL,Kim-1,NAG,Cyst C and serum SCr levels were determined.According to AKI standard,65 patients were recruited into AKI group( serum SCr value increased by 50％ ),and the rest 40 patients were in non-AKI group.The changes of the parameters were recorded and analyzed.Urine NGAL,Kim-1,Cyst C were respectively determined by enzyme linked immuno sorbent assay (ELISA).The urine NAG was determined by nitro phenol (PNP) colorimetric detection.The SCr were detected by turbidity method.The individual and combined diagnostic values of these parameters for AKI were assessed using receiver-operating characteristic (ROC) curve and the area under the curve (AUC).Results There was no significant difference on SCr,NGAL,KIM-1,NAG and CystC between wo groups before operation (P ＞ 0.05 ),The level of each biological marker was significantly increased in AKI group than that in none AKI group at different time points after operation( P＜0.001 ).The levels of NAG,CystC,NGAL and KIM-1 in the AKI group were significantly higher at 24,48,and 72 hours after surgery than those before surgery ( P＜0.001 ).Giving a comprehensive evaluation,the above four parameters were at their best sensitivity at 48 hours after surgery,with an AUC of 0.901 (95％ CI;0.769 ～ 0.938).Conclusion The biological markers of AKI in heart surgery patients are significantly increased after operation.Joint marker detection can be used in the early diagnosis of AKI after adult heart surgery. Key words: Heart surgery; Acute kidney injury; Urinary neutrophil gelatinase-associated lipocalin; Serum creatinine