The value of combined detection of serum CysC, urinary β2-MG, and L-FABP in early diagnosis of acute renal injury after cardiac surgery

Objective To explore the value of combined detection of serum cystatin C (CysC), urinary β2-microglobulin (β2-MG), and liver type fatty acid binding protein (L-FABP) in early diagnosis of acute renal injury after cardiac surgery. Methods 126 patients undergoing cardiac surgery in our hospital from April 2015 to August 2016 were selected as the subjects, according to the occurrence of acute renal injury after operation, 48 cases were divided into acute renal injury (AKI) group and 78 cases into non-acute renal injury (non AKI) group, the levels of serum CysC, urine β2-MG, and L-FABP were detected in the two groups. Receiver operating characteristic (ROC) curve was used to analyze the effects of serum CysC, urine β2-MG, L-FABP in the early diagnosis of acute renal injury after cardiac surgery. Results The incidence of AKI after cardiac surgery was 38.10% (48/126); the serum CysC level in group AKI was significantly higher than that in non AKI group (P<0.05); the levels of urine β2-MG and L-FABP were significantly higher than those in non AKI group (P<0.05); the area under curve (AUC) of serum CysC for AKI diagnosis after cardiac surgery was 0.874 (P<0.05), with diagnostic sensitivity 85.7%, and specificity 76.5%; the AUC area of urinary β2-MG for AKI diagnosis after cardiac surgery was 0.754 (P<0.05), with diagnostic sensitivity 92.9%, and specificity 73.5%, respectively; the AUC area of urinary L-FABP for AKI diagnosis after cardiac surgery was 0.834 (P<0.05), with diagnostic sensitivity 92.9%, and specificity 74.1%. The AUC area of combined diagnosis of the three was 0.914 (P<0.05), with the diagnostic sensitivity 92.1%, and specificity 82.4%. Conclusions Serum Cys C, urine β 2-MG and L-FABP levels were significantly increased in patients with AKI. The diagnosis of the three alone has a certain reference value, which is lower than the combined diagnosis. The combined diagnosis of the three can provide an important reference for screening acute renal injury after heart surgery. Key words: Cardiac surgical procedures; Postoperative complications; Acute kidney injury; Cystatin C; beta 2-microglobulin; Liver type fatty acid-binding protein