Abstract: ［Abstract］Objective〖HTSS〗To assess the clinical significance of neutrophil gelatinase-associated lipocalin(NGAL)and cystatin C （Cys C）for acute kidney injury (AKI) after valvular disease operation.
  〖WTHZ〗Methods〖HTSS〗Ninety patients with valvular disease after surgery were selected and divided into AKI group(37 cases) and non-AKI group(53 cases) according to the occurrence of AKI. Blood samples were collected before surgery and 2,4,6,8,12,24,48 hours after surgery. The serum NGAL level was determined by enzyme-linked immunosorbent assay. The serum creatinine（SCr） levels were determined by creatinine sarcosine oxidase method. The serum Cys C levels were determined by immune projection turbidimetry.
  〖WTHZ〗Results〖HTSS〗SCr levels in both groups increased first and then decreased. The change of SCr level in AKI group was larger than that in non-AKI group. SCr in AKI group increased significantly at 12 h after surgery. There were statistically significant differences between two groups, time points and their interaction(P＜0.05). Serum NGAL level in the AKI group increased first and then decreased, while serum NGAL level in the non-AKI group decreased gradually. Serum NGAL level in the AKI group was higher than that in the non-AKI group. Serum NGAL level in the AKI group increased significantly at 2 h after surgery. There were statistically significant differences between groups, time points and their interaction(P＜0.05). The level of blood Cys C increased gradually in twe groups. The variation amplitude of serum Cys C level in AKI group was greater than that in non-AKI group. Serum Cys C level in the AKI group increased significantly at 6h after surgery. There were statistically significant differences between groups, time points and their interaction(P＜0.05). 
  〖WTHZ〗Conclusion〖HTSS〗Serum NGAL concentration of the AKI group increased significantly at 2 h after valvular disease replacement. Serum Cys C level of the AKI group began to increase at 6 h after surgery. The increase time of both was earlier than the increase time of SCr level. Serum NGAL and serum Cys C can be used as markers for the early diagnosis of AKI after valvular disease operation.

Key words: heart valve diseases, acute kidney injury, neutrophil gelatinase-associated lipocalin, cystatin C