Abstract: Objective　To investigate the change and significance on urinary neutrophil gelatinase-associated lipocalin（NGAL）and serum cystatin C（Cys C）in paraquat poisoning patients with early acute kidney injury（AKI）. Methods　The blood and urine specimens from 85 patients with paraquat poisoning were collected immediately after admission（≤15 min），2，4，6，8，10，12，18，24，36，48，72 h and 5，7 d.According to the occurrence of AKI，they were classified into AKI group（62 cases）and non-AKI group（23 cases）.A total of 20 healthy subjects were enrolled as control group.The urinary NGAL level was determined by enzyme-linked immunosorbent assay（ELISA）. The serum creatinine（SCr）levels were determined by sarcosine oxidase method. The serum Cys C levels were determined by immuno turbidimetry. The admission immediate detection values were as the baseline values.  Results　In 85 patients with paraquat poisoning，62 patients had AKI（72.94%）. In AKI group at each time point since the beginning of 18h，the SCr levels increased significantly，which were significantly higher than the baseline values and those in the control group（P<0.01）.In AKI group，24，36，48，72 h and 5，7 d SCr levels were significantly higher than those in non-AKI group（P<0.01）.In non-AKI group at each time point，SCr levels had no statistical significance with those in the control group（P>0.05）.Serum Cys C levels in AKI group at 6h were significantly higher than the baseline values（P<0.01）.After the time point，the levels increased gradually and were higher than those in the control group and the baseline values（P<0.01）.In non-AKI group，serum Cys C levels since the beginning of 10h increased significantly，and had a significant difference compared with those in the normal control group and the baseline values（P<0.01）. In AKI group，NGAL levels at 2h were significantly higher than the baseline values，and had gradual rising trend after that time point. Compared with those in the control group and the baseline values，the differences were statistically significant（P<0.01）.In non-AKI group，NGAL levels at 10h began gradually increased，and compared with those in the control group and the baseline values，the difference was statistically significant（P<0.01）.In AKI group，NGAL levels at each time point were obviously higher than those in non-AKI group（P<0.01）. Conclusions　With paraquat poisoning after 2 h，urinary NGAL level is markedly elevated，and serum Cys C in 8h begins to increase.The diagnosis time of AKI is shorter than that of SCr. Urinary NGAL and serum Cys C can be markers for the early diagnosis of AKI after paraquat poisoning.

Key words: Neutrophil gelatinase-associated lipocalin, Cystatin C, Paraquat, Acute kidney injury