Objective  To investigate the predictive value of serum cystatin C (CysC) combined with retinol-binding protein(RBP) in neonates with acute kidney injury(AKI) secondary to sepsis.

  Methods  The clinical data of 82 full-term neonates with sepsis was analyzed. They were divided into AKI group (34 cases) and non-AKI group (48 cases) according to occurrence of secondary AKI. Another 50 full-term newborns without organic diseases admitted to our department due to abnormal pregnancy were randomly selected as control group. The differences of serum CysC and RBP levels among the three groups were evaluated, and the area under the curve (AUC) of Receiver operator characteristic (ROC) curve was used to analyze the value of CysC and RBP in the diagnosis of AKI secondary to neonatal sepsis.

  Results  The levels of serum CysC and RBP in the AKI group were significantly higher than those in the non-AKI group and control group (P < 0.05), and there were no significant differences in above indicators between non-AKI group and control group (P>0.05). The levels of serum CysC and RBP in patients in AKI stage 2 and 3 were significantly higher than those in AKI stage 1, and the above indicators in the complication group and poor-prognosis group were significantly higher than the non-complication group and good-prognosis group (P < 0.05). The sensitivities of serum CysC or RBP alone in the diagnosis of AKI secondary to neonatal sepsis were 82.4% and 73.5% respectively, and the specificities were 70.8% and 79.2% respectively. The sensitivity and specificity of combined indicators were 88.2% and 70.7% respectively.

  Conclusion  The levels of serum CysC and RBP will significantly increase in neonates with renal injury secondary to sepsis. The two indicators have high reliability in predicting AKI secondary to neonatal sepsis, and the combination of the two markers can help to improve the prediction ability of AKI.