Serum KIM-1 and Cystatin Levels as the Predictors of Acute Kidney Injury in Asphyxiated Neonates

Asphyxia may lead to serious complications, among which acute kidney injury (AKI) is the most common. Early diagnosis of AKI can help prevent impaired acid-base, fluid, and electrolyte balance that may lead to life-threatening complications. This study aimed to evaluate the effect of kidney injury molecule-1 (KIM-1) and cystatin-C in the early diagnosis of AKI among asphyxiated neonates.

This case-control study was conducted on 45 asphyxiated neonates, 24 of whom were in the control group and 23 cases were in the case group. Creatinine (Cr), KIM-1, and cystatin-C were measured for participants within 8 h and 4 days after birth and compared between case and control groups.

The mean level of Cr-Standardized KIM-1 measured within 8 h and 4 days after birth was significantly higher in the case group, compared to the control group (P-value<0.05). The mean level of Cr-Standardized cysteine, only 4 days after birth, was significantly higher in the case group, compared to the control group (P-value<0.05). A receiver operating characteristic (ROC) curve analysis demonstrated that between the two biomarkers with two measurements, the KIM-1 Cr-Standardized within 4 days had the highest area under the curve (AUC) (0.751, 95% CI: 0.597-0.905). Moreover, the results of ROC curve analysis showed that Cr-Standardized KIM-1 within 4 days after birth with a critical value of >0.67 ng/ml allowed to predict kidney failure in newborns with 57.1 % sensitivity and 86.4 % specificity.

The findings of the present study show that high-specificity KIM-1 is a good biomarker for the early detection of acute renal failure in asphyxiated infants; however, similar expectations cannot exist with regards to cystatin-C for at least the first 8 h after birth.