Acute Kidney Injury Is Associated with Higher Serum Cys-C and NGAL Concentrations, and Risk of Mortality in Premature Calves with Respiratory Distress Syndrome

SIMPLE SUMMARY: This study aimed to evaluate hypoxic acute kidney injury in premature calves with respiratory distress syndrome using kidney-specific biomarkers. Ten-term healthy calves and 70 premature calves with respiratory distress syndrome were included in the study. At admission and 72 h, arterial blood gas analysis to evaluate hypoxia and serum blood urea nitrogen, creatinine, phosphorus, cystatin-C, neutrophil gelatinase-associated lipocalin, uromodulin, and liver-type fatty acid-binding protein concentrations were measured for evaluation of kidney functions. Acute renal failure developed in 38.5% of premature calves with respiratory distress syndrome. The mortality risk in premature calves with acute renal failure was four times higher than in those without acute kidney injury. In addition, serum cystatin-C and neutrophil gelatinase-associated lipocalin concentrations were significantly higher in calves with acute kidney injury than those without. In conclusion, it causes acute renal failure in premature calves with respiratory distress syndrome. Cystatin-C and neutrophil gelatinase-associated lipocalin were found to be useful markers of hypoxic-acute kidney injury in premature calves with respiratory distress syndrome. ABSTRACT: The purpose of the present study was to establish the development of acute kidney injury (AKI) and evaluate the usefulness of kidney-specific biomarkers in diagnosing AKI in premature calves with respiratory distress syndrome (RDS). Ten-term healthy and 70 premature calves with RDS were enrolled. Clinical examination, blood gases, and chemical analysis were performed at admission and 72 h. Serum concentrations of blood urea nitrogen (BUN), creatinine (Cre), phosphorus (P), cystatin-C (Cys-C), neutrophil gelatinase-associated lipocalin (NGAL), uromodulin (UMOD), and liver-type fatty acid-binding protein (L-FABP) were measured to evaluate kidney injury. Our findings showed that 38.5% of the premature calves with RDS developed AKI. The RDS-AKI group had a 4-fold higher mortality risk than the RDS-non-AKI group. Cys-C, with 90% and 89% specificity, and NGAL, with 100% sensitivity and 85% specificity, were the most reliable biomarkers to determine AKI in premature calves. The usefulness of any biomarker to predict mortality was not found to be convincing. In conclusion, AKI can develop as a consequence of hypoxia in premature calves and may increase the risk of mortality. In addition, serum Cys-C and NGAL concentrations may be useful in the diagnosis of AKI in premature calves with RDS.