Renal Function and Novel Urinary Biomarkers In Infants with Neonatal Encephalopathy

Aim Perinatal asphyxia is associated with multi-organ injury including acute kidney injury (AKI). New urinary biomarkers may detect more subtle renal injury. Methods Urinary biomarkers (Albumin, Beta-2-Microglobulin, Cystatin-C, Epidermal-Growth-Factor, Neutrophil-Gelatinase-Associated-Lipocalin, Osteopontin, Uromodulin) were serially measured from day 1-7 in term infants with perinatal asphyxia and controls and compared to “Kidney Disease Improving Global Outcome” scoring of renal injury and to encephalopathy grade. Results Infants exposed to perinatal asphyxia(n=82) and term controls(n=10) had 255 urine samples taken. Thirty-nine infants underwent therapeutic hypothermia, 4 died and 30 infants had acute kidney injury. Infants with acute kidney injury had significantly higher levels of urinary Albumin(Day 2), Cystatin-C(Day 1,2,3 and 7), Neutrophil-Gelatinase-Associated-Lipocalin(Day 2,3 and 7) and Osteopontin(Day 2,3 and 7) and lower Epidermal-Growth-Factor and Uromodulin(Day 1) compared to those without AKI. Day 2 Cystatin-C predicted AKI with an area-under-receiver-operating-characteristic-curve of 0.89, p<0.001, cut-off 9.8 x 104pg/ml. NE grade II/III infants had significantly elevated levels of urinary Cystatin-C, Neutrophil-Gelatinase-Associated-Lipocalin and decreased EGF compared to grade 0/I infants. Conclusion Asphyxiated infants who develop acute kidney injury have significantly altered urinary biomarkers postnatally. Validation of neonatal AKI urinary biomarkers in a large prospective study is required. Long-term follow-up of infants post-asphyxial insult for chronic renal injury is advised. This article is protected by copyright. All rights reserved.