Altered urinary excretion of allantoin and purine catabolites in neonates with necrotizing enterocolitis

Abstract

Necrotizing enterocolitis (NEC) is a complex gastrointestinal disease that affects premature infants. We hypothesize that biochemical markers of hypoxia and oxidative stress may be predictive of the different stages of NEC. Urine specimens were collected from premature infants over day 2 and 3 of life. The concentrations of purines and allantoin were determined using HPLC and GCMS. All concentrations were taken as a ratio to creatinine. The presence and clinical severity of NEC was determined at week 2 of life using the Bell staging system. Compared to control subjects (n=16), we found allantoin and purine concentrations to be significantly higher in neonates who developed NEC. Our data revealed that neonates who developed NEC (n=8), had NEC scare (n=4), or died (n=6) had significantly elevated uric acid levels. Allantoin levels were found to be highest in neonates who died, increased over time in neonates who developed NEC, began high and decreased over time in neonates with NEC scare, and were lowest in control neonates. These preliminary data indicate that uric acid may be useful in identifying acutely ill neonates while allantoin appears to be most predictive of NEC. These data suggest that oxidative stress may play a significant role in the pathophysiology of NEC.