May oxidative stress biomarkers in cord blood predict the occurrence of necrotizing enterocolitis in preterm infants?

Introduction: Oxidative stress (OS) is strongly involved in the pathogenesis of many preterm newborn diseases; this is due to the low efficiency of neonatal antioxidant systems unable to counteract the harmful effects of free radicals (FRs). Hypoxic-ischemic events and inflammation, involved in necrotizing enterocolitis (NEC) pathogenesis, are responsible of the overproduction of FRs, generating OS. Aim: To test the hypotesis that OS markers levels in cord blood may early identify the newborns at high risk to develop NEC. Materials and methods: 332 preterm newborns of gestational age (GA) between 24 and 33 week and birth weight (BW) between 460 and 2540 g were consecutively recruited in three european neonatal intensive care units. Markers of potential OS risk: non-protein bound iron (NPBI), and markers of FRs damage: advanced oxidation protein products (AOPP) and total hydroperoxides (TH), were measured in the cord blood. Associations between NEC and OS markers were checked through inferential analysis. Results: Out of 332 preterm babies, 29 developed NEC. Babies with NEC had a BW and a GA significantly lower than healthy babies. AOPP, TH and NPBI cord blood levels were significantly higher in babies with NEC than in babies without (respectively mean AOPP = 28.05 +/- 21 vs 15.80 +/- 7.14; p < 0.05; TH = 154.48 +/- 84.67 vs 107.40 +/- 61.01; p < 0.05; NPBI = 2.21 +/- 3.98 vs 0.95 +/- 1.59; p < 0.05). Conclusions: The determination of OS biomarkers in cord blood can be useful in identifying babies at high risk for NEC and in devising new strategies to ameliorate perinatal outcome.