Biochemical markers of oxidative stress and retinopathy of prematurity

Abstract

We read with interest the article by Perrone et al. regarding the association of free-radical related diseases (FRDs) and biochemical markers of oxidative stress (OS) in infantile cord blood [1], testing the hypothesis that the levels of OS markers in cord blood might predict the onset of FRDs including retinopathy of prematurity (ROP). The authors noted that this study was of inadequate power to define the relative increase risk for each FRD, although globally the risk was increased with elevated cord blood levels of OS markers. Oxidative stress (OS)markers in cord blood reflect OS occurring prenatally. However, unlike other FRDs, ROP has not been linked to fetal exposure to antepartum production of free radicals; it is considered to develop mainly as a consequence of post-natal, as opposed to intrauterine, aetiopathogenic mechanisms [2]. In a previous study, Perrone et al. found no association between biochemical plasma markers of lipid and protein oxidation in cord blood, i.e. total hyperoxides (TH) and advanced oxidation protein products (AOPP), and the risk of developing ROP [3]. In fact, TH and AOPP plasma levels were found to increase significantly in both ROP and non-ROP preterm infants during the first three weeks of life. Thus using cord blood OS markers to predict the development of ROP is likely to underestimate the risk. In this paper the severity of ROP in examined infants is not reported, nor if any baby needed treatment, and in their previous study, onlymild