Oxidative stress biomarkers in pediatric medicine - A 2013 update

A large body of circumstantial evidence emphasizes the critical role of reactive oxygen species (ROS), including superoxide anion and nitric oxide (NO), in acute and chronic pediatric diseases. About 15 years ago, measurement of oxidative damage affecting tissues and organs using specific biomarkers was introduced into the field of pediatric medicine. This chapter is intended to describe recent progress in clinical application of oxidative stress biomarkers in pediatric medicine. First, this chapter briefly presents the biochemistry and pathophysiology of ROS and antioxidative defense systems. Second, it discusses the interrelationship of endothelial dysfunction, NO system blockade, and oxidative stress. Third, it presents a list of clinically applicable biomarkers, along with pediatric diseases in which enhanced oxidative stress might be involved. The discussion emphasizes that many good biomarkers are readily measurable using enzyme-linked immunosorbent assay. Fourth, this chapter presents age-related reference normal ranges of oxidative stress biomarkers, including urinary acrolein-lysine, 8-hydroxy-2′-deoxyguanosine, nitrite/nitrate, and pentosidine. Furthermore, our new and interesting data related to oxidative stress and antioxidative defenses in congenital metabolic disorders, such as Wilson disease, urea cycle defects, citrin deficiency, and phenylketonuria, are presented. Rapid diagnostic tests for measuring blood levels of total hydroperoxides and biological antioxidative potential and urinary levels of 8-hydroxy-2′-deoxyguanosine are also explained. Finally, this chapter describes recent clinical studies that have evaluated the efficacy of antioxidative intervention for oxidative-stress-related diseases. Repeated measurement of multiple appropriate parameters will enable us to discern the pathophysiological patterns of pediatric diseases and guide our therapies appropriately.