ABSTRACT
Concentrations of circulating antioxidants were considered being important in the pathogenesis of diseases in preterm infants. Plasma total antioxidant status [TAS], some preventive and chain breaking antioxidants were studied in 20 preterm infants with respiratory distress on the first and fifth day of life. Ten preterm infants without respiratory distress and ten full term healthy neonates were also evaluated. On the first day of life, the plasma TAS, uric acid, transferrin % saturation levels were significantly high in the preterm infants with respiratory distress. On the contrary, serum albumin, total iron binding capacity [TIBC], ceruloplasmin, red blood cell superoxide dismutase [SOD] and red blood cell glutathione peroxidase [GSHPx] levels were significantly low, By the fifth postnatal day, plasma TAS, uric acid, transferrin % saturation, and red cell GSHPx levels were significantly decreased while, serum bilirubin, ceruloplasmin, TIBC and red cell SOD levels were significantly increased in preterm infants with respiratory distress. The duration of oxygen therapy was negatively correlated with plasma TIBC and was positively correlated with transferrin % saturation on the first and fifth day of life. Plasma TAS, uric acid, serum bilirubin and transferrin % saturation were significantly high while, serum albumin and TIBC were significantly low in non-survived preterm infants who had respiratory distress. Recurrent apneas, elevated uric acid levels and decreased TlBC on the first day of life in addition to increased duration of oxygen therapy and high transferrin % saturation on the fifth day of life, were significant predictors of mortality. These major postnatal changes in blood antioxidant activity in preterm infants with respiratory distress may influence their susceptibility to oxygen toxicity