There are disparate data regarding whether bilirubin is protective or toxic during free radical
related illness among neonates. Seventy one infants with gestational age (GA) of <32 weeks and/or birth
weight (BW) of <1500 g, who survived beyond 4 weeks and completed physical examinations were enrolled
in this study. The infants were divided into two groups based on the presence or absence of advanced
retinopathy of prematurity (ROP), grade III intraventricular hemorrhage (IVH), grade III necrotizing
enterocolitis (NEC), respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), sepsis or
severe fungal infection (SFI). The mean of total serum bilirubin (TSB) of the first 14 days of life were
measured and compared between these two groups. A significant lower TSB were found in severe form of
ROP (P<0.001), grade III NEC (P=0.008), grade III IVH (P=0.021), SFI (P=0.003) and sepsis (P=0.007) in
comparison to mild or disease free status. Moreover, the cut-off point of 5.1 mg/dl for the mean of TSB had
the sensitivity of 88.1% and specificity of 84.6% to detect severe grades of ROP. Also the cut-off point of
3.25 mg/dl had 97.2% sensitivity and 100% specificity in order to distinguish SFI. It is concluded that
bilirubin may play an antioxidant role in vivo as in vitro; and protect preterm infant against these free radical
related disorders. Our findings suggest that not only the upper limits of serum bilirubin, but also the lower
limits must be taking into account in order to both preventing from neurotoxic effects and free radical based
illnesses, respectively |