Objective: Phototherapy is the standard therapeutic approach for neonatal hyperbilirubinemia. Oxidative effects of phototherapy may have potential harms, including DNA damage. Unconjugated bilirubin (UCB) might also possess antigenotoxic potential. Intensive phototherapy is more efficacious than conventional phototherapy in treating hyperbilirubinemia. This study aimed to assess the impact of hyperbilirubinemia and the two different types of phototherapy on DNA damage in peripheral blood mononuclear cells of neonates.
Study design: The study was conducted on term neonates with non-hemolytic hyperbilirubinemia and control healthy neonates. Genotoxicity was assessed using single-cell gel electrophoresis (Comet assay) in peripheral mononuclear cells. Blood samples were obtained at enrollment in all infants and after intensive or conventional phototherapy in jaundiced infants.
Result: DNA damage did not significantly differ between jaundiced and non-jaundiced neonates (11.4±8.7 and 10.9±8.3 arbitrary units (AU), respectively, P=0.58). It increased significantly after exposure to phototherapy compared with prephototherapy values (45.6±14.7 vs 11.4±8.7 AU, respectively, P<0.001). The duration of phototherapy correlated positively with markers of DNA damage (r=0.86, P<0.001); however, the intensity of used light did not significantly impact genotoxicity.
Conclusion: Hyperbilirubinemia does not influence DNA damage, whereas both conventional and intensive phototherapy are associated with DNA damage in term infants with hyperbilirubinemia.