Biliary atresia (BA), a devastating cholestatic disorder of infants, is characterized by an idiopathic obstruction to the bile flow. It usually presents itself during the first several months after birth. Without early diagnosis, Kasai portoenterostomy, and meticulous follow-ups, the resulting cholestasis causes progressive liver failure. Oxidative stress represents an abnormal phenomenon inside cells or tissues caused by a disturbance in the reactive oxygen species (ROS). Excessive free radicals cause impairment in fatty tissues and DNA causing abnormal gene expression, with proliferation disturbances or cell death. The investigators of the present study examined the perioperative ROS in patients with BA.

The trial enrolled 15 patients with BA and 4 normal subjects as controls. They were evaluated for ROS, serum superoxide dismutase (SOD), urinary 8-iso prostaglandin F2α (8-iso-PGF2α) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) preoperatively and 30 days subsequently. These different values were then compared with serum liver function tests and histologic grades of liver cholestasis. 

The results declared that the preoperative serum SOD was 6.1 IU/mL, urinary 8-iso-PGF2α was 1969 pg/mg Cre, and urinary 8-OHdG was 37.1 ng/mg Cre in patients with BA. Thirty days postoperatively, the serum SOD was 5.2 IU/mL, urinary 8-iso-PGF2α was 1761 pg/mg Cre, and urinary 8-OHdG was 42.1 ng/mg Cre. However, no significant difference was found between the two periods, when evaluated for ROS. Moreover, no evidence of difference in ROS was reported between control group and BA patient group. Urinary 8-iso-PGF2α was remarkably lower in control group in contrast to preoperative BA patient group.

To conclude, urinary 8-iso-PGF2α is high and significantly associated with serum bilirubin in patients with BA. The increased levels of urinary 8-iso-PGF2α and antioxidant activity is affected by several factors such as liver inflammation, lipid malabsorption, and tissue disorders due to jaundice. Nevertheless, it can be assumed urinary 8-OHdG as oxidative DNA damage can persist, irrespective of the success of the operation of cholestasis, 30 days postoperatively.

Source: Hashizume N, Tanaka Y, Asagiri K, et al. Perioperative reactive oxygen species in infants with biliary atresia: A retrospective observational study. Medicine (Baltimore). 2020;99(31):e21332.