Phototherapy causes DNA damage in peripheral mononuclear leukocytes in term infants.
OBJECTIVE
Our aim was to determine whether endogenous mononuclear leukocyte DNA strand is a target of phototherapy.


METHODS
The study included 65 term infants aged between 3-10 days that had been exposed to intensive (n = 23) or conventional (n = 23) phototherapy for at least 48 hours due to neonatal jaundice, and a control group (n = 19). DNA damage was assayed by single-cell alkaline gel electrophoresis (comet assay). Plasma total antioxidant capacity and total oxidant status levels were also measured, and correlation between DNA damage and oxidative stress was investigated.


RESULTS
Mean values of DNA damage scores in both the intensive and conventional phototherapy groups were significantly higher than those in the control group (p < 0.001). Mean values and standard deviation were 32 (9), 28 (9), 21 (7) arbitrary unit, respectively. Total oxidant status levels in both the intensive and conventional phototherapy groups were significantly higher than those in the control group (p = 0.005). Mean (standard deviation) values were 18.1 (4.2), 16.9 (4.4), 13.5 (4.2) micromol H2O2 equivalent/L, respectively. Similarly, oxidative stress index levels in both the intensive and conventional phototherapy groups were significantly higher than those in the control group (p = 0.041). Plasma total antioxidant capacity and total bilirubin levels did not differ between the groups (p > 0.05). There were no significant correlations between DNA damage scores and bilirubin, total oxidant status and oxidative stress levels in either phototherapy group (p > 0.05).


CONCLUSIONS
Both conventional phototherapy and intensive phototherapy cause endogenous mononuclear leukocyte DNA damage in jaundiced term infants.
Aycicek
Ali
A
Pediatrics Department, Medical Faculty, Harran University, Sanliurfa, Turkey. ayciceka@hotmail.com
Kocyigit
Abdurrahim
A
Erel
Ozcan
O
Senturk
Hakan
H
D016022:Case-Control Studies; D020552:Comet Assay; D004249:DNA Damage; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007567:Jaundice, Neonatal / Q000097:blood / Q000628:therapy*; D007963:Leukocytes, Mononuclear / Q000378:metabolism / Q000528:radiation effects*; D008297:Male; D018384:Oxidative Stress; D010789:Phototherapy / Q000009:adverse effects* / Q000379:methods; D013997:Time Factors