TY - JOUR TI - Low total antioxidant status is implicated with high 8-hydroxy-2-deoxyguanosine serum concentrations in phenylketonuria AU - Schulpis, KH AU - Tsakiris, S AU - Traeger-Synodinos, J AU - Papassotiriou, AU - L JO - Clinical Biochemistry PY - 2005 VL - 38 TODO - 3 SP - 239-242 PB - PERGAMON-ELSEVIER SCIENCE LTD SN - 0009-9120 TODO - 10.1016/j.clinbiochem.2004.11.006 TODO - PKU; total antioxidant status; phenylalanine; 8-hydroxy-2-deoxyguanosine TODO - Background: Phenylketonuria (PKU), an inborn error of metabolism, is treated with a low phenylalanine (Phe) lifelong diet, which can be characterized as vegetarian. 8-Hydroxy-2-deoxyguanosine (8-OHdG) is highly implicated in degenerative diseases. Objective: To evaluate the effect of plasma total antioxidant status (TAS) and Phe on the serum marker of DNA damage, 8-OHdG, in PKU. Methods: Twenty-four PKU patients on a strict diet (group A), 25 PKU patients on a “loose diet’ (group B), and 24 healthy children (controls) participated in this study. Plasma TAS was evaluated spectrophotometrically. 8-OHdG and Phe were measured in blood with immunoassays. Results: TAS levels were significantly higher (P < 0.001) in group A (1458 140 mu mol/L) and controls (1452 +/- 235 mu mol/L) than those in group B (907 150 mu mol/L). In contrast, 8-OHdG serum levels were 2-fold higher in group B (0.22 +/- 0.03 ng/mL) as compared with those in group A (0.11 +/- 0.02 ng/mL) and 3-fold higher than those in controls (0.08 0.02 ng/mL) (P < 0.001). As expected, Phe levels were also significantly higher in group B than those in the other study groups. Positive correlation coefficients were found between Phe and 8-OHdG levels, whereas negative correlations were evaluated between TAS and 8-OHdG in all groups. Conclusions: The high Phe and the low TAS plasma levels in PKU patients on a “loose diet” may induce DNA oxidation, as evidenced by the measured high 8-OHdG level in their sera. 8-OHdG evaluation may be a useful marker of increased risk for a neurodegenerative process. (C) 2004 The Canadian Society of Clinical Chemists. All rights reserved. ER -