@article{3093467,
    title = "Low total antioxidant status is implicated with high
8-hydroxy-2-deoxyguanosine serum concentrations in phenylketonuria",
    author = "Schulpis, KH and Tsakiris, S and Traeger-Synodinos, J and Papassotiriou, and L",
    journal = "Clinical Biochemistry",
    year = "2005",
    volume = "38",
    number = "3",
    pages = "239-242",
    publisher = "PERGAMON-ELSEVIER SCIENCE LTD",
    issn = "0009-9120",
    doi = "10.1016/j.clinbiochem.2004.11.006",
    keywords = "PKU; total antioxidant status; phenylalanine; 8-hydroxy-2-deoxyguanosine",
    abstract = "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."
}