Plasma oxidation status and antioxidant capacity in psoriatic children.

Psoriasis, a chronic inflammatory skin disease, is associated with oxidative stress of serum lipoproteins. In psoriatic children we evaluated the activity and levels of myeloperoxidase, the activity of paraoxonase-1 (PON1) and biochemical markers of lipid peroxidation, to investigate wether an unbalance between oxidant-antioxidants occurs very early in psoriasis. A total of 52 patients affected by psoriasis and 48 sex-age-matched healthy controls were enrolled. Serum MPO levels were measured using ELISA method. MPO and PON1 activities (paraoxonase, arylesterase and lactonase) were evaluated by spectroscopic methods. Our results demonstrated a significant increase of MPO levels and activity in psoriatic subjects. PON1 activities were found to be significantly decreased. A positive correlation has been established between the MPO/PON1 ratio and levels of lipid peroxides in all psoriatic patients. These results suggest that an unbalance between MPO and PON1 can reflect in higher oxidative stress in serum lipoproteins.