8-hydroxydeoxyguanosine in urine as an index of oxidative damage to DNA in the evaluation of atopic dermatitis.

8-hydroxydeoxyguanosine (8-OHdG) is one of the products which are excreted in urine as a result of oxidative damage to DNA. We investigated the feasibility of using 8-OHdG in urine as an index for oxidative damage to DNA in atopic dermatitis (AD). Seventeen patients with long-standing AD and 17 healthy volunteers were enrolled in this study. The severity of AD was evaluated by SCORAD index. Eosinophils, total IgE and lactate dehydrogenase-5 in peripheral blood were measured as clinical parameters for AD. A newly developed enzyme-linked immunosorbent assay method was used to measure urine 8-OHdG. The AD patients showed significantly higher levels (P < 0.0001) of 8-OHdG in their urine than corresponding controls. Urine 8-OHdG levels showed as strong a positive correlation as other haematological parameters did using the SCORAD index. Thus, we conclude that the urine 8-OHdG levels can also serve as a biochemical index of tissue damage and can act as a useful tool in the clinical evaluation of AD.