Oxidative stress change by systemic corticosteroid treatment among patients having active graves ophthalmopathy

Objectives: To measure the 8-hydroxy-2′-deoxyguanosine (8-OHdG) level in patients having active Graves ophthalmopathy (GO) and to compare this oxidative stress biomarker and the clinical evolution of patients after systemic corticosteroid treatment. Methods: In 8 euthyroid patients having active GO, we determined the 8-OHdG levels in urine before, during, and after intensive corticosteroid therapy. Clinical activity and ophthalmopathy index scores were assessed. Nine age- and sex-matched healthy volunteers served as control subjects. Results: The mean 8-OHdG level was statistically significantly increased in patients having active GO compared with that of controls (17.47 vs 5.97 ng/mg of creatinine, P < .001). During and after maximal systemic corticosteroid treatment, patients had statistically significantly lower mean 8-OHdG levels (7.19 and 10.18 ng/mg of creatinine, respectively) compared with the mean level before treatment. These changes were accompanied by decreases in clinical activity and ophthalmopathy index scores. The urinary 8-OHdG levels were subsequently elevated in 2 patients having recurrent active GO when corticosteroid therapy was tapered or withdrawn. Conclusions: Oxidative stress may have a role in the pathogenesis of GO. Urinary 8-OHdG level can be used not only as a noninvasive biomarker of oxidative stress in patients having GO but also as an objective and quantitative parameter in the follow-up of patients during immunosuppressive treatment.