Antioxidant status of bilirubin and uric acid in patients with myasthenia gravis.

Oxidative stress and changes in antioxidant status have been implicated in the pathogenesis of inflammatory and autoimmune diseases, and free radicals can cause considerable damage to the acetylcholine receptors. 388 individuals, including 97 patients with myasthenia gravis (MG), 135 patients with multiple sclerosis (MS) and 156 healthy controls, were assessed for serum levels of bilirubin and uric acid (UA), in order to determine the levels of these natural antioxidants in the serum. We found that serum UA levels in patients with MG were significantly lower (266.03 ± 93.09 μmol/l) compared with those of the healthy control group (338.87 ± 107.10 μmol/l, p = 0.001). However, there was no significant difference of serum UA levels between patients with MG and those with MS (p = 0.071). We also found that serum levels of total, direct and indirect bilirubin in patients with MG were significantly lower, compared with those in the healthy control group, whether male or female. From this study, we conclude that serum levels of bilirubin and UA are lower in MG patients.