Real-time oxidative stress biomarkers measured in patients with Hashimoto’s thyroiditis—an electron paramagnetic resonance study

Although the role of presence of thyroid dysfunction for overproduction of free radicals has been elucidated, the data about the role of autoimmunity in Hashimoto’s thyroiditis (HT) to sustain the presence of oxidative stress despite the normal serum thyroid hormone levels are scarce. The present study aimed by using electron paramagnetic resonance spectroscopy (EPR) methods to elucidate the radical mechanisms included in the pathogenesis of HT by following out the sera levels of some “real-time” oxidative stress biomarkers. We investigated 14 newly diagnosed patients with euthyroid HT and 35 subjects with HT treated with levothyroxine. Twenty-three healthy subjects were included as controls. All samples were measured in triplicate and presented as arbitrary units. We found statistically significant elevated levels of ascorbate radical (Asc•) in euthyroid HT patients and in HT patients treated with levothyroxine compared to controls. Reactive oxygen species (ROS) products were statistically higher in both studied patient groups compared to controls. Our study showed also statistically significant increases in the levels of registered nitric oxide radical (NO•) in both groups of HT patients compared to controls. Oxidative stress is increased similarly in both euthyroid HT and HT patients under treatment with LT4 and these data reinforce the idea that this is consequence of autoimmunity per se. Our results determine that the addition of antioxidants that includes vitamin C and vitamin E in the treatment plan of HT patients in all stages of disease will normalize the disbalance in oxidative stress biomarkers.