Abstract
Introduction: Graves’ disease (GD), an autoimmune disorder caused by high levels of auto-antibodies against the thyroid-stimulating hormone receptor, is considered the most common cause of thyrotoxicosis, characterized by features such as goiter, ophthalmopathy and dermopathy. In our country, the administration of antithyroid drugs (ATD) is the first line of treatment in this disease. Side effects are rare but some of them, such as agranulocytosis or liver damage, may become serious.
Case presentation: We report the case of a 20-year-old female patient who was diagnosed with GD after being previously diagnosed with viral hepatitis A. Treatment was initiated with methimazole 30 mg/day, and three weeks later she developed intense hepatic cytolysis and cholestatic syndrome, therefore the ATD was stopped. A suspicion of autoimmune liver disease was raised, and a liver biopsy was performed in order to establish the diagnosis. The next therapeutic option for hyperthyroidism was radioactive iodine (RAI). Three months following RAI, the patient presented severe hypothyroidism, thereupon treatment with levothyroxine was initiated.
Conclusions: Although severe acute liver injury is rare, mild liver dysfunction is quite common in patients with GD. The overproduction of thyroid hormones, or the treatment with ATD through immune mediated processes or drug reactions, represent possible mechanisms responsible for liver damage.