Severe hyperthyroidism without symptoms due to nonthyroidal illness in a child with acute hepatitis: case report and literature review

Abstract

While liver enzyme changes are frequently reported in hyperthyroidism, liver dysfunction itself can lead to alterations in thyroid hormone metabolism. However, the exact relationship between hyperthyroidism and liver dysfunction is unclear. We report an 11‐year‐old boy presenting with acute hepatitis of unknown etiology, who was incidentally found to have asymptomatic biochemical hyperthyroidism. Despite significant total and free T4 elevation, clinical evidence of thyrotoxicosis was absent. Thyroid I‐123 uptake was also reduced. Additional testing revealed slight T3 elevation and significant rT3 elevation. Graves' and Hashimoto's thyroiditis testing was negative. We hypothesize that the biochemical hyperthyroidism was due to transient thyroiditis. Although an etiology for the boy's hepatitis was never determined, and an undiagnosed infectious etiology causing subacute thyroiditis was considered, subsequent testing showing positive thyroid peroxidase antibodies, suggesting autoimmune Hashimoto's thyroiditis as the likely cause of the hyperthyroidism. We believe, furthermore, that the absence of symptoms was the result of concurrent nonthyroidal illness resulting in the biochemical findings of slight T3 elevation and significant rT3 increase despite significant T4 elevation.

Age Moderates the Impact of TRAbs on Thyroid Hormones and Hepatic Function in Patients with Graves’ Disease

“…Previous studies demonstrated that HDF in GD is due to excessive T3 inducing hepatocyte death through activation of the mitochondrial-dependent apoptosis pathway [22][23][24][25]. Many researchers proposed that the injury mechanism seems to be relative hypoxia in the hepatic perivenular regions because of liver oxygen consumption without corresponding blood flow increase [26][27][28]. In this study, FT3 and FT4 were significantly increased in GD patients with HDF, which was consistent with a previous study [25].…”