COVID-19: a cause of recurrent Graves’ hyperthyroidism?

Abstract

To the Editor Although recent evidence suggests that COVID-19 can affect practically all organs, data on the impact of SARS-CoV-2 on the thyroid gland are very scarce. Two patients with Graves' disease (GD) and COVID-19 have been recently published [1], and we would like to provide more evidence with two more cases. Patient 1 was a 45-year-old woman with a 12-year medical history of GD. She had 2 previous episodes of hyperthyroidism that were treated with antithyroid drugs (ATD), first in 2008 after diagnosis (ATD for 22 months) and then at a relapse in 2015 (ATD for 25 months). She also had Graves' ophthalmopathy that was treated with corticosteroids for 3 months in 2018. At the beginning of March 2020, her thyroid function was normal, with free thyroxine levels (FT4) of 1.36 ng/dL (normal range, 0.93-1.7 ng/dL) and serum thyroid-stimulating hormone levels (TSH) of 0.75 µIU/ mL (normal range, 0.27-4.2 µIU/mL), although anti-TSH receptor antibodies (anti-TSHR-Ab) were slightly elevated (1.9 mIU/mL; normal range < 1.5 mIU/mL). In May 2020, she developed bilateral pneumonia and was diagnosed with SARS-CoV-2 infection. This patient also presented palpitations and nervousness. Her blood test results showed a TSH of < 0.005 µIU/mL, a FT4 of > 7.7 ng/dL and an anti-TSHR-Ab of 28.7 mIU/mL. Thyroid ultrasound showed hypervascularization. She started methimazole (MMI) at a daily dose of 40 mg, which resulted in a rapid normalization of her thyroid function. No deterioration of her ophthalmopathy was observed. The MMI dosage of 40 mg/day was reduced to 5 mg/day during follow-up and she shows improvement in her condition after 3 months of treatment.

COVID-19 and endocrine and metabolic diseases. An updated statement from the European Society of Endocrinology

“…Patients are reportedly negative for thyroid antibodies [ 112 ]. In addition, autoimmune thyroiditis or Graves’ disease can occasionally be triggered by the “cytokine storm” induced by SARS-CoV-2 infection [ 113 ]. Possible complications related to these autoimmune disorders include thyrotoxicosis, hypothyroidism, and Graves’ ophtalmopathy.…”

Graves’ disease and Graves’ orbitopathy following COVID-19

“…Upon genetic predisposition, Graves’ disease (GD) is believed to be triggered by nongenetic factors, including infections [ 1 ]. The immune system plays a role in Coronavirus disease 2019 (COVID-19), being involved in its clinical course and outcome [ 2 ].…”

“…A number of cases of autoimmune disorders in patients with COVID-19 have been reported, suggesting that the virus itself, or the response of the immune system, may act as a trigger in predisposed individuals [ 2 ]. Recently, three cases of new-onset GH occurring after COVID-19 were observed [ 2 , 3 ], but all of them without a clinically overt GO, concerning which, this is to our knowledge the first report. Being GD the most frequent cause of hyperthyroidism and GO its most frequent extrathyroidal manifestation, the association might be causal.…”

SARS-CoV-2-related thyroid disorders: a synopsis for nuclear medicine thyroidologists

“…1 Direct and indirect effects of SARS-CoV-2 on thyroid cells and the hypothalamus-pituitarythyroid axis cases). The fourth patient had no history of previous thyroid diseases and developed Graves' disease 2 months after COVID-19 [13,14]. Overall, such anecdotal data implicate SARS-CoV-2 infection as a potential driver for new cases or recurrences of Graves' disease.…”