FRI463 A Case Of Post COVID-19 Subacute Thyroiditis: A Thyroid Equivalent Of Long COVID?

Disclosure: N. Shiraliyeva: None. A. Rios Chen: None. E. Azimi-Nekoo: None. P. Kishore: None. Background: The thyroid can be affected by COVID-19 either directly through viral infection or indirectly through abnormal immune regulation (1). We report a case of subacute thyroiditis (SAT) induced by COVID-19 in which thyroid function (TFT) abnormalities lasted for over a year. Case Presentation: A 36 year old woman with a history of T2DM presented to the clinic with tachycardia, chills, tremors, and subjective fever. On exam, she had mild diffuse non-tender thyromegaly. History was significant for COVID-19 infection one month prior and she denied taking any supplement, including biotin. Laboratory data revealed TSH of 0.064 (0.270-4.2 uIU/mL), prior 0.3 in 2017, FT4 of 1.24 (0.75 – 2.0 ng/dL), TT3 129 (60 - 181.0 ng/dL ), negative TSI, TRAb, and TPO antibodies. Thyroid ultrasound demonstrated normal vascularity and no evidence of thyroid enlargement or nodules. Nuclear medicine uptake scan exhibited low thyroid uptake of 5.9 %. A diagnosis of COVID-19-related SAT (COVID-SAT) was made and she was treated with propranolol. She continued to have palpitations and TSH remained low for 15 months. TSH normalized at 17 months and repeat thyroid uptake scan demonstrated a normal uptake at 15.5%. Conclusion: SAT is a self-limited inflammatory thyroid disorder usually preceded by a viral upper respiratory tract infection. COVID-SAT has been described in multiple patients. Like typical SAT, COVID-SAT can present with neck pain, asthenia, fever and palpitations (1). COVID-19 infection can cause SAT either directly through ACE-2 mediated viral invasion of cells or indirectly through abnormal immune regulation leading to cytokine storm (1). Our literature search found 20 patients with COVID-SAT. The vast majority were middle-aged females with no history of thyroid issues. In most cases of COVID-SAT, TFT abnormalities lasted 4 to 8 weeks (1). Our patient is unique in that her TFT abnormalities lasted for over a year, which is different from the usual course of SAT or COVID-SAT. Prospective studies on patients with long COVID without associated thyroid disorders demonstrated that TFT and anti-thyroid antibodies did not play a significant role in long COVID (2). We speculate that the suppression of TSH and low thyroid uptake for >1 year, may represent a form of long COVID of the thyroid. More studies are needed to elucidate the mechanism of long term effects of COVID infection on the thyroid and thyroid function. References: 1. Ruggeri RM et al. SARS-COV-2-related immune-inflammatory thyroid disorders: facts and perspectives. Expert Review of Clinical Immunology. 2021 Jul;17(7):737-759. 2. Lui DTW et al. A prospective follow-up on thyroid function, thyroid autoimmunity and long COVID among 250 COVID-19 survivors. Endocrine. 2023 Jan 3:1–12. doi: 10.1007/s12020-022-03281-8. Epub ahead of print. PMID: 36596904; PMCID: PMC9810240. Presentation: Friday, June 16, 2023