RESUMO
INTRODUCTION: While cases of Thyroiditis after COVID mRNA vaccination are reported, the recovery duration is not yet determined. Therefore, we present the time course of two healthy middle-aged South Asian patients who developed symptomatic, biochemical, and radiological evidence of Thyroiditis following COVID 19(mRNA) vaccine administration. Despite being more than six months post-vaccination, both are still hypothyroid, requiring levothyroxine replacement. CASE DESCRIPTION: Case 1: A 35-year-old male presented with palpitations and neck pain ten days after receiving the first dose of the Pfizer-BioNTech vaccine, initial labs showing biochemical hyperthyroidism TSH -0.07uIU/mL (0.450-4.50uIU/mL), Free T 4 (0.82-1.77ng/dL4) -3.04ng/dl, TotalT3 (71-80ng/dl) -200ng/dl. He was started on propranolol and ibuprofen for symptom control. During four months of follow up, he was euthyroid with TSH -2.060 uIU/mL Free T4 1.04ng/dl, Total T3 122ng/dl, and five months of follow up showed hypothyroidism with TSH -5.730uIU/mL, Free T4 -1.00ng/dl, Total T3 109ng/dl. Due to fatigue and weight gain symptoms, he was started on Levothyroxine 25mcg daily. Case 2: A 41-year-old female presented after the second dose of Pfizer BioNTech vaccine four weeks prior. Initial workup confirmed biochemical hyperthyroidism (TSH-0.019uIU/mL, Free T4 -2.52ng/dl, TotalT3-233ng/dl). During five-month follow-up, laboratory workup showed hypothyroidism with TSH -8.570uIU/mL, Free T4 0.98ng/dl, Total T3-111ng/dl, and still requiring Thyroid hormone replacement for the past six months. She was started on levothyroxine 25mcg daily increased to levothyroxine 25mcg nine pills/week to target TSH 0.5 to 5.0uIU/mL. At the time of diagnosis, both had TPO (Thyroid Peroxidase)-negative, TSI (Thyroid Stimulating immunoglobulin)-negative, and no autonomic nodules on thyroid ultrasound. Case 2 also had a Technetium-99m pertechnetate uptake scan, which showed decreased radiotracer uptake in both the lobes of thyroid gland. DISCUSSION: Thyroiditis is an inflammatory disorder diagnosed based on clinical and laboratory findings. While there have been cases reports of Subacute Thyroiditis following immunizations, such as the influenza vaccine, the mechanism of thyroiditis after the COVID mRNA vaccine remains unclear. Subacute Thyroiditis typically manifests as a triphasic clinical course of thyrotoxicosis, followed by hypothyroidism and a return to the euthyroid state;however, mRNA vaccine-induced Thyroiditis seems to have a different disease course. In our observation of these case series, both patients remained in the hypothyroid state requiring Levothyroxine replacement eight-and twelve-months post-vaccination, respectively. Whether they developed permanent thyroid damage or are able to recover with prolonged recovery time is still unclear, which needs further follow-up in the future.
RESUMO
Effects of Covid19 vaccine (authorized by the Food and Drug Administration and manufactured by Pfizer-BioNTech, Moderna) on thyroid are still not reported. We present two cases of healthy middle aged south Asian patients who developed hyperthyroidism symptoms and confirmed as subacute thyroiditis (SAR) following the administration of COVID 19 (mRNA) vaccines within 2-6 weeks. Interestingly, both of them received PfizerBioNTech vaccine CASE 1 A 35 year-old male with Past Medical History (PMH) of seasonal allergies with palpitations and neck pain 10 days after receiving first dose of Pfizer-BioNTech vaccine. Initial labs after 2 weeks of vaccination showed biochemical hyperthyroidism. Repeat labs trended down. DOSE -1 : 03/26/21, DOSE -2 : 04/18/21 TEST DATE 04/13/21 : TSH (0.450- 4.50uIU/mL) - 0.07uIU/mL , Free T 4 (0.82-1.77ng/dL4) - 3.04ng/dl, TotalT3 (71 - 180ng/dl) - 200ng/dl, TPO(Thyroid Peroxidase) - negative, TSI(Thyroid Stimulating immunog lobulin) - negative, Thyroid Ultrasound - No nodules 04/22/21 : TSH - 0.012uIU/mL, Free T 4 - 2.11ng/dl, TotalT3-198ng/dl CASE 2 A 41 year old female with unremarkable PMH was referred by Primary care physician(PCP) for evaluation of secondary amenorrhea and infertility. She did receive her second dose of PfizerBioNTech vaccine 4 weeks prior. Initial work up confirmed biochemical hyperthyroidism. Repeat tests 4 weeks later trended down with clinial improvement of symptoms. DOSE -1 : 12/2020, DOSE -2 : 01/2021 TEST DATE 02/21 : TSH-0.019uIU/mL, Free T4 - 2.52ng/dl, TotalT3-233ng/dl 03/21 : TSH- 0.006uIU/mL, Free T4 -3.06ng/dl TotalT3- 257ng/dl . TPO -negative, TSI - negative, Thyroid Ultrasou nd - No nodules, Technetium-99m pertechnetate uptake scan - decreased radio tracer uptake in both the lobes of the thyroid gland. 04/21 : TSH - 0.020uIU/mL, Free T 4 - 1.51ng/dl, TotalT3-102ng/dl The mechanism of SAR induced by mRNA covid19 vaccine still remains unclear Some unique characteristics seen in this case study -Incidence - in young and middle age group, both male and female got affected -Ethniciity - both are of South Asian ethnicity -Never had COVID infection in the past -Seen with both the first dose and second dose of vaccination The cross recognition between the coronavirus spike protein targeted with the mRNA vaccine and healthy thyroid cell antigen exists as evidenced by this case. Hence association of COVID vaccination with SAT should be considered as a significant addition to literature.