RF35 | PSAT299 Thyroid Eye Disease Activation After mRNA SARS-CoV-2 Vaccination in Patients With Autoimmune Thyroid Disease

BACKGROUND: Occurrence of Graves’ disease (GD) has been reported following SARS-CoV-2 vaccine administration, but little is known about thyroid eye disease (TED) after SARS-CoV-2 vaccination. CASE 1: A 50-year-old non-smoker male was diagnosed with GD in March 2019 and treated with methimazole. In April 2020, he developed TED with bilateral proptosis, pain, erythema and diplopia and clinical activity score (CAS) 6/7. Following poor response to 3-month oral steroids, he underwent total thyroidectomy in November 2020. In six weeks, his TED improved (CAS 4/7) and thyroid stimulated immunoglobulin (TSI) levels normalized from 4.13 IU/l (preoperatively) to 0.70 IU/l (reference< 1.75 IU/l). In January 2021, he received 2 doses of the mRNA BNT162b2-SARS-CoV-2 vaccine (Pfizer-BioNTech). Three weeks after the second dose, TED deteriorated significantly with severe eye pain, lid swelling, conjunctival erythema, and worsening proptosis and diplopia (CAS 6/7). TSI levels rose to 4.45 IU/l, while patient was euthyroid on levothyroxine (TSH 2.3 mIU/l). He received 12 weekly methylprednisolone infusions (cumulative dose of 4.5 g) with limited response. He was then treated with three monthly cycles of intravenous tocilizumab with partial response (CAS 5/7). CASE 2: A 71-year-old non-smoker female had a 40-year history of hypothyroidism, controlled on levothyroxine. In March 2021, three days after her second dose of the mRNA-1273 SARS-CoV-2 vaccine (Moderna), she developed bilateral eye swelling and burning. She initially received anti-histamines and steroid eye drops without improvement. By August 2021, her eyes further deteriorated with eye pain, redness, lid edema and erythema, diplopia, and worsening proptosis (CAS 4/7). She also experienced 20 Ib weight loss, palpitations, tremors, and heat intolerance. TSI index was 5.5 (reference ≤1.3), TSH was undetectable, and FT4 1.4 ng/dl (reference 0.93-1.70 ng/dl). Levothyroxine was discontinued. Two weeks later she was admitted to the hospital with loss of color vision and decreased visual acuity in the right eye. She received 2 daily doses of 1 g intravenous methylprednisolone and intravenous teprotumumab on hospital day 3. She responded well to teprotumumab infusions every 3 weeks, with return of color vision and improvement of proptosis and periorbital edema (CAS 1/7). DISCUSSION: Activation of TED has so far only been described in four patients following SARS-CoV-2 vaccination. Here we report two more cases: one of TED deterioration in a GD patient with prior TED, and one of de novo TED progressing to dysthyroid optic neuropathy in a patient with a long history of Hashimoto's hypothyroidism. Possible etiologies include a maladaptive autoimmune/inflammatory syndrome from polyclonal B cell stimulation by adjuvants or activation of preexisting autoimmune disease. The possibility of new onset or deterioration of TED after SARS-CoV-2 vaccination in patients with underlying autoimmune thyroid disease and its mechanism should be further studied. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m., Monday, June 13, 2022 1:18 p.m. - 1:23 p.m.