P3373 - Recurrent TNF-Inhibitor-Induced Thyroiditis in a Patient With Crohn’s Disease

Richard Vaca, MD¹, Ayanna Lewis, MD²
1Icahn School of Medicine at Mount Sinai, New York, NY; 2Mount Sinai Morningside & West, New York, NY

Introduction: TNF-inhibitors (TNFi) are widely-used for immune-mediated diseases such as Crohn’s disease. Thyroiditis is a rare complication of TNFi use in patients with Crohn’s disease without primary thyroid disease.

Case Description/

Methods: A Crohn’s patient on six months of adalimumab, with no known history of thyroid disease, presented to the emergency room with new-onset palpitations. Work up revealed supraventricular tachycardia, a suppressed TSH (< 0.01 uIU/mL, nl:0.4 – 4.2), and high free t4 (2.64 ng/dL, nl:0.82 – 1.77). Thyroid antibodies (TSI, TRAb, and anti TPO) were negative and a thyroid ultrasound was normal. Adalimumab was held and methimazole was started for a total of 18 months due to concern for drug-induced thyroiditis. Thyroid function tests (TFTs) normalized in 4 months with resolution of palpitations. Four years later, due to poorly controlled Crohn’s disease on upadacitinib, he was started on infliximab. His abdominal pain and diarrhea improved, however after 3 months of therapy he developed palpitations, anxiety and insomnia. TFTs again showed a suppressed TSH (< 0.01 uIU/mL, nl:0.4 – 4.2) and high free t4 (2.11 ng/dL, nl:0.80 – 1.5). Thyroid antibodies were again negative. He was advised to stop infliximab and methimazole was re-started. His TFTs normalized within 2 weeks and all other symptoms of hyperthyroidism resolved.

Discussion: TNFi can have unpredictable effects on thyroid function (1). We report a case of recurrent thyroiditis resulting in symptomatic hyperthyroidism in a patient treated with 2 different TNFi, suggesting a class effect. In both instances, TNFi cessation and use of methimazole resolved the hyperthyroidism. Although no evidence of autoimmune thyroid disease was found, it has been reported that antibodies against TNFi may cause thyroid gland damage, usually after 3 to 6 months of treatment, suggesting a drug-antibody mechanism (2). Absence of viral prodrome and recurrence after re-exposure made viral thyroiditis unlikely. Thyroid disease while on TNFi drugs should not delay treatment with these agents, but rather result in clinicians having a low threshold for suspecting drug-induced thyroiditis if there is an acute worsening.

1.Paschou SA, Myroforidis A, Loi V, Poulou A, et al. The effect of anti-TNF therapy on thyroid function in patients with inflammatory bowel disease. Endocr J. 2018 Nov 29;65(11):1121–5.
2.Cerniglia B, Judson MA. Infliximab-Induced Hypothyroidism: A Novel Case and Postulations concerning the Mechanism. Case Rep Med. 2013;2013:216939



Disclosures:
Richard Vaca indicated no relevant financial relationships.
Ayanna Lewis: Jansen Biotech – Advisory Committee/Board Member.

Richard Vaca, MD¹, Ayanna Lewis, MD². P3373 - Recurrent TNF-Inhibitor-Induced Thyroiditis in a Patient With Crohn’s Disease, ACG 2025 Annual Scientific Meeting Abstracts. Phoenix, AZ: American College of Gastroenterology.