Subacute thyroiditis in a patient with juvenile idiopathic arthritis undergoing etanercept treatment: a case report and review of the literature

Abstract

We report on a 24-year-old woman with juvenile idiopathic arthritis (JIA) who developed subacute thyroiditis (SAT) while being treated with etanercept. She had suffered from JIA for 12 years, and her arthritis proved refractory to treatment with ibuprofen, prednisolone, and methotrexate. For the past 5 years, the patient had been treated successfully with etanercept at 25 mg/week. The patient more recently complained of high fever and lassitude, and presented with anterior neck swelling and tenderness. Palpation of the thyroid gland revealed it to be warm, erythematous, tender, and diffusely swollen. Laboratory tests revealed an increased erythrocyte sedimentation rate and C-reactive protein level. Thyroid function tests revealed decreased levels of thyrotropin-stimulating hormone, increased levels of free triiodothyronine, free thyroxine, and thyroglobulin, and an absence of thyroid autoantibodies. Sonography showed a diffusely reduced predominantly hypoechoic thyroid gland. Unenhanced computed tomography of the neck showed a homogeneously and mildly reduced thyroid gland. Serum titers of several viruses were not significant and so were considered unlikely to be the pathogens. On the basis of these presented findings, we diagnosed SAT, and etanercept therapy was withdrawn. The patient was treated with antibiotics and an increased prednisolone dose was initiated. She became symptom free and showed improved laboratory test results within 2 weeks, and was euthyroid by 3 months. Three months later, the patient developed hypothyroidism, although 6 months further on, the patient was asymptomatic on prednisolone, methotrexate, and levothyroxine therapy. In conclusion, whether SAT is a specific adverse event in this case in response to etanercept remains unclear. Nevertheless, the possibility of SAT should be considered in such patients on etanercept treatment.

Subacute Thyroiditis: Clinical Presentation and Long Term Outcome

“…The disease is thought to have a viral origin, with possible pathogens including mumps virus, hepatitis B and C viruses, cytomegalovirus, enterovirus, and coxsackie viruses A and B [2]. However, the exact etiology of SAT is unknown.…”

Asymptomatic thyroiditis presenting as pyrexia of unknown origin: a case report

“…It usually follows viral infection commonly an upper respiratory tract infection and spontaneously regresses [ 3 , 4 ]. Common viruses implicated in the etiopathogenesis include mumps, echovirus, hepatitis b, hepatitis C, cytomegalovirus, and coxsackieviruses [ 5 ]. Some genetic factors, such as human leukocyte antigen (HLA) Bw35, might affect individuals’ susceptibility to possible viral pathogens; they were reported to play a role in the pathogenesis of the disease [ 6 ].…”

A rare case showing subacute thyroiditis-like symptoms with amyloid goiter after anti-tumor necrosis factor therapy

“…Etanercept is a TNF inhibitor that acts as a decoy receptor for TNF-α by competitively inhibiting the binding of TNF-α to its cell surface receptor. Several reports describe patients developing thyrotoxicosis while on etanercept (2) (3) (4) (5) . All of these patients were initially suspected of having subacute thyroiditis because they showed thyroid pain without thyroid antibodies, but no thyroid amyloidosis was documented.…”

“…Tumor necrosis factor (TNF)-α has been implicated in the pathogenesis of numerous inflammatory conditions, and its inhibition has proven efficacious in the treatment of autoimmune diseases, such as rheumatoid arthritis and inflammatory bowel disease. Recently, several cases of thyrotoxicosis have been reported in association with anti-TNF therapy using etanercept (2) (3) (4) (5) . However, thyrotoxicosis accompanied by an amyloid goiter after anti-TNF therapy has never been reported.…”