Indications for Thyroid Antibody Testing

Autoimmune Thyroid Disease Evaluation

Thyroid antibodies should be measured when autoimmune thyroid disease is suspected based on clinical presentation or abnormal thyroid function tests 1
Anti-thyroid peroxidase (TPO) antibodies are more predictive than anti-thyroglobulin (Tg) antibodies for diagnosing autoimmune thyroid dysfunction 2, 3
In suspected Graves' disease, TSH receptor antibodies (TRAb) should be tested as they are the hallmark of this condition and can predict treatment response 4

Children with type 1 diabetes should be tested for anti-thyroid peroxidase and anti-thyroglobulin antibodies soon after diagnosis 2, 5, 6
Thyroid-stimulating hormone (TSH) should be measured at diagnosis when clinically stable or after glycemic control has been established 2, 7
If initial thyroid function tests are normal, they should be rechecked every 1-2 years or sooner if the patient has positive thyroid antibodies or develops symptoms of thyroid dysfunction 2, 6
Autoimmune thyroid disease occurs in 17-30% of patients with type 1 diabetes, making screening essential 2, 3

Patients receiving immune checkpoint inhibitors should be monitored for thyroid dysfunction 1, 4
Thyroid antibody testing is warranted when thyroid dysfunction is detected during immunotherapy, as these medications can trigger autoimmune thyroiditis 1
In patients with unexplained fatigue, weight changes, or abnormal thyroid function tests during immunotherapy, additional testing for thyroid antibodies is indicated 1, 4

Thyroid antibodies should be tested in patients with unexplained thyrotoxicosis to differentiate between Graves' disease and thyroiditis 1, 4

Thyroid function tests may be misleading if performed during acute illness or metabolic derangement; they should be repeated after metabolic stability is achieved 2, 3