Elevated Graves' Disease-Specific Thyroid-Stimulating Immunoglobulin and Thyroid Stimulating Hormone Receptor Antibody in a Patient With Subacute Thyroiditis.

Anu Alvin Mathew,Mc Anto Antony,Roshin Papaly,Lakshya Chandra,Alvin Maliakal

doi:10.7759/cureus.19448

Abstract

Subacute thyroiditis can be rarely associated with autoimmune thyroid disorders. It includes Graves' disease which is characterized by the presence of a highly specific antibody known as thyroid-stimulating hormone (TSH) receptor antibody (TRAb). There are three types of TRAb: TSH receptor stimulating antibody (TSAb) which stimulates the TSH receptor causing Graves' disease, TSH receptor blocking antibody (TBAb) which blocks the TSH receptor causing hypothyroidism, and a neutralizing antibody which does not alter the thyroid function. There are two assays used to check the TRAb: the thyroid-stimulating immunoglobulin (TSI) assay and the TSH receptor-binding inhibitor immunoglobulin (TBII) assay out of which the TSI assay measures the stimulating antibody which is specific for graves' disease. Although autoimmune thyroid disorders can rarely occur following subacute thyroiditis, their clinical presentation is usually compatible with the type of antibody detected in the patient’s serum.We present a unique case of a 44-year-old patient who presented with subacute thyroiditis followed by the development of persistent hypothyroidism even in the presence of elevated Graves' disease-specific TSI and TRAb.

Highlights

Graves’ disease is the most common cause of hyperthyroidism in which antibodies directed against the thyroid-stimulating hormone (TSH) receptor cause continuous stimulation of the thyroid gland leading to hyperthyroidism
Autoimmune thyroid disorders can rarely occur following subacute thyroiditis, their clinical presentation is usually compatible with the type of antibody detected in the patient’s serum
We present a unique case of a 44-year-old patient who presented with subacute thyroiditis followed by the development of persistent hypothyroidism even in the presence of elevated Graves' disease-specific thyroid-stimulating immunoglobulin (TSI) and TSH receptor antibody (TRAb)

Summary

Introduction

Graves’ disease is the most common cause of hyperthyroidism in which antibodies directed against the thyroid-stimulating hormone (TSH) receptor cause continuous stimulation of the thyroid gland leading to hyperthyroidism. We present an extremely unique case of a patient with persistent hypothyroidism who presented with subacute thyroiditis in the presence of significantly elevated Graves’ disease-specific antibodies. The patient presented to the endocrinology clinic in April 2019 for the initial consultation She reported experiencing a gradual improvement with the resolution of all the symptoms with the use of prednisone. How to cite this article Alvin Mathew A, Papaly R, Maliakal A, et al (November 10, 2021) Elevated Graves’ Disease-Specific Thyroid-Stimulating Immunoglobulin and Thyroid Stimulating Hormone Receptor Antibody in a Patient With Subacute Thyroiditis. Due to the development of persistent hypothyroidism, the thyroid peroxidase (TPO) antibody was checked, which was in the normal range but the repeat TRAb was still elevated at 4.75 IU/L (

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Disclosures