What is the Difference Between Thyroglobulin and Antithyroglobulin

The key difference between thyroglobulin and antithyroglobulin is that thyroglobulin is a protein made by the thyroid gland, while antithyroglobulin is an antibody or protein that is made in response to thyroglobulin by the immune system.

Thyroglobulin and antithyroglobulin are two important proteins that influence the function of the thyroid gland. The thyroid gland is an endocrine gland found in vertebrates. In humans, it is at the front of the neck and consists of two connected lobes. The thyroid gland is also located below Adam’s apple. The functional unit of the thyroid gland is the spherical-shaped thyroid follicle. Thyroid follicle is lined with follicular cells (thyrocytes) and occasional parafollicular cells. Moreover, thyroid gland secretes three hormones, including triiodothyronine (T3), thyroxine, (T4), and calcitonin. The thyroid hormones influence protein synthesis and growth and development in children, while calcitonin plays a role in calcium homeostasis.

CONTENTS

1. Overview and Key Difference
2. What is Thyroglobulin  
3. What is Antithyroglobulin
4. Similarities – Thyroglobulin and Antithyroglobulin
5. Thyroglobulin vs Antithyroglobulin in Tabular Form
6. Summary – Thyroglobulin vs Antithyroglobulin

What is Thyroglobulin?

Thyroglobulin is a protein made by the thyroid gland. This protein has a molecular weight of 660 kDa. It is also a dimeric glycoprotein produced by the follicular cells of the thyroid. Thyroglobulin is used entirely within the thyroid gland. The human thyroglobulin is a homodimer of subunits, with each containing 2768 amino acids.

Thyroglobulin protein is in all vertebrates, and it is the main precursor to thyroid hormones. Thyroid hormones are produced when thyroglobulin’s tyrosine residues are combined with iodine, and the protein is subsequently cleaved. Each thyroglobulin protein molecule contains approximately 100 to 200 tyrosine residues. But only a small number of these tyrosine residues are subjected to iodination by thyroperoxidase in the follicular colloid. Moreover, the metabolism of thyroglobulin occurs in the liver via thyroid gland recycling of the thyroglobulin. The circulating thyroglobulin has a half-life of 65 hours. Furthermore, thyroglobulin has been shown to interact with binding immunoglobulin proteins.

What is Antithyroglobulin?

Antithyroglobulin is an antibody or protein that is made in response to thyroglobulin by the immune system. Normally, antithyroglobulin is not found in the body. However, antithyroglobulin can be present in 1 in 10 normal individuals in small amounts. A greater percentage of antithyroglobulin can be observed in patients with thyroid carcinoma. The presence of these antibodies can result in falsely low (or rarely falsely high) levels of reported thyroglobulin.

People may need a test called thyroglobulin antibody test if the healthcare provider feels that they have a thyroid disorder. Thyroglobulin antibodies can be found in people who have thyroid problems such as underactive thyroid (hypothyroidism) or overactive thyroid (hyperthyroidism). Thyroglobulin antibodies attack thyroglobulin proteins and can destroy the thyroid gland. Moreover, antithyroglobulin is found in patients with Hashimoto’s thyroiditis or Graves’s disease. In addition, antithyroglobulin is also found in patients with Hashimoto’s encephalopathy, which is a neuroendocrine disorder related to but not caused by Hashimoto’s thyroiditis.

What are the Similarities Between Thyroglobulin and Antithyroglobulin?

• Thyroglobulin and antithyroglobulin are two important proteins that influence the function of the thyroid gland.
• Both are made up of amino acids.
• They can interact with each other.
• They can be measured through specific tests in the laboratory.

What is the Difference Between Thyroglobulin and Antithyroglobulin?

Thyroglobulin is a protein made by the thyroid gland, while antithyroglobulin is an antibody or protein that is made in response to thyroglobulin by the immune system. Thus, this is the key difference between thyroglobulin and antithyroglobulin. Furthermore, thyroglobulin is measured through a thyroglobulin test, while antithyroglobulin is measured through an antithyroglobulin test.

The below infographic presents the differences between thyroglobulin and antithyroglobulin in tabular form for side by side comparison.

Summary – Thyroglobulin vs Antithyroglobulin

Thyroid is a butterfly-shaped endocrine gland that sits low on the front of the neck. Thyroglobulin and antithyroglobulin are two important proteins that can influence the function of the thyroid gland. Thyroglobulin is a protein made by the thyroid gland, while antithyroglobulin is an antibody that is made in response to thyroglobulin by the immune system. So, this summarizes the difference between thyroglobulin and antithyroglobulin.

Reference:

1. “Thyroglobulin.” An Overview | ScienceDirect Topics.
2. Burke, Darla. “Antithyroglobulin Antibody Test: Purpose, Procedure, and Risks.” Healthline, Healthline Media.

Image Courtesy:

1. “Thyroid hormone synthesis” By Häggström, Mikael (2014). “Medical gallery of Mikael Häggström 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.008. ISSN 2002-4436. (Public Domain) via Commons Wikimedia