Thyroglobulin Antibodies

July 21, 2020

What are thyroglobulin antibodies?

Thyroglobulin is a large protein stored in the thyroid gland and is a prohormone aiding in the production of both T3 and T4. Special enzymes called proteases break T3 and T4 from thyroglobulin, so they are released into the body.  Thyroglobulin antibodies (TgAb) are proteins that can be measured in your blood.

What role do thyroglobulin antibodies play in the body?

Healthy people usually have thyroglobulin circulating in their bloodstream but it can be increased in several thyroid conditions. Circulating thyroglobulin antibodies, however, are a hallmark of autoimmune diseases affecting the thyroid.

The thyroid is a small, butterfly-shaped gland in the neck. It produces the hormones triiodothyronine (T3) and thyroxine (T4) which are vital for cellular metabolism in the human body. If the thyroid produces too much of these hormones it causes hyperthyroidism, where the cells work faster than usual. If, however, the thyroid produces too little of these hormones then it can cause hypothyroidism.

The immune system makes antibodies to detect and fight proteins which are usually found in the body. For example, if you have a cold or flu, your body will make antibodies to recognise and fight it off in future. However, in some people, their immune system makes antibodies to fight thyroglobulin, a hormone naturally present in the thyroid gland.

How does thyroglobulin antibodies affect my wellbeing?

Thyroglobulin antibodies are detected in up to 90% of Hashimoto’s disease patients.

Hashimoto’s disease causes an underactive thyroid or hypothyroidism. Because your immune system attacks the thyroid, the gland is damaged and it is unable to produce enough thyroid hormones.

The symptoms of Hashimoto’s are like those of hypothyroidism and include:

  • Weight gain
  • Tiredness
  • Joint and muscle pain
  • Constipation
  • Dry, thin hair
  • Depression
  • Slow heart rate
  • Memory issues

Thyroglobulin antibodies are also present in some people with Graves’ disease.

The condition is also autoimmune where the immune system mistakes the thyroid as foreign. Graves’s disease causes the thyroid to make more thyroid hormones than the body needs and can result in hyperthyroidism. If you have Grave’s disease, you may have some of the common symptoms of an overactive thyroid, like:

  • Fast and irregular heartbeat
  • Goitre (a large swelling in your neck)
  • Diarrhoea or frequent bowel movements
  • Tiredness
  • Muscle weakness
  • Trembling hands
  • Trouble sleeping
  • Weight-loss

Some research also shows that elevated thyroglobulin antibody levels are associated with an increased risk for thyroid cancer. Equally, in some people who have thyroid cancer, their immune system produces thyroglobulin antibodies which can interfere with blood test results and give false readings.

How can I improve my result?

Although the medical world is not entirely sure why the body’s immune system attacks itself, it is thought to involve a combination of genetic and environmental factors.

The good news is that it is possible to control the symptoms associated with autoimmune thyroid disorders with a healthy lifestyle, particularly diet and exercise. You will also likely be prescribed medication if you have an underactive thyroid.

Good nutrition is essential for staying healthy and helping to manage autoimmune disease.

People with autoimmune thyroid disorders should avoid eating foods rich in iodine or taking iodine supplements as these can make symptoms worse. It’s also important that you get enough calcium in your diet as well as vitamin D. Some research shows that individuals with thyroid disorders are susceptible to low levels and they may increase the risk of developing a disease. Your body needs both these nutrients for optimum immune function as well as strong, healthy bones.

It is also important to eat food sources which are rich in vitamin B12, particularly because 30% of individuals with an autoimmune thyroid disorder are vitamin B12 deficient. Good sources include:

  • red meat
  • liver
  • sardines
  • salmon
  • dairy products [8]

Exercise is important for all aspects of your health. If you have an autoimmune thyroid disorder, you may not feel like exercising but it may help to manage your symptoms and make you feel better mentally. However, you mustn’t overdo it because that may make your symptoms worse.

Some people find short sessions of high-intensity interval training (HIIT) beneficial as well as weight training using heavy weights and low reps.

During HIIT sessions, energy is used quickly so you may even be able to shorten your sessions from 30 minutes to 15. You may find it easier to exercise in the morning because your normal body clock will naturally wake you up and you will burn fat faster during this time.

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References

[1] NHS South Tees Hospitals NHS Foundation Trust. (2020). Thyroglobulin Antibody (THYAB). Available at: https://www.southtees.nhs.uk/services/pathology/tests/thyab/

[2] British Thyroid Foundation. (2018). Your Thyroid Gland. Available at: http://www.btf-thyroid.org/information/your-thyroid-gland

[3] Zhao, L et al. (2013). Glycosylation of Sera Thyroglobulin Antibody in Patients with Thyroid Diseases. European Journal of Endocrinology: 168, pp 585-592

[4] National Institute of Diabetes and Digestive and Kidney Diseases. (2020). Hashimoto’s Disease. Available at: https://www.niddk.nih.gov/health-information/endocrine-diseases/hashimotos-disease

[5] National Institute of Diabetes and Digestive and Kidney Diseases. (2020). Graves; Disease. Available at: https://www.niddk.nih.gov/health-information/endocrine-diseases/graves-disease

[6] Qin, J et al. High Thyroglobulin Antibody Levels Increase the Risk of Differentiated Thyroid Carcinoma. Dis Markers

[7] Brierley, J. (2015). Understand Your Blood Test Results. Available at: https://www.uhn.ca/PatientsFamilies/Health_Information/Health_Topics/Documents/Understand_Blood_Test_Results-differentiated_thyroid_cancer.pdf

[8] Harris, C. (2012). Thyroid Disease and Diet – Nutrition Plays a Part in Maintaining Thyroid Health. Today’s Dietician: 14(7), pp 40.

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This information has been medically reviewed by Dr Nicky Keay

Nicola has extensive clinical and research experience in the fields of endocrinology and sport and exercise medicine. Nicky is a member of the Royal College of Physicians, Honorary Fellow in the Department of Sport and Exercise Sciences at Durham University and former Research Fellow at St. Thomas' Hospital.

Dr Nicky Keay

Dr Nicky Keay

BA, MA (Cantab), MB, BChir, MRCP.