What is Anti-TPO?
The thyroid peroxidase (TPO) enzyme is a vital enzyme produced by the thyroid gland. It is involved in the utilization of iodine for the production of thyroid hormones crucial for the regulation of body temperature, weight, growth, and development. Anti-thyroid peroxidase (Anti-TPO) is produced by the immune system of the body to target the TPO enzyme.
The anti-TPO test measures the amount of anti-TPO antibodies in the blood. The presence of anti-TPO antibodies in elevated levels indicates that the person is affected by an autoimmune thyroid disorder such as Grave’s disease or Hashimoto’s thyroiditis leading to an overactive or underactive thyroid gland which as a result affects the overall health of an individual.
How is the Test Performed?
The anti-TPO test is typically performed in the morning as the antibody level is most stable at that time. The test involves a simple blood draw which is then analyzed in the laboratory.
Preparation
- The test does not require fasting.
- Inform your doctor about any medication you are taking as certain medicines may interfere with the test results.
- Don’t take stress before or during the test as it might affect the results.
- If you are on a special diet you must discuss it with your doctor.
Collection
- A highly experienced phlebotomist draws blood from the vein using a needle.
- The collected sample is then transferred into the chemically-treated tube.
- The sample is then sent to the laboratory for analysis.
Laboratory analysis
- Once the laboratory receives the sample, a trained technologist analyzes the sample using advanced techniques such as enzyme-linked
- immunosorbent assay (ELISA) or chemiluminescence immunoassay (CLIA).
- The result is then compared with the standard reference range.
What are the symptoms that prompt this test?
The anti-TPO test is recommended by healthcare providers to individuals showing the signs and symptoms of autoimmune thyroid disorders. Early diagnosis and treatment are crucial for effective management of the disease. Below some of the symptoms are mentioned that a diseased person exhibits;
Symptoms associated with hypothyroidism
- Thinning of hair
- Dry skin
- Weight gain
- Intolerance to cold
- Reduced heart rate
- Constipation
- Lowered energy levels
- Persistent fatigue
Mental changes such as depression or mood swings.
Symptoms associated with hyperthyroidism
- Intolerance to heat
- Tremors
- Nervousness
- Irritability
- Fast or irregular heart rate
- Increase in appetite
Symptoms associated with autoimmune thyroid disorders
- Muscle or joint pain
- Goiter
- Infertility issues
- Irregular periods in women
- Brain fog
What are Normal Ranges for This Test?
The results of the anti-TPO test may vary due to different factors including the presence of broken red blood cells, elevated fat content in serum, or concentration of bilirubin. The generally accepted reference range is mentioned below;
Negative – 0 to 34 IU/mL
Positive – More than 34 IU/mL
**The above-mentioned values are general guidelines only and may vary between laboratories due to the methodology used.**
What Happens if Test Results Show Abnormal Levels?
If the test results indicate elevated levels of anti-TPO antibodies in the blood the person is affected with a thyroid disorder. The healthcare provider will give a treatment and management plan according to the diagnosis.
Elevated Levels of anti-TPO indicate
- Hashimoto’s thyroiditis
- Grave’s disease
- Post-partum thyroiditis
- Rheumatoid arthritis
- Lupus
- Type 1 diabetes
For hypothyroidism, hormone replacement therapy is suggested whereas for hyperthyroidism anti-thyroid medications are recommended. In either case lifestyle changes including stress management, regular exercise, and incorporation of a balanced diet are crucial.
