Thyroxine and triiodothyronine - these thyroid hormones are produced by the thyroid gland. In addition, the C-cells of this organ are able to secrete calcitonin. What it is? This hormone is an indicator of calcium metabolism and can be produced not only in the thyroid gland, but also in other organs. The lungs and thymus were especially successful in this. Calcitonin is involved in the regulation of mineral metabolism and has a complex chemical structure consisting of a chain of amino acids. Any violation of this sequence leads to the fact that the hormone loses its biological activity.
Calcitonin - what is it?
If there are any malfunctions in the functioning of the body, then doctors are asked to donate blood for analysis to determine the cause. Sometimes it reveals the content of a large amount of an element such as calcitonin. What it is? This is a thyroid hormone produced in her C-cells. It is a tumor marker that allows diagnosing thyroid cancer and examining calcium metabolism in the body.
Whatis the function of calcitonin?
The main function of calcitonin is to antagonize parathyroid hormone, which is produced by the parathyroid glands and also regulates calcium metabolism and increases its content in the blood. Calcitonin contributes to the regulation of phosphorus and calcium levels. Receptors for this substance are found in the blood (monocytes), placenta, lungs, liver, bone cells, central nervous system, genitals, kidneys.
In the skeleton, this hormone prevents the leaching of calcium, thereby supporting the structure of bones. Calcitonin is very important in cases where mineral s alts are consumed in large quantities. This situation happens during the active growth of the child, pregnancy and lactation.
For the blood, this hormone is also important and has a hypocalcemic effect. Calcitonin promotes the excretion of s alts along with urine and reduces their uptake in the intestine. It also lowers blood levels of phosphorus, which affects the digestive tract and kidneys.
The thyroid gland produces this hormone in small amounts, and its content in the blood is never high. It can also be produced in the intestines, but in very small doses.
Calcitonin in the blood
Why is it necessary to test for calcitonin? From the C-cells that produce this hormone, a malignant tumor of the thyroid gland grows - medullary cancer, or C-cell carcinoma. This tumor growsslowly but very persistently, spreading metastases to the lymph nodes of the neck and many other organs. She is very difficult to treat with chemotherapy.
Since C-cells produce the hormone calcitonin, its sharp increase in the blood may indicate the presence of medullary thyroid cancer. Early diagnosis of this disease has saved a large number of human lives.
When is blood donated for calcitonin?
C-cell tumors are often hereditary. All relatives of the patient should regularly donate blood for this hormone. In addition, such diagnostics are used to detect recurrence of a malignant tumor. If during the operation histology confirms the presence of medullary cancer, then subsequently blood for calcitonin will need to be taken every 3 months or six months.
There are other reasons for getting this test:
- to identify ailments due to impaired calcium metabolism;
- for diagnosing osteoporosis;
- to identify producing tumors;
- with frequent bone fractures and signs of their diseases.
Calcitonin norm
It should be remembered that there is no such thing as the lower limit of the hormone norm when testing blood for calcitonin. The norm will be even if its level in the blood is zero. It is important that it does not exceed the upper limit of normal.
In different laboratories, the rate of calcitonin in the blood may vary. This is explained by the fact that different reagents and specialized equipment are used for the study. In addition, the result depends on age and gender. The study is carried out by two methods: enzyme immunoassay and immunochemiluminescent.
The ELISA method has the following reference values for a hormone such as calcitonin:
- the norm for women is 0.07–12.97 pg/ml;
- the norm for men is 0.68–32.26 pg/ml;
- the norm in children is up to 79 pg/ml.
Norm for immunochemiluminescent method:
- women – 1.46 pmol/l;
- men – 2.46 pmol/l.
The result of the analysis in women may vary during pregnancy and while breastfeeding.
What can high hormone levels mean?
If a patient's calcitonin is elevated, no matter how much, this is in any case a very serious problem that requires a more in-depth examination by highly professional and competent specialists. If the indicator of calcitonin in the blood is more than 100 pg / ml, then with almost 100% certainty we can talk about the presence of a malignant formation. The higher the level of the hormone, the more advanced the tumor is and the more likely it is to detect metastases in the lymph nodes and other organs.
If a patient has nodules in the thyroid gland and he was prescribed a fine needle biopsy, which showed that they are benign, and the hormone calcitonin is elevated in the blood, thenit is necessary to trust the result of the analysis more, since it is almost always correct. With a very strong increase in the level of the hormone in the blood, surgical treatment is required to completely remove the thyroid gland along with the surrounding lymph nodes.
In addition to medullary cancer, hormone levels may increase in the presence of the following diseases:
- C-cell hyperplasia;
- Zollinger-Ellison syndrome;
- alcoholic cirrhosis;
- cancerous tumors of neuroendocrine nature;
- pernicious anemia;
- pseudohypoparathyroidism;
- carcinoid syndrome;
- thyroiditis and pancreatitis;
- benign lung disease;
- chronic renal failure.
If these diseases are confirmed, they must be treated.
Conclusion
For many patients, doctors prescribe a blood test for calcitonin. What it is? This is a thyroid hormone, an increase in the level of which may indicate the presence of a malignant tumor of this organ. With the timely detection of medullary cancer and surgical treatment, it can be confidently stated that such a problem will no longer exist. In addition to this disease, other reasons also cause an increase in the level of the hormone, which, with timely access to a doctor, can also be successfully treated.
