Why this test?
- To calculate the percentage of transferrin saturation with iron, to determine exactl volume of iron the blood carries.
- To estimate iron reserves in the body.
- To determine whether anemia is caused by iron deficiency or other causes, such as chronic disease or vitamin B12 deficiency.
- For the diagnosis of iron poisoning or hereditary hemochromatosis - a disease associated with increased absorption and accumulation of iron.
In what cases is it prescribed?
- If any deviations are detected as a result of a general blood test, a test for hemoglobin, hematocrit, erythrocytes.
- In case of suspicion of iron deficiency or overload of the body with iron (hemochromatosis).
- In case of suspicion of poisoning with tablets containing iron.
- When monitoring the effectiveness of the treatment of anemia and conditions accompanied by an overload of the body with iron.
Iron is a trace element that is absorbed from food and then transported by the body by transferrin, a special protein produced in the liver. Iron is necessary for the formation of red blood cells. It is the most important component of hemoglobin - the protein that fills red blood cells, which allows them to carry oxygen from the lungs to organs and tissues. Iron is also part of the muscle protein myoglobin and some enzymes. Normally, the body contains 4-5 g of iron. About 70% of this amount is iron «embedded» in the hemoglobin of erythrocytes, the rest of the iron is stored in tissues in the form of ferritin and hemosiderin.
When there is not enough iron, for example, in the case of a decrease in its intake with food or frequent bleeding, its level in the blood decreases, the body uses iron from the reserve. With a long-term shortage, iron reserves are depleted, which can lead to anemia.
On the other hand, if there is too much iron, it can cause its excessive accumulation and damage to the liver, heart, and pancreas. In the early stages, iron deficiency may be asymptomatic. If a person is otherwise healthy, then signs of the disease appear only when the hemoglobin drops below 100 g/l. Anemia is characterized by chronic weakness, dizziness, headache.
With severe iron deficiency anemia, a person may complain of shortness of breath, chest pain, severe headaches, and weakness in the legs. Children may have learning difficulties. In addition to the main ones, there are several other signs characteristic of iron deficiency: the desire to eat unusual products (chalk, clay), burning of the tip of the tongue, regurgitation (cracks in the corners of the mouth). Symptoms of excess iron: pain in the joints, weakness, fatigue, abdominal pain, decreased sex drive, heart rhythm disorders.
About 3-4 mg of iron (0.1% of the total amount) circulates in the blood «in connection» with the protein transferrin. It is his level that is measured in this analysis. The amount of serum iron can vary significantly on different days and even during the same day (maximum in the morning hours). Therefore, the measurement of the level of serum iron is almost always combined with other tests, such as a test for the total iron-binding capacity of the serum (ZZZS), ferritin, transferrin.
Using the indicators of VLDL and transferrin, it is possible to calculate the percentage of saturation of transferrin with iron, which shows how much iron is transported in the blood. The use of various analyzes reflecting the exchange of iron in the body provides more complete and reliable information about iron deficiency or iron overload than a single indicator of serum iron.