Transferrin (Tf) is a protein that transports iron in the body and sends it to its destination, where its deficiency occurs. In addition, this protein has another name – siderophin.
It should not be confused with ferritin (a protein complex containing iron).
What is this Tf?
The iron that enters the human body along with the food in the gastrointestinal tract (gastrointestinal tract), in the digestive system, is in the trivalent stage. To be absorbed into the digestive system, iron must enter the bivalent state.
This happens through many factors that are involved in this transformation:
- Vitamin C
- Enzymes for the cleavage of Fe molecules.
- Microflora in the digestive tract.
After the transition from iron to the bivalent stage in the intestinal mucosa and its intestine 12, duodenal, it returns to the initial degree and connects with the ferritin and with the help of transferrin goes to its destination in the cells of the tissues of the organs.
To fill Tf with iron ions in the composition of the molecule, in the transported protein, there are special chambers (spaces) that accept these ions. Depending on which space is filled with iron, transferrin can transport iron through one of its 4 forms.
Each form of transferrin has its place for iron ions:
- Transferrin A (mono-ferrous): the iron of the molecule occupies only space A
- Transferrin B (mono-ferrous): the transported iron ions are only in the chamber of space B
- Diuretic transferin: spaces A and B are occupied by iron ions.
The Tf molecule can take only 2 iron ions and at the moment of its movement in the body, it finds a cell that needs iron, and this cell indicates it. Transferrin enters this cell and gives it iron ions.
The ions of the iron molecule transported by transferrin are distributed strictly according to their purpose. In molecules of the placenta and erythron molecules, iron ions are sent only to chamber A, to organs of the liver and internal organs, ions of space B.
The path of iron in the body.
Other characteristics of the transport protein transferrin
Tf, which has the ability to combine with Fe ions from the trivalent state, produces not only the delivery of ions to the target, but also produces iron reserves and actively participates in the process of erythropoiesis (in the synthesis of hemoglobin).
The function that transferrin performs in erythropoiesis:
- Recognition of young red blood cells (reticulocytes) involved in the synthesis of hemoglobin
- The task of the Tf molecule is to collect iron ions, which were released in the decomposition process of the erythrocyte molecule. Pure ferric iron is very toxic to the body, therefore, transferrin saves the body’s cells from danger.
- Transferrin belongs to the acute phase proteins in the beta-globulin complex. The permanent place of its interruption is mucous. There, the transferrin searches for the Fe ions and joins them, taking them to the cells, depriving the pathogenic microbes of a favorable life and nutritional environment.
- The properties of the Tf to work with metals negatively affect the body when the plutonium molecules enter it. Transferrin does not understand that it is not iron that binds to plutonium ions and takes it to the store.
The producers of Tf protein transported are the liver and the brain. The gene of the person responsible for this production, and is on the third chromosome.
The complete absence, or deficiency of this transporter protein, is a hereditary disease.
What is transferrin and where is it from?
This pathology at the genetic level has an autosomal recessive form. A manifestation of this path is an anemia of a hypochromic nature, called atransferrinemia.
When does a doctor ask for a study?
The doctor is sent for analysis to identify transferrin in the blood:
- When there are deviations of normal hemoglobin in the KLA (total blood count), the number of erythrocytes and hematocrit molecules
- Deviations in the amount of iron: excess, or its deficiency
- Pathology of hemochromatosis: symptoms of the pathology, this is pain in the joints, pain in the intestines, general fatigue, reduced sexual desire, a violation of the rhythm of the heart
- Chronic liver disease
For the behavior of this analysis, you need specialized equipment and not all clinical laboratories have it.
The cost of analysis in the Invitro laboratory is 120 UAH. (605 rub.), Plus the cost of blood collection service 30 UAH. (200 rubles).
Therefore, the concentration of transferrin is determined by the OZHSS method is the index of the total capacity of serum binder. In agreement with this capacity of the serum, the coefficient of filling of Tf with Fe ions is determined.
This relationship varies between 25.0%, up to 30.0%, although there are cases of large discrepancies of 10.0% to 50.0%.
Characteristics of the transferrin research.
Tf has the properties to bind more iron ions than it weighs.
Iron is an important element in the functionality of the body. Iron ions are an integral part of the hemoglobin molecules.
Hemoglobin is a protein that is filled with empty red blood cells and transports oxygen ions through cells.
The Fe is filled with one third of the transferrin protein binding centers, while the remaining two thirds are reserved.
The degree of filling of transferrin with iron ions reflects the indicators, the iron binding properties of the serum, as well as the latent form of the iron binding capacity of the serum molecules and the saturation percentage of transferrin protein.
The research method of transferrin is used to recognize the iron concentration status, as well as the saturation of the transport protein by its results:
- In iron deficiency, the transferrin index increases, so that Tf can bind with a small amount of iron ions in the serum fluid
- The quantitative part of transferrin depends directly on the function of the liver, its ability to synthesize this type of protein, as well as human nutrition and the proper functioning of your intestines. If the liver cells are affected by cirrhosis, the transferrin production is significantly reduced. With an insufficient content in the food protein, there is also a lack of transport protein.
- To evaluate the situation with the metabolism, it is necessary to analyze the blood for iron, as well as the iron binding properties of the serum, to find out how much hemoglobin is transported by the blood and how much iron is transferred by the transferrin.
- The study is done to learn about the stock of iron in the human body.
- And also, to check – anemia is caused by a lack of iron, or has a different etiology.
Method for the determination of iron – immunoturbidimetry.
According to the results of the immunoturbidimetry analysis, the concentration of transferrin in the blood plasma is visible. This concentration can be increased and its percentage reaches indicator 20.
The reasons for the change in the coefficients may be: the properties of Fe to bind with other types of proteins.
Immunoturbidimetry analysis assigned to determine the changes that are associated with iron deficiency and cause pathological anemia.
Characteristic indicators: an increase in the content of this protein, with a decrease in the Fe part in the serum biological fluid. The result of this action is a decrease in the saturation of proteins with Fe ions.
Its quantitative composition is observed in the results:
- In women, more than this protein by 10%.
- With pregnancy in the 3rd trimester, transferrin in concentrations of up to 50.0%.
- The greater a person is, the concentration decreases.
- With inflammation in the body, the concentration of transferrin drops sharply.
The analysis of the plasma concentration index of Tf is assigned for the diagnostic study of all types of anemia, malignant neoplasms, helminth invasions and in case of hemochromotosis of the disease.
For the results of the analysis of immunoturbidimetry to be as reliable as possible, it is necessary to donate blood on an empty stomach. The study is done from freshly drawn venous blood.
Do you know why venous blood coagulates rapidly?
Deciphering the result of biochemistry.
The norm depends on the age of the patient and the state of his body. In women in the third trimester of pregnancy, fluctuations in this coefficient occur in the direction of their increase.
The standard figure is: