Transferrin in serum

Transferrin refers to the β-globulin. The main function of transferrin is transport of absorbed iron to its depot( liver, spleen), into reticulocytes and their precursors in the red bone marrow. Trans-ferrin is capable of binding ions of other metals( zinc, cobalt, etc.).Of the total amount of transferrin in the human body, only 25-40% contains iron. In human plasma, transferrin is present in four forms: apotransferrin, which is devoid of iron;two monoferrforms containing iron in one of both binding sites and diferritransferrin. The main place for the synthesis of transferrin is the liver. The mammary gland produces a protein with transferrin-like properties - lactoferrin. In comparison with the content of iron in the blood serum, the transferrin level and iron saturation are more stable values ​​with less pronounced differences in sex and age. Iron transferrin saturation ratio is the percentage of serum iron to transferrin expressed as a percentage. Normally, it is 20-55%.Calculation formula: saturation factor =( serum iron / transferrin) x100.Saturation of transferrin less than 20% is a sign of reduced delivery of iron to the erythrocyte sprout of red bone marrow.

Determination of transferrin in serum is the most reliable test for the evaluation of iron deficiency anemia. The reference values ​​of transferrin concentration are presented in the table.

Table Reference values ​​of serum transferrin concentration

Table Reference values ​​of serum transferrin concentration

The main reasons for the decrease in serum transferrin concentration include the inhibition of synthetic processes in hepatocytes in chronic hepatitis, cirrhosis, chronic nephropathy, starvation, neoplastic processes, as well as a significant loss of protein in a non-frotic syndrome or afflictionthe small intestine. Concentration of transferrin may be increased in iron deficiency anemia, in women with pregnancy in the last trimester and in taking oral contraceptives.

There are 4 types of violations of transferrin content in combination with changes in the concentration of iron and OZHSS.

■ Increase in transferrin content with a decrease in serum iron concentration. A characteristic sign of iron deficiency anemia. Similar changes are observed in pregnancy and in childhood, but they are less pronounced. An increase in the content of transferrin in these cases is associated with an increase in its synthesis.

■ Increased concentrations of transferrin and iron in serum. Note when taking oral contraceptives, which is due to the effect of the estrogen contained in them.

■ Reduction of transferrin content and increased serum iron concentration. Such changes are detected under conditions that lead to an increase in the amount of iron in the depot( idiopathic hemochromatosis, hypoplastic, hemolytic and megaloblastic anemia), they arise because of inhibition of protein synthesis under the influence of high concentrations of iron.

■ Reduced serum transferrin and iron concentrations. Observe with many pathological conditions: protein starvation, acute and chronic infections, liver cirrhosis, surgical interventions, tumors, etc.