Plasma transferrin is an iron-binding protein; is a glycoprotein of 79.57 kD, its gene is located on chromosome 3q21;it is generated mainly by liver parenchymal cells. Transferrin has two iron binding sites, each binding the ferric ion (Fe3 +). Normally, only one third of the transferrin binding sites are occupied.

Unlike sideremy, which shows large diurnal variation, serum transferrin level is more constant. Transferrin delivers iron to erythroid precursors and other cells by binding to specific receptors on the cell surface

Recommendations for determining transferrin (in combination with serum iron and ferritin):

• Differential diagnosis of anemia, especially microcytic and / or hypochromic

• Evaluation of iron deficiency anemia, thalassemia, sideroblastic anemia

• The diagnosis of iron overload and hemochromatosis.

Transferrin saturation can be calculated according to the formula:

                                 Serum iron (mg / dL)

       TFS (%) = —————————————- x 70.9

                               Transferrin (mg / dL)

Reference values :

Transferrin 200-360 mg / dL

16-45% transferrin saturation.

Increases:

• iron deficiency anemia, • pregnancy • oral contraceptives (TFS is normal).

Decreases:

• Anemia of chronic disease (sometimes transferrin may be normal), sideroblastic anemia • (sometimes transferrin may be normal), • hemolytic anemia (sometimes transferrin may be normal) • Protein deficiency: increased malnutrition or loss (burns syndrome nephrotic liver disease), • acute liver disease, congenital atransferinemia •, • iron overload syndromes, hemochromatosis (slightly lower).