Normal transferrin is saturated with iron ?
Ans. is `b' i.e., 35% o In normal individuals, transferrin is about one third saturated with iron, yielding serum iron levels that average 120 g/dl in men and 100 g/dl in women. Serum ferritin o Most of the ferritin is stored is different organs (liver, spleen, bone marrow). o Very small amounts of ferritin normally circulate in the plasma. Since plasma ferritin is derived largely form the storage pool of body iron, its level correlate well with body iron stores. i.e., when there is iron depletion, body store of iron is reduced that inturn leads to decrease in plasma ferritin. Transferrin saturation and iron binding capicity 3 Iron is transpoed in the plasma by transferrin. o Normally transferrin is 33% saturated (77% free) with iron, yield serum iron levels that average 100-120 g/dl. So, if serum transferrin will be 100% saturated the serum iron will be 300 g/dl. that means the total iron binding capacity of transferrin is 300 to 350 g/dl. o When iron store is depleted e.g., in iron dificiency anemia, there is increased synthesis of transferrin that results in increased total iron binding capacity. o When iron store is repleted e.g., anemia of chronic disease, there is decreased synthesis of transferrin that results in decreased total iron binding capacity. Serum transferrin receptors Erythroid precursors have receptors for transferrin by which they recieve iron from transferrin that is utilized for hemoglobin synthesis. o When erythroid precursors mature, these receptors are shed into plasma and can be masured as serum transferrin receptors concentration. o In iron deficiency state, there is increased erythropoisis in bone marrow --> T concentration of erythroid precursor that results in increased total number of transferrin receptor T serum transferrin receptor concentration.
20%
35%
50%
70%