1. Background

• transferrin is a serum protein which act to bind and transport iron
• transferrin receptors are found on the cell surface of cells and regulate iron uptake into the cells; these receptors are abundant in tissues which have a high need for iron, i.e.,
• RBC precursors, liver, placenta
• acquired atransferrinemia has been reported and is thought to arise from the presence of anti-transferrin antibodies following multiple transfusions

2. Genetic Defect

• genetic defect -> defective expression of transferrin -> decreased accessability of iron to RBC precursors -> micro-cytic, hypochromic anemia
• the transferrin gene was cloned and sequenced and regulatory binding sites for metals and other DNA enhancers identified (Park et al., PNAS 82:3149 [1985])
• iron-response elements regulate the expression of both the transferrin and transferrin receptor genes and act to upregu-late the genes in an iron-deficiency state and down-regulate in iron overload states

1. Anemia

• pallor, splenomegaly
• anorexia, systolic murmer
• irritability, tachycardia
• pica

2. Complications

1. CBC

• hypochromic, microcytic anemia

2. Smear

• anisocytosis and poikilocytosis

3. Iron Studies

• decreased serum ferritin (elevated with hemosiderosis)
• decreased serum iron "
• decreased or absent transferrin (TIBC)

1. Supportive

• no treatment for underlying disorder
• PRBC transfusions and purified transferrin injections have only a transient effect
• management of hemosiderosis with chelation (desferrioxamine) therapy (see Thalassemia - Beta)