Question

Viscosity of blood is increased during anemia. True or False. Why?

Answer 1

Anemia of chronic disease is characterized by decreased production of erythrocytes in the setting of chronic diseases such as chronic inflammatory conditions, plasma cell dyscrasias, congestive heart failure, and chronic renal failure.  Patients with anemia of chronic disease typically have abnormally low levels of erythropoietin, the growth factor which stimulates erythropoiesis (the production of red blood cells), and a subset of these patients are resistant to erythropoietin supplementation.  The cause of the anemia is still unknown.   

Erythropoietin circulates from its site of synthesis in the kidney to the bone marrow where it binds to membrane bound receptors on erythroid precursors.  Binding prevents apoptosis of these cells, allowing them to generate new erythrocytes.  Erythropoietin activity is antagonized by soluble erythropoietin receptor, which binds circulating erythropoietin, preventing it from acting in the bone marrow.  Soluble erythropoietin receptor is a truncated form of the membrane bound receptor, which lacks the transmembrane and cytosolic domains.