What is erythropoietin (EPO)?
Erythropoietin (EPO) is a hormone produced by the kidney that promotes the formation of red blood cells by the bone marrow. The kidney cells that make erythropoietin are sensitive to low oxygen levels in the blood that travels through the kidney. These cells make and release erythropoietin when the oxygen level is too low. A low oxygen level may indicate a diminished number of red blood cells (anemia), or hemoglobin molecules that carry oxygen through the body.
Erythropoietin (EPO) definition and facts
- Erythropoietin (EPO) is a hormone produced by the kidney.
- Erythropoietin promotes the formation of red blood cells by the bone marrow.
- The erythropoietin hormone level can be detected and measured in the blood (the EPO test).
- Measurement of the blood erythropoietin level can be used to detect certain medical conditions.
- Erythropoietin can be synthesized and used as a treatment of some forms of anemia.
- Erythropoietin has been misused as a performance-enhancing drug by some athletes.
What does erythropoietin do? Why do we need it?
Erythropoietin stimulates the bone marrow to produce more red blood cells. The resulting rise in red cells increases the oxygen-carrying capacity of the blood.
As the prime regulator of red cell production, erythropoietin’s major functions are to:
Promote the development of red blood cells.
Initiate the synthesis of hemoglobin, the molecule within red blood cells that transports oxygen.
Chemically, erythropoietin a protein with an attached sugar (a glycoprotein). It is one of a number of similar glycoproteins that serve as stimulants for the growth of specific types of blood cells in the bone marrow.
Normal levels of erythropoietin range from 4 up to 24 mU/ml (milliunits per milliliter)
Medical Use of erythropoietin:
They are used in treating anemia resulting from chronic kidney disease, chemotherapy induced anemia in patients with cancer, inflammatory bowel disease (Crohn’s disease and ulcerative colitis) and myelodysplasia from the treatment of cancer (chemotherapy and radiation). Erythropoietin is an essential hormone for red blood cell production. Without it, definitive erythropoiesis does not take place. Under hypoxic conditions, the kidney will produce and secrete erythropoietin to increase the production of red blood cells by targeting CFU-E, proerythroblast and basophilic erythroblast subsets in the differentiation. Erythropoietin has its primary effect on red blood cell progenitors and precursors (which are found in the bone marrow in humans) by promoting their survival through protecting these cells from apoptosis, or cell death.
Side Effects of Erythropoietin:
The package inserts include boxed warnings of increased risk of death, myocardial infarction, stroke, venous thromboembolism, and tumor recurrence, particularly when used to increase the hemoglobin levels to more than 11 g/dL to 12 g/dL.