Erythropoietin Test

Overview :

Erythropoietin is produced primarily in the kidneys but interacts with other factors in the bone marrow to increase red cell production. EPO is unique among the blood cell growth factors, because it is the only one that behaves like a hormone.

Erythropoietin acts as the principal regulator in the production of red blood cells (erythrocytes) by controlling the number, the kinds, and the survival of the cells. Because of this ability, it is being investigated for use in cancer patients to prevent anemia (hemoglobin concentration in the blood is lower than normal), or to treat anemia that has been induced by chemotherapy and bone marrow transplantation (BMT).

The correction of anemia can result in reduced transfusion requirements, so the erythropoietin test is used to diagnose anemia, including the anemia of end-stage renal disease. Erythropoietin determination is also valuable in diagnosing a condition known as polycythemia, when increased numbers of red blood cells occur. Levels of erythropoietin are extremely low in polycythemia vera but are normal or high in secondary polycythemia. It happens rarely, but cysts in the liver or kidneys, as well as tumors in the kidneys or brain, can also produce erythropoietin. Patients with these conditions can have high levels of erythropoietin and may develop secondary polycythemia.

Kidney disease can cause anemia and many patients on kidney dialysis will require monthly EPO tests to check their hemoglobin levels.

Some athletes use EPO to enhance performance, as the increased red cell volume adds more oxygen-carrying capacity to the blood. Adverse reactions to this practice can include clotting abnormalities, headache, seizures, high blood pressure, nausea, vomiting, diarrhea, and rash.