erytropoetyn

Erytropoetyn, also known as erythropoietin (EPO) in English, is a glycoprotein hormone that regulates red blood cell production. In adults it is produced primarily by the peritubular interstitial cells of the kidneys, with smaller contributions from the liver during fetal life. Its synthesis is closely tied to tissue oxygen levels and rises in response to hypoxia.

EPO acts by binding to erythropoietin receptors on erythroid progenitor cells in the bone marrow. This activates intracellular signaling pathways (notably JAK2–STAT5) that promote the survival, proliferation, and differentiation of these cells into mature red blood cells. Over several days, increased reticulocyte production leads to higher hemoglobin and hematocrit.

Medical use and formulations: Recombinant human erythropoietin and its analogs are used to treat anemia associated with chronic kidney disease, cancer chemotherapy, HIV infection, and certain bone marrow failure conditions. Available drugs include epoetin alfa, epoetin beta, and darbepoetin alfa, the latter having a longer half-life and allowing less frequent dosing. Therapy aims to reduce transfusions and improve quality of life, with dosing and target hemoglobin guided by clinical guidelines and patient risk.

Safety and regulation: Potential risks include hypertension and an increased risk of thromboembolic events if hemoglobin rises too quickly or too high. Rare cases of pure red cell aplasia due to neutralizing antibodies have been reported. In oncology, ESAs may affect tumor progression or survival in some settings, leading to regulatory restrictions. Erythropoietins are monitored in sports and are banned as performance-enhancing agents; detection methods are used in anti-doping programs.

History and availability: Recombinant erythropoietin was developed in the 1980s, transforming anemia management. Biosimilars are now available in many regions under regulatory oversight.