Erythropoietin (EPO; synonyms: erythropoietin, epoetin, historically also hematopoietin) is a glycoprotein hormone that belongs to the cytokines as a growth factor.
In adults, erythropoietin is produced predominantly by endothelial cells (specialized flat cells lining the inside of blood vessels) in the kidney (85-90%) and 10-15% by hepatocytes (liver cells) in the liver. In the fetus (human embryo after formation of internal organs; from the 9th week of pregnancy), synthesis occurs predominantly in the liver. It increases erythropoiesis (formation and development of erythrocytes (red blood cells)).
Erythropoietin is synthesized through several intermediate steps by remodeling the “hypoxia-induced factor” (HIF; transcription factor that regulates the supply of oxygen to the cell by establishing a balance between oxygen demand and oxygen supply) in the cells expressing erythropoietin (biosynthesis from genetic information). It is then transported via the bloodstream to the bone marrow, where it binds to the erythroblast (precursor of erythrocytes), leading to the maturation of the cells. The stimulus for synthesis is the decrease in oxygen saturation (SpO2) in the renal arteries.
The procedure
Material needed
- Blood serum
Preparation of the patient
- Not required
Disruptive factors
- Not known
Normal value (blood serum)
| Normal value in U/l | 5-25 |
Indications
- Anemia (anemia)
- Tumor marker (for follow-up in paraneoplastic erythropoietin formation).
Interpretation
Interpretation of increased values
- Polyglobulia (erythrocytosis; increase in the number of red blood cells (RBCs) above the physiological normal value).
- Hypoxia (oxygen deficiency) – caused by many different causes:
- Chronic anemia (anemia) of non-renal origin (non-renal).
- Acute blood loss and chronic bleeding, unspecified.
- Pulmonary disease, unspecified
- Heart disease, unspecified
- Neoplasms, such as renal tumors (renal cell carcinoma), adrenal tumors, ovarian carcinoma (ovarian cancer), uterine tumors (uterine tumors), hepatocellular carcinomas, brain tumors.
- In the 2nd and 3rd trimester (third trimester), erythropoietin levels are physiologically elevated
Interpretation of decreased values
- AIDS (Acquired Immune Deficiency Syndrome).
- Chronic renal insufficiency (kidney weakness).
- Dialysis (blood washing)
- Hunger states
- Hypothyroidism (underactive thyroid gland)
- Renal (kidney-related) anemia
- Tumor anemia (anemia that can occur in malignant tumors (cancer)).
- Polycythaemia vera (PV) – disease in which there is an increase in all cell series in the blood.
Other notes
- Erythropoietin for therapy is produced by genetic engineering.
- Red-hand letter on human epoetins (darbepoetin alfa, epoetin alfa, epoetin beta, epoetin theta, epoetin zeta, methoxy polyethylene glycol-epoetin beta): new warning regarding severe drug-induced skin reactions (severe cutaneous adverse reactions; SCARs).
