Reference Range
Erythropoietin testing, in combination with other tests, can be used to differentiate polycythemia vera from secondary polycythemia. It can also help differentiate between appropriate and inappropriate secondary polycythemia.
Normal findings [1] : 5-35 IU/L
Interpretation
Elevated erythropoietin levels are associated with the following:
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Anemia due to thalassemia [2]
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Anemia due to bone marrow suppression
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Secondary polycythemia (appropriate [eg, high-altitude, lung disease] or associated with erythropoietin-secreting tumors)
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Pregnancy
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Testosterone therapy
Suppressed erythropoietin levels are associated with the following:
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Anemia due to chronic kidney disease or other chronic diseases (eg, rheumatoid arthritis, HIV infection) [3, 4]
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After transfusion
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Estrogen therapy
Collection and Panels
Specimen type: Serum
Patient instruction: No need for fasting
Collection tube: Red-top tube or gel-barrier tube
Unacceptable conditions: Grossly hemolyzed specimens
Specimen preparation: Separate serum from cells and transfer to transport tube
Storage/transport temperature: Refrigerated
Stability: Refrigerated, 7 days; frozen, 2 weeks
Panels: None
Background
Description
Erythropoietin is produced by the liver during fetal life. After birth, the kidneys constitute the major source of production. Erythropoietin, a member of class 1 cytokines, is a 30.4-kDa glycoprotein composed of 4 chains of carbohydrate and a protein chain composed of 193 amino acids that undergo a cleavage process, resulting in the production of mature erythropoietin (165 amino acids).
Erythropoietin is secreted by fibroblasts in the renal cortex. These cells possess specific regulatory mechanisms, called hypoxia-inducible factors (HIFs), which, under hypoxic conditions, stimulate the production of erythropoietin, which stimulates the production of erythrocytes.
Indications/Applications
Erythropoietin testing, in combination with other tests, can be used to differentiate polycythemia vera from secondary polycythemia. It can also help differentiate between appropriate and inappropriate secondary polycythemia.
In some conditions, erythropoietin testing can be used in the assessment and differentiation of anemia, especially in patients receiving erythropoietin replacement therapy with an inadequate response.
Considerations
Erythropoietin has been used as a doping agent, since it can improve performance by improving tissue oxygenation.