Erythropoietin - Test, Procedure & Cost

Introduction

Erythropoietin (EPO), also known as erythropoetin, haematopoietin, or haemopoietin, is a glycoprotein cytokine secreted mainly by the kidneys in response to cellular hypoxia; it stimulates red blood cell production (erythropoiesis) in the bone marrow. Low levels of EPO (around 10 mU/mL) are constantly secreted in sufficient quantities to compensate for normal red blood cell turnover. Common causes of cellular hypoxia resulting in elevated levels of EPO (up to 10 000 mU/mL) include anaemia and hypoxemia due to chronic lung disease.

Function

• EPO helps make red blood cells. Red blood cells deliver oxygen to the tissues in your body. Oxygen turns into energy, and your tissues release carbon dioxide. Your red blood cells also transport carbon dioxide to your lungs for you to exhale.
• Normally, when specialized cells in your kidneys detect low blood oxygen levels, they increase the production of EPO. EPO then tells the spongy tissue inside your bones (bone marrow) to make more red blood cells.
• When cells in your kidneys sense that there’s sufficient oxygen in your blood, they reduce the production of erythropoietin.
• Certain conditions can affect how much EPO your kidneys make. They may make too much or not enough. This results in low levels of red blood cells or high levels of red blood cells.

High levels of Erythropoietin

Increased EPO levels may be due to secondary polycythemia. This is an overproduction of red blood cells that occurs in response to an event such as a low blood oxygen level. The condition may occur at high altitudes or, rarely, because of a tumour that releases EPO.

Low levels of Erythropoietin

Lower-than-normal EPO levels may be seen in chronic kidney failure, anaemia of chronic disease, or polycythemia vera.

Normal levels of Erythropoietin

A normal range for your EPO levels may be between 4 and 26 mU/mL.

Your EPO test results may vary according to several factors, including your:

• Age.
• Biological sex.
• Overall health.

Treatment of low levels of Erythropoietin

The most common treatment to directly correct anaemia due to low EPO levels is recombinant erythropoietin (erythropoietin-stimulating agents or ESAs). This is an artificial (synthetic) version of natural EPO. Healthcare providers clone the gene for EPO and give them to you by injection (shot) to stimulate the production of more red blood cells.

ESAs may cause:

• High blood pressure.
• Fever.
• Dizziness.
• Nausea.
• Pain at the injection site.