Erythropoietin

The erythropoietin serum test measures the concentration of EPO in the blood.

The erythropoietin serum test is done for several reasons, such as:

• To evaluate the cause of anemia, which is a condition where the blood has a low number of RBCs or hemoglobin, the protein that carries oxygen in the RBCs. 

• To differentiate between different types of anemia, such as iron deficiency anemia, vitamin B12 deficiency anemia, hemolytic anemia, aplastic anemia, and anemia of chronic disease.

• To diagnose and monitor polycythemia, which is a condition where the blood has a high number of RBCs.

• To assess the function of the kidneys, which are the main source of EPO production. Kidney disease can impair the ability of the kidneys to produce enough EPO, leading to anemia.

• To monitor the response to treatment with synthetic EPO (rHuEPO), which is used to treat some cases of anemia caused by kidney disease, cancer chemotherapy, or HIV infection.

The erythropoietin serum test may be recommended in the following situations:

• When a person has signs or symptoms of anemia or polycythemia.

• When a person has abnormal results from other blood tests that measure RBCs, such as complete blood count (CBC), hemoglobin, hematocrit, or reticulocyte count.

• When a person has a known or suspected kidney disease that may affect EPO production.

• When a person is receiving rHuEPO therapy and needs to monitor its effectiveness and dosage.

Abnormal results of the erythropoietin serum test may indicate various conditions that affect the production or function of RBCs. Some examples are:

• Low EPO levels: This may indicate anemia due to decreased EPO production by the kidneys, such as in chronic kidney disease, or due to increased destruction of RBCs, such as in hemolytic anemia or sickle cell anemia. Low EPO levels may also indicate bone marrow disorders that impair RBC production, such as aplastic anemia or leukemia.
• High EPO levels: This may indicate polycythemia due to increased EPO production by the kidneys or other sources, such as tumors. High EPO levels may also indicate an appropriate response to low oxygen levels in the blood, such as in high-altitude living, lung disease, heart disease, or smoking.
• Normal or low-normal EPO levels: This may indicate anemia due to decreased RBC production by the bone marrow that is not related to EPO levels, such as iron deficiency anemia, vitamin B12 deficiency anemia, or anemia of chronic disease.

The erythropoietin serum test is a simple blood test that involves the following steps:

• A healthcare professional will clean a small area of skin on your arm with antiseptic and insert a needle into a vein. When the needle is inserted, you can experience a little squeeze or sting.
• The healthcare professional will collect a small amount of blood into a tube or syringe and remove the needle. You may feel some pressure when the needle comes out.
• The healthcare professional will apply pressure and a bandage to stop any bleeding and prevent infection.
• The blood sample will be analyzed at a laboratory.

Morning samples taken between 7.30 am and 12.00 PM are recommended. Inform your healthcare provider if you are taking any medications, supplements, or herbal remedies that may affect your EPO levels, such as rHuEPO, steroids, or blood thinners. You should also inform your healthcare provider if you have any medical conditions or allergies that may affect the test. You can receive detailed instructions from your healthcare practitioner on how to get ready for the test.

The erythropoietin serum test is often ordered with other blood tests that measure RBCs and related parameters, such as:

• Complete blood count (CBC): To evaluate the number and size of RBCs, white blood cells (WBCs), and platelets in the blood.
• Hemoglobin: To measure the amount of oxygen-carrying protein in the RBCs.
• Hematocrit: To measure the percentage of blood volume that is occupied by RBCs.
• Reticulocyte count: To measure the number of immature RBCs in the blood, which reflects the rate of RBC production by the bone marrow.
• Iron studies: To measure the levels of iron and related proteins in the blood, such as serum iron, total iron-binding capacity (TIBC), transferrin, and ferritin. Iron is an essential component of hemoglobin and is needed for RBC production.
• Vitamin B12 and folate: To measure the levels of these vitamins in the blood, which are also needed for RBC production.
• Kidney function tests: To measure the levels of creatinine and blood urea nitrogen (BUN) in the blood, which reflect the function of the kidneys.

• EPO test
• Serum erythropoietin test
• Erythropoietin hormone test

Polycythemia is a medical condition characterized by an abnormal increase in the number of red blood cells in the bloodstream. Red blood cells, also known as erythrocytes, are responsible for carrying oxygen from the lungs to the rest of the body and transporting carbon dioxide back to the lungs for elimination.