Haptoglobin (HP) Test
Reviewed
Also called: Hemoglobin-binding protein, HPT, Hp
This test measures the amount of haptoglobin in your blood. Haptoglobin is a protein made by your liver to get rid of the hemoglobin outside your red blood cells.
Specimen: Blood
Why this test may be ordered
- To diagnose hemolytic anemia
- To see if another type of anemia or blood disorder is causing symptoms
- To check for a reaction to a blood transfusion
Preparation and collection
You don't need any special preparations for a haptoglobin test.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
To understand the results of a haptoglobin test, your provider will consider your symptoms, medical history, and the results of other blood tests. Tell your provider if you are taking any medicines. Some medicines may cause your haptoglobin test results to be higher or lower than normal.
- Lower than normal: Otherwise, a haptoglobin level that is lower than normal may be a sign of: Hemolytic anemia, Liver disease, Reaction to a transfusion. Limitation: A low haptoglobin level is normal for infants less than six months old. Next step: Your provider may order other blood tests to help make a diagnosis.
- Higher than normal: A haptoglobin level that is higher than normal may be a sign of: Ulcerative colitis, Acute rheumatic disease, such as arthritis or other conditions that affect the joints, bones, and muscles, A severe infection, Diabetes. Limitation: However, haptoglobin testing is not usually used to diagnose or monitor conditions related to high haptoglobin levels. Next step: To understand the results of a haptoglobin test, your provider will consider your symptoms, medical history, and the results of other blood tests.
- A low haptoglobin level is normal for infants less than six months old.
- Certain medicines may cause test results to be higher or lower than normal.
- Severe blood loss and conditions that worsen kidney function may also affect haptoglobin level results.
- High haptoglobin levels may be a sign of an inflammatory disease, but haptoglobin testing is not usually used to diagnose or monitor conditions related to high haptoglobin levels.
What to do next
If you have questions about your results, talk to your provider.
- What is a haptoglobin test used for?
- What do the results mean?
- Is there anything else I need to know?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.