Platelet associated antibodiesDefinition:
A test for platelet-associated antibodies shows if you have antibodies against platelets in your blood.
How the Test is Performed:
A sample of blood will be taken from your vein.
How to Prepare for the Test:
Adults do not need to take any special steps to prepare for this test.
How the Test will Feel:
You may feel slight pain or a sting when the needle is inserted to draw blood. You may feel some throbbing afterward.
Why the Test is Performed:
You may need this test when you have a low platelet count (thrombocytopenia). It is used to detect antibodies against platelets.
A negative test is normal.
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean:
Abnormal results show that you have antiplatelet antibodies. These are proteins made by your body that attach to platelets and destroy them. This causes a low platelet count, which can lead to excessive bleeding.
Antiplatelet antibodies may appear in the blood for unknown reasons (idiopathic thrombocytopenic purpura or ITP). It can also be a side effect of certain drugs such as gold, heparin, quinidine, and quinine. These drugs can sometimes cause the immune system to attack its own platelets as foreign.
Veins and arteries vary in size so it may be harder to take a blood sample from one person than another.
Other slight risks from having blood drawn may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Current tests cannot tell for sure whether a low platelet count (thrombocytopenia) is caused by immune problems. Therefore, your doctor will make a diagnosis based on other tests and examinations.
This test is often performed because you have a bleeding problem. Bleeding may be more of a risk for you than for people who do not have bleeding problems.
Nichols WL. Von Willebrand disease and hemorrhagic disorders: Abnormalities of platelet and vascular function. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 176.
Warlemtom TE. Thrombocytopenia due to platelet destruction and hypersplenism. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, Weitz JI, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Saunders Elsevier; 2012:chap 134.