What does an abnormal platelet function test mean?
What does the test result mean? The interpretation of results of the various types of platelet function tests depends on why the tests were performed. In the investigation of excessive bleeding or the potential for bleeding during surgery, abnormal results may indicate the presence of a platelet disorder.
What does high collagen ADP mean?
The collagen-ADP cartridge usually produces abnormal results with platelet disorders and von Willebrand disease but produces a normal closure time with aspirin-like drugs because of their high ADP concentrations.
What is normal PFA?
Normal closure times range from 77 to 133 seconds for the Col/ADP membrane and 98-185 seconds for the Col/Epi membrane. The PFA-100 has been tested in persons with bleeding disorders.
What does an abnormal PFA mean?
Abnormal PFA-100 closure time is associated with increased platelet aggregation in patients presenting with chest pain. J Thromb Thrombolysis.
What causes abnormal platelet function?
A platelet disorder affects normal blood clotting. Disorders that can cause problems in platelet function include: Idiopathic thrombocytopenic purpura (bleeding disorder in which the immune system destroys platelets) Chronic myelogenous leukemia (blood cancer that starts inside bone marrow)
What is a PFA-100 blood test?
The PFA-100 is a device that simulates high shear dependent platelet function in vitro and thus is particularly useful for screening for von Willebrand’s disease (VWD).
What does PFA measure?
The PFA test is a new laboratory screening test of platelet function that measures both platelet adhesion and aggregation (primary hemostasis).
What causes low platelet function?
Factors that can decrease platelet production include: Leukemia and other cancers. Some types of anemia. Viral infections, such as hepatitis C or HIV.
How is platelet dysfunction treated?
Bone marrow disorders are often treated with platelet transfusions or removing platelets from the blood (platelet pheresis). Chemotherapy may be used to treat an underlying condition that is causing the problem. Platelet function defects caused by kidney failure are treated with dialysis or medicines.
What does a normal Col/epi and Col/ADP closure time indicate?
Normal closure times with both COL/EPI and COL/ADP indicate normal platelet function. The COL/EPI membrane is more sensitive to disorders of primary hemostasis, but is less specific. A prolonged closure time with COL/EPI membrane and a normal closure time with COL/ADP may be the result of: Thrombocytopenia. Anemia.
What is a platelet function test?
Test Information. The PFA is a screening test for platelet dysfunction. The cartridge membrane is coated with collagen, and with one of two platelet agonists (epinephrine or ADP).
What is the difference between Col/ADP and Col/epi membrane?
The COL/EPI membrane is more sensitive to disorders of primary hemostasis, but is less specific. A prolonged closure time with COL/EPI membrane and a normal closure time with COL/ADP may be the result of: Aspirin therapy affects the COL/EPI more than the COL/ADP closure time.
How do platelets respond to collagen and epinephrine?
The platelets adhere to the collagen and aggregate in response to the collagen and epinephrine (or ADP). The response measured is known as the Closure Time (CT) and is reported in seconds.