Platelet IgG Immunoassay (Serum/Plasma)

Your healthcare provider may order this test to help diagnose a suspected condition, check for an infection after a possible exposure, or screen for a health problem before symptoms appear. It can also be used to monitor an ongoing illness or to see how well a current treatment is working.

Your doctor may recommend this test if you have unexplained low platelet counts (thrombocytopenia), unusual bleeding or bruising, or symptoms that suggest your immune system is attacking your blood cells. It’s also used to monitor treatment responses in certain autoimmune disorders.

Before the test, your provider will explain the procedure and answer any questions you have. Most people need little or no preparation, although you may be asked to avoid food or fluids for a short time, pause certain medications, or follow other simple instructions depending on the sample needed. Be sure to mention any medications, supplements, or allergies.

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. If you’re on blood-thinning medication, let your doctor know before the test.

During the test, a small sample is collected, most often with a soft swab from the nose or throat or through a simple blood draw. The sample is then examined in a laboratory or with a rapid point-of-care device that looks for the specific marker the test is designed to detect. Most results come back within a few hours to several days.

Blood is drawn and tested using an immunoassay method to detect IgG antibodies specific to platelets. The result indicates whether these antibodies are present at levels that may affect platelet function.

Results are usually reported as positive, negative, or inconclusive. A positive result means the marker being tested for was detected, a negative result means it was not found, and an inconclusive result may need to be repeated. Your healthcare provider will review your result with you, explain what it means in your situation, and discuss any follow-up care.

A positive result suggests the presence of platelet-targeting antibodies, which may explain your symptoms. A negative result means no detectable antibodies were found, but other causes of low platelets could still exist.