Phosphatidylserine IgG Antibody, Serum

What This Test Measures

Phosphatidylserine is a fat-like molecule (phospholipid) normally located on the inner surface of cell membranes. Sometimes the immune system mistakenly produces antibodies against it. This test detects and measures the amount of IgG-class antibodies directed against phosphatidylserine in a blood (serum) sample.

Why It May Be Ordered

Your healthcare provider may order this test when evaluating unexplained blood clots, recurrent pregnancy loss, or symptoms that raise concern for an antiphospholipid syndrome or other autoimmune condition. It is usually part of a panel of related antibody tests rather than a stand-alone diagnosis.

How the Sample Is Collected

A routine blood draw from a vein in your arm is used to obtain the serum sample. No special preparation is typically required unless your provider gives other instructions. Tell your care team about any medications or recent illnesses, as these can sometimes affect results.

Understanding Your Results

Results are usually reported as a value with a reference interval, along with a positive, negative, or equivocal interpretation depending on the laboratory. A single positive result does not confirm a diagnosis; providers often repeat testing and combine it with other antiphospholipid antibody tests and your symptoms. Discuss what your specific result means with your provider.