Serum Immunoassay for Anti-Cardiolipin Antibodies (IgG and IgM)

What This Test Measures

The test detects two types of antibodies—IgG and IgM—that target cardiolipin, a lipid-protein complex. These antibodies can be elevated in conditions where the immune system mistakenly attacks healthy tissues, such as in systemic lupus erythematosus (SLE) or other autoimmune diseases.

Why It Might Be Ordered

Your healthcare provider may order this test if you have symptoms suggestive of autoimmune disease, such as joint pain, fatigue, or unexplained fevers, or if you have a known history of conditions like lupus, rheumatoid arthritis, or antiphospholipid syndrome.

Sample Collection and Preparation

A blood sample is drawn from a vein, typically in your arm. The blood is processed to separate serum (the liquid part after clotting), which is then tested for antibody levels. No special preparation is needed, but fasting may not be required unless specified by your provider.

What to Expect Before the Test

You may experience mild discomfort or bruising at the injection site, but most people tolerate blood draws well. If you have a history of needle phobia or bleeding disorders, let your provider know to discuss alternatives.