Serum or Plasma Immunoassay for Anti-Cardiolipin Antibodies (IgG)
This test measures the level of antibodies in your blood that target cardiolipin, a fatty substance found in cell membranes. These antibodies may be linked to certain autoimmune conditions or blood clotting issues.
["Helps assess potential autoimmune or clotting disorders by detecting unusual antibody activity against cardiolipin."]
Key facts at a glance
- LOINC
- 16486-3
- Short code
- BRUCAB
- Synonyms
- B abortus IgA+IgG+IgM Ser-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube
- Units
- N/A
- Ref low
- 20
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme Immunoassay (EIA) / ELISA
- CPT
- 86622
- SNOMED
- 395127008
- Specimen volume
- 1-2 mL of serum
- Stability
- Stable for 7 days at 2-8°C; for longer storage, freeze at -20°C or below
- Hemolysis max
- 100
- Lipemia max
- 200
- Icterus max
- 40
- TAT
- 24–72 hours
- Order
- routine
What This Test Measures
Cardiolipin is a phospholipid found in cell membranes, particularly in heart tissue. When your immune system mistakenly produces antibodies against cardiolipin, it may indicate an autoimmune response or increased risk of blood clots. This test specifically looks for IgG antibodies that target cardiolipin, which can be part of a broader evaluation for conditions like lupus or antiphospholipid syndrome.
Why It Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms or risk factors for autoimmune diseases, such as unexplained joint pain, fatigue, or a history of blood clots. It may also be used as part of a screening or monitoring plan for conditions like systemic lupus erythematosus (SLE) or other connective tissue disorders.
Sample Collection and Preparation
A blood sample is drawn from a vein, usually in your arm. The blood is then processed to separate serum (liquid part after clotting) or plasma (liquid part before clotting). This sample is sent to a lab for testing using an immunoassay method, which detects the presence of IgG antibodies against cardiolipin.
What to Expect Before or After Testing
There are no special preparations needed before the test. You may feel slight discomfort during the blood draw, but it typically resolves quickly. If you’re on blood-thinning medication, let your provider know before testing, as it may affect results or safety.
Reference range
Negative: < 1:20; Equivocal: 1:20-1:40; Positive: > 1:40 (titers vary by assay manufacturer)N/A
No fasting required. Patient should avoid antibiotic therapy prior to testing if possible, as early treatment may suppress antibody production. Inform clinician of any recent vaccinations or travel history to endemic regions.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
IgG Anti-Cardiolipin Antibodies
Frequently asked questions
What does a high or low result mean?
Can this test be used to diagnose lupus or other autoimmune diseases?
Does this test require fasting?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 15, 2026. · Read our editorial policy