Cardiolipin Antibody (IgG) - Quantitative
This test measures the amount of antibodies your body produces against cardiolipin, a fatty substance found in cell membranes. These antibodies may be linked to certain autoimmune conditions or blood clotting issues.
["This test helps assess potential autoimmune or inflammatory risks related to cardiolipin antibodies."]
Key facts at a glance
- LOINC
- 20669-8
- Short code
- CARDA
- Synonyms
- Cardiolipin IgA Titr Ser
- Category
- chemistry
- Sample
- serum
- Container
- Serum Separator Tube (SST, tiger-top) or Red-Top tube
- Units
- N/A
- Ref low
- 20
- Ref high
- 1
- Critical range
- — – 80 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme-Linked Immunosorbent Assay (ELISA)
- CPT
- 86147
- SNOMED
- 115341008
- Specimen volume
- 1-2 mL serum (minimum 0.5 mL)
- Stability
- Stable at room temperature for 4 hours; refrigerated (2-8°C) for 7 days; frozen at -20°C or below for up to 6 months; avoid repeated freeze-thaw cycles
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like joint pain, fatigue, or unexplained blood clots, or if you have a family history of autoimmune diseases. It’s also sometimes used alongside other tests to evaluate conditions like lupus or other connective tissue disorders.
What to Expect Before the Test
No special preparation is needed. A blood sample will be taken from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause discomfort. If you’re on blood thinners, let your provider know before the test.
What the Results Mean
Results are typically reported as a concentration level (e.g., units per milliliter). High levels may suggest an autoimmune response, but they don’t diagnose a specific condition alone. Your provider will interpret results in the context of your symptoms and other tests.
Common Conditions Linked to Cardiolipin Antibodies
Elevated levels may be associated with autoimmune diseases like lupus, rheumatoid arthritis, or other inflammatory conditions. They can also appear in people with blood clotting disorders or those who have had certain infections.
Reference range
Negative: <1:20; Equivocal: 1:20-1:80; Positive: >1:80 (titers vary by laboratory; results expressed as APL IgA units or titer dilution)N/A
No special patient preparation required. Fasting is not necessary.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Cardiolipin antibodies are sometimes used as a marker in the diagnosis of autoimmune conditions, particularly when other tests are inconclusive. They can help guide treatment decisions, such as managing blood clotting risks or monitoring autoimmune activity. However, they are not definitive on their own and are often part of a broader diagnostic evaluation.
Short name
IgG Cardiolipin Antibody
Frequently asked questions
What does a positive result mean?
Will I need more tests if my cardiolipin antibody test is positive?
Can lifestyle changes help if my cardiolipin antibody levels are elevated?
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