Anti-Cardiolipin Phospholipid Antibody (IgG) - Serology (Qualitative or Quantitative)
This test measures the presence of antibodies against cardiolipin, a phospholipid found in cell membranes, which may be linked to certain autoimmune or inflammatory conditions.
["Helps assess potential autoimmune or thrombotic risks through antibody detection in your blood."]
Key facts at a glance
- LOINC
- 51812-6
- Short code
- COX2G
- Synonyms
- C burnet Ph2 IgG Ser IA-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST, gold-top) or red-top (no additive) tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme Immunoassay (EIA) / Chemiluminescent Immunoassay (CLIA) detecting IgG antibodies against Coxiella burnetii phase 2 antigen
- CPT
- 86638
- SNOMED
- 428481002
- Specimen volume
- 1–2 mL of serum (minimum 0.5 mL)
- Stability
- Serum stable at room temperature for 8 hours, refrigerated (2–8°C) for 7 days, or frozen at ≤ -20°C for longer storage. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 150
- Icterus max
- 50
- TAT
- 24–96 hours
- Order
- routine
What This Test Measures
Cardiolipin antibodies are part of a broader group of antibodies that can be detected in conditions like lupus, antiphospholipid syndrome, or other autoimmune disorders. This test specifically looks for IgG antibodies against cardiolipin, a phospholipid that plays a role in cell membrane function. Elevated levels may indicate an immune response that could be associated with blood clotting issues or autoimmune activity.
Why It Might Be Ordered
Your healthcare provider may order this test if you have symptoms or risk factors for autoimmune diseases, such as recurrent miscarriages, blood clots, or joint pain. It may also be used to monitor conditions like lupus or antiphospholipid syndrome.
Sample Collection and Preparation
A blood sample is drawn from a vein in your arm. The blood is processed to separate serum (the liquid part after clotting) for testing. This test can be qualitative (yes/no presence) or quantitative (measuring exact levels).
Common Conditions Monitored
Elevated levels of cardiolipin antibodies may be linked to autoimmune conditions like systemic lupus erythematosus (SLE) or antiphospholipid syndrome, which can cause blood clots or pregnancy complications. They may also be found in other inflammatory or connective tissue disorders.
Reference range
Negative: <1:100; Equivocal: 1:100–1:200; Positive: >1:200. Reference values vary by laboratory and assay manufacturer; results should be interpreted alongside phase 1 IgG titers to distinguish acute from chronic Q fever infection.N/A
No special patient preparation is required. Acute and convalescent serum samples (drawn 2–4 weeks apart) are recommended for accurate serologic diagnosis of Q fever.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Anti-Cardiolipin Antibody (IgG)
Frequently asked questions
What does a positive result mean?
Can this test be done at home?
How long does it take to get results?
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.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 15, 2026. · Read our editorial policy