Serum Anti-Cardiolipin Antibody (IgG and IgM) by Immunoassay
This test measures the presence of antibodies against cardiolipin, a phospholipid found in cell membranes, which may be linked to certain autoimmune conditions.
["Antibodies to cardiolipin can help identify potential autoimmune or inflammatory processes."]
Key facts at a glance
- LOINC
- 48891-6
- Short code
- COX2IGA
- Synonyms
- C burnet Ph2 IgA Titr Fld IF
- Category
- chemistry
- Sample
- serum
- Container
- Sterile, leak-proof container or serum separator tube (SST)
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Indirect Immunofluorescence Assay (IFA)
- CPT
- 86638
- SNOMED
- 313327003
- Specimen volume
- 1-2 mL serum
- Stability
- Serum stable at room temperature for 8 hours; refrigerated at 2-8°C for 7 days; frozen at -20°C or below for long-term storage (up to 6 months). Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 50
- Icterus max
- 25
- TAT
- 48–168 hours
- Order
- routine
What This Test Measures
The test detects two types of antibodies—IgG and IgM—that target cardiolipin. These antibodies can be elevated in conditions such as lupus, antiphospholipid syndrome, or other autoimmune disorders. The results help healthcare providers assess for autoimmune activity or risk factors.
Why It Might Be Ordered
Your doctor may recommend this test if you have symptoms like unexplained blood clots, recurrent miscarriages, joint pain, or signs of an autoimmune disease. It can also be part of a broader evaluation for conditions like systemic lupus erythematosus (SLE) or other connective tissue disorders.
Common Conditions Linked to Elevated Results
High levels of anti-cardiolipin antibodies may suggest an increased risk of autoimmune-related blood clotting disorders (antiphospholipid syndrome) or other inflammatory conditions. However, not everyone with these antibodies will develop symptoms.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before the blood draw if your test includes other lab work. Wear comfortable clothing and plan for the test to be done at a clinic or lab.
Reference range
Titer < 1:50 considered negative; Titer >= 1:50 considered positive indicating past exposure or chronic Q fever infection. IgA antibodies against phase 2 antigen are particularly useful for diagnosing chronic Q fever.N/A
No fasting required. Patients should inform their healthcare provider of any current antibiotic therapy, recent vaccinations, or immunosuppressive medications as these may affect antibody titers.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Anti-Cardiolipin Antibodies (IgG/IgM)
Frequently asked questions
How long does it take to get my results?
Can I take anything before the test?
Will this test be done if I’m pregnant?
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