Anti-Cardiolipin Antibody, IgG (Serum) - Immunoassay
This test measures the presence of antibodies against cardiolipin, a protein found in cell membranes, which may be linked to certain autoimmune conditions.
["Helps assess risk for autoimmune disorders or lupus-related blood clotting issues."]
Key facts at a glance
- LOINC
- 9710-5
- Short code
- COXPH1M
- Synonyms
- C burnet Ph1 IgM Titr Ser
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube without anticoagulant
- Units
- N/A
- Ref low
- 16
- Ref high
- 1
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Immunofluorescence Assay (IFA)
- CPT
- 86638
- SNOMED
- 122310008
- Specimen volume
- 1-2 mL serum
- Stability
- Stable for 7 days at 2-8°C; for longer storage, freeze at -20°C or below
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
Why This Test Might Be Ordered
Your doctor may recommend this test if you have symptoms of autoimmune diseases, such as unexplained joint pain, fatigue, or a history of blood clots. It may also be used to monitor conditions like systemic lupus erythematosus (SLE) or antiphospholipid syndrome (APS).
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before drawing blood. Wear a comfortable shirt for easy access to your arm. Bring any medications or supplements you’re taking to discuss with your provider.
How the Test Works
A small sample of your blood is drawn from a vein in your arm. The blood is then tested in a lab using an immunoassay to detect specific antibodies against cardiolipin. The result indicates whether your immune system is producing these antibodies.
Possible Results and Their Meaning
Results are reported as either positive or negative for IgG antibodies. Elevated levels may suggest an autoimmune response, but they don’t confirm a diagnosis alone. Your doctor will review the results alongside other tests and symptoms.
Reference range
Negative: <1:16; Equivocal: 1:16-1:32; Positive: ≥1:64 (titer-dependent on laboratory-specific protocol)N/A
No fasting required. Patient should be informed about the test purpose; acute and convalescent serum samples (2-4 weeks apart) are recommended for seroconversion assessment.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Anti-CL IgG (Serum)
Frequently asked questions
Anti-cardiolipin antibodies can be associated with autoimmune diseases like lupus or APS, which increase the risk of blood clots or miscarriages. While not all positive results indicate a serious condition, they may prompt further evaluation.
A positive result means your blood contains antibodies against cardiolipin. This could signal an autoimmune process, but your doctor will consider other factors, such as symptoms and additional tests, to determine next steps.
Some autoimmune conditions may be influenced by diet, stress, or supplements. Discuss any recent changes with your doctor to ensure accurate interpretation of your 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.
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 16, 2026. · Read our editorial policy