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Anti-Cardiolipin Phospholipid Antibody (IgG) - Quantitative

Published: August 9, 2026Updated: August 15, 2026

This test measures the level of antibodies in your blood that target cardiolipin, a phospholipid found in cell membranes. These antibodies may be linked to certain autoimmune conditions or blood clotting issues.

Quick summary

["This test helps evaluate potential autoimmune or clotting disorders by detecting abnormal antibody responses to cardiolipin."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 15, 2026Editorial policy

Key facts at a glance

LOINC
110995-8
Short code
COXPG1
Synonyms
C burnet Ph1 IgG Msmt Ser
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or red-top tube; transfer serum to sterile aliquot tube
Units
N/A
Ref low
0
Ref high
1
Critical range
— – 800 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Immunofluorescence Assay (IFA)
CPT
86638
SNOMED
313327003
Specimen volume
1-2 mL serum (minimum 0.5 mL)
Stability
Serum stable at room temperature for 8 hours; refrigerated (2-8°C) for 7 days; frozen (-20°C or below) for up to 4 weeks. Avoid repeated freeze-thaw cycles.
Hemolysis max
100
Lipemia max
100
Icterus max
50
TAT
48–168 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms or risk factors for autoimmune diseases like lupus, rheumatoid arthritis, or antiphospholipid syndrome. It could also be used to monitor conditions involving abnormal blood clotting or inflammation.

What to Expect During the Test

A blood sample will be drawn from a vein, usually in your arm. You may feel a slight pinch, but it typically doesn’t cause significant discomfort. The test involves processing the blood sample to measure IgG antibodies against cardiolipin.

Your blood sample will be sent to a lab where it is analyzed using an immunoassay method to detect the presence and concentration of IgG antibodies specific to cardiolipin.

This method ensures accurate measurement of antibody levels, which helps determine if your immune system is producing abnormal responses to this phospholipid.

The results indicate the concentration of IgG antibodies in your blood. Elevated levels may suggest an autoimmune condition or increased risk of blood clots, but interpretation depends on clinical context and other test results.

Elevated levels might prompt further evaluation, including additional blood tests or monitoring for symptoms related to autoimmune or clotting disorders.

Reference range

Negative: <1:16; Phase 1 IgG titer <1:200 typically indicates past exposure without chronic infection. Titers ≥1:800 are suggestive of chronic Q fever.N/A

Specimen: serum

No special preparation required. Fasting is not necessary. Patient should be informed that this test detects antibodies to Coxiella burnetii, the causative agent of Q fever, and results may require follow-up testing.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Anti-cardiolipin antibodies can be associated with autoimmune diseases such as systemic lupus erythematosus (SLE) or antiphospholipid syndrome, which increases the risk of blood clots. They may also appear in other inflammatory conditions. While not all positive results indicate a specific diagnosis, they can guide further medical evaluation.

Short name

IgG Anti-Cardiolipin Antibody

Frequently asked questions

What does a positive result mean?
A positive result means your blood contains higher-than-normal levels of IgG antibodies against cardiolipin. This may raise concerns about autoimmune activity or blood clotting risks, but it doesn’t diagnose a condition alone. Your doctor will consider your symptoms, other test results, and medical history to determine next steps.
How often should I get this test?
The frequency depends on your medical condition and symptoms. If you have an autoimmune disorder or clotting history, your doctor may recommend periodic testing. If this test is part of routine monitoring, follow their guidance on timing and intervals.
Can lifestyle changes affect this test result?
While lifestyle factors like diet, stress, or certain medications may influence immune activity, they typically don’t directly alter antibody levels measured in this test. However, they can impact overall health and symptoms related to conditions this test may help identify.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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