Cardiolipin Antibody (IgG) - Serum
This test measures the presence of antibodies against cardiolipin, a lipid found in cell membranes, which may be linked to certain autoimmune conditions.
This test helps assess potential autoimmune or inflammatory risks, often used alongside other tests for conditions like lupus or antiphospholipid syndrome.
Key facts at a glance
- LOINC
- 42731-0
- Short code
- CLGPG
- Synonyms
- Cardiolipin IgG B2GP1 dep MoM Ser
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube without anticoagulant
- Units
- N/A
- Ref low
- 0
- Ref high
- 1
- Critical range
- — – 3 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Enzyme-linked immunosorbent assay (ELISA) for detection of IgG anti-cardiolipin antibodies dependent on beta-2 glycoprotein 1 (β2GP1) cofactor, results expressed as multiple of the median (MoM)
- CPT
- 86147
- SNOMED
- 426954006
- Specimen volume
- 1 mL serum (minimum 0.5 mL)
- Stability
- Stable for 8 hours at room temperature (15-25°C); 2 weeks at 2-8°C; 6 months at -20°C or below. Avoid repeated freeze-thaw cycles. Hemolyzed, lipemic, or icteric specimens may yield unreliable results.
- Hemolysis max
- 100
- Lipemia max
- 50
- Icterus max
- 25
- TAT
- 24–72 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like unexplained blood clots, recurrent miscarriages, or chronic joint/muscle pain. It may also be used to monitor conditions like lupus or antiphospholipid syndrome, where these antibodies are known to play a role.
What to Expect Before the Test
No special preparation is needed. Bring any medications you’re currently taking, as some may affect results. Avoid alcohol for 24 hours before testing if instructed by your provider.
What the Test Involves
A blood sample is drawn from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause discomfort. The process takes about 5 minutes, and you can resume normal activities afterward.
What the Results Mean
Results are qualitative (positive/negative) and indicate whether antibodies are present. Elevated levels may suggest an autoimmune condition, but they don’t diagnose it alone. Your provider will interpret results in context with your symptoms and other tests.
Reference range
Negative: <10 GPL-U (IgG phospholipid units) or <1.0 MoM; Indeterminate: 10-40 GPL-U or 1.0-2.0 MoM; Positive (low-medium): 40-80 GPL-U or 2.0-3.0 MoM; Positive (high): >80 GPL-U or >3.0 MoM. Reference ranges vary by manufacturer and laboratory.N/A
No fasting required. Patients should be informed that false-positive results may occur with recent infections or certain medications. Confirmatory testing should be performed at least 12 weeks apart as per international consensus criteria.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
IgG Anti-Cardiolipin Antibody
Frequently asked questions
What Does Elevated/High/Normal Mean?
How Often Should I Get This Test?
Can I Take Anything to Lower My Antibody Levels?
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 10, 2026. · Read our editorial policy