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Anti-Cardiolipin Antibody (IgG) with High-Sensitivity Immunoassay

Published: August 9, 2026Updated: August 16, 2026

This test measures the presence of antibodies against cardiolipin, a phospholipid found in cell membranes, often used to evaluate for lupus anticoagulant or antiphospholipid syndrome.

Quick summary

["This test helps assess potential blood clotting issues or autoimmune conditions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
58761-8
Short code
CBUR2G
Synonyms
C burnet Ph2 IgG Titr CSF IF
Category
chemistry
Sample
csf
Container
Sterile, leak-proof, screw-cap cryovial or CSF collection tube (polypropylene preferred). Tubes should be free of preservatives that may interfere with immunofluorescence detection.
Units
N/A
Ref low
0
Ref high
1
Critical range
— – 128 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Immunofluorescence Assay (IFA)
CPT
86638
SNOMED
122460008
Specimen volume
Minimum 0.5 mL of cerebrospinal fluid; optimal volume 1.0–2.0 mL
Stability
Room temperature: 2 hours; Refrigerated (2–8°C): 7 days; Frozen (-20°C or below): up to 30 days. Avoid repeated freeze-thaw cycles. Ship on cold packs if not delivered same day.
Hemolysis max
200
TAT
48–96 hours
Order
routine

What This Test Measures

Anti-cardiolipin antibodies are proteins your immune system produces in response to certain phospholipids in your blood. High levels may suggest an autoimmune condition or increased risk of blood clots, though they are not definitive on their own.

Why It Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like unexplained blood clots, recurrent miscarriages, or other signs of antiphospholipid syndrome. It may also be part of a broader evaluation for conditions like lupus or other autoimmune disorders.

What to Expect Before the Test

No special preparation is needed unless instructed by your provider. You may have blood drawn from a vein in your arm, similar to other routine blood tests.

What the Results Mean

Results are typically reported as positive or negative for IgG antibodies. Elevated levels may indicate an increased risk of clotting or autoimmune activity, but further testing and clinical correlation are needed for diagnosis.

Reference range

Titer <1:16: Negative (no detectable antibodies); Titer 1:16–1:64: Equivocal/borderline; Titer ≥1:128: Positive, suggestive of past exposure or chronic Q fever infectionN/A

Specimen: csf

No special patient preparation is required. Inform the ordering physician of any recent antibiotic therapy, as it may affect antibody titers. Lumbar puncture should be performed under sterile conditions by qualified personnel.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Positive results for anti-cardiolipin antibodies can be associated with antiphospholipid syndrome, a condition linked to an increased risk of blood clots and pregnancy complications. They may also appear in other autoimmune diseases like lupus. However, they are not alone sufficient for diagnosis; additional tests and clinical findings are required.

Short name

Anti-Cardiolipin IgG (High-Sensitivity)

Frequently asked questions

What does a positive result mean?
A positive result suggests your immune system may be producing antibodies against cardiolipin, which could be linked to conditions like antiphospholipid syndrome or other autoimmune disorders. Your provider will discuss next steps based on your symptoms and test results.
Can this test be done at home?
No, this test requires a blood sample collected by a healthcare professional in a clinical setting.
How often should I get this test?
Your provider will determine the frequency based on your symptoms, medical history, and other test results. Follow-up may be needed if initial results are elevated or if you have ongoing symptoms.
  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 16, 2026. · Read our editorial policy