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Anti-Cardiolipin Antibody (IgG) - Quantitative

Published: August 9, 2026Updated: August 17, 2026

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

Quick summary

["This test helps assess potential autoimmune or clotting risks by detecting unusual antibody activity."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
110021-3
Short code
AChR Block Ab Msmt Ser
Synonyms
AChR Block Ab Msmt Ser
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
22
Ref high
198
Critical range
— – 10000 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82553
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like unexplained fatigue, joint pain, or a history of blood clots. It’s also sometimes checked in people with autoimmune diseases like lupus or rheumatoid arthritis, or if you’ve had unexplained miscarriages.

What to Expect Before the Test

No special preparation is usually 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.

What the Test Involves

A healthcare professional will insert a needle into a vein in your arm to collect a blood sample. You may feel a slight pinch, but it’s usually over quickly. The blood is then sent to a lab for analysis.

What the Results Mean

Results are compared to a standard range, but exact values can vary by lab. High levels may suggest an autoimmune condition or increased risk of clotting, while normal levels usually indicate no significant antibody activity.

Reference range

Adult males: 22-198 U/L; Females: 22-198 U/LN/A

Specimen: serum

No special preparation required. Inform provider of any chest pain or symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Anti-Cardiolipin IgG

Frequently asked questions

What does elevated or low antibody levels indicate?
Elevated levels of anti-cardiolipin antibodies may be associated with autoimmune diseases like systemic lupus erythematosus (SLE) or antiphospholipid syndrome, which can increase the risk of blood clots or recurrent pregnancy loss. However, not everyone with these antibodies has symptoms.
What if my results are normal?
Normal results mean your antibody levels are within the expected range, but they don’t rule out all possible causes of symptoms like fatigue or joint pain. Follow-up with your doctor if you have ongoing concerns.
How often should I get this test?
Your doctor will determine the frequency based on your medical history, symptoms, and other test results. Some patients may need retesting every few months or years, depending on their condition.
  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 17, 2026. · Read our editorial policy