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Cardiolipin Antibody (IgG) - Serum

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

This test measures the presence of antibodies against cardiolipin, a component found in cell membranes, often linked to autoimmune conditions.

Quick summary

["Helps evaluate potential autoimmune or inflammatory responses in your blood."]

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

Key facts at a glance

LOINC
45057-7
Short code
ACAPNL
Synonyms
Cardiolipin IgA+IgG+IgM Pnl Ser
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or red-top tube without anticoagulant
Units
N/A
Ref low
0
Ref high
10
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Enzyme-Linked Immunosorbent Assay (ELISA)
CPT
86147x3
SNOMED
395111002
Specimen volume
1-2 mL of serum (minimum 0.5 mL)
Stability
Serum stable for 8 hours at room temperature, 7 days at 2-8°C, or 3 months at -20°C. Avoid repeated freeze-thaw cycles.
Hemolysis max
100
Lipemia max
100
Icterus max
50
TAT
24–72 hours
Order
routine

What Is Cardiolipin Antibody Testing Used For?

Cardiolipin antibodies are sometimes checked when doctors suspect autoimmune disorders, such as lupus or other connective tissue diseases. They may also be considered in patients with unexplained blood clots or heart-related symptoms, though they are not the primary test for these conditions alone.

How Is This Test Performed?

A blood sample is drawn from a vein in your arm. The sample is sent to a lab where it is tested using an immunoassay method to detect cardiolipin-specific IgG antibodies. Results are reported as either positive or negative, without a standard numeric range.

What Might High or Low Results Indicate?

Positive results suggest an immune response against cardiolipin, which can be associated with autoimmune conditions like antiphospholipid syndrome (APS) or lupus. However, false positives can occur, so further evaluation by your healthcare provider is needed.

When Might You Need This Test?

Your doctor may order this test if you have symptoms like unexplained blood clots, recurrent miscarriages, heart valve issues, or other signs of autoimmune activity. It is sometimes included in broader screening for conditions like lupus or other connective tissue diseases.

Reference range

Negative: <10 GPL U/mL (IgG), <10 MPL U/mL (IgM), <10 APL U/mL (IgA); Positive: ≥10 GPL/MPL/APL U/mL. Results reported separately for IgA, IgG, and IgM isotypes.N/A

Specimen: serum

No fasting required. Patient should be well-hydrated. Avoid sample collection during active infection or inflammation if possible, as this may elevate anticardiolipin antibody titers.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Cardiolipin antibodies are part of a group of antiphospholipid antibodies that may contribute to autoimmune disorders. While they can be detected in people with conditions like lupus or antiphospholipid syndrome, they are not definitive on their own. Doctors use them as part of a broader evaluation to assess risk for complications like blood clots or pregnancy complications.

Short name

IgG Cardiolipin Antibody

Frequently asked questions

Why might my doctor recommend this test?
Your doctor may suggest this test if you have symptoms or risk factors for autoimmune diseases, such as unexplained blood clots, recurrent pregnancy loss, or other signs of immune system involvement. It helps identify whether your body is producing antibodies against cardiolipin, which can be part of a larger evaluation.
What does a positive result mean for my health?
A positive result means your blood contains antibodies against cardiolipin, which may be linked to autoimmune conditions like antiphospholipid syndrome or lupus. However, this does not diagnose the condition alone. Your doctor will discuss next steps, which may include additional tests or monitoring.
Do I need to prepare for this test?
No special preparation is needed for this blood test. You may have some mild discomfort from the needle, but it usually goes away quickly. Avoid alcohol or certain medications for 24 hours before the test if instructed by your doctor.
  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