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Cardiolipin Antibody (IgG) – Phospholipid-Associated Autoantibody (Screen)

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

This blood test checks for antibodies that may indicate an autoimmune response targeting a phospholipid found in cell membranes, sometimes linked to certain blood clotting disorders.

Quick summary

A screen for rare antibodies that could signal potential blood clotting risks or autoimmune conditions.

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

Key facts at a glance

LOINC
105791-8
Short code
BC-SPM-CT
Synonyms
Carbpnm resist SPM Ct Bld +Qn NAA prb
Category
chemistry
Sample
whole-blood
Container
Positive blood culture bottle (aerobic or anaerobic) transferred to a sterile, leak-proof, DNA-free microcentrifuge tube or assay-specific transport tube for molecular testing.
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
probe-amp-tar
CPT
87153 (Identification of bacteria by nucleic acid probe; carbapenem resistance gene detection by amplified probe technique). Additional reflex code may include 87798 if performed as part of a multiplex panel.
SNOMED
122450008 | Microbial sensitivity test| + 426396005 | Carbapenem resistance|
Specimen volume
0.2–1 mL aliquot taken from a positive blood culture bottle; volume dependent on specific NAA assay requirements.
Stability
Stable for 24–48 hours at 2–8°C in original blood culture bottle. Once aliquoted, process within 2 hours at room temperature or refrigerate at 2–8°C for up to 24 hours per most assay package inserts. Avoid repeated freeze-thaw cycles.
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
1–4 hours
Order
routine

What This Test Measures

The test detects IgG antibodies against cardiolipin, a natural lipid (fat) molecule present in cell membranes. These antibodies may be produced by the immune system in response to inflammation or autoimmune processes, though their exact cause isn’t always clear.

Why It’s Ordered

Your healthcare provider may recommend this test if you have symptoms like unexplained bruising, blood clots, or recurrent miscarriages, or if you have a family history of autoimmune disorders or blood clotting issues.

Common Conditions Linked to Positive Results

Positive results can sometimes be associated with autoimmune conditions like lupus, antiphospholipid syndrome, or other inflammatory disorders. However, many people test positive without symptoms.

What to Expect Before the Test

No special preparation is needed. You’ll have a small needle inserted into your arm for a simple blood draw, similar to other routine blood tests.

Reference range

Reportable as Cycle Threshold (Ct) value. The presence of the SPM gene is reported as Detected or Not Detected. Lower Ct values indicate higher bacterial gene load. Typical Ct cutoffs vary by assay; consult laboratory-specific interpretive criteria.N/A

Specimen: whole-blood

No special patient preparation is required. Specimen is obtained from a positive blood culture flagged by the blood culture instrument, not a direct patient draw.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Cardiolipin IgG (Screen)

Frequently asked questions

How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab. Follow-up with your healthcare provider is recommended to discuss next steps if your results are positive or abnormal.
Can I fast before this test?
No fasting is required for this test. However, always inform your healthcare provider about any medications or supplements you’re taking, as they may affect results.
What does a positive result mean?
A positive result suggests the presence of cardiolipin antibodies, which may raise concerns for autoimmune or clotting-related conditions. Further testing, like confirmatory assays or additional blood work, may be needed to explore these possibilities.
  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