Home Biomarkers Anti Cardiolipin IgG

Anti Cardiolipin IgG

Blood clotting Biomarker

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Collection Type: Blood

Body System

Related System: Blood clotting

Overview

Anti‑cardiolipin IgG is an autoantibody directed against cardiolipin, a phospholipid found on cell membranes. The laboratory test measures the concentration of IgG-class anticardiolipin antibodies, reported in GPL (IgG phospholipid) units, and is used to detect antiphospholipid antibodies that promote abnormal blood clotting. Persistent high levels are associated with antiphospholipid syndrome (APS), which causes venous or arterial thrombosis and pregnancy complications (recurrent miscarriage, fetal loss). Testing is indicated in unexplained clots, recurrent pregnancy loss, stroke in the young, or when systemic autoimmune disease (e.g., lupus) is suspected. Levels can be transiently elevated after infections or certain drugs; true clinical risk rises with persistent, higher titers. APS is more commonly diagnosed in women; age and concomitant autoimmune disease affect pretest probability.

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Test Preparation

No special preparation is required

Why Do I Need This Test

Profile: Blood clotting (antiphospholipid/APS) panel - Symptoms: unexplained venous/arterial thrombosis, recurrent miscarriages, ischemic stroke at a young age, unexplained thrombocytopenia, or prolonged aPTT - Diagnoses/monitoring: helps diagnose antiphospholipid syndrome and assess thrombotic risk in autoimmune disease - Reasons for abnormal levels: autoimmune production (primary or secondary to SLE), recent infection, certain drugs - Biological meaning: positive IgG indicates increased risk of clotting and pregnancy morbidity (risk correlates with titer and persistence) - Behaviors/lifestyle: smoking, estrogen use, and immobility increase clot risk but don’t directly cause the antibody - Family history: family history of autoimmune disease, recurrent thrombosis, or recurrent pregnancy loss may prompt testing

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Understanding Test Results

<20 GPL units: negative no clinically significant anticardiolipin IgG detected; low risk from this antibody alone.
20–40 GPL units: low/borderline positive may be transient (post‑infection/drug).
If clinical suspicion is low, repeat testing is advised; isolated low titers carry modest risk.
40–80 GPL units: moderate positive increased likelihood of clinical antiphospholipid syndrome when persistent; associated with higher thrombotic and pregnancy-complication risk.
>80 GPL units: high positive strong association with APS and substantial risk of venous/arterial thrombosis and pregnancy morbidity, especially if confirmed on repeat testing ≥12 weeks apart.
Notes: A single positive result can be transient; diagnostic significance requires persistence on repeat testing after ≥12 weeks and correlation with clinical events.
IgG titers are generally more predictive of clinical events than IgM; laboratory methods and unit definitions vary, so interpret against lab-specific reference ranges and clinical context.

Normal Range

0-20 GPL units

FAQs

Q: What does a positive anti-cardiolipin IgG mean?

A: A positive anti-cardiolipin IgG indicates an antiphospholipid antibody linked to higher risk of blood clots, stroke and pregnancy loss. A single positive result can be transient (infection, medication); diagnosis of antiphospholipid syndrome requires persistent positivity on repeat testing at least 12 weeks apart plus relevant clinical events. Results need clinical correlation; a specialist can advise further tests and potential anticoagulation.

Q: What is anti-cardiolipin used for?

A: Anti-cardiolipin testing detects antibodies against cardiolipin and is used to help diagnose antiphospholipid syndrome. Clinicians order it when patients have unexplained blood clots, recurrent miscarriages or fetal loss, strokes or thrombocytopenia, or when autoimmune disease (e.g., lupus) is suspected. Positive results, repeated 12 weeks apart, support diagnosis and guide anticoagulation and pregnancy management.

Q: What is the anti-cardiolipin IgM test for?

A: The anti‑cardiolipin IgM test measures IgM antibodies against cardiolipin to help evaluate antiphospholipid syndrome (APS). It’s ordered for unexplained blood clots, recurrent miscarriages, or in autoimmune disease like lupus. Positive results indicate increased risk of thrombosis or pregnancy complications and are interpreted alongside IgG and beta‑2 glycoprotein I tests; abnormal results are usually repeated after 12 weeks.

Q: What if my cardiolipin is high?

A: If your cardiolipin (anticardiolipin antibody) is high, it can indicate antiphospholipid antibodies linked to increased risk of blood clots and pregnancy loss. Repeat testing after 12 weeks is needed to confirm persistence; transient positives can follow infections or medications. Your clinician will evaluate symptoms, autoimmune conditions, and consider preventive measures or anticoagulation if you’ve had clots or pregnancy complications.

Q: What is the main function of cardiolipin?

A: Cardiolipin is a unique mitochondrial inner‑membrane phospholipid that maintains membrane curvature and stability and anchors respiratory chain complexes, optimizing electron transport and ATP synthesis. It supports assembly and function of oxidative phosphorylation machinery, influences mitochondrial dynamics and membrane potential, and participates in signaling such as apoptosis and mitophagy. Loss or remodeling of cardiolipin impairs energy production and cellular health.

Q: Can ANA titer go back to normal?

A: Yes ANA titers can fall or become negative in some people. Titers often decline with effective treatment or during remission of autoimmune disease, and they may be transient after infections or certain medications. However, ANA can also remain persistently positive without active disease. Repeat testing and clinical correlation guide interpretation; discuss results and management with your clinician.