Home Biomarkers Anti-Phospholipid (IgG)

Anti-Phospholipid (IgG)

Autoimmune disorder Biomarker

Sample Needed

Collection Type: Blood

Body System

Related System: Autoimmune disorder

Overview

Anti-phospholipid (IgG) refers to IgG-class antibodies that bind phospholipids or phospholipid‑binding proteins (most commonly cardiolipin or β2‑glycoprotein I). The test measures the concentration of these IgG antibodies in blood to detect immune activity that promotes blood clotting. Elevated anti‑phospholipid IgG is associated with antiphospholipid syndrome (APS), which causes arterial or venous thrombosis and recurrent pregnancy loss, and can occur with systemic autoimmune diseases (e.g., SLE) or transiently after infections. Testing is considered for unexplained clots, recurrent miscarriages, or thrombocytopenia. Positivity is more common and clinically important in women of reproductive age; transient low positives can occur in all ages, while persistent high IgG confers higher thrombotic risk.

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Test Preparation

A duly filled coagulation requisition form (Annexure - CR/05) is mandatory for sample collection
With prior consent from the treating physician, it is recommended to discontinue heparin for 1-day and oral anticoagulants for 7-days before sample collection, as these drugs may affect test results

Why Do I Need This Test

Profile: Autoimmune disorder (anti‑phospholipid/APS panel) - Indications: unexplained venous/arterial thrombosis, recurrent pregnancy loss, unexplained thrombocytopenia, evaluation of SLE patients - Diagnoses/monitoring: antiphospholipid syndrome, risk stratification for thrombosis in autoimmune disease - Reasons for abnormal levels: true autoimmune antibody production, recent infections, certain drugs, or transient immune activation - Biological meaning: positive IgG indicates autoantibody-mediated prothrombotic tendency - Lifestyle/family: smoking, estrogen therapy increase clot risk; family history of autoimmune disease or thrombosis may prompt testing

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Understanding Test Results

Values <20 GPL units are considered negative/normal and carry no specific APS-related thrombotic risk.
Values 20–40 GPL units are low/borderline positive; these may be transient (e.g., after infection) and confer modest or uncertain risk—repeat testing in 12 weeks is required.
Values ≥40 GPL units (high‑positive) are strongly associated with antiphospholipid syndrome and a higher risk of arterial or venous thrombosis and pregnancy morbidity, especially if positivity is persistent on repeat testing after ≥12 weeks.
Isolated low positives without clinical events often need observation; high or persistent IgG positivity plus clinical criteria (thrombosis or pregnancy complications) supports an APS diagnosis and usually prompts anticoagulation/management.
False positives can occur with acute illnesses or certain medications; laboratory methods and cutoffs vary, so interpret with the reporting lab’s reference and clinical context.

Normal Range

0-20 GPL units

FAQs

Q: What is the anti phospholipid IgG test used for?

A: The antiphospholipid IgG test detects IgG-class antibodies against phospholipid-binding proteins. It’s used to help diagnose antiphospholipid syndrome in people with unexplained arterial or venous blood clots, recurrent miscarriages, or certain autoimmune symptoms. Results aid risk assessment for thrombosis and pregnancy complications and guide treatment decisions such as anticoagulation or specialist referral. Positive tests are usually repeated to confirm diagnosis.

Q: What does a positive antiphospholipid antibody mean?

A: A positive antiphospholipid antibody test means the immune system makes antibodies that increase risk of blood clots and pregnancy problems (recurrent miscarriage, stillbirth, preeclampsia). A single positive result can be transient, so repeat testing after 12 weeks is recommended. Diagnosis of antiphospholipid syndrome needs persistent antibodies plus clinical events; management depends on symptoms and often involves anticoagulation.

Q: What is the normal range for IgG anti phospholipids?

A: IgG antiphospholipid antibody results vary by lab, but common cutoffs are: negative <20 units (GPL or U); 20–40 units low/borderline; ≥40 units moderate–high (with >80 often classed as high for anticardiolipin IgG). Anti–β2‑glycoprotein I IgG uses similar thresholds. Interpret results with the ordering clinician because methods and units differ.

Q: What are the three antibodies in apla syndrome?

A: Antiphospholipid (APLA) syndrome is defined by three main antibodies: lupus anticoagulant, anticardiolipin antibodies, and anti–beta2‑glycoprotein I antibodies. These autoantibodies target phospholipid–protein complexes, promote clot formation and are linked to recurrent arterial or venous thrombosis and pregnancy complications. Diagnosis requires persistent positivity on repeated testing at least 12 weeks apart alongside clinical features.

Q: Is lupus anticoagulant serious?

A: Lupus anticoagulant can be serious: it’s an autoantibody that increases risk of blood clots (veins and arteries), stroke, and pregnancy complications like recurrent miscarriage. It may be transient or part of antiphospholipid syndrome. Detection warrants specialist assessment and sometimes long-term anticoagulation to prevent thrombosis. With proper monitoring and treatment the risks can be reduced, but prompt medical follow-up is important.

Q: Can antiphospholipid antibodies be cured?

A: Antiphospholipid antibodies often cannot be “cured.” They may be transient after infections, but persistent positivity defines antiphospholipid syndrome (APS). Treatment focuses on preventing clots and pregnancy loss—typically long-term anticoagulation and risk-factor control. In selected severe or refractory cases immunomodulatory therapies are used. Regular monitoring and individualized management reduce complications, but eradication of antibodies is uncommon.