ImmunologyRheumatology

Anti Phospholipid Antibody

Normal Range
< 15 U/mL (Negative)
Sample Type
Serum
Fasting
No
Unit
U/mL

Function

Anti-Phospholipid Antibodies (APA) are autoantibodies that mistakenly target the body's own phospholipids and proteins associated with cell membranes. Their presence interferes with the normal blood clotting process. This test typically looks for several types of antibodies, including Anticardiolipin (IgG, IgM) and Lupus Anticoagulant. They are key markers for an autoimmune pro-thrombotic state.

Why it is Ordered

Physicians order this test when a patient experiences unexplained blood clots (Deep Vein Thrombosis or Stroke) or recurrent pregnancy loss (miscarriages), particularly in the second or third trimester. It is also used in the diagnostic workup for Systemic Lupus Erythematosus (SLE) or other connective tissue diseases to assess the risk of thrombotic complications.

Associated Conditions

  • Antiphospholipid Syndrome (APS): A disorder characterized by recurrent arterial or venous thrombosis and/or pregnancy losses.
  • Systemic Lupus Erythematosus (SLE): Many Lupus patients carry these antibodies.
  • Thrombocytopenia: A low platelet count is often seen alongside these antibodies.
  • Preeclampsia: Increased risk of early-onset or severe high blood pressure during pregnancy.

Check Your Result

Check Your Result

Interactive
U/mL

Enter your lab result to see where you stand compared to the standard reference range.

Why Context Matters

A single positive APA result is NOT diagnostic of Antiphospholipid Syndrome. These antibodies can appear temporarily during acute infections (like syphilis or certain viruses) or due to specific medications. To confirm a diagnosis of APS, the international consensus criteria require the test to be positive on two or more occasions, at least 12 weeks apart. Therefore, a 'second opinion' via re-testing after three months is mandatory for clinical diagnosis.

Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.

Clinical References

Source-of-truth databases and clinical guidelines for Anti Phospholipid Antibody:

Related Indicators

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Medically Reviewed by Dr. Binoy Babu, MBBS

Board Certified Doctor • 10+ Years Clinical Experience

Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.

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