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Beta-2-glycoprotein I (APO2B1) Antibody, Serum

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

This test measures the presence of antibodies against a protein called beta-2-glycoprotein I, which is involved in blood clotting and immune system regulation. It may be used to evaluate conditions like antiphospholipid syndrome.

Quick summary

["This test helps assess certain autoimmune or blood-clotting disorders."]

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

Key facts at a glance

LOINC
31256-1
Short code
B2 Glycoprot1 Ab Ser Ql
Synonyms
B2 Glycoprot1 Ab Ser Ql
Category
glucose
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Might This Test Be Ordered?

Your healthcare provider may recommend this test if you have symptoms or a history suggestive of conditions like lupus, thrombophilia (increased risk of blood clots), or other autoimmune disorders. It may also be used to monitor treatment progress or diagnose unexplained clotting issues.

What Does the Test Involve?

A blood sample is drawn from a vein, usually in your arm. The sample is then sent to a lab for analysis to detect specific antibodies against beta-2-glycoprotein I. The results help determine if these antibodies are present at levels that may indicate an underlying condition.

What Are Common Reasons for Testing?

This test is often part of a broader evaluation for antiphospholipid syndrome, a condition where the immune system mistakenly attacks blood clotting proteins, leading to an increased risk of clots. It may also be used in patients with recurrent miscarriages, stroke, or other unexplained clotting events.

What Do the Results Mean?

Positive results indicate the presence of antibodies against beta-2-glycoprotein I, which may suggest an underlying autoimmune or thrombophilic condition. However, results alone do not diagnose a specific condition; they are typically interpreted alongside clinical findings and other tests.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Beta-2-Glycoprotein I Antibodies and Health Conditions

Short name

Beta-2 Glycoprotein I Antibody

Frequently asked questions

What preparation is needed before the test?
No special preparation is required for this blood test. You may continue with your normal activities, but avoid heavy exercise or eating a large meal right before your appointment. If you are on blood thinners, inform your healthcare provider before the test.
How long will it take to get the results?
Test results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your healthcare provider will discuss the results with you during a follow-up visit.
Can I fast before this test?
No fasting is required for this test. However, if you have any questions about your medications or health status, always consult your healthcare provider before the test.
  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