Synonyms
- Anti-β2 Glycoprotein 1
- Beta-2 Glycoprotein 1 Antibodies
Test Includes
Semiquantitative results for IgG antibodies against β2-glycoproteins
Expected Turnaround Time
2 - 3 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Information
Related Documents
For more information, please view the literature below.
Procedures for Hemostasis and Thrombosis: A Clinical Test Compendium
Specimen Requirements
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Red-top tube or gel-barrier tube
Storage Instructions
Room temperature
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 15 days |
Refrigerated | 15 days |
Frozen | 15 days |
Freeze/thaw cycles | Stable x3 |
Test Details
Use
Assess the risk of thrombosis in patients who may be at risk for antiphospholipid syndrome (APS). This test should be used in conjunction with current traditional anticardiolipin and anticoagulant tests.1
Limitations
Anti-β2-glycoprotein 1 should not be used alone as a screening test for antiphospholipid syndrome.
Methodology
Enzyme-linked immunosorbent assay (ELISA) to detect antibodies binding to a microtiter plate coated with purified β2-glycoprotein 1 antigen
Reference Interval
<20 units
Additional Information
Recently, an international consensus group of experts in the diagnosis and management of antiphospholipid syndrome (APS) concluded that β2-GP1 IgG and IgM antibodies should be included as diagnostic criteria for APS.2 This group determined that the presence of one or both of these antibodies is an independent risk factor for thrombosis and pregnancy complications.3
A common aspect to all assays for anticardiolipin antibodies (ACA) is the requirement that the assay system include a source of plasma proteins.3 It has been determined that, in many patients, β2-glycoprotein 1 (β2-GP1) is the plasma factor required for ACA binding.3,4 Solid-phase enzyme immunoassays that detect antibodies that bind to β2-GP1 in the absence of phospholipid are now part of the diagnostic arsenal for APS. β2-GP1-dependent binding is frequently detected in patients with clinical symptoms of APS.3 All three isotypes of anti-β2-GP1 (IgG, IgM, and IgA) have been associated with thrombosis.3,5,6 ACA that do not require β2-GP1 are usually transient and not clinically significant. Studies have shown that ACA associated with infections tend to not be β2-GP1-dependent.4 This supports the conclusion that anti-β2-GP1 assays may be more specific for APS than ACA.4,7,8 While the majority of patients with LA will also test positive for ACA and β2-GP1 antibodies, approximately 30% of patients tested will have discordant results.9,10 Approximately 20% of patients who test negative for ACA will test positive for β2-GP1.9 Anti-β2-GP1 testing can be useful in the evaluation of patients with positive ACA results and a clinical picture that is not consistent with APS.3,4,8 A negative anti-β2-GP1 result in this context would not support a diagnosis of APS. Anti-β2-GP1 testing can also support the diagnosis of APS in patients with a strong clinical picture for APS with negative LA and ACA results.8
Footnotes
1. Adcock DM, Bethel MA, Macy PA. Coagulation Handbook. Aurora, Colo: Esoterix−Colorado Coagulation; 2006.
2. Miyakis S, Lockshin MD, Atsumi T, et al. International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS). J Thromb Haemost. 2006 Feb; 4(2):295-306. 16420554
3. Reddel SW, Krilis SA. Testing for and clinical significance of anticardiolipin antibodies. Clin Diagn Lab Immunol. 1999 Nov; 6(6):775-782. 10548562
4. Carreras LO, Forastiero RR, Martinuzzo ME. Which are the best biological markers of the antiphospholipid syndrome? J Autoimmun. 2000 Sep; 15(2):163-172. 10968904
5. Brey RL, Abbott RD, Curb JD, et al. Beta(2)-glycoprotein 1-dependent anticardiolipin antibodies and risk of ischemic stroke and myocardial infarction: The Honolulu Heart Program. Stroke. 2001 Aug; 32(8):1701-1706. 11486093
6. Greco TP, Amos MD, Conti-Kelly AM, Naranjo JD, Ijdo JW. Testing for the antiphospholipid syndrome: Importance of IgA anti-beta 2-glycoprotein I. Lupus. 2000; 9(1):33-41. 10713645
7. Levine JS, Branch DW, Rauch J. The antiphospholipid syndrome. N Engl J Med. 2002 Mar 7; 346(10):752-763. 11882732
8. Harris EN, Pierangeli SS, Gharavi AE. Diagnosis of the antiphospholipid syndrome: A proposal for use of laboratory tests. Lupus. 1998; 7(Suppl 2):S144-S148. 9814693
9. Hirsh J, Anand SS, Halperin JL, Fuster V; American Heart Association. Guide to anticoagulant therapy: Heparin: A statement for healthcare professionals from the American Heart Association. Circulation. 2001 Jun 19; 103(24):2994-3018. 11413093
10. Triplett DA. Coagulation abnormalities. In: McClatchey KD, ed. Clinical Laboratory Medicine. 2nd ed. Philadelphia, Pa: Lippincott Williams and Wilkins; 2002:1033-1049.
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 163882 | Beta-2 Glycoprotein I Ab, IgG | 16135-6 | 163881 | Beta-2 Glycoprotein I Ab, IgG | GPI IgG units | 16135-6 |
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