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HelpTest Code GB2GP Beta-2 Glycoprotein 1 Antibodies, IgG, Serum
Reporting Name
Beta 2 GP1 Ab IgG, SUseful For
Evaluating patients with suspected antiphospholipid syndrome by identification of beta-2 glycoprotein 1 IgG antibodies
First-line test when antiphospholipid syndrome is strongly suspected, in conjunction with cardiolipin antibodies (IgG and IgM) and lupus anticoagulant testing
Estimating the risk of thrombosis and/or pregnancy-related morbidity in patients with systemic lupus erythematosus
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumAdditional Testing Requirements
Diagnostic criteria for antiphospholipid syndrome include the presence of at least one of the following: lupus anticoagulant, anticardiolipin, and anti-beta-2 glycoprotein 1 IgG or IgM antibodies. Consider ordering CLPMG / Phospholipid (Cardiolipin) Antibodies, IgG and IgM, Serum; MB2GP / Beta-2 Glycoprotein 1 Antibodies, IgM, Serum; and ALUPP / Lupus Anticoagulant Profile, Plasma concurrently with this test.
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 21 days | |
| Frozen | 21 days |
Reference Values
<15.0 SGU (negative)
15.0-39.9 SGU (weakly positive)
40.0-79.9 SGU (positive)
≥80.0 SGU (strongly positive)
Results are reported in standard IgG anti-beta 2 glycoprotein 1 units (SGU).
Reference values apply to all ages.
Day(s) Performed
Monday through Saturday
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
86146
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| GB2GP | Beta 2 GP1 Ab IgG, S | 44448-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| GB2GP | Beta 2 GP1 Ab IgG, S | 44448-9 |
Interpretation
Positive results for beta-2 glycoprotein 1 (B2GPI) IgG antibodies, in association with specific clinical manifestations, may be diagnostic for antiphospholipid syndrome (APS). Low levels of B2GPIIgG antibodies, especially in the absence of other criteria phospholipid antibodies, should be interpreted with a high degree of suspicion.
Documentation of persistent anti- B2GPIIgG antibodies is a requirement for the diagnosis of definite APS. Antibodies must be detected on 2 or more occasions at least 12 weeks apart to fulfill the laboratory diagnostic criteria for APS.
Detection of B2GPIantibodies using the enzyme-linked immunosorbent assay method or other solid-phase immunoassays is not affected by anticoagulant treatment.
Clinical Reference
1. 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;4(2):295-306
2. Pengo V, Bison E, Denas G, Jose SP, Zoppellaro G, Banzato A. Laboratory diagnostics of antiphospholipid syndrome. Semin Thromb Hemost. 2018;44(5):439-444
3. Barbhaiya M, Zuily S, Naden R, et al. The 2023 ACR/EULAR antiphospholipid syndrome classification criteria. Arthritis Rheumatol. 2023;75(10):1687-1702
4. Lozier J, Takahashi N, Putnam F W: Complete amino acid sequence of human plasma beta 2 glycoprotein 1. Proc Natl Acad Sci U S A. 1984;81(12):3640-3644
5. Audrain MAP, El-Kouri D, Hamidou MA, el al. Value of autoantibodies to beta(2)-glycoprotein 1 in the diagnosis of antiphospholipid syndrome. Rheumatology (Oxford). 2002;41(5):550-553
6. Lakos G, Favaloro EJ, Harris EN, et al. International consensus guidelines on anticardiolipin and anti-beta 2-glycoprotein I testing: report from the 13th International Congress on Antiphospholipid Antibodies. Arthritis Rheum. 2012;64(1):1-10
7. Devreese KMJ. Solid phase assays for antiphospholipid antibodies. Semin Thromb Hemost. 2022;48(6):661-671
8. Tebo AE. Laboratory evaluation of antiphospholipid syndrome: An update on autoantibody testing. Clin Lab Med. 2019;39(4):553-565
9. Cousins L, Pericleous C, Khamashta M, et al. Antibodies to domain I of beta-2-glycoprotein I and IgA antiphospholipid antibodies in patients with ‘seronegative’ antiphospholipid syndrome. Ann Rheum Dis. 2015;74(01):317-319
10. Nakamura H, Oku K, Amengual O, et al. First-line, non-criterial antiphospholipid antibody testing for the diagnosis of antiphospholipid syndrome in clinical practice: A combination of anti-beta2 -glycoprotein I domain I and anti-phosphatidylserine/prothrombin complex antibodies tests. Arthritis Care Res (Hoboken). 2018;70(4):627-634
Report Available
2 to 6 daysMethod Name
Enzyme-Linked Immunosorbent Assay (ELISA)