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Test Code B2GPG Beta-2 Glycoprotein 1 Antibodies, IgG, Serum

Reporting Name

Beta 2 GP1 Ab IgG, S

Useful For

Evaluation of patients with suspected antiphospholipid syndrome by identification of beta-2 GP1 IgG antibodies

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type


Specimen Required


Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL

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 U/mL (negative)

15.0-39.9 U/mL (weakly positive)

40.0-79.9 U/mL (positive)

≥80.0 U/mL (strongly positive)

Results are expressed in arbitrary units.

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


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

Clinical Reference

1. Caronti B, Calderaro C, Alessandri C, et al: Beta 2 glycoprotein 1 (beta 2 GP1) mRNA is expressed by several cell types involved in anti-phospholipid syndrome-related tissue damage. Clin Exp Immunol 1999;115:214-219

2. Lozier J, Takahashi N, Putnam F: Complete amino acid sequence of human plasma beta 2 glycoprotein 1. Proc Natl Acad Sci USA 1984;81:3640-3644

3. Kra-Oz Z, Lorber M, Shoenfeld Y, Scharff Y: Inhibitor(s) of natural anti-cardiolipin autoantibodies. Clin Exp Immunol 1993;93:265-268

4. Wong RCW, Flavaloro EJ, Adelstein S, et al: Consensus guidelines on anti-beta 2 glycoprotein I testing and reporting. Pathology 2008 Jan;40(1):58-63

5. Audrain Ma, El-Kouri D, Hamidou MA, et al: Value of autoantibodies to beta(2)-glycoprotein 1 in the diagnosis of antiphospholipid syndrome. Rheumatology (Oxford) 2002;41:550-553

Method Description

Purified beta-2 GPI antigen is bound to the wells of a polystyrene microwell plate under conditions that will preserve the antigen in its native state. Prediluted controls and diluted patient sera are added to separate wells, allowing any beta-2 GPI IgG antibodies present to bind to the immobilized antigen.


Unbound sample is washed away and an enzyme-labeled antihuman IgG conjugate is added to each well. A second incubation allows the enzyme-labeled antihuman IgG to bind to any patient antibodies that have become attached to the microwells. After washing away any unbound enzyme-labeled antihuman IgG, the remaining enzyme activity is measured by adding a chromogenic substrate and measuring the intensity of the color that develops. The assay can be evaluated spectrophotometrically by measuring and comparing the color intensity that develops in the patient wells with that of a 5-point calibration curve. The standard used to construct this curve is referenced to the reference calibrators for IgG beta-2-Glycoprotein I available from the Rheumatology Lab, Seton Hall University, St. Joseph's Hospital and Medical Center. Results are reported out semiquantitatively in standard IgG anti-beta-2 GPI units (SGU).(Package Insert: QUANTA Lite beta 2 GP1 IgG ELISA, Inova Diagnostics, March 2016 Revision 18)

Report Available

Same day/1 to 6 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus OK

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Secondary ID