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Test Code 76480025 Beta-2 Glycoprotein Antibody, IgM

Performing Laboratory

Barnes-Jewish Hospital Laboratory


Multiplex Flow Immunoassay

Literature Reference:

Package Insert: BioPlex 2200 APLS IgM kit. BioRad Laboratories, Inc. 10/2013

Specimen Requirements

Specimen Type: Serum

Container/Tube: Plain Red Top

Specimen Volume: Full tube

Day(s) Test Set UP

Monday through Sunday

Cut-off time: 1000

Turnaround Time:

STAT: not available

Routine: results will be available the day of testing

Reference Values

Beta-2 Glycoprotein

Antibiody, IgM

Units Interpretation
  < 20 GPL Units/mL Negative
  > 20 GPL Units/mL Positive


Interpretive data for IgG: Beta-2 glycoprotein 1 (Beta-2 GP1) antibodies are a more specific marker of the thrombotic risk. It is expected that some samples will be ACL positive and Beta-2 GP1 negative. In order to improve specificity, the International Congress on Antiphospholipid Antibodies recommends Beta-2 GP1 antibodies of IgG or IgM isotype (> the 99th percentile), obtained twice, at least 12 weeks apart, to support a diagnosis of antiphospholipid syndrome. The cutoff for this assay was developed from data based on the 99th percentile. The Beta-2 GP1 IgM test can produce false positive results due to cross-reactivity with Rheumatoid factor. These results were obtained with the BioRad BioPlex 2200 System. Beta-2 GP1 IgM values obtained with different manufacturers' assay methods may not be used interchangeably.

Test Classification and CPT Coding


Additional Information

For BJH Laboratory Use Only


Analyte Stability:

See Analyte Stability Chart


Laboratory Processing Instructions:

Test performed in BJH Core Lab. Processed by automated line and aliquot stored refrigerated for batch analysis. Completed specimens are stored refrigerated for 5 days.

LOINC Code Information


Name LOINC Code
Beta-2 Glycoprotein Antibody, IgG 44449-7


Specimen Transport Temperature