Antiphospholipid Syndrome
A comprehensive range of Enzyme Immunoassays help clarify the investigation of Antiphospholipid syndrome.
Antiphospholipid syndrome (APS), also known as Hughes syndrome, is an autoimmune condition associated with reccurring vascular thrombosis and pregnancy morbidity. APS is divided up into primary APS where the condition occurs alone, and secondary APS where the condition occurs in association with another autoimmune disease such as systemic lupus erythematosus (SLE).
Clinical Significance
Antibodies targeting cardiolipin, β2-glycoprotein-1 (β2GP-1) and phosphatidylserine are commonly found in patients with the clinical symptoms of APS. Specifically, antibodies to cardiolipin are found in up to 77 % of patients with primary APS. Evidence has demonstrated that the antibodies target a complex of the phospholipid and the plasma binding protein β2GP-1. The exact mechanism by which antiphospholipid antibodies cause thrombosis is unknown but possible mechanisms include the activation of the tissue factor pathway and the inhibition of the protein C pathway.
Diagnostic Criteria
For a patient to be diagnosed with APS they must first meet one of the clinical criteria which are:
i) one or more episodes of arterial, venous, or small vessel thrombosis in any tissue or organ
ii) pregnancy morbidity including foetal death, premature birth and spontaneous abortion.
Once a patient's clinical symptoms fulfil the clinical criteria, diagnosis of APS can be confirmed if one of the laboratory criteria is met. In 2006 the laboratory criteria were revised and now include a positive β2GP-1 IgG or IgM EIA test alongside a positive cardiolipin IgG or IgM test. The laboratory criteria also include the non-EIA lupus anticoagulant test which measures the in vitro activation of the coagulation cascade. Laboratory tests should be performed on two or more occasions at least 12 weeks apart. Transient increases in antibodies to cardiolipin and β2GP-1 may be detected in patients with bacterial infections although these are not usually associated with thrombosis.
Sapporo Standards
The Standardization Committee of the European Forum for Antiphospholipid Antibodies have supported the introduction of HCAL and EY2C9 IgG and IgM standards. These standards are monoclonal antibodies that have dual functionality for both cardiolipin and β2GP-1 (results expressed in μg/mL). The monoclonal nature of these standard preparations ensures reproducibility1-3
The BINDAZYME Anti Cardiolipin and Anti β2GP-1 S range IgG and IgM assays are calibrated against these Sapporo reference preparations.
Ordering Information
| Description | Pack | Code |
|---|---|---|
| Anti Cardiolipin IgG EIA | 96 test | MK027 |
| Anti Cardiolipin IgA EIA | 96 test | MK028 |
| Anti Cardiolipin IgM EIA | 96 test | MK029 |
| Anti Cardiolipin IgG/IgM COMBI EIA EIA | 96 test | MK071 |
| Anti Cardiolipin IgGAM Screen EIA | 96 test | MK030 |
| Anti β2GP-1 IgG EIA | 96 test | MK040 |
| Anti β2GP-1 IgA EIA | 96 test | MK041 |
| Anti β2GP-1 IgM EIA | 96 test | MK042 |
| Anti β2GP-1 IgGAM Screen EIA | 96 test | MK043 |
| NEW Anti Cardiolipin IgG S Kit | 96 test | MK127 |
| NEW Anti Cardiolipin IgA S Kit | 96 test | MK128 |
| NEW Anti Cardiolipin IgM S Kit | 96 test | MK129 |
| NEW Anti Cardiolipin IgGAM Screening S Kit | 96 test | MK130 |
| NEW Anti β2GP-1 IgG S Kit | 96 test | MK140 |
| NEW Anti β2GP-1 IgA S Kit | 96 test | MK141 |
| NEW Anti β2GP-1 IgM S Kit | 96 test | MK142 |
| NEW Anti β2GP-1 IgGAM Screening S Kit | 96 test | MK143 |
| Anti Phosphatidylserine IgG EIA | 96 test | MK050 |
| Anti Phosphatidylserine IgA EIA | 96 test | MK051 |
| Anti Phosphatidylserine IgM EIA | 96 test | MK052 |
1. Ichikawa, K. et al. A chimeric antibody with the human y1 constant region as a putative standard for assays to detect IgG β2-glycoprotein 1-dependent anticardiolipin and anti-β2-glycoprotein 1 antibodies. Arthritis Rheum 1999; 42:2461-2470.
2. Fontain, M. et al. Persistent Problems with Standardization of Immunoassays for Anti-Cardiolipin Antibodies Thromb Haemost 2001; 86:1123-1124
3. Tincani, A. et al. Anticardiolipin Antibody Assay: a Methodological Analysis for a better Consensus in Routine Determinations. A Cooperative Project of the European Antiphospholipid Forum. Thromb Haemost 2001; 86 575-583
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