Antiphospholipid syndrome

Cardiolipin antibodies | ß2-Glycoprotein I antibodies

Cardiolipin antibodies

Products

Article No.

No. of tests

EliA Cardiolipin IgG 14-5529-01 4x12
EliA Cardiolipin IgM 14-5530-01 4x12
EliA Cardiolipin IgA NEW! 14-5528-01 2x12
Varelisa Cardiolipin Antibodies Screen 158 96 96 tests
Varelisa Cardiolipin IgG Antibodies 155 96 96 tests
Varelisa Cardiolipin IgM Antibodies 156 96 96 tests
Varelisa Cardiolipin IgA Antibodies 157 96 96 tests

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Performance characteristics
EliA APS (pdf)
EliA APS IgA (pdf) NEW!

Antigens

Unlike most other autoantigens, cardiolipin is not a protein, but a phospholipid. Phospholipids are major components of the membranes of living cells and of organelles within these cells. Cardiolipin is located in bacterial membranes, mitochondria and chloroplasts.

Cardiolipin is made up of two phosphatidic acid groups, each attached to a glyceride moiety by a phosphodiester bond, and joined by a central glycerol moiety.

Antibodies bind to the complex of cardiolipin and the cofactor ß2-GPI.

Our assays are coated with purified cardiolipin.

Antibody specificity and prevalence

  • Antiphospholipid syndrome (APS) (one of two laboratory criteria for the diagnosis of APS)
  • Stroke (7%), stroke in young patients (18%)
  • Pregnancy loss*: 3 or more consecutive pregnancy losses (15%), in 2nd or 3rd trimester (30%), with growth retardation and late loss (40%)
  • Secondary APS in SLE (10-15%)
  • Connective tissue diseases such as SLE (44%), RA (4-49%), scleroderma (25%), juvenile chronic arthritis (42%) (numbers of secondary APS included)
  • Infectious diseases such as Lyme disease (32%), syphilis (75%), leprosy (67%), tuberculosis (53%) and others (Q fever, AIDS)
  • Epilepsy (11%)
  • Healthy individuals (0-7.5%)

* numbers refer to antiphospholipid antibodies in general

Information about antiphospholipid syndrome

Disease activity

High aCL levels are associated with increasing risk of thrombosis or foetal loss. Raised anticardiolipin antibody levels may be detected many years prior to the expression of thrombosis or foetal loss. The risk of foetal loss increases from 6.5% (aCL-negative) to 15.8% with aCL-positivity.

When is the measurement recommended?

  • Suspicion of antiphospholipid syndrome
  • Foetal loss
  • Stroke in young patients
  • Unexplained thrombosis
  • In discussion: migraine, epilepsy, chorea, heart valve disease, skin ulcers etc.

Antibody isotypes

IgG is accepted as the most frequent and most important isotype in aCL detection. However, the measurement of IgM and IgA is also recommended to prevent the loss of some risk patients. The clinical association of different aCL isotypes is a matter of debate in the literature.

References

Moris V, Mackworth-Young C (1996)  |  Khamashta MA, Hughes GRV (1996)  |  Roubey RA (1999)   

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ß2-Glycoprotein I antibodies

ProductsArticle No.No. of tests
EliA ß2-Glycoprotein I IgG 14-5532-01 4x12
EliA ß2-Glycoprotein I IgM 14-5533-01 4x12
EliA ß2-Glycoprotein I IgA NEW! 14-5531-01 2x12
Varelisa ß2-Glycoprotein I Antibodies Screen 190 96 96 tests
Varelisa ß2-Glycoprotein I (IgG) Antibodies 187 96 96 tests
Varelisa ß2-Glycoprotein I (IgM) Antibodies 188 96 96 tests
Varelisa ß2-Glycoprotein I (IgA) Antibodies 189 96 96 tests

Antigens

ß2-Glycoprotein I (ß2GPI) binds to negatively charged substances such as phospholipids and lipoproteins. An increasing number of studies indicate that ß2GPI is required as a cofactor or is even the "real" antigen for the binding of antiphospholipid antibodies. The conformational epitopes for anti-ß2GPI develop when it interacts with a lipid membrane composed of negatively charged phospholipids or when ß2GPI is adsorbed on a polyoxygenated polystyrene plate.

ß2GP1 is a 50 kDa plasma protein composed of five homologous motifs of approximately 60 amino acids.

ß2GP1 in our assays is purified from human plasma.

Antibody specificity and prevalence

  • Antiphospholipid syndrome (APS)
  • Ischaemic stroke (24%) 
  • Pregnancy loss (7-14%) 
  • Connective tissue diseases such as SLE (36%), rheumatoid arthritis (RA), scleroderma, juvenile chronic arthritis 
  • Epilepsy (18%) 
  • Healthy individuals (very rarely)

(available numbers vary widely because of different methods and isotypes)

Information about antiphospholipid syndrome

Disease activity

High levels are associated with increasing risk of thrombosis or foetal loss.

When is the measurement recommended?

  • Foetal loss 
  • Stroke in young patients
  • Unexplained thrombosis 
  • in aCL-negative patients with suspected APS 
  • in aCL-positive patients possibly having APS to confirm the diagnosis

Antibody isotypes

According to the Classification Criteria for Definite Antiphospholipid Syndrome (2006), IgG and IgM are the relevant isotypes for the detection of antibodies against ß 2 glycoprotein I. Nevertheless, an increasing number of studies also indicate clinical relevance for the isotype IgA. 

Detection methods

For antibody detection, ß2GP1 must be bound to a lipid membrane composed of negatively charged phospholipids. Alternatively, ß2GP1 can be adsorbed onto a polyoxygenated (irradiated) polystyrene plate.

References

Matsuura E, Koike T (1996)  |  Reddel SW, Krilis SA (1999)  |  Tincani A, Balestieri G, Spatola L et al. (1998)  

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