Anti-cardiolipin antibodies

schematic representation of antibody.

Anti-cardiolipin antibodies (ACA) are antibodies often directed against cardiolipin and found in several diseases, including syphilis,^[1] antiphospholipid syndrome, livedoid vasculitis, vertebrobasilar insufficiency, Behçet's syndrome,^[2] idiopathic spontaneous abortion,^[3] and systemic lupus erythematosus (SLE).^[4] They are a form of anti-mitochondrial antibody. In SLE, anti-DNA antibodies and anti-cardiolipin antibodies may be present individually or together; the two types of antibodies act independently.^[5] This is in contrast to rheumatoid arthritis^[6] with systemic sclerosis (scleroderma)^[7] because anti-cardiolipin antibodies are present in both conditions, and therefore may tie the two conditions together.

Anti-cardiolipin antibodies can be classified in two ways:

• As IgM, IgG or IgA
• As β₂-glycoprotein dependent or independent
  • In autoimmune disease ACA are beta-2 glycoprotein dependent
  • syphilis ACA^[1] are beta-2 glycoprotein independent and can be assayed using the Venereal Disease Research Laboratory test

Apolipoprotein H involvement

β₂-glycoprotein I has been identified as Apolipoprotein H and is required for the recognition of ACA in autoimmune disease.^[8] Only a subset of autoimmune anti-cardiolipin antibodies bind Apo-H, these anti-apolipoprotein antibodies are associated with increased thrombosis.

References

1. Tringali GR, Julian AJ, Halbert WM (1969). "Effect of 2-mercaptoethanol treatment on anticardiolipin reactivity in sera from syphilitics and false positive reactors". The British journal of venereal diseases 45 (3): 202–4. doi:10.1136/sti.45.3.202. PMC 1048465. PMID 5346419.
2. Hull RG, Harris EN, Gharavi AE, et al. (1984). "Anticardiolipin antibodies: occurrence in Behçet's syndrome". Ann. Rheum. Dis. 43 (5): 746–748. doi:10.1136/ard.43.5.746. PMC 1001520. PMID 6497467.
3. Petri M, Golbus M, Anderson R, Whiting-O'Keefe Q, Corash L, Hellmann D (1987). "Antinuclear antibody, lupus anticoagulant, and anticardiolipin antibody in women with idiopathic habitual abortion. A controlled, prospective study of forty-four women". Arthritis Rheum. 30 (6): 601–606. doi:10.1002/art.1780300601. PMID 3111489.
4. Harris EN, Gharavi AE, Boey ML, et al. (1983). "Anticardiolipin antibodies: detection by radioimmunoassay and association with thrombosis in systemic lupus erythematosus". Lancet 2 (8361): 1211–1214. doi:10.1016/S0140-6736(83)91267-9. PMID 6139567.
5. Harris EN, Gharavi AE, Loizou S, et al. (1985). "Crossreactivity of antiphospholipid antibodies". Journal of clinical & laboratory immunology 16 (1): 1–6. PMID 3981615.
6. Keane A, Woods R, Dowding V, Roden D, Barry C (1987). "Anticardiolipin antibodies in rheumatoid arthritis". Br. J. Rheumatol. 26 (5): 346–350. doi:10.1093/rheumatology/26.5.346. PMID 3664159.
7. Malia RG, Greaves M, Rowlands LM, et al. (1988). "Anticardiolipin antibodies in systemic sclerosis: immunological and clinical associations". Clin. Exp. Immunol. 73 (3): 456–60. PMC 1541778. PMID 2974767.
8. McNeil HP, Simpson RJ, Chesterman CN, Krilis SA (1990). "Anti-phospholipid antibodies are directed against a complex antigen that includes a lipid-binding inhibitor of coagulation: beta 2-glycoprotein I (apolipoprotein H)". Proc. Natl. Acad. Sci. U.S.A. 87 (11): 4120–4124. doi:10.1073/pnas.87.11.4120. PMC 54059. PMID 2349221.