Cardiolipin IgM ELISA
The Calbiotech anti-Cardiolipin (aCL) IgM ELISA Kit is intended for the detection of IgM antibody to Cardiolipin in human serum or plasma.
Measurement of IgG, IgM and IgA cardiolipin autoantibodies (aCL) by EIA is the standard procedure for the detection of antiphospholipid antibodies (aPL) in patients with suspected antiphospholipid syndrome (APS). High aCL concentrations are associated with increased risk of venous and arterial thrombosis, recurrent pregnancy loss and thrombocytopenia. Patients with the anti-cardiolipin syndrome have one of the above clinical features and have antibodies to cardiolipin and/or a positive lupus anticoagulant test. The antibodies present to cardiolipin may be of the IgG, IgA, IgM isotypes. Testing for the various antibody isotypes to cardiolipin aid in diagnosis of the anti-phospholipid syndrome in patients with SLE or lupus-like disorders. Binding of aCL to CL in patients with autoimmune diseases is dependent on the presence of the cofactor beta-2-glycoprotein I (beta2-GPI); this binding is independent of beta-2-GPI in patients with infectious diseases (e.g., syphilis, tuberculosis). Recognition of the role of beta-2- GPI in the binding of aCL led to development of assay for direct measurement of beta-2-GPI autoantibodies using beta-2-GPI as antigen, allowing a clear distinction between beta-2-GPI autoantibodies and those that bind to CL alone.
Diluted patient serum (serum diluent contains sorbent to remove Rheumatoid Factor and human IgG interference) is added to wells coated with purified aCL antigen. aCL specific IgM antibody, if present, binds to the antigen. All unbound materials are washed away and the enzyme conjugate is added to bind to the antibody-antigen complex, if present. Excess enzyme conjugate is washed off and substrate is added. The plate is incubated to allow the hydrolysis of the substrate by the enzyme. The intensity of the color generated is proportional to the amount of specific IgM antibody in the sample.
- Barka N, Reagan K, Agopian M, Peter JB. Frequency of anticardiolipin and antiphosphatidylserine antibodies in patients with suspected antiphospholipid syndrome. Clin Chem 1995;41:5.
- Khamashta MA, Hughes GRV. Detection and importance of anticardiolipin antibodies. J Clin Pathol 1993;46:104-7.
- Reyes H, Dearing L, Bick RL, Shoenfeld Y, Peter JB. Laboratory diagnosis of antiphospholipid syndromes. Lab Clin North Am 1995;15:85-108.
- Harris EN, Pierangeli S. Anticardiolipin antibodies: specificity and function. Lupus 1994;3:217-22.
- Barka N. Phospholipid autoantibodies – phosphatidylserine. In: Peter JB, Shoenfeld Y, editors. Autoantibodies. Amsterdam: Elsevier 1996:630-4.
- Triplett DA. Assays for detection of antiphospholipid antibodies. Lupus 1994;3:281-7.
- Khamashta MA, Cuadrado MJ, Mujic F, et al. The management of thrombosis in the antiphospholipid antibody syndrome. N Engl J Med 1995;332:993-7.
- Olee T, Pierangeli S, Handley H, et al. A monoclonal IgG anticardiolipin antibody from a patient with the antiphospholipid syndrome is thrombogenic in mice. Proc Natl Acad Sci 1996;931:8606-11.
- Hughes GRV. The antiphospholipid syndrome: ten years on. Lancet 1993;342:341-4.