Anticardiolipin Antibodies (ACA), IgG, IgM, Quantitative
Anticardiolipin Antibodies (ACA), IgG, IgM, QuantitativeUpdated November 9 2006
    
Number
161802
CPT
86147 (x2)
Related InformationRelated Information - Updated November 12 2004
  • Antiphosphatidylserine, IgG, IgM, IgA
  • Beta-2 Glycoprotein I Antibodies, IgG, IgA, IgM
    • Synonyms
    ACA; Antiphospholipids; Cardiolipin Antibodies
    Test Includes
    IgG and IgM anticardiolipin antibodies
    Specimen
    Serum
    Volume
    1 mL
    Minimum Volume
    0.5 mL
    ContainerContainer - Updated November 9 2006
    Red-top tube or gel-barrier tube
    Storage Instructions
    Refrigerate
    Causes for RejectionCauses for Rejection - Updated July 13 2004
    Hemolysis; lipemia; icteric specimen
    Reference Interval
    Normal: 0-10 GPL and 0-9 MPL; see also Anticardiolipin Antibodies (ACA), IgA, IgG, IgM.
    UseUse - Updated July 13 2004
    Anticardiolipin antibodies are often present in individuals with the antiphospholipid antibody syndrome. 1,2
    LimitationsLimitations - Updated November 11 2004
    ACA can often be observed during the convalescent phase of acute bacterial and viral infections and in individuals with syphilis. These infection-induced antibodies are usually transient and are not associated with an increased risk of clinical complications. In general, all patients that test positive for ACA should be retested after six to eight weeks to rule out transient antibodies that are usually of no clinical significance.
    MethodologyMethodology - Updated July 13 2004
    Enzyme-linked immunosorbent assay (ELISA) detecting isotype- specific ACA binding to a microtiter plate coated with purified cardiolipin antigen.
    Additional InformationAdditional Information - Updated July 13 2004
    Individuals with the antiphospholipid antibody syndrome (APS) have an increased risk for stroke, myocardial infarction, venous thrombosis, thromboembolism, thrombocytopenia, and/or recurrent miscarriages. In 1999, an international consensus conference found that one criterion for the serologic diagnosis of "definite antiphospholipid syndrome" is the presence of anticardiolipin antibody of IgG and/or IgM isotype, at medium or high titer, on two or more occasions, at least six weeks apart.3 The presence of ACA of moderate to high titer for IgG is strongly associated with both arterial and venous thrombosis and recurrent pregnancy loss.2,7,8 The IgM isotype of ACA has also been shown to be associated with venous thrombosis. 7 Other studies found that ACA of the IgA isotype at moderate to high titer can also be associated with increased risk of APS. 2,12
    ACA antibodies are quite common in the general population and are not always associated with APS. Studies indicate that there is a higher prevalence of IgM positives than IgG in the general population with these isotypes occurring in 9.4% and 6.5% of the population, respectively. 4 The incidence of these ACA is even higher in normal pregnancy with detection rates of 17% for IgM and 10.6% for IgG. 5 Many of these antibodies are transient and not associated with APS. The diagnosis of APS should not be made on the basis of a single ACA result but rather on repeated positive results obtained at least six weeks apart. 1
    The Venereal Disease Research Laboratory (VDRL) agglutination test that has been used for decades in the diagnosis of syphilis is based on the detection of antibodies to cardiolipin. 6 The first solid-phase immunoassays for ACA were developed in the early 1980's.6 These solid- phase assays are at least 100 fold more sensitive than the classical VDRL assay and produce many more positive results. In general, ACA are considered to be more sensitive than lupus anticoagulants (LA) for the detection of APS.7 The ACA test is positive in 80% to 90% percent of patients with APS 9 and ACA are implicated in approximately five times more cases of APS than are LA. 2 However, LA are considered to be more specific for APS than ACA.2,9 Due to the heterogeneity of antibodies associated with APS, both LA and ACA testing is recommended when APS is suspected. 7,10
    ACA are frequently observed in patients with other autoimmune disorders and malignancies. Individuals with ACA secondary to these other conditions are at increased risk of developing APS. A variety of therapeutic drugs can induce the production of ACA. These drug-induced antibodies may be clinically significant if they persist. 2,11
    FootnotesFootnotes - Updated August 29 2006
      1. Adcock DM, Jensen R, Johns CS, Macy PA. Coagulation Handbook. Austin Texas: Esoterix Coagulation; 2002.
       2. Bick RL. Antiphospholipid thrombosis syndromes. Clin Appl Thromb Hemost. 2001 Oct; 7 (4):241-258.
       3. Wilson WA, Gharavi AE, Koike T, et al. International consensus statement on preliminary classification criteria for definite antiphospholipid syndrome: report of an international workshop. Arthritis Rheum. 1999 Jul; 42(7):1309-1311.
       4. Vila P, Hernandez MC, Lopez-Fernandez MF, Batlle J. Prevalence, follow-up and clinical significance of the anticardiolipin antibodies in normal subjects. Thromb Haemost. 1994 Aug; 72(2):209-213.
       5. Soloninka CA, Laskin CA, Wither J. Clinical utility and specificity of anticardiolipin antibodies. J Rheumatol. 1991 Dec; 18(12):1849-1855.
       6. Levine JS, Branch DW, Rauch J. The antiphospholipid syndrome. N Engl J Med. 2002 Mar 7; 346(10):752-763.
       7. Carreras LO, Forastiero RR, Martinuzzo ME. Which are the best biological markers of the antiphospholipid syndrome? J Autoimmun. 2000; 15(2):163-172.
       8. Reddel SW, Krilis SA. Testing for and clinical significance of anticardiolipin antibodies. Clin Diagn Lab Immunol. 1999; 6(6):775-782.
       9. Harris EN, Pierangeli SS, Gharavi AE. Diagnosis of the antiphospholipid syndrome: a proposal for use of laboratory tests. Lupus. 1998; 7(Suppl 2):S144-S148.
       10. Brandt JT, Triplett DA, Alving B, Scharrer I. Criteria for the diagnosis of lupus anticoagulants: An update. On behalf of the Subcommittee on Lupus Anticoagulant/Antiphospholipid Antibody of the Scientific and Standardization Committee of the ISTH. Thromb Haemost. 1995; 74(4):1185-1190.
       11. Jenson R. The antiphospholipid antibody syndrome. Clin Hemost Rev. November 2001; 15(11).
       12. Lopez LR, Santos ME, Espinoza LR. Clinical significance of immunoglobulin A versus immunoglobulins G and M anticardiolipin antibodies in patients with systemic lupus erythematosus. Correlation with thrombosis, thrombo- cytopenia, and recurrent abortion. Am J Clin Pathol. 1992; 98(4):449-454.

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