Synonym
- ACA
- aCL antibodies
- Cardiolipin antibodies
Tubes
- Red top tube or serum gel separator tube
- 5-7 mL of venous blood from adults
- 3 mL of venous blood from the pediatric patient
Additional information:
- This test is typically a send out test
- The method used is ELISA (Enzyme-Linked Immunosorbent Assay) and are quantitative
- Reject for hemolysis, lipemia or microbial contamination
Info
Anticardiolipin antibodies are IgM, IgG and IgA autoantibodies formed against cardiolipins, which are phospholipid molecules, found in the cell membranes and platelets. The presence of anticardiolipin autoantibodies increases risk of development of recurrent thrombi in blood vessels.
Additional information:
Cardiolipin antibodies are the commonest form of antiphospholipid antibodies. Others are:
- Lupus anticoagulant
- Anti-beta2 glycoprotein I
- Anti-phosphatidylserine
- Anti-phoshatidylcholine
- Anti-phosphatidylethonalamine
Cardiolipin antibodies along with other antiphospholipid antibodies are a part of the diagnostic work-up to classify antiphospholipid antibody syndromes.
Clinical
The anticardiolipin (aCL) antibody test is performed in the evaluation of the following conditions:
- As part of the evaluation of unexplained thromobotic episodes (e.g. deep venous thrombosis, pulmonary emboli)
- As part of the evaluation of recurrent miscarriage
- As part of the evaluation of thrombocytopenia (low platelet count)
- As part of the evaluation of prolonged activated plasma thromboplastin test (aPTT)
- To confirm clinical findings suggestive of SLE or other autoimmune disorder when the primary test results are unremarkable
Additional information:
- If any aCL antibodies are detected, the test is usually repeated after at least 6 weeks to determine whether the antibody is persistent or temporary
- An aCL antibody test may be needed to determine the cause of a positive VDRL test for syphilis. Patients with aCL antibodies may show a false positive result with the VDRL/RPR test for syphilis as the reagent used in this test contains phospholipids
- Though sensitive, the aCL assay is not very specific
- The predictive value of the test is increased with concurrent assays for lupus anticoagulant (LA) and beta-2 glycoprotein I (B2-GPI)
Nl Result
Consult your laboratory for their normal ranges as these may vary somewhat from the ones listed below.
The results of the aCL antibody test are reported in units of GPL and MPL. The results are reported quantitatively, and generally reported into categories of low (negative), borderline, medium, and high (positive).
- GPL = IgG antiphospholipid antibody
- MPL = IgM antiphospholipid antibody
| GPL | MPL |
|---|
| Low (Negative) | <15 | <6 |
| Borderline | 15-20 | 6-10 |
| Medium | 21-80 | 11-50 |
| High (Positive) | >80 | >50 |
A normal result is Low (Negative).
High Result
Medium or high titers on two or more occasions at least six weeks apart are suggestive of antiphospholipid syndrome.
A positive result may also be associated with:
- Systemic lupus erythematosus (SLE)
- Lupus like disease
- Arterial thrombosis
- Venous thrombosis
- Thrombocytopenia
- Immune thrombocytopenic purpura (ITP)
- Recurrent pregnancy loss
- Postnatal maternal complications
- Migraine headaches
- Cerebrovascular accident (CVA)
- Transient ischemic attack (TIA)
- Severe alcoholic liver disease
- Chorea
- Drug reactions
- Epilepsy
- Active infections
- Endocarditis
Low Result
N/A.
References
- Bidot CJ et al. Antiphospholipid antibodies (APLA) in immune thrombocytopenic purpura (ITP) and antiphospholipid syndrome (APS). Am J Hematol. 2006 Jun;81(6):391-6.
- Lab Tests Online®. Cardiolipin antibodies: The test. [Home page on the Internet]. ©2001-2006. Last reviewed on October 4, 2004. Available at URL: http://www.labtestsonline.org/understanding/analytes/cardiolipin/test.html Last accessed on July 24, 2006.
- Laboratory Corporation of America®.Anticardiolipin Antibodies (ACA), IgA, IgG, IgM. [Homepage on the internet]©2003. Last updated on November 12, 2004. Available at URL: http://www.labcorp.com/datasets/labcorp/html/chapter/mono/se031400.htm Last accessed on July 24, 2006.
- Muir KW et al. Anticardiolipin antibodies in an unselected stroke population. Lancet 1994 Aug 13;344(8920):452-6.
- Reddel SW et al. Testing for and Clinical Significance of Anticardiolipin Antibodies. Clinical and Diagnostic Laboratory Immunology, 1999;6(6):775-782
- Rolla R et al. Antiphospholipid antibodies associated with alcoholic liver disease specifically recognize oxidized phospholipids. Gut 2001;49:852-859
- Ward AM et al. Measuring cardiolipin antibodies. BMJ 1995;310:1472-1473