Anticardiolipins Antibodies

Clinical Significance

Cardiolipin is found only in membranes of bacteria and mitochondria. The name ‘Cardiolipin’ is derived from the fact that it was first found in animal hearts, where it is especially abundant, but it  can be found in mitochondria of  all animal tissues. for e.g. it amounts to about 10% of the phospho lipids of bovine heart muscle and 20% of the phospholipids of the mitochondrial membrane.

Functions of Cardiolipin


·        Is a potent stimulator of steroidogenesis (formation of Steroid)
·        A specific role in the import of proteins into mitochondria.
·        It binds in a highly specific way to the DNA in chromatin.
·        It appears to have a functional role in the regulation of Gene expression.

Anticardiolipin (ACL) occurs a


1.       Primary ACL      
2.       Secondary ACL seen in association with the following conditions


         ·         SLE, RA,SJOGREN’S,SYNDROME,SCLERODERMA,MCTD.
         ·         Infections  (Bacteria, Predominantly viral , Pneumocystiscarinii)
         ·         Drugs (Eg Chloropromazine, Procanamide, Antibiotics, etc)
         ·         Lymphoproliferative disease (malignant lymphoma, HCL)

Anti cardiolipin auto antibodies have the following clinical conditions


1.                   Venous and arterial thrombosis.
2.                   Deep venous thrombosis
3.                   Thrombocytopenia       
4.                   Recurrent spontaneous abortion
5.                   Myocardial Infarction.

Antiphospholipid Syndrome

  The antiphospolipid syndrome is defined as a clinical disorder with recurrent arterial and venous thrombotic events, Pregnancy wastage and/ or Thrombocytopenia in the presence of the lupus anticoagulant and / or moderate to high positive anticardiolipin test.

Clinical features


1.      Thrombosis
2.       Pregnancy
3.       Nervous system disorder

AntiCardiolipin Antibodies.

ACA belong to a group of antibodies that react with negatively charged phospholipids .phospholipids represents the most important class of membrane lipids and are found in all biomembranes.it is an autoantibody to component of cell membrane.it may occur in connective tissue disease such as SLE or independently.Raised  level of IgA,IgG,and IgM  are strongly associated with venous and arterial thrombosis,thrombocytopenia, recurrent fetal loss and myocardial infarction as well as neurological condition .High levels of anti-cardiolipin antibodies represent an increased risk factor for future thrombotic events.There is probably no difference between anti-cardiolipin antibody and antibodies to the other phospholipids. 


Anticardiolipin antibody is one of the few autoantibodies that have assays,which allows the identification and quantification of specific(IgG,IgM and IgA).The IgG was the major predictor of thrombosis and pregnancy loss while the IgM class was associated especially with hemolytic anemia in addittion to thrombosis.Besides the identification of different,the antibody titer seems an useful predictor of pathogenicity(even though it is still not clear that quantity of antibody is the best or the only one).The higher titer of IgG anticardiolipin antibody correlates strongly with thrombosis and fetal loss. Most patients with antiphospholipid synndrome have medium to high IgG anticardiolipin antibody levels.


Clinical Significance


The anticardiolipin antibody is measured in an ELISA test.There are many classes of anticardiolipin antibody(IgG,IgM,IgA)The IgG type of anticardiolipin antibody is the type that is most often associated with complications.


Significance of the antibodies 

1. Antibodies associated with infections,drugs tend to have IgM more than IgG.
2. Results in the inconculsive range and positive results for IgM only should be carefully interpreted.
3. Most patients with antiphospholipid antibody syndrome have moderate or high levels of anticardiolipin antibodies and are positive for IgG only or for IgG and IgM.
4. A Correlation exists between IgA and thrombocytopenia.

Clinical Applications

1. Differential diagnosis of patients with unexplained venous thrombosis(25%)CVT(60%),transient ischemic attack(37%) and premature  coronary artery thrombosis(18%)
2. Women having ACL have about 50-70% chance of fetal wastage and abortions.
3. ACL should be compulsorily searched for in patients of Warfarin failure.
4. ACL is recommended as  a routine supportive method for prenatal follow-up of pregnant patients.
5. To diagnose the etiology for symptoms as defined in clinical significance .
6. The detection is straight forward by using solid phase ELISA,measuring all three  antibodies.
7. Most of the drug induced ACL antibodies are of IgM type.