Cardiolipin is a key component in the structure of mitochondria. However, the body sometimes creates antibodies that mistakenly attack this compound. Find out what the cardiolipin antibody test is and what the results can mean.
What is Cardiolipin?
Cardiolipin is an important component found in mitochondria. Mitochondria are special structures found in the body’s cells that are responsible for producing energy [1].
More specifically, cardiolipin is a phospholipid (a type of fat) that helps form the inner wall (otherwise known as the membrane) of the mitochondria structure [1].
As a part of the membrane of mitochondria, cardiolipin has several functions, including regulating various proteins and triggering apoptosis, which is the process that eliminates and recycles old and damaged cells [1, 2].
Structure of Cardiolipin
Many of the effects of cardiolipin are due to its unique structure.
For example, cardiolipin contains more fatty acids than most other phospholipids. The fatty acids make cardiolipin cone-shaped, allowing it to interact with many proteins [3].
The structure of cardiolipin is also able to change, allowing it to adapt into different shapes [4].
Cardiolipin Antibodies
Sometimes, the immune system may produce antibodies that mistakenly attack the body’s own cardiolipins. These cardiolipin antibodies may cause several negative health effects, including increased risk for blood clots and pregnancy complications [5].
Cardiolipin antibodies (also known as anticardiolipin antibodies) are associated with a number of health conditions, some of which include [5]:
- Syphilis
- Antiphospholipid syndrome
- Systemic lupus erythematosus
- Behçet’s disease
However, the presence of cardiolipin antibodies in the blood does not necessarily indicate a problem. According to some estimates, cardiolipin antibodies can be detected in about 1% to 5% of healthy people [5].
Cardiolipin Antibody Testing
A cardiolipin antibody test detects cardiolipin antibodies in the blood. The test requires a blood sample that is usually taken from a vein in the arm.
This test is typically performed when a patient experiences unexplained blood clots, recurrent miscarriages, or autoimmune disease symptoms [5].
There are actually three types of cardiolipin antibodies — IgG, IgM, and IgA [5].
The types most commonly tested for are IgG and IgM as those two are the most strongly associated with autoimmune diseases. IgA may be tested if results for the other two types are negative, but there is still a clinical suspicion that cardiolipin antibodies are involved [5].
Cardiolipin antibodies may be transient, meaning they may be detectable at one point, but not later on. If someone tests positive for cardiolipin antibodies on an initial test, a second test may be performed later to confirm that the antibodies are persistent [5].
In addition, healthy individuals can test positive for cardiolipin antibodies [5].
Normal Range
Normal ranges can vary between laboratories due to differences in equipment, techniques, and chemicals used. If your results are outside of the normal range, it may not necessarily mean there is something wrong. However, a normal result also doesn’t mean a particular medical condition is absent. Always talk with your doctor to learn more about your test results.
Cardiolipin antibody tests are usually reported as a positive or negative result.
However, a higher concentration of antibodies may be a strong indication of autoimmune disease [5].
Tests can measure IgG (GPL) or IgM (MPL), which may have different cut-off points to be considered positive or negative [6].
Several different manufacturers offer cardiolipin tests, so the interpretation of results highly depends on the type of test used [6].
For example, some types may consider GPL or MPL values greater than 5 to be a positive result. However, other types of tests require a value greater than 10 to be considered a positive result [5].
What Do Cardiolipin Antibody Test Results Mean?
Always talk with your doctor to learn more about your test results.
The results of a cardiolipin antibody test are either positive or negative.
A negative result means no cardiolipin antibody was detected in the blood. However, cardiolipin antibodies may take some time to develop in those with autoimmune disorders [5].
A positive result means that cardiolipin antibody was detected in the blood. As mentioned earlier, the presence of cardiolipin antibodies may indicate several diseases, such as:
- Syphilis
- Antiphospholipid syndrome (APS)
- Systemic lupus erythematosus (SLE)
- Behçet’s disease
The cardiolipin antibody test is often performed in patients who experience unexplained blood clots or recurrent miscarriages. This is because autoimmune disorders like APS and SLE can alter the blood’s ability to clot, which can lead to thrombosis (blood clots) and pregnancy complications [5].
Other types of tests may be performed to confirm the diagnosis of a disorder.
However, positive test results don’t necessarily indicate a health problem. Many healthy individuals test positive for cardiolipin antibodies [5].
Additionally, infections or certain medications (such as phenytoin or valproate) can cause a temporary increase in cardiolipin antibodies [7].
Takeaway
The immune system sometimes produces antibodies against cardiolipin, an important component inside the mitochondria of cells. Testing for cardiolipin antibodies is usually performed in patients with unexplained blood clots or recurrent miscarriages. A positive result may indicate an autoimmune disorder, although healthy people can also test positive.
