What are the other Names for this Test? (Equivalent Terms)
- APA (Antiphospholipid Antibodies) Test
- APLA (Antiphospholipid Antibodies) Test
What is Antiphospholipid Antibodies Test? (Background Information)
- The body produces certain proteins in blood, known as antibodies, to fight foreign invaders. Antibodies fight invaders by creating immunity against any foreign microorganisms. In some individuals, the body starts producing antibodies against its own cells and tissues. Such antibodies are called autoantibodies
- Antiphospholipid antibodies (APLA) are one such type of autoantibodies, which are directed against the phospholipids, normally present in the human body. Phospholipids are lipid particles that are a part of the outermost layer of cells; they play an important role in blood clotting
- The presence of antiphospholipid antibodies may cause any of the following:
- Increase one’s risk for blood clots (thrombosis)
- Cause narrowing or irregularity of the blood vessels (vasculopathy)
- Low platelet count (thrombocytopenia)
- Miscarriage in pregnant women
- Brain stroke or a heart attack
There are various types APLAs, but the 3 most widely measured ones, are lupus anticoagulant, anticardiolipin antibody, and anti-β2 (beta-2) glycoprotein I. The other APLAs include anti-prothrombin, anti-phosphatidylserine, and anti-annexin.
What are the Clinical Indications for performing the Antiphospholipid Antibodies Test?
- A healthcare provider may order the Antiphospholipid Antibodies (APLA) Test:
- When an individual has signs and symptoms of thrombotic episodes, such as shortness of breath, headaches, pain and swelling in the extremities
- If a woman has had recurrent miscarriages
- To evaluate a prolonged PTT (partial thromboplastin time)
- To aid in the evaluation of antiphospholipid syndrome (that includes the presence of thrombosis, miscarriages, and low blood platelet count)
- Often, to aid in the diagnosis of an autoimmune disorder, such as systemic lupus erythematous (SLE)
- A healthcare provider may order one or more tests, to detect the type of antiphospholipid antibodies present, depending on the individual’s medical history and clinical signs and symptoms
- Detection of the specific type and class of antiphospholipid antibodies helps in determining the cause of the condition and in managing the condition appropriately
How is the Specimen Collected for Antiphospholipid Antibodies Test?
Following is the specimen collection process for Antiphospholipid Antibodies (APLA) Test:
Sample required: Blood
Process: Insertion of a needle into a vein (arm).
Preparation required: No special preparation is needed, prior to the test.
What is the Significance of the Antiphospholipid Antibodies Test Result?
The significance of Antiphospholipid Antibodies Test is as follows:
- A negative test result only indicates that a specific antibody type was not present, at the time of the test. If the clinical suspicion is very high, or if an autoimmune disorder is diagnosed in an individual, then one or more tests may be performed. The test may have to be repeated at regular intervals, to detect the formation of antiphospholipid antibodies
- A positive result should be interpreted carefully. Low to moderate levels of one or more antibodies is typically temporary, occurring due to a drug, an infection, some cancers, or HIV. Sometimes, low to moderate levels of antibodies are formed in ‘normal’ individuals, as they age. This is called a false positive result
- Moderate to high levels of one or more antiphospholipid antibodies, which persist when tested again (8-10 weeks later), indicate the possible continued presence of that specific antibody. In this scenario, a positive test is significant
- The presence of antiphospholipid antibodies in individuals, diagnosed with antiphospholipid syndrome, usually signifies an increased risk of having recurrent and severe symptoms
- The test is interpreted together with an individual’s clinical signs and symptoms
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
- Occasionally, Antiphospholipid Antibodies Testing may be performed, to help determine the cause of a positive venereal disease research laboratory (VDRL) test, or rapid plasma reagin (RPR) test for syphilis
- False-positive test results are a possibility in those individuals, who take drugs, such as procainamide, quinidine, penicillin, and phenytoin
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.