The Lupus Anticoagulant Evaluation with Reflex test contains 1 test with 4 biomarkers.
Brief Description: The Lupus Anticoagulant Evaluation test is used to screen for lupus anticoagulants, also known as antibodies with phospholipid-protein specificity.
Also Known As: LA Test, LAC Test, Lupus Anticoagulant Panel Test, Lupus Inhibitor Test, LA Sensitive PTT Test, PTT-LA Test,
Collection Method: Blood Draw
Specimen Type: Plasma
Test Preparation: No preparation required
Test Includes Reflexes:
PTT-LA and dRVVT with Reflex Confirmations
- If PTT-LA Screen is prolonged (>40 seconds), then Hexagonal Phase Confirmation will be performed at an additional charge (CPT code(s): 85598).
- If Hexagonal Phase Confirmation is positive or weakly positive, then Thrombin Clotting Time will be performed at an additional charge (CPT code(s): 85670).
- If dRVVT Screen is prolonged (>45 seconds), then dRVVT Confirm will be performed at an additional charge (CPT code(s): 85597).
- ?If dRVVT Confirm is positive, then dRVVT 1:1 Mixing Study will be performed at an additional charge (CPT code(s): 85613).
When is a Lupus Anticoagulant test ordered?
Testing for lupus anticoagulant is recommended in addition to other tests when:
- A vein or artery has had an inexplicable blood clot; signs and symptoms might range from exhaustion, sweating, and rapid breathing with a pulmonary embolism to discomfort, swelling, and discolouration in the leg with deep vein thrombosis.
- A person can have APS symptoms, which may resemble the ones listed above.
- A woman has repeated miscarriages.
- A individual undergoes an extended PTT test.
- Particularly for people being tested for APS, testing is typically repeated about 12 weeks after the initial results to ensure that the presence of lupus anticoagulant is still present.
A doctor may occasionally repeat one or more of the lupus anticoagulant screening tests, typically the PTT, on a person who first tests negative for the substance but who nonetheless has an autoimmune disease like lupus to see if the antibody has grown since the previous time the test was conducted. The reason for this is because the lupus anticoagulant could manifest in the person at any time.
What does a Lupus Anticoagulant blood test check for?
Autoantibodies, which are made by the immune system that mistakenly target specific parts of the body's own cells, are lupus anticoagulants. They specifically target phospholipids and phospholipid-associated proteins that are present in the cell's outermost layer. These autoantibodies raise a person's chance of getting a blood clot by interfering with the blood clotting process in a mechanism that is not completely understood. A battery of tests known as lupus anticoagulant testing can find LA in blood.
The name of the lupus anticoagulant test may sound strange or be unclear for two reasons:
- Although LA testing is not used to diagnose lupus and LA are commonly absent in lupus patients, lupus anticoagulants were originally discovered in patients with the inflammatory disease. LA can also happen to persons who have other medical issues or take certain medications. About 2-4% of the general population has antibodies, and those with no known risk factors can nevertheless develop them.
- Since LA really reduces clotting in laboratory tests used to assess coagulation, the term "anticoagulant" is a part of the name. For instance, they prevent the clotting-causing chemical processes in the partial thromboplastin time test, which is frequently used to gauge clotting. However, the presence of LA in the human body is linked to a higher risk of unneeded blood clot formation. It's important to note that lupus anticoagulant doesn't by itself make the body bleed.
Lupus anticoagulant cannot be readily measured and is not detectable by a single test. Utilizing a panel of consecutive tests for which there is no standardization, LA is typically detected.
Initial testing usually consists of one or more phospholipid-based assays, such as the PTT, the LA-sensitive PTT, or the diluted Russell viper venom test. All of these tests track the length of time needed for a sample to clot; LA increases that length of time.
To confirm or rule out the presence of lupus anticoagulant, certain follow-up tests are carried out according on the outcomes of these initial tests.
LA may make it more likely for blood clots to form in arteries and veins, frequently in the legs' veins. These clots have the potential to obstruct blood flow to any area of the body, resulting in pulmonary embolism, heart attack, or stroke. LA is linked to repeated miscarriages as well. It has been hypothesized that LA may directly destroy the tissue of the placenta, impairing its development, and that LA may also induce clots to form that clog blood arteries of the placenta, impairing growth of the unborn baby.
One of the three principal antiphospholipid antibodies linked to a higher risk of thrombosis and antiphospholipid antibody syndrome, an autoimmune condition characterized by excessive blood clot formation and pregnancy-related problems, is the lupus anticoagulant. Beta-2 glycoprotein 1 antibody and cardiolipin antibodies make up the other two. Both separately and collectively, they enhance a person's propensity to clot improperly. If all three antibodies are present, people with APS are more likely to clot. However, those with LA seem to experience thrombosis more frequently.
Antiphospholipid antibodies do not always cause symptoms. About 5% of healthy adults have antiphospholipid antibodies.
Lab tests often ordered with a Lupus Anticoagulant test:
- Antiphospholipid Antibodies
- Thrombin Time
- PT and INR
- Cardiolipin Antibodies
- Protein C and S
- Factor V Leiden Mutation
- Beta-2 Glycoprotein 1 Antibodies
Conditions where a Lupus Anticoagulant test is recommended:
The Lupus Anticoagulant Evaluation with Reflex test is essential in diagnosing and monitoring various conditions, including:
Antiphospholipid Syndrome (APS): APS is an autoimmune disorder characterized by abnormal clotting and recurring miscarriages. The presence of lupus anticoagulant antibodies is a hallmark of this condition.
Unexplained Blood Clotting: Individuals with recurrent or unexplained blood clotting incidents may undergo this test to determine if lupus anticoagulant antibodies are contributing to the issue.
Autoimmune Disorders: Lupus anticoagulant antibodies can be present in patients with autoimmune conditions like systemic lupus erythematosus (SLE).
How does my health care provider use a Lupus Anticoagulant test?
Testing for lupus anticoagulant is a set of procedures used to find the anticoagulant in blood. An autoantibody called LA is linked to excessive blood clot formation. Testing with LA may be done to assist identify the root cause of:
- a mysterious blood clot in an artery or vein
- Multiple miscarriages
- an extended PTT test without explanation. LA testing assists in determining if a prolonged PTT is caused by a nonspecific inhibitor, such as the lupus anticoagulant, or a nonspecific inhibitor, such as an antibody against a particular coagulation factor.
Using LA testing also allows for:
- Antiphospholipid syndrome is diagnosed with testing for cardiolipin antibody and anti-beta2-glycoprotein I.
- To help with the diagnosis of an excessive clotting condition, tests like factor V Leiden or proteins C and S are often used.
- Identifying the transient or persistent nature of the lupus anticoagulant
There is no single test or established process to identify LA in blood, and it cannot be quantified directly. The presence or absence of the autoantibody is determined by a set of tests:
- It is advised to perform two tests to find lupus anticoagulant. The two assays with the highest sensitivity are the LA-sensitive PTT and the dilute Russell viper venom test, both of which utilize very little phospholipid reagent. To confirm or rule out the presence of lupus anticoagulant, follow-up testing is done. These may consist of:
- Mixing study: A PTT or DRVVT is run on the mixture after an equal volume of patient plasma and "normal" pooled plasma have been combined.
- Correction/neutralization: A PTT-LA or DRVVT is carried out after adding an excessive amount of phospholipids to the patient sample.
What do my Lupus Anticoagulant test results mean?
The outcomes of the several LA tests either point in the direction of LA or away from it. The lab report could be a little technical, but it typically gives an explanation of the findings and indicates if LA is present or not. The best people to interpret the results of LA testing, like the results of other tests for clotting problems, are medical professionals with experience in excessive clotting diseases.
Even though the initial LA tests may differ, they often start with a PTT that is extended. Normal PTT results could indicate the absence of LA. The LA-sensitive PTT may be required since the test may not be sensitive enough to identify LA.
To help with the diagnosis of antiphospholipid syndrome, lupus anticoagulant testing is frequently combined with tests for cardiolipin antibody and anti-beta2-glycoprotein I antibodies.
Most Common Questions About the Lupus Anticoagulant Evaluation with Reflex test:
Purpose and Clinical Significance
What is the Lupus Anticoagulant Evaluation with Reflex test used for?
The Lupus Anticoagulant Evaluation with Reflex test is primarily used to determine if lupus anticoagulants (LA) are present in the blood. These are autoantibodies associated with clotting disorders and increased risk of excessive blood clotting.
Why is the Lupus Anticoagulant Evaluation with Reflex test ordered?
The test is often ordered when an individual has an unexplained prolonged partial thromboplastin time (PTT) test or when someone has recurrent miscarriages, deep vein thrombosis, or other symptoms suggestive of a clotting disorder.
Interpretation of Results
What do the results of the Lupus Anticoagulant Evaluation with Reflex test indicate?
A positive result for the test suggests the presence of lupus anticoagulants in the blood. This can be indicative of antiphospholipid syndrome or other autoimmune disorders, such as systemic lupus erythematosus. However, the presence of LA doesn't confirm a diagnosis but is one piece of the diagnostic puzzle.
What is the "reflex" in the Lupus Anticoagulant Evaluation with Reflex test?
If the initial screening tests indicate the possible presence of a lupus anticoagulant, then reflex testing (additional, more specific tests) is performed to confirm the result and potentially quantify the antibody.
Disease and Complications
Can the Lupus Anticoagulant Evaluation with Reflex test diagnose other conditions besides lupus?
Yes. While the test is often associated with lupus, a positive result can also indicate antiphospholipid syndrome (APS) or be seen in other conditions like infections, medications, or other autoimmune disorders.
What complications can arise from having lupus anticoagulants?
The presence of lupus anticoagulants can increase the risk of developing blood clots in veins and arteries, which can lead to complications like stroke, deep vein thrombosis, or recurrent miscarriages.
Relation with Other Tests
How does the Lupus Anticoagulant Evaluation with Reflex test compare to other antiphospholipid tests?
While the Lupus Anticoagulant Evaluation is one test to detect antiphospholipid antibodies, there are others like the anti-cardiolipin antibody and anti-beta2-glycoprotein I tests. Each of these tests can detect different autoantibodies associated with antiphospholipid syndrome.
If I have a positive Lupus Anticoagulant Evaluation with Reflex test, does it mean I have lupus?
No, a positive test indicates the presence of lupus anticoagulants in the blood, but it doesn't confirm a diagnosis of systemic lupus erythematosus (SLE). The autoantibodies can be found in other conditions as well.
Are lupus anticoagulants related to the drug anticoagulants?
No, the term "lupus anticoagulant" can be misleading. Lupus anticoagulants are autoantibodies that increase the risk of clotting, whereas drug anticoagulants are medications that reduce clotting.
Understanding the Lupus Anticoagulant Evaluation with Reflex test and its implications can assist healthcare providers in diagnosing clotting disorders and determining the best course of action for patient care. As with many diagnostic tests, it's important to consider the results in conjunction with clinical symptoms and other diagnostic information.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.