Lupus Anticoagulant Blood Test Results Explained


Lupus Anticoagulant [LA] is what is known as an “autoantibody.” It is associated with extra blood clot formations that are generally unnecessary. This blood test helps to determine the cause of numerous conditions that may result because there is excessive clotting that is occurring.

The issue with the lupus anticoagulant blood test results is that no one single test is able to provide determinate results. Only a series of tests can tell if there is a blood clotting issue that is affecting a person’s health. The two most common tests that are used to detect LA is the DRVVT and the PTT-LA blood tests. Depending on the results, additional tests may also be conducted to confirm a diagnosis or determine the extent of the health issue.

It is typically ordered when someone has the signs or symptoms of a blood clot. There may also be specific issues within a person’s medical history that may indicate the need to test for LA.

What Do the Test Results Mean?

The lupus anticoagulant blood tests will either come back as normal or abnormal. Even when a blood clot may be suspected, most patients are going to have a normal result reported from this blood test. When an abnormal result occurs, then a medical provider may suspect one of these potential health issues based on the individual’s medical history.

1. Unexplained blood clots in a vein or an artery, including deep vein thrombosis that may be difficult to detect otherwise.
2. Miscarriages that are occurring on a frequent basis.
3. Prolonged clotting that is happening because of natural inhibitors, such as an antibody.

If the blood tests are considered to be abnormal, then a follow-up blood test about 3 months later will be ordered to confirm that the results are valid or still present. This is especially important if a medical provider suspects an autoimmune disorder is causing the health issue, such as APS. A series of abnormal results will lead a medical provider to the likelihood that LA is present.

What Can Affect the Results?

The two most common reasons for a prolonged clotting result is the presence of a heparin contaminant or a lupus anticoagulant. Depending on an individual’s personal medical history, however, a medical provider may also suspect the presence of syphilis. That’s because the antibodies created for fighting this STD can produce a false positive on the LA blood test results.

There may also be a positive or abnormal result that occurs when someone suffers from chronic inflammation, certain cancers, or certain autoimmune diseases. Medical providers have also noticed that people who take certain medications may also have results that are false positive or negative. Before the LA blood test occurs, a complete examination and interview regarding current health habits and medications is necessary.

How Are Abnormal Results Treated?

If an individual isn’t suffering from any symptoms, then no treatment may be necessary for the condition that the blood tests have confirmed. If blood clots are forming, then individuals are usually treated with heparin, which acts as an anticoagulant. Several months of warfarin therapy may also be recommended to help thin out the blood to prevent clotting. The risk of thrombosis occurring repetitively is much higher when the lupus anticoagulant has been confirmed, so sometimes a lifetime prescription for anticoagulant medication is ordered.

People most at risk for having a positive LA blood test are women who are pregnant or of a child-bearing age. Up to 5% of women are affected by some sort of excessive clotting disorder that develops. Those who have autoimmune disorders of any type are also exposed to a higher level of clotting risk.

Sample Collection Is Critical For Accurate Results

There are a number of variables that may affect the accuracy of the lupus anticoagulant blood test results. Special tubes are used for the blood draw and the plasma is removed for testing through the use of a centrifuge. If enough blood is not collected, then it cannot become clotted. Too many platelets in a blood sample can also compromise the integrity of the test. High hematocrit levels can also affect test results.

This blood test can be taken at any time and is recommended any time someone has had the signs or symptoms of a potential blood clot. It is especially important for women who have had frequent miscarriages. Based on a specific medical history, there are several treatment options available to minimize the effects of this condition so that a long, fulfilling life can be enjoyed.