LUPUS ANTICOAGULANT WITH REFLEX
Also known as
LA, LAC, Lupus Inhibitor, LA Sensitive PTT, PTT-LA, Dilute Russell Viper Venom Test, DRVVT, Modified Russell Viper Venom Test, MRVVT
The test is ordered by the doctor to investigate why a blood clot occurred. It is also used to evaluate a prolonged partial thromboplastin time, to investigate why miscarriages occurred, or to assess antiphospholipid syndrome. The tests are not used to diagnose lupus.
The test is ordered by the doctor when he or she suspects that the patient is exhibiting signs of a blood clot in the vein or the artery. It is also ordered when a patient has a prolonged partial thromboplastin time or has had recurrent miscarriages.
This is a blood test. The doctor draws a sample of blood from a vein in the arm.
There is no special preparation needed for the test.
This test consists of a series of test which detects the presence of LA in the blood. Lupus anticoagulants are autoantibodies that are made by the immune system. Autoantibodies mistakenly recognize the body’s cells as threats and attack them. They specifically draw out phospholipids and certain proteins linked to phospholipids found in the cell membrane as targets. The autoantibodies obstruct the blood clotting process and increase the risk of the individual developing a blood clot. The interference of the antibodies in the clotting process is not yet fully understood. There is no single test that is used to detect the presence of lupus anticoagulants. In addition, they can not be measured directly in the blood. LA is determined by a panel of sequential tests that have not yet been standardized. There are a series of initial tests, after which follow-up tests are ordered on the basis of the results.
Lupus anticoagulants increase the risk of blood clots developing in the veins and arteries - it quite often occurs in the legs, a condition known as deep vein thrombosis. The blood cots may hinder the flow of blood in different parts of the body leading to a heart attack or a pulmonary embolism. Lupus anticoagulants are also associated with recurring miscarriages. In addition, LA has been linked to clots forming and blocking the blood vessels of the placenta, deeply impacting the growth of a developing baby. LA may also attack the tissue of the placenta, hindering the development.
In addition, lupus anticoagulants are one of the three primary antiphospholipid antibodies which have been linked to the increased risk of APS (antiphospholipid antibody syndrome), thrombosis, organ failure, and complications in pregnancies. Thrombosis is very common in people who have lupus anticoagulants in their bodies. People who have LA may not always have symptoms associated with them.
LA is a series of tests that detects the presence of autoantibodies in the blood. Associated with blood clot formation, the tests are used to identify the causes of an unexplained blood clot (thrombosis) in a vein or artery or recurrent miscarriages in a woman. It is also used to determine the cause of a prolonged partial thromboplastin time. LA testing aids in identifying if a prolonged PTT is because of a specific inhibitor, like an antibody against a specific coagulation factor, or because of a nonspecific inhibitor like the lupus anticoagulant, or due to deficiency in coagulation factor(s). LA testing is also used alongside tests for cardiolipin antibody and anti- beta2-glycoprotein, I to diagnose antiphospholipid syndrome (APS) as well as factor V Leiden, antithrombin, or proteins C, and S to aid in diagnosing an excessive clotting disorder (thrombophilia). It is also helpful in determining whether the lupus anticoagulant is temporary or persistent. Since there is no standardized testing for LA and it can not be measured directly, there are a series of tests that are used to confirm or rule it out. The process is twofold. First, an LA screen is used, which consists of two tests used to detect LA – the DRVVT and PTT-LA. After this, follow-up testing is used to confirm whether the patient has LA in their blood or not. This may consist of a mixing study which consists of mixing an equal volume of patient plasma with normal pooled plasma, and a PTT, or DRVVT being performed on this mixture. Or it can consist of a correction/neutralization where an excess of phospholipids is added to a patient sample, and a PTT-LA or DRVVT is performed on it.
The test is ordered with a series of other tests when:
- A patient has an unexplained blood clot in a vein or artery. He or she may exhibit symptoms like pain, swelling, and discoloration in the leg in the case of deep vein thrombosis (DVT) to fatigue, sweating, and rapid breathing with a pulmonary embolism (PE).
- A patient has symptoms of APS, and these include pain, swelling, and discoloration in the leg in the case of deep vein thrombosis (DVT) to fatigue, sweating, and rapid breathing with a pulmonary embolism (PE).
- A woman experiences recurrent miscarriages
- A patient has a prolonged PTT test which is unexplained
The testing may either indicate the likelihood of LA or rule out the likelihood of the disease. While the lab report tends to be complicated, it does indicate whether LA is present or absent. LA tests must be evaluated by lab technologists, and doctors who have experience in dealing with excessive clotting disorders. The tests for LA tend to begin with a PTT, which is prolonged and may have to be followed up with an LA-sensitive PTT. Results that indicate the presence of LA imply that a patient’s symptoms are due to LA to some degree. Results that show that LA is not present indicate that signs and symptoms are due to other reasons such as a deficiency in coagulation factors.
Related Tests: Antiphospholipid Antibodies, Partial Thromboplastin Time, (PTT, aPTT), Thrombin Time, Antithrombin, Cardiolipin Antibodies, Beta-2 Glycoprotein 1 Antibodies, Prothrombin Time and International Normalized Ratio (PT/INR), Factor V Leiden Mutation and PT 20210 Mutation, Homocysteine, Protein C, and Protein S
Frequently ordered together
Activated Partial Thromboplastin Time APTT
Homocysteine
THROMBIN TIME
PROTEIN C-ACTIVITY
PROTEIN S ACTIVITY
CARDIOLIPIN IGG AB
CARDIOLIPIN IGM AB
FACTOR V-LEIDEN
Beta-2 glycoprotein 1 antibody igM
Beta-2 glycoprotein 1 antibody igG
Cardiolipin Antibody IgA
Thrombin Clotting Time with Reflex to Mixing Studies
Prothrombin Time with INR
16.00$
28.00$
21.00$
47.00$
47.00$
26.00$
35.00$
88.00$
35.00$
35.00$
35.00$
21.00$
14.00$
