Anti Phospholipid Test - IgG

Antiphospholipid IgG test is a screening test (a test carried out to detect potential disorders) to determine IgG antibodies against cardiolipin and other proteins responsible for blood clotting. The test detects antiphospholipid syndrome (APS) by checking the level of antibodies present in the body.

APS is an autoimmune disorder in which the human body makes proteins (called antibodies) that end up attacking its own cells. This specific syndrome can result in an increased risk of formation of excessive blood clots, called excessive clotting disorder. Blood clots are clumps of blood that are usually formed as a result of an injury. A clotting disorder means people have an increased tendency to develop clots.

Coming back to the APS, while antibodies are formed to protect the human body, in some cases, they end up attacking the body instead. In the case of APS, these antibodies attack proteins found on the outermost layer of a cell. These proteins are called cardiolipins. This attack interferes with the formation of blood clots.

The antibodies that attack cardiolipins are called cardiolipin antibodies. These antibodies are a type of autoantibodies (because they are an antibody attacking a person's own tissues). These antibodies are frequently found with other antibodies such as lupus anticoagulant and anti-beta-2 glycoprotein.

This type of disorder can result in excessive clotting disorder, a low number of platelets and pregnancy issues like miscarriages (accidental abortion) or pre-eclampsia (high blood pressure).

Some people are at a high risk of developing the antiphospholipid syndrome. It is important that these people take the test to know if the body has an abnormal level of blood clots being formed. High-risk people are:

• People who smoke
• People on prolonged bed rest
• Pregnant women and women in their postpartum period
• Women taking birth control pills and hormone therapy
• People with cancer and kidney disease

It can occur in both people with lupus and without lupus. With this test, people can know if they are at a higher risk of thrombosis (the formation of blood clots) and can take the required treatment for the same.

Lupus, Antiphospholipid syndrome (Hughes syndrome), Ischaemic thrombosis, Stroke

For the antiphospholipid IgG test, cardiolipin antibodies are tested. The immune system produces these cardiolipin antibodies, but they target the antibodies' own cardiolipin molecules. They are found in the outermost layer of body cell membranes and platelets present in the blood.

Autoantibodies are necessary because they help in regulating blood clotting. This test is important for detecting the presence of cardiolipin antibodies in the blood.

Cardiolipin is very important in the blood clotting process. High cardiolipin levels are associated with an increased risk of recurrent blood clots in veins and arteries, especially in the deep veins of the legs or the lungs.

A person should get undergo the antiphospholipid IgG test if they come under the following categories for abnormal blood clots:

• Pregnant and the postpartum stage
• Women taking hormone therapy and birth control pills
• People battling cancers
• Have repeated miscarriages and SLE

Commonly seen symptoms of antiphospholipid antibody syndrome are migraines, severe headaches, partial dementia, seizures and cardiovascular diseases. The IgG test shows if there is a high level of cardiolipin antibody. The test shows diseases such as excessive clotting and autoimmune conditions like lupus.

It is essential to get tested when you have more than one or more incidents of blood clots in your veins or arteries. Repeated incidents of miscarriages in the second and third trimester are usually signs of autoimmune disease and need to be checked as soon as possible

After collecting and obtaining the IgG test report, your healthcare professional identifies the antiphospholipid antibodies level. In case of abnormal levels of antiphospholipid, another test is recommended after a gap of 12 weeks.

Before the Test

Before undergoing the antiphospholipid IgG test, it is unlikely that your doctor will require you to take any special precautions. However, if you are to take this test with another one that requires special preparation, your doctor may suggest fasting for a specific time. Always speak with your doctor before a test.

During the Test

For the antiphospholipid IgG test, the phlebotomist will take a blood sample from your arm. Here's what will happen during the test:

• The likely puncture site will be sterilised with antiseptic.
• A tourniquet will be secured around your arm to make your veins stand out.
• A needle will be inserted into a chosen vein to draw the blood. This may cause a brief pinch for a few seconds.
• The blood will be collected in a vial/small test tube, and a label will be affixed with your details.

After the Test

Following the blood collection:

• A bandage will be placed over the insertion site to stem any bleeding.
• Bruising can happen. If you feel lightheaded (an uncommon side effect), you may be advised to rest for a few minutes.
• In case of persistent bleeding, pain, or rashes at the puncture site, contact your doctor.

The goal of this test is to make sure there are no other causes of symptoms and complications.

So the parameters this test considers are:

• As per the guidelines set by the International Society on Thrombosis and Hemostasis, the test checks for the presence of Lupus anticoagulant. Lupus anticoagulants are autoantibodies produced by our immune system, but instead of attacking foreign substances, these antibodies attack the body's own cells.
• The test also checks for the presence of Anticardiolipin antibodies. These are the autoantibodies produced by the immune system. They target the cardiolipin molecules. A higher or even a medium-range is what your physician will look for.
• The final thing the test considers is Anti-β2GP1antibody (commonly found in patients with autoimmune disorders such as APS). These antibodies should be present at a level higher than normal for the test to be positive.

The normal values and reference ranges of the test may vary from lab to lab. Please refer to the ranges mentioned in the report and consult a doctor to understand the interpretation of lab reports.

The antiphospholipid screening test is used for the detection of the type of antiphospholipid syndrome. Test results of antiphospholipid may vary according to age, sex, health conditions, medical history, family disease history, diet patterns and much more. If it falls under the normal range, the chart shows the safe levels.

A negative result of the antiphospholipid test shows cardiolipin antibodies are not present in the blood. Or if they are present, they cannot be detected. However, it is not unusual to detect them in someone’s blood due to some infections as people grow older. In these cases, the number of antibodies present is not significant. But your physician would evaluate the results for you.

In case of a positive result of the antiphospholipid test, another test is conducted after 12 weeks. If the result still comes positive, it indicates you are at an increased risk of higher-than-normal blood clotting and miscarriages.

However, a positive result does not mean you will develop blood clots. Cardiolipin antibodies are a risk factor; they do not predict whether a patient will be subjected to frequent and excessive blood clots in the future.

Also, if patients do have blood clots, this test does not predict the severity or frequency of future instances.