Immunoglobulin A Test - IgA

The immunoglobulin test checks the problem with the immune system. Sometimes our body makes too many or too few immunoglobulins due to different conditions. Few immunoglobulins in our blood cause infections. While too many leads to allergies or an overactive immune system.

Immunoglobulin (Ig) is a protein that works as an antibody. Plasma cells and lymphocytes are responsible for its production. Immunoglobulins play an important role in the immune system of the body. They help in destroying foreign substances like bacteria, viruses, etc. Immunoglobulins can live either on the edges of the cells or move freely in the blood. Circulating immunoglobulins are antibodies.

There are five immunoglobulin types. They are IgA, IgD, IgE, IgG and IgM. Each isotope has different properties and the ability to fight with specific antigens. IgA is found in the gut, saliva, tears, breast milk, respiratory tract, etc. mucosal area and helps in the prevention of pathogen colony. IgA makes up 15% of the total antibodies.

Your consulting physician may prescribe an IgA test to diagnose issues with the immune system. IgA tests are also done for the diagnosis of recurrent infections, especially of the lungs, stomach, sinuses, intestines or chronic diarrhoea.

IgA tests are also prescribed to people suffering from HIV/AIDS or multiple myeloma. IgA test results help to identify the autoimmune conditions in which the body makes antibodies against healthy tissues mistakenly, such as arthritis, lupus and celiac disease. Zero or low levels of IgA puts the patient at higher risk for autoimmune conditions, infections, allergies and asthma.

IgA nephropathy (IgAN) is another such condition in which IgA deposits in the kidney, causing end-stage renal failure.

The prevalence and outcomes of IgAN are highly variable when compared between different parts of the world. IgAN is a serious problem in India owing to its higher prevalence in Asia, especially India. Few studies show the prevalence of IgA nephropathy in the southern part of India. When compared with the data from the rest of the world, the results of patients from India are alarming and saddening, almost 50%, which is a burden in itself.

Recurrent infections, Chronic diarrhoea, IgA Nephropathy, HIV/AIDS.

Some conditions or family history cause the body to make too many or too few immunoglobulins. Having deficient immunoglobulins in the blood gives you a greater chance of getting infections. Also gives the idea that you have allergies or an overactive immune system.

IgA antibodies shield body surfaces that are in contact with foreign substances. These antibodies are found in blood, saliva and tears. IgA antibodies constitute around 10-15% of the total antibodies.

Bodies of some people do not produce IgA antibodies due to some reasons. They have a higher chance of developing a potentially life-threatening reaction to a procedure like a blood transfusion.

The immunoglobulin test is prescribed by a doctor if the person has infections of the lungs, sinuses, intestines or stomach. The IgA test is also prescribed in the following conditions:

• Persistent Diarrhoea
• Fevers having no relatable causes
• Allergies
• Unintended weight loss
• Skin rashes
• Illness after travelling

Some diseases for which an IgA Test can be prescribed are:

• HIV/AIDS or multiple myeloma
• IgA nephropathy
• Arthritis
• Lupus
• Celiac disease

The IgA test is applicable for people of any gender or age.

The doctor recommends immunoglobulin A test when a person has signs of chronic inflammation, recurrent infections. When healthcare practitioners suspect excess or abnormal immunoglobulin production, they recommend IgA tests. Doctor orders this test intermittently to observe the course of a person's condition.

Before the Test

Typically, no special preparations are required for an immunoglobulin A test. However, if you are undergoing this test alongside another one, your healthcare provider may advise you on specific dietary restrictions. It's always best to consult with your doctor before the test for personalised guidance.

During the Test

The blood sample will be drawn from a vein in your arm. Here's what you can anticipate during the test:

• The area where the needle will be inserted will be cleaned with an antiseptic.
• A tourniquet band will be placed around your arm to make the veins easier to locate.
• A quick pinch may be felt as the needle is inserted into the vein to draw the blood. This process typically takes a few seconds.
• The collected blood will be stored in a vial or a small test tube labelled with your test details.

After the Test

Once the blood is collected:

• An adhesive plaster will be placed over the puncture site to prevent bleeding.
• Mild bruising may occur, feeling dizzy is less common. You might be advised to rest for a few minutes.
• Consult  with your healthcare provider if you experience bleeding, pain, or rashes at the puncture site.

Some immunoglobulin A test parameters are:

• Test the levels of IgA in blood
• Monitor excess or deficiency of IgA
• Test Antibodies

These are the only parameters covered under this test. An IgA test checks the level of immunoglobulins or antibodies in the blood. Antibodies are nothing but proteins produced by your immune system to ward off harmful substances like bacteria and viruses. The result of the IgA test is not expressed as positive or negative. If the value is on the higher side or lower side, it is an indicator of a disorder with the immune system.

The range for the immunoglobulin A test varies according to the age of the person. Given below is a table for reference:

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 main component of the immunoglobulin A test is the antibodies. If the result of the immunoglobulin A test shows a high level of IgA antibodies, then it could be an indication of the following conditions:

• Allergies
• Autoimmune disorders like rheumatoid disorder, lupus or celiac disease
• Inflammatory Bowel Disease
• Chronic infections
• Liver-related Disease
• Cancer such as lymphoma or leukaemia

Low levels of IgA interprets the following conditions:

• Diabetes Complications
• Kidney Disease or Kidney Failure
• HIV/AIDS

High or low levels of Immunoglobulins is not the diagnosis of any of the above-mentioned diseases and a doctor should be consulted for better IgA test results interpretation.