immunoglobulin IgA, IgG and IgM Infections

Often infections? The test measures the amount of immunoglobulins (Ig for short) in the blood, distinguishing between three different types: IgA, and IgG and IgM. These are abbreviations for the immunoglobulin classes: A, G and M.

Immunoglobulins

Immunoglobulins, or antibodies, are proteins produced by humans to clear foreign substances and fight infections (viruses, bacteria or parasites).

Immunoglobulins are produced by specific white blood cells (B cells). Each group of identical cells makes one specific immunoglobulin. Sometimes a group of cells goes haywire and makes far too much of one type of immunoglobulin. This is then at the expense of other immunoglobulins, so the immune system no longer works properly against infections.

IgA is mainly found in the stomach, intestines, saliva and breast milk.

IgM is often the first antibody produced during an infection and is later 'relieved' by IgG. IgG is produced in larger quantities or on second contact with the antigen. IgG can get to the unborn child through the placenta of the pregnant woman and provides the baby's defenses in the first six months.


When is this test done?

If there are complaints of frequent and/or recurrent infections, the doctor may request an immonoglobulin test. This involves testing for IgA, IgG and IgM. Based on the test, it can be checked whether the amount and composition of immunoglobulins in the blood is normal. Sometimes this is done because an excessively high total protein was previously found.

A cause of an excessively high total protein concentration may be that one of the immunoglobulins is made in excess. It can also be that someone has an infection much more often than normal. then you would like to know if all three classes of immunoglobulins are present in normal amounts.

What does the result mean?

Normal

If the amount of each of the immunoglubulins is normal, then there is a small chance that the more frequent occurrence of infections is caused by a lack of immunoglobulins.

Slightly elevated

A slight elevation of the immunoglobulins often occurs during or just after an infection. If in doubt, the further composition of the immunoglobulins can be looked at.

Highly elevated

Strong elevation can occur with a severe infection or when a group of cells has "run wild" and too much of one or more immunoglobulins is made. Additional testing is used to further examine the composition and determine exactly which type of immunoglobulin is present in excess.

Lowered

If all the different classes of immunoglobulins are reduced, it means that a person is very vulnerable to infections. The cause may be a disturbed production of white blood cells in the bone marrow. It is possible that a disturbed production is due to the displacement of healthy white blood cells by a tumor.

A reduced amount of immunoglobulins can also occur as a result of hereditary defects. This will often become apparent in childhood.

There may also be protein loss in the urine due to kidney disease. Loss of immunoglobulins in the urine means that the kidneys are also losing many other proteins. This can occur in advanced stages of diabetes (diabetes mellitus), autoimmune diseases, or chronic inflammation of the kidney.