Immunoglobulins or antibodies, play an important role in the immune system and help fight against harmful bacteria and viruses in the body. There are five classes of antibodies and several subclasses. Immunoglobulin A or IgA protects against infections of the membranes that line the mouth, airways, and digestive tract. IgA antibodies can also be found in saliva, tears, and breast milk.
What might a low result mean?
Some people are born with low or absent levels of IgA and low levels can also be seen in those with kidney damage or a problem with the intestines.
This can cause false negative results on other antibody based tests, such as the IgA based tests used to identify coeliac disease.
What might a high result mean?
High levels of IgA may be seen in some autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus (SLE), and also in liver diseases, such as cirrhosis and chronic hepatitis.