Immunoglobulin A, IgA, is produced in the mucous membranes of the body. It is found in all mucous secretions, such as tears and saliva, as well as in the blood. Type A is unique in that it doesn’t break down when exposed to enzymes. This makes it an important disease fighting component in the body. Aside from Type A, there are four other types of immunoglobulin present in the blood. IgG is present in the greatest amount. IgA and IgM are also present in large amounts. The antibodies IgD and IgE are also present, but in much lower quantities.
Each type of immunoglobulin has a specific function in the immune system. Type A is present in mucous membranes, and is responsible for helping the body fight infections in these areas. While this may not seem like a large job, the mucous membranes of the body are expansive, and, without their protection, would leave an open pathway into the body.
There are various health conditions that can lead to low levels of Immunoglobulin A in the body. When the body does not have sufficient quantities of Type A Immunoglobin, the person may be diagnosed with selective IgA deficiency. This is considered a disease of the autoimmune system. Some diseases, such as gonorrhea, can destroy Immunoglobulin A in the body, leading to a deficiency.
A person that suffers from selective Immunoglobulin A deficiency will have normal levels of the other antibodies in their body. The patient will also have fully functioning T-cells, phagocytes, and other components of the immune system. The exclusive absence of Type A Immunoglobin is what gives the disease the name selective IgA deficiency.
Selective Immunoglobulin A deficiency is a relatively common immunodeficiency illness. People suffering from this ailment may appear perfectly healthy, or they may suffer from problems related to the deficiency. The most common ailment associated with selective IgA deficiency is a greater susceptibility to common illnesses such as ear infections, bronchitis and sinusitis.
People that suffer from selective Immunoglobulin A deficiency are more susceptible to autoimmune disorders such as Rheumatoid Arthritis and Lupus. Patients who suffer from a selective IgA deficiency are also more prone to allergies and asthma. Eczema is another condition that occurs in people suffering from this deficiency.
Occasionally, deposits of Immunoglobulin A can build up on the kidneys. This leads to a condition known as IgA nephropathy. IgA nephropathy is considered a chronic condition. Doctors are not sure what leads to the buildup of Type A Immunoglobulin on the kidneys with this ailment.