An immunoglobulin deficiency is a medical condition characterized by low levels of immunoglobulin. There are a number of immunoglobulins in the body, with A, D, E, G, and M immunoglobulins being among the most common and most important. When people do not have adequate supplies of immunoglobulins, they are less able to fight off disease and can be prone to getting sick. They may also be more vulnerable to infections that individuals with healthy immune systems could easily fight off.
The immunoglobulins are part of the body's humoral immunity. They are produced by B lymphocytes and are capable of carrying antibodies that will bind to antigens. Antibodies can neutralize antigens by preventing them from binding with cells in the body and they can also act to tag infectious material so it can be destroyed by the immune system. People lacking immunoglobulins have less effective humoral immunity, although their cellular immunity remains intact.
Some cases of immunoglobulin deficiency are inherited. There are a number of genetic conditions involving B lymphocytes that can limit the number of immunoglobulins produced. Other patients have an acquired immunoglobulin deficiency, which may be secondary or primary. Primary deficiencies are caused by diseases that directly impact the B cells, while secondary deficiencies emerge as part of an overall disease process.
Patients can be diagnosed with an immunoglobulin deficiency with a blood test to count levels of immunoglobulins in the blood. Some patients are symptomatic and may only be diagnosed during the course of routine bloodwork, such as the screening of blood donations performed at blood banks. Other patients have clear immune problems that lead to a workup, during which the low levels of immunoglobulins in the blood will be noted.
Immunoglobulin deficiency treatments vary, depending on the cause. In a secondary deficiency, treating the underlying disease should resolve the problem. With primary deficiencies, treating the condition that is damaging the B cells may raise immunoglobulin levels. Treatments can include bone marrow transplants, as well as injections of immune serum that introduce donor immunoglobulin to the patient's body.
As long as immunoglobulin levels remain low, patients are an increased risk for getting sick. Patients are usually advised to exercise precautions, including avoiding environments where people are sick with contagious diseases. The deficiency will also be noted in the patient's chart so that care providers are aware of the patient's circumstances and know to take additional precautions with that patient.