Common variable immunodeficiency is a primary immunodeficiency disorder characterized by very low antibody (immunoglobulin) levels despite a normal number of B cells (lymphocytes).
Common variable immunodeficiency is usually diagnosed between the ages of 20 and 40 but may appear earlier or later in life. The number of B cells is usually normal, but the cells do not mature and thus cannot produce immunoglobulins. In some people with this disorder, T cells (lymphocytes) also malfunction. The genetic mutation that causes common variable immunodeficiency can be inherited, but more often, it occurs spontaneously.
Recurring sinus and lung infections, particularly pneumonia, are common. People may develop a chronic cough, cough up blood, or have difficulty breathing. Diarrhea may occur, and food may not be absorbed well from the digestive tract. The spleen may enlarge.
Up to 25% of people develop autoimmune disorders. In autoimmune disorders, the immune system attacks the body's own tissue (see Autoimmune Disorders). Examples are autoimmune blood disorders (such as immune thrombocytopenia, autoimmune hemolytic anemia, and pernicious anemia), Addison disease, thyroiditis, and rheumatoid arthritis. Stomach cancer and lymphoma develop in 10% of people.
Doctors suspect the disorder when people have typical symptoms. Blood tests are done to measure immunoglobulin levels and to determine how well the body produces immunoglobulins in response to vaccines.
Infusions of immune globulin (antibodies obtained from the blood of people with a normal immune system) are given throughout life to provide the missing immunoglobulins. Antibiotics are promptly given to treat infections. Autoimmune disorders are treated as needed with rituximab (a monoclonal antibody also used to treat lymphomas and rheumatoid arthritis), a corticosteroid, and/or other drugs that suppress or otherwise modify the immune system's activity.
Most people have a normal life span, but if another disorder, such as lymphoma or an autoimmune disorder develops and is hard to treat, life span may be shortened.
Last full review/revision February 2014 by James Fernandez, MD, PhD