Common Variable Immunodeficiency (CVID), also known as hypogammaglobulinemia, is an antibody deficiency that leaves the immune system unable to defend against bacteria and viruses, resulting in recurrent and often severe infections. The immune system is composed of white blood cells. White blood cells are made in the bone marrow and travel through the bloodstream and lymph nodes. They are a first line of defense and protect against “foreign” invaders such as germs and bacteria. Patients diagnosed with CVID are missing different forms of white blood cells which decreases immune function. The resulting effects may include a pattern of repeated infections, severe infections and/or infections that are unusually hard to cure. These infections may attack any body
The exact cause and genetic inheritance pattern of CVID is unknown in most cases. CVID symptoms vary from person to person. CVID can be associated with autoimmune disorders that affect other blood cells causing low numbers of white cells or platelets, anemia, arthritis and other conditions.
CVID can be diagnosed anytime from childhood through adulthood. As with other antibody deficiencies, the most common types of recurrent infections involve the ears, sinuses, nose, bronchi and lungs. These include:
• Ear infections
• Gastrointestinal infections
CVID may be suspected in patients with a history of recurrent infections involving the lungs, bronchi, ears or sinuses. An accurate diagnosis can be made through screening tests that measure immunoglobulin levels or the number of B cells in the blood.
CVID is treated with immunoglobulin replacement therapy (IRT). IRT treatments must be given regularly and are life-long. Our allergist/immunologist will make the appropriate referral to a specialty pharmacy that will provide CVID patients with the IRT drug prescribed, as well as instruction on proper administration. Acuite infections that result from CVID are treated with antibiotics, though patients may need treatment for a longer duration than an individual without CVID.
To learn more about immunodeficiencies visit the Immune Deficiency Foundation website. Specific detail on immunoglobulins is outlined below.
Antibodies, also known as immunoglobulins (Ig) are a form of protein. The body produces antibodies when antigens are present. Parasites, bacteria, cancer cells, and viruses are examples of antigens. When the immune system accidentally attacks and destroys healthy body tissue, antibodies are produced. The four types of antibodies, IgA, IgG, IgM, and IgE, all have specific functions to combat antigens in the body. These antibodies are measured with a simple blood test.
IgA antibodies protect the surfaces of the body susceptible to foreign substances. They are located in areas such as in the nose, eyes, ears, digestive tracts, tears, saliva and blood. IgA antibodies are also present in breast milk, where they are passed along to babies to help strengthen their immune system.
All body fluids contain the IgG antibody. They are vital in fighting both bacterial and viral infections. IgG antibodies are the only antibodies that may pass through the placenta in pregnant women to protect the fetus.
IgM antibodies are the largest antibody, accounting for 5 percent to 10 percent of antibodies. They are found in the lymph fluid and blood. IgM antibodies are the first line of defense when an infection is detected. They help stimulate the immune system to combat foreign substances.
IgE antibodies trigger the body to respond against foreign matter like pollen, mold spores, pet dander, and other allergens. They are present in the lungs, skin and mucous membranes. IgE levels are typically high in patients with conditions such as allergies and asthma.