People with common variable immunodeficiency may have a chronic cough, cough up blood, or have difficulty breathing (due to frequent sinus and lung infections) and may have diarrhea.
To diagnose the disorder, doctors measure immunoglobulin levels and determine how well the body produces immunoglobulins in response to vaccines.
Immune globulin is given throughout life to provide the missing immunoglobulins, and antibiotics are given to treat the frequent infections.
(See also Overview of Immunodeficiency Disorders Overview of Immunodeficiency Disorders Immunodeficiency disorders involve malfunction of the immune system, resulting in infections that develop and recur more frequently, are more severe, and last longer than usual. Immunodeficiency... read more .)
Common variable immunodeficiency is a primary immunodeficiency disorder Primary immunodeficiency Immunodeficiency disorders involve malfunction of the immune system, resulting in infections that develop and recur more frequently, are more severe, and last longer than usual. Immunodeficiency... read more . It is usually diagnosed between the ages of 20 and 40 but may appear earlier or later in life. The number of B cells B cells One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more 
(a type of lymphocytes) is usually normal, but the cells do not mature and thus cannot produce immunoglobulins (antibodies Antibodies One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more ). In some people with this disorder, T cells T cells One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more also malfunction.
Up to 25% of people develop autoimmune disorders Autoimmune Disorders An autoimmune disorder is a malfunction of the body's immune system that causes the body to attack its own tissues. What triggers an autoimmune disorder is not known. Symptoms vary depending... read more . In autoimmune disorders, the immune system attacks the body's own tissue. Examples are autoimmune blood disorders (such as immune thrombocytopenia Immune Thrombocytopenia (ITP) Immune thrombocytopenia (ITP) is a bleeding disorder caused by decrease in the number of platelets (thrombocytes) that occurs in a person who does not have another disorder that affects platelets... read more 
, autoimmune hemolytic anemia Autoimmune Hemolytic Anemia Autoimmune hemolytic anemia is a group of disorders characterized by a malfunction of the immune system, resulting in the production of autoantibodies that attack red blood cells as if they... read more , and pernicious anemia Vitamin Deficiency Anemia Vitamin deficiency anemia results from low or depleted levels of vitamin B12 or folate (folic acid). People may be weak, short of breath, and pale. Nerves may malfunction. Blood tests can detect... read more ), Addison disease Adrenal Insufficiency In adrenal insufficiency, the adrenal glands do not produce enough adrenal hormones. Adrenal insufficiency may be caused by a disorder of the adrenal glands, a disorder of the pituitary gland... read more 
, thyroiditis Hashimoto Thyroiditis Hashimoto thyroiditis is chronic, autoimmune inflammation of the thyroid gland. Hashimoto thyroiditis results when antibodies in the body attacks the cells of the thyroid gland—an autoimmune... read more , and rheumatoid arthritis Rheumatoid Arthritis (RA) Rheumatoid arthritis is an inflammatory arthritis in which joints, usually including those of the hands and feet, are inflamed, resulting in swelling, pain, and often destruction of joints.... read more 
.
Stomach cancer Stomach Cancer A Helicobacter pylori infection is a risk factor for stomach cancer. Vague abdominal discomfort, weight loss, and weakness are some typical symptoms. Diagnosis includes endoscopy and biopsy... read more 
and lymphoma Overview of Lymphoma Lymphomas are cancers of lymphocytes, which reside in the lymphatic system and in blood-forming organs. Lymphomas are cancers of a specific type of white blood cells known as lymphocytes. These... read more 
develop in 10% of people.
The genetic mutations that cause common variable immunodeficiency can be inherited, but more often, they occur spontaneously.
Symptoms of CVID
Recurring sinus and lung infections, particularly pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more 
, are common. People may develop a chronic cough, cough up blood, or have difficulty breathing. People with CVID who have frequent lung infections can develop bronchiectasis Bronchiectasis Bronchiectasis is an irreversible widening (dilation) of portions of the breathing tubes or airways (bronchi) resulting from damage to the airway wall. The most common cause is severe or repeated... read more in which the airways become widened (dilated), making it more difficult to clear mucus and to move air in and out of the lungs.
Diarrhea may occur, and food may not be absorbed well from the digestive tract. The spleen may enlarge.
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.
Diagnosis of CVID
Blood tests
Doctors suspect common variable immunodeficiency 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.
If common variable immunodeficiency is diagnosed, doctors do tests yearly to check for disorders that commonly develop in people with this disorder, such as autoimmune disorders, cancers, and lung disorders. Tests may include blood tests, spirometry Lung flow rate measurements 
(lung tests that measure how much air is inhaled and exhaled and how long each breath takes), and imaging (such as computed tomography).
Treatment of CVID
Immune globulin
Antibiotics to treat infections
Immune globulin (antibodies obtained from the blood of people with a normal immune system) is given throughout life to provide the missing immunoglobulins. It may be injected into a vein (intravenously) once a month or under the skin (subcutaneously) once a week or once a month.
Antibiotics are promptly given to treat infections. Sometimes antibiotics are taken regularly to prevent infections.
Autoimmune disorders are treated as needed with drugs (such as rituximab, etanercept, infliximab, or corticosteroids) that suppress or otherwise modify the immune system's activity.
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Immune Deficiency Foundation: CVID Community Center: General information on common variable immune deficiency, including information on diagnosis and treatment and advice for people affected
