Both males and females may have CVID. In the majority, the diagnosis is not made until the third or fourth decade of life. However, about 20% of patients have symptoms of the disease or are found to be immunodeficient in childhood. Because the immune system is slow to mature, the diagnosis of CVID is generally not made until after the age of 4.
The usual presenting features of CVID are recurrent infections involving the ears, nasal sinuses, bronchi (breathing tubes) and lungs (respiratory tract). When the lung infections are severe and occur repeatedly, permanent damage with widening and scarring of the bronchial tree, a condition termed bronchiectasis, may develop.
The organisms commonly found in these sinopulmonary infections are bacteria that are widespread in the population and that often cause pneumonia (Hemophilus influenzae, pneumococci, and staphylococci) even in people who do not have CVID. The purpose of treatment of lung infections is to prevent their recurrence and the accompanying chronic and progressive damage to lung tissue. A regular cough in the morning and the production of yellow or green sputum may suggest the presence of chronic bronchitis or bronchiectasis.
Patients with CVID may also develop enlarged lymph nodes in the neck, the chest or abdomen. The specific cause is unknown, but enlarged lymph nodes may be caused by infection, an abnormal immune response or both. Similarly, enlargement of the spleen is relatively common, as is enlargement of Peyer’s patches which are collections of lymphocytes in the walls of the intestine.
In some cases, other collections of inflammatory cells, called granulomas, can be found in lungs, lymph nodes, liver, skin or other organs. These are largely composed of cells called monocytes and macrophages. They may be a response to an infection, but the cause is not really known.
Although patients with CVID have depressed antibody responses and low levels of immunoglobulins in their blood, some of the antibodies that are produced by these patients may attack their own tissues (autoantibodies). These autoantibodies may attack and destroy blood cells, like red cells, white cells or platelets. Although, most individuals with CVID present first with recurrent bacterial infections, in about 20% of cases the first manifestation of the immune defect is a finding of very low platelets in the blood or severe anemia due to destruction of red cells. Autoantibodies may also cause other diseases such as arthritis or endocrine disorders, like thyroid disease.
Gastrointestinal complaints such as abdominal pain, bloating, nausea, vomiting, diarrhea and weight loss are not uncommon in CVID. Careful evaluation of the digestive organs may reveal malabsorption of fat and certain sugars or inflammatory bowel disease. If a small sample (biopsy) of the bowel mucosa is obtained, characteristic changes may be seen. These changes are helpful in diagnosing the problem and treating it. In some patients with digestive problems, a small parasite called Giardia lamblia has been identified in the biopsies and in the stool samples. Eradication of these parasites by medication may eliminate the gastrointestinal symptoms.
Some patients with CVID who may not be receiving optimal immunoglobulin replacement therapy may also develop a painful inflammation of one or more joints. This condition is called polyarthritis. In the majority of these cases, the joint fluid does not contain bacteria. To be certain that the arthritis is not caused by a treatable infection; the joint fluid may be removed by needle aspiration and studied for the presence of bacteria. In some instances, a bacterium called Mycoplasma may be the cause and can be difficult to diagnose. The typical arthritis associated with CVID may involve the larger joints such as knees, ankles, elbows and wrists. The smaller joints, like the finger joints, are rarely affected. Symptoms of joint inflammation usually disappear with adequate immunoglobulin therapy and appropriate antibiotics. In some patients, however, arthritis may occur even when the patient is receiving adequate immunoglobulin replacement.
Finally, patients with CVID may have an increased risk of cancer, especially cancer of the lymphoid system or gastrointestinal tract.