An immune deficiency disease may be caused either by an inherited defect in the cells of the immune system or by an environmental agent. In the case of an inherited defect, the resulting disease is referred to as primary immune deficiency disease. According to the World Health Organization, there are more than 200 of these sometimes life-altering or life-threatening inherited defects – some are relatively rare, some are quite common. Primary immune deficiency disease affect many thousands of children and adults in the U.S.
When the damage is caused by an environmental agent, the resulting disease is referred to as secondary immune deficiency disease. Secondary immune deficiencies can be caused by exposure to radiation or toxic chemicals, chemotherapy, malnutrition and burns.
Common variable immune deficiency (CVID) is a primary immune deficiency characterized by onset between 24 months of age and young adulthood with increased susceptibility to infection, diminished response to vaccines and low levels of serum immunoglobulins (antibodies).
The genetic causes are not known in most cases. Its name is derived from the fact that it is a relatively common form of immunodeficiency and the degree of deficiency (and therefore the clinical course) varies greatly from patient to patient.
Individuals may experience meningitis or other systemic bacterial infections, recurrent eye or skin infections and gastrointestinal symptoms including chronic diarrhea and bloating. They have increased susceptibility to malignancies, especially lymphomas, and may also develop breast cancer, prostate cancer and skin cancer.