ABSTRACT
Immunodeficiency diseases are a major cause of mortality and morbidity worldwide. Immune deficient states can be subdivided into primary immune deficiency diseases due to a hereditary or intrinsic defect in the immune system, or secondary immune deficiency as the result of infection, such as HIV, administration of cytotoxic drugs, as with cancer chemotherapy, or metabolic states, such a malnutrition, that compromise the immune system. Primary immune deficiency diseases provide valuable insight into the nature of the immune response and the physiology of the human immune system.
