title: Current perspectives on primary immunodeficiency diseases.
abstract: Since the original description of X-linked agammaglobulinemia in 1952, the number of independent primary immunodeficiency diseases (PIDs) has expanded to more than 100 entities. By definition, a PID is a genetically determined disorder resulting in enhanced susceptibility to infectious disease. Despite the heritable nature of these diseases, some PIDs are clinically manifested only after prerequisite environmental exposures but they often have associated malignant, allergic, or autoimmune manifestations. PIDs must be distinguished from secondary or acquired immunodeficiencies, which are far more common. In this review, we will place these immunodeficiencies in the context of both clinical and laboratory presentations as well as highlight the known genetic basis.
authors.affiliation: Division of Rheumatology, Allergy and Clinical Immunology, Department of Internal Medicine, University of California at Davis School of Medicine, Davis, CA, USA.
authors.forename: Arvind
authors.initials: A
authors.lastname: Kumar
authors.forename: Suzanne S
authors.initials: SS
authors.lastname: Teuber
authors.forename: M Eric
authors.initials: ME
authors.lastname: Gershwin
mesh_terms: D001327:Autoimmune Diseases / Q000276:immunology*; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000145:classification / Q000453:epidemiology / Q000209:etiology / Q000235:genetics / Q000276:immunology