ABSTRACT
Immunodeficiency diseases are a major cause of mortality and morbidity worldwide. Most immune deficiency states are classified on the basis of the major component of immunity impacted. This chapter describes the clinical presentations of immune deficiency diseases affecting all arms of adaptive and innate immunity and the different diagnostic approaches for humoral, cell-mediated, phagocytic, and complement deficiencies. In vivo tests, functional tests, and laboratory tests for the various types of immune deficiencies are described and evaluated in detail. A special section is dedicated to the screening for congenital T-cell deficiencies (such as severe combined immune deficiency) in newborns. The chapter closes with a section dedicated to the importance of molecular genetics in the diagnosis of primary immune deficiencies.
