Purpose of review: This issue of Current Opinion in Allergy and Clinical Immunology is focused on primary immunodeficiency diseases (PIDs). Like every disorder, PID has its own specific history, starting with the discovery of agammaglobulinemia in 1952 and still expanding at a rapid pace, covering, at the time of this publication, more than 180 genetically determined disorders. However, as this report attempts to demonstrate, the history of PID is intertwined with the development of modern medicine and is the direct result of the innovative thinking of physician scientists who introduced new concepts in pathology, microbiology, biochemistry, and immunology, based on carefully designed experiments. As a consequence of the novel ideas put forth in the late 19th century, progress in public health, the discovery of antimicrobials, and the utilization of biologic products led to the recognition of genetically determined defects of Immunity and the design of effective treatment strategies.
Recent findings: The discovery of the structure of DNA, its replication, and the mapping of the human genome has transformed the field of PID into a predictable science of cutting edge therapies and diagnostic concepts.
Summary: This review illustrates the historic events that led to the discovery, classification, and molecular definition of PID.