Primary immunodeficiency

Primary immunodeficiencies are a large group of disorders in which part of the immune system is missing or does not function normally from birth, distinguishing them from secondary immunodeficiencies caused by disease, medication or environmental exposure. As of 2019 more than 430 distinct inborn errors of immunity had been identified, most individually rare, and about 1 in 500 people in the United States are born with some form of primary immunodeficiency. Most cases are genetic and most are diagnosed in children under one year old, though milder forms can go unrecognized until adulthood. They can produce persistent or unusual infections, auto-inflammatory disease, tumors and dysfunction of various organs. The first specific primary immunodeficiency, X-linked agammaglobulinemia, was identified by Ogden Bruton in 1952. Treatment is tailored to the specific disorder and includes immunoglobulin replacement therapy, prophylactic antibiotics or antivirals, immune-suppressing therapy for autoimmune features, and, experimentally, stem cell transplantation and gene therapy.