Severe Combined Immunodeficiency

Severe combined immunodeficiency (SCID) is a group of inherited disorders characterized by profound defects in both cellular and humoral immunity, resulting in markedly reduced or absent T lymphocytes. Clinically, the disease presents with early-onset opportunistic infections, failure to thrive, and chronic diarrhea. Without treatment, affected infants usually die within the first years of life. Any infant with persistent lymphopenia should be evaluated for severe combined immunodeficiency. Treatment includes hematopoietic stem cell transplantation, gene therapy for selected forms, and enzyme replacement therapy in adenosine deaminase (ADA)-deficient SCID. If severe combined immunodeficiency is suspected, live vaccines should not be administered.

Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology