title: Thymic deficiency in Down's syndrome.
abstract: Children with Down's syndrome (DS) often have small and abnormal thymuses, with lymphocyte depletion, diminution of the cortex, and loss of corticomedullary demarcation--a picture resembling thymic involution. Besides this, they have markedly enlarged Hassall's corpuscles, some surrounded by a sheath of lymphocytes. Patients with DS are known to have increased numbers of respiratory infections; they also have a higher incidence of lymphatic leukemia than do individuals who do not have DS. Studies of cell-mediated (thymic-dependent) immunity demonstrate that children with DS have both diminished numbers of T cells as well as functional deficiency of these cells.
mesh_terms: D002648:Child; D002675:Child, Preschool; D004314:Down Syndrome / Q000276:immunology* / Q000473:pathology*; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D007223:Infant; D007231:Infant, Newborn; D007372:Interferons / Q000096:biosynthesis; D008222:Lymphokines / Q000096:biosynthesis; D008297:Male; D013950:Thymus Gland / Q000473:pathology*
chemical_list: D008222:Lymphokines; D007372:Interferons