title: Lymphocyte diversity in a 9-year-old boy with idiopathic CD4+ T cell lymphocytopenia.
abstract: Since CD4+ lymphocytopenia can be caused by disturbed thymic T-cell maturation, we investigated the T-cell subsets of a 9-year-old boy fulfilling the diagnostic criteria for CD4+ lymphocytopenia in a follow-up period of 4 years. We found (I) reduced CD45RA expression, (II) enhanced CD45RO expression and (III) a significant increase in gamma delta TCR-bearing T cells. An accelerated apoptosis (11%) was observed in the CD45RO+, but not CD45RA+ subset. These findings provide evidence that a disturbed thymic T-cell maturation process might play a role in the pathogenesis of CD4+ lymphocytopenia.
authors.affiliation: Department of Pediatrics, University of Innsbruck, School of Medicine, Innsbruck, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Frühwirth
authors.forename: K
authors.initials: K
authors.lastname: Clodi
authors.forename: A
authors.initials: A
authors.lastname: Heitger
authors.forename: N
authors.initials: N
authors.lastname: Neu
mesh_terms: D017209:Apoptosis; D002648:Child; D005500:Follow-Up Studies; D006801:Humans; D017493:Leukocyte Common Antigens / Q000032:analysis; D008297:Male; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D018344:T-Lymphocytopenia, Idiopathic CD4-Positive / Q000276:immunology*
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta; D017493:Leukocyte Common Antigens