title: High prevalence of circulating CD4+CD28- T-cells in patients with small abdominal aortic aneurysms.
abstract: OBJECTIVE
  To assess the possible role of proinflammatory CD28- T cells in abdominal aortic aneurysms (AAAs). Animal studies and human tissue studies suggest a role for interferon (IFN)-gamma-producing T cells in the development and progression of AAAs.
  
  
  RESULTS
  Fluorescence-activated cells sorter analysis of peripheral blood samples and measurement of AAA size using sonography were performed in 101 AAA patients and 38 healthy controls. Peripheral percentages of CD28- T cells of the CD3+CD4+ and the CD3+CD8+ were enriched in AAA patients with 7.8+/-8.8% and 41.9+/-15.7% compared with healthy controls with 2.2+/-6.1% and 24.9+/-15.5%, respectively (P=0.002 and P<0.001, respectively). Both CD4+CD28- and CD8+CD28- T cells produced large amounts of IFN-[gamma] and perforin. Patients with small AAAs (<4 cm) showed higher peripheral levels of CD4+CD28- T cells than those with larger AAAs (P=0.025). Immunohistological examinations revealed 39.1+/-17.2% CD4+CD28- and 44.0+/-13.8% CD8+CD28- in AAA tissue specimens with inflammatory infiltratestes.
  
  
  CONCLUSIONS
  IFN-gamma- and perforin-producing CD28- T cells are present in the periphery and the vessel wall of a majority of AAAs. This observation in humans favors the concept of a T cell-mediated pathophysiology of AAAs, especially during the early development of AAAs.
authors.affiliation: Department of Internal Medicine, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Christina
authors.initials: C
authors.lastname: Duftner
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Seiler
authors.forename: Peter
authors.initials: P
authors.lastname: Klein-Weigel
authors.forename: Heike
authors.initials: H
authors.lastname: Göbel
authors.forename: Christian
authors.initials: C
authors.lastname: Goldberger
authors.forename: Christian
authors.initials: C
authors.lastname: Ihling
authors.forename: Gustav
authors.initials: G
authors.lastname: Fraedrich
authors.forename: Michael
authors.initials: M
authors.lastname: Schirmer
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000453:epidemiology / Q000276:immunology* / Q000473:pathology*; D017209:Apoptosis / Q000276:immunology; D015415:Biomarkers; D018106:CD28 Antigens / Q000378:metabolism*; D017252:CD3 Complex / Q000378:metabolism; D015704:CD4 Antigens / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D016827:CD8 Antigens / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000378:metabolism; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D018106:CD28 Antigens; D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D007371:Interferon-gamma