title: Changes in sputum T-lymphocyte subpopulations at the onset of severe exacerbations of chronic obstructive pulmonary disease.
abstract: CD8+ve T-cell responses play a primary role in chronic obstructive pulmonary disease (COPD), but there is little information regarding COPD exacerbations. Sputum induction is a relatively non-invasive and safe method to study airway inflammation. The aim of the study was to investigate changes in airway T-lymphocyte subpopulations at the onset of severe COPD exacerbations via analysis of sputum. Induced sputum samples were collected from 12 COPD patients aged (mean+/-sd) 69+/-7 years, ex-smokers (68+/-23 pack-years), mean FEV1 (%predicted) 40+/-14 at the onset of an acute severe exacerbation requiring hospital admission and 16 weeks after remission of the exacerbation. Inflammatory cells and T-lymphocyte subpopulations (CD4, CD8, Tc1, Tc2) were measured using chemical and double immunocytochemical methods. Increased percentages of sputum neutrophils (P=0.002) and decreased CD4/CD8 and CD8-IFNgamma/CD8-IL4+ve (Tc1/Tc2) cell ratios (P=0.03, P=0.02, respectively) were found at the onset of exacerbation compared to stable state. We conclude that a CD8+ve type-2-mediated immune response is induced at the onset of severe COPD exacerbation.
authors.affiliation: Medical School, Department of Thoracic Medicine, University of Crete, P.O. Box 1352, Heraklion 71110, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Tsoumakidou
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Tzanakis
authors.forename: Georgios
authors.initials: G
authors.lastname: Chrysofakis
authors.forename: Despina
authors.initials: D
authors.lastname: Kyriakou
authors.forename: Nikolaos M
authors.initials: NM
authors.lastname: Siafakas
mesh_terms: D000208:Acute Disease; D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology*; D012907:Smoking / Q000276:immunology; D013183:Sputum / Q000166:cytology / Q000276:immunology*; D018709:Statistics, Nonparametric; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology