title: Immunological basis of reversible and fixed airways disease.
abstract: Asthma is characterized by airflow obstruction that is usually completely reversible either spontaneously or in response to treatment. However, a small subset of patients with asthma display FAO (fixed airflow obstruction) despite optimal treatment, a feature more commonly associated with smoking-induced COPD (chronic obstructive pulmonary disease). Why some asthma patients develop FAO is not understood, and it is not clear whether (i) they represent a subset of patients with more severe disease, (ii) they share some characteristics of patients who develop COPD, or (iii) they represent a different disease entity altogether. The present review compares the pulmonary inflammatory profile of asthma patients with FAO with those without FAO, as well as COPD sufferers. The inflammation in asthma patients with FAO can vary from neutrophilic with CD8 T-cell involvement, similar to that of COPD, to eosinophilic with CD4 Th2 cell involvement, akin to that of asthma patients without FAO. Although studies of FAO in asthma sufferers would benefit hugely from consistent inclusion criteria, further research work is also required to shed more light on the immunological processes involved.
authors.affiliation: COPD Research Group, Department of Immunology, Nottingham Respiratory Biomedical Research Unit, University of Nottingham, and Department of Respiratory Medicine, Nottingham City Hospital, Nottingham NG7 2UH, UK.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Tubby
authors.forename: Tim
authors.initials: T
authors.lastname: Harrison
authors.forename: Ian
authors.initials: I
authors.lastname: Todd
authors.forename: Lucy
authors.initials: L
authors.lastname: Fairclough
mesh_terms: D000818:Animals; D001249:Asthma / Q000276:immunology*; D001992:Bronchoalveolar Lavage Fluid; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D007107:Immune System; D008024:Ligands; D020782:Matrix Metalloproteinases / Q000378:metabolism; D051379:Mice; D053683:Oncostatin M / Q000378:metabolism; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D000094632:Thymic Stromal Lymphopoietin
chemical_list: D016207:Cytokines; D008024:Ligands; D014409:Tumor Necrosis Factor-alpha; D053683:Oncostatin M; D020782:Matrix Metalloproteinases; D000094632:Thymic Stromal Lymphopoietin