title: Targeted therapy of bronchitis in obstructive airway diseases.
abstract: Guidelines for the management of obstructive airway diseases do not emphasize the measurement of bronchitis to indicate appropriate treatments or monitor response to treatment. Bronchitis is the central component of airway diseases and contributes to symptoms, physiological and structural abnormalities. It can be measured directly and reliably by quantitative assay of spontaneous or induced sputum. The measurement is reproducible, valid, and responsive to treatment and to changes in disease status. Bronchitis may be eosinophilic, neutrophilic, mixed, or paucigranulocytic (eosinophils and neutrophils not elevated). Eosinophilic bronchitis is usually a Th2 driven process and therefore a sputum eosinophilia of greater than 3% usually indicates a response to treatment with corticosteroids or novel therapies directed against Th2 cytokines such as IL-4, IL-5 and IL-13. Neutrophilic bronchitis which is a non-Th2 driven disease is generally a predictor of response to antibiotics and may be a predictor to therapies targeted at pathways that lead to neutrophil recruitment such as IL-8 (eg anti-CXCR2), IL-17 (eg anti-IL17) etc. Paucigranulocytic disease may not warrant anti-inflammatory therapy. Several novel monoclonals and small molecule antagonists have been evaluated in clinical trials with variable results and several more are likely to be discovered in the near future. The success of these agents will depend on appropriate patient selection by accurate phenotyping or characterization of bronchitis.
authors.affiliation: Firestone Institute for Respiratory Health, St Joseph's Healthcare & Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Angira
authors.initials: A
authors.lastname: Dasgupta
authors.forename: Helen
authors.initials: H
authors.lastname: Neighbour
authors.forename: Parameswaran
authors.initials: P
authors.lastname: Nair
mesh_terms: D001991:Bronchitis / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D058990:Molecular Targeted Therapy / Q000379:methods; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000473:pathology
keywords: Bronchitis; Eosinophilic bronchitis; Neutrophilic bronchitis; Sputum quantitative assay