Matthew Richard William Rossall1, Paul Aidan Cadden2, Stephanie Dawn Molphy2, Jonathan Plumb2, Dave Singh2. 1. University of Manchester, Medicines Evaluation Unit, The Langley Building, Southmoor Road, Manchester, M23 9QZ, UK. Electronic address: mrossall@meu.org.uk. 2. University of Manchester, Medicines Evaluation Unit, The Langley Building, Southmoor Road, Manchester, M23 9QZ, UK.
Abstract
BACKGROUND: Novel therapies are being developed for patients with moderate to severe asthma. These patients may have neutrophilic airway inflammation. Induced sputum is commonly used as an endpoint in clinical trials of asthma therapies. We have performed repeated induced sputum sampling in moderate to severe asthma patients to understand the variability of cell counts, including neutrophils, and performed power calculations for studies in this group of patients. METHODS: Nineteen patients with moderate to severe asthma with evidence of airflow obstruction (FEV1 ≤ 80% predicted) and suboptimal control (ACQ ≥ 1) performed repeated induced sputum separated by 1 month. RESULTS: The Ri of neutrophil percentage and absolute eosinophil count demonstrated good (0.61) and moderate (0.56) repeatability respectively, but there was a poor level of agreement for eosinophil percentage and absolute neutrophil counts. The within subject SD for sputum neutrophil percentage was 15.8. In cross over studies, sample sizes of n = 14 and n = 54 are required to detect changes in neutrophil percentages by 20 and 10 % respectively at 90% power. CONCLUSIONS: Sputum neutrophil percentage has good reproducibility in patients with moderate to severe asthma.
BACKGROUND: Novel therapies are being developed for patients with moderate to severe asthma. These patients may have neutrophilic airway inflammation. Induced sputum is commonly used as an endpoint in clinical trials of asthma therapies. We have performed repeated induced sputum sampling in moderate to severe asthmapatients to understand the variability of cell counts, including neutrophils, and performed power calculations for studies in this group of patients. METHODS: Nineteen patients with moderate to severe asthma with evidence of airflow obstruction (FEV1 ≤ 80% predicted) and suboptimal control (ACQ ≥ 1) performed repeated induced sputum separated by 1 month. RESULTS: The Ri of neutrophil percentage and absolute eosinophil count demonstrated good (0.61) and moderate (0.56) repeatability respectively, but there was a poor level of agreement for eosinophil percentage and absolute neutrophil counts. The within subject SD for sputum neutrophil percentage was 15.8. In cross over studies, sample sizes of n = 14 and n = 54 are required to detect changes in neutrophil percentages by 20 and 10 % respectively at 90% power. CONCLUSIONS: Sputum neutrophil percentage has good reproducibility in patients with moderate to severe asthma.
Authors: Alessandra Chiappori; Laura De Ferrari; Chiara Folli; Pierluigi Mauri; Anna Maria Riccio; Giorgio Walter Canonica Journal: Clin Mol Allergy Date: 2015-10-01
Authors: P E Silkoff; M Laviolette; D Singh; J M FitzGerald; S Kelsen; V Backer; C Porsbjerg; P O Girodet; P Berger; J N Kline; S Khatri; P Chanez; V S Susulic; E S Barnathan; F Baribaud; M J Loza Journal: Respir Res Date: 2016-04-23