RT Journal Article
SR Electronic
T1 Variability of sputum inflammatory mediators in COPD and Alpha-1-antitrypsin deficiency
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP erj01628-2011
DO 10.1183/09031936.00162811
A1 H. Stone
A1 G. McNab
A1 A.M.Wood
A1 R.A. Stockley
A1 E. Sapey
YR 2012
UL http://erj.ersjournals.com/content/early/2012/06/14/09031936.00162811.abstract
AB There is inherent daily variability of sputum inflammatory mediators in stable state patients with usual COPD. The variability of pulmonary inflammation in patients with alpha-1-antitrypsin deficiency (A1ATD) is unknown. The current study aimed to quantify this variability, in comparison to patients with usual COPD, in order to facilitate power calculations for proof of concept trials of putative specific anti-inflammatory agents in both patient groups.Sputum interleukin 8, myeloperoxidase, leukotriene B4 and differential cell counts were measured in 12 patients with usual COPD and 12 patients with A1ATD on 9 occasions over a 1 month period. All samples were taken in the stable clinical state.There was significant daily variability in all measured mediators in all patients. A1ATD patients had higher sputum concentrations of interleukin-8 and leukotriene B4 compared with usual COPD, although lower levels of myeloperoxidase and absolute neutrophil counts. Patients with usual COPD had more intra-patient variability; those with A1ATD demonstrated greater inter-patient variability.There are increased concentrations of pulmonary inflammatory mediators, but fewer sputum neutrophils in A1ATD compared with usual COPD. The daily variability of inflammatory mediators and cell counts was significantly reduced in both patient groups by averaging sequential samples. This can be utilised to perform power calculations for future proof of concept studies; averaging 3 sequential samples appears optimum.