title: Assessment of pulmonary neutrophilic inflammation in emphysema by quantitative positron emission tomography.
abstract: BACKGROUND
  Neutrophilic inflammation is understood to be of pathogenetic importance in chronic obstructive pulmonary disease (COPD) and may be quantified using 18-fluorodeoxyglucose positron emission tomography-computed tomography ((18)FDG PET-CT) as a noninvasive, spatially informative biomarker.
  
  
  OBJECTIVE
  To assess the potential usefulness of (18)FDG PET-CT as a surrogate measure of pulmonary neutrophilic inflammation in patients with usual COPD and α(1)-antitrypsin deficiency (AATD).
  
  
  METHODS
  (18)FDG PET-CT imaging was performed in 10 patients with usual COPD, 10 patients with AATD, and 10 healthy control subjects. Pulmonary (18)FDG uptake was estimated by three-dimensional Patlak graphical analysis as an indicator of pulmonary neutrophilic glycolytic activity. Patients with AATD were treated with 12 weekly intravenous infusions of AAT augmentation therapy before repeat imaging. (18)FDG uptake, lung physiology, lung density, and systemic markers of inflammation were compared for all groups at baseline and, in patients with AATD, at baseline and on treatment.
  
  
  RESULTS
  (18)FDG uptake in the upper lung of patients with usual COPD was greater compared with the healthy control group (P = 0.009) and correlated with measures of disease severity (FEV(1)% predicted, r = -0.848, P = 0.001; FEV(1)/FVC, r = -0.918, P < 0.001; Kco% predicted, r = -0.624, P = 0.027; 15th percentile point, r = -0.709, P = 0.011). No significant difference was observed between measurements at baseline and on treatment in patients with AATD.
  
  
  CONCLUSIONS
  Quantitative (18)FDG PET-CT has a potential role as an imaging biomarker in mechanistic and interventional studies in patients with usual COPD. The data support previous evidence of distinct functional characteristics of neutrophils in COPD. Clinical trial registered with https://eudract.ema.europa.eu/index.html (EudraCT 2007-004869-18).
authors: Department of Respiratory Medicine, University Hospitals Coventry and Warwickshire, Clifford Bridge Road, Coventry, CV2 2DX, UK.
authors: Deepak R
authors: DR
authors: Subramanian
authors: Lee
authors: L
authors: Jenkins
authors: Ross
authors: R
authors: Edgar
authors: Nabil
authors: N
authors: Quraishi
authors: Robert A
authors: RA
authors: Stockley
authors: David G
authors: DG
authors: Parr
mesh_terms: D000368:Aged; D001991:Bronchitis / Q000000981:diagnostic imaging* / Q000276:immunology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D005541:Forced Expiratory Volume; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D018375:Neutrophil Activation; D049268:Positron-Emission Tomography; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000276:immunology*; D012016:Reference Values; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed; D006113:United Kingdom; D019896:alpha 1-Antitrypsin Deficiency / Q000000981:diagnostic imaging / Q000503:physiopathology
chemical_list: D018836:Inflammation Mediators; D019788:Fluorodeoxyglucose F18