TY - JOUR T1 - Airway inflammation and airway pathophysiology in older asthmatics JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p710 AU - Celeste Porsbjerg AU - Peter Gibson AU - Jeffrey Pretto AU - Cheryl Salome AU - Nathan Brown AU - Greg King Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p710.abstract N2 - Background: Asthma morbidity increases with ageing, which may partially result from alterations in airway pathophysiology. We aimed to describe determinants of ventilatory function and airway responses in older asthmatics to further our understanding of pathophysiological mechanisms.Methods: Bronchoconstriction was induced with hypertonic saline (HTS) in 30 asthmatics aged over 54 years (75% female). The response dose ratio (RDR,%change/mg saline) was used to quantify challenge response: RDRFEV1/FVC reflecting airway narrowing, and RDRFVC reflecting airway closure. These measures were regressed against markers of airway inflammation (Induced sputum (s-) neutrophils and eosinophils and exhaled NO).Results: Average (SD) FEV1 was 78%pred (16), FVC 91% (12) with 13% (9) fall in FEV1 during HTS challenge. Baseline ventilatory function was inversely correlated with s-neutrophils (r=-0.61, -0.53 and -0.56 for FEV1%, FVC% and FEV1/FVC respectively, all p<0.05), as well as sputum markers of neutrophils (neutrophil elastase, IL-8 and MMP), but not s-eosinophils (p>0.05 for all).In contrast, the challenge response was predicted by eNO (RDRFEV1/FVC: r= 0,42, p=0,05), indicating airway narrowing associated with airway inflammation. Age predicted an increased RDRFVC (r=0,47 p=0.02), suggesting an increasing tendency to airway closure with ageing.Conclusions: In older asthmatics, the pattern of inflammation bears important relationships to airway physiology. Neutrophilic inflammation is an important determinant of baseline ventilatory function, whereas airway reactivity relates to eosinophilic inflammation. Age is also determinant of airway closure, consistent with an age-related reduction in parenchymal airway support. ER -