Increased C-reactive protein is associated with airway wall thickness in steroid-naive asthma

Abstract

BackgroundAsthma is characterized by chronic airway inflammation and remodeling. Levels of serum high-sensitivity C-reactive protein (hs-CRP) reflect airway eosinophilic inflammation. However, the relation between hs-CRP and the development of airway wall thickening remains unknown. ObjectiveTo evaluate whether serum hs-CRP is associated with airway geometry in asthma. MethodsForty-eight steroid-naive patients with asthma, 51 patients with asthma treated with inhaled corticosteroids, and 38 aged-matched healthy controls were studied cross-sectionally. Serum hs-CRP levels, lung function, and inflammatory cell counts in sputum were measured. Quantitative computed tomographic analysis of the apical segment of the right upper lobe was performed. ResultsSerum hs-CRP levels were significantly elevated in steroid-naive patients with asthma compared with controls and steroid-treated patients with asthma and were associated with airflow limitation. In steroid-naive patients, serum hs-CRP levels were correlated with airway wall thickness (r = 0.88, P < .001) and sputum eosinophil percentage (r = 0.75, P < .001). Multivariate analysis showed a significant association between hs-cRP levels and forced expiratory volume in 1 second (percentage predicted; R2 = 0.65, P = .001). ConclusionSerum hs-CRP may be a useful systemic biomarker of airway eosinophilia in steroid-naive asthma and has potential utility as a marker for the development of airway wall thickening. Trial RegistrationUniversity Hospital Medical Information Network (www.umin.ac.jp/ctr/index/htm); identifier, UMIN000006724.