Abstract
Changes in airway inflammation can be studied with bronchoalveolar lavage, but the widespread use of this procedure is limited by its invasiveness. The aim of this study was to evaluate the usefulness of induced sputum as a non-invasive alternative to bronchoalveolar lavage for studying changes in airway inflammation in patients with asthma. Thirty patients were treated for 12 weeks with an inhaled corticosteroid (fluticasone propionate [FP], 250 μg twice daily) or a short-acting beta-agonist (salbutamol [Sb], 400 μg twice daily) in a double-blind, double-dummy, randomized parallel group study. Sputum induction with hypertonic saline solution was performed twice before treatment and after 4, 8, 10, and 11 weeks of treatment. Bronchoalveolar lavage fluid divided into two pools (first 60 mL portion as bronchoalveolar lavage/bronchial wash [BAL/BW] and subsequent 80 mL as bronchoalveoalar lavage [BAL]) was obtained before and after 12 weeks of treatment. Changes in cell differentials and plasma-protein leakage (α2-macroglobulin, albumin, and their ratio [relative coefficient of excretion, RCE]) were analyzed in induced sputum and were compared with changes in BAL/BW and BAL. During treatment with FP, the PC20histamine (interpolated concentration of histamine that caused a fall in FEV1 of 20% of the baseline value) increased (P <.0001), and the percentage of eosinophils (P =.004), levels of α2-macroglobulin (P =.09) and RCE (P =.007) decreased in sputum. These changes were different from those in the Sb group (PC20histamine P <.0001, eosinophils P =.004, α2-macroglobulin P =.003, RCE P =.01), in which α2-macroglobulin showed a significant increase (P =.015). Changes in the percentage of eosinophils and in the levels of α2-macroglobulin in sputum were associated with changes in the PC20histamine (Rs = –0.59, P =.007 and Rs = –0.47, P =.03, respectively). These correlations did not reach significance in BAL/BW and BAL fluid. The statistical power to detect changes in induced sputum was higher for the percentage of eosinophils and similar for plasma protein leakage as compared with analysis of BAL/BW and BAL fluid. We conclude that the analysis of induced sputum is a useful, non-invasive alternative to bronchoalveolar lavage for assessing the effects of antiinflammatory drugs in asthma. (J Lab Clin Med 2000;136:39-49)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.