Tobramycin Nebulizer Solution in severe COPD patients colonized with Pseudomonas aeruginosa: effects on bronchial Inflammation

Abstract

Airway colonization with Pseudomonas aeruginosa is frequent in severe chronic obstructive pulmonary disease (COPD) and may lead to progressive inflammatory damage. Inhaled Tobramycin Nebulizer Solution (TNS; a preservative-free formulation) is an effective therapy in chronic P aeruginosa infection in cystic fibrosis and bronchiectasis. In this study we aimed to investigate the effects of a TNS short course on inflammatory markers in bronchial secretions from multiresistant P aeruginosa-colonized patients with severe COPD. To the authors' knowledge, this is the first study to examine this in cases of severe COPD. Thirteen COPD patients (GOLD criteria 3-4; mean age 72.7+/- 8 years; mean basal forced expiratory volume in 1 second (FEV(1)) 34.8%+/-8.1%; mean FEV(1)/forced vital capacity 0.6+/-0.1) were enrolled. All patients were colonized with P aeruginosa and resistant to oral/intravenous specific antibiotics. Eosinophilic cationic protein (ECP), interleukin-1 beta (IL-1beta), interleukin-8 (IL-8), tumor necrosis factor alfa (TNF-alpha), and cell counts were measured in spontaneous secretions before and after a 2-week TNS course (300 mg twice daily). The TNS course induced a significant reduction in IL-1beta (P<0.03), IL-8 (P<0.02), ECP (P<0.01) concentrations, and in eosinophil count (P<0.01). TNF-alpha levels, and neutrophil and lymphocyte counts were not significantly affected. The second week of treatment proved crucial in terms of efficacy. P aeruginosa density was lowered after 6 months; severe acute exacerbations were reduced by 42%. TNS reduced the inflammatory impact of P aeruginosa in multiresistant, P aeruginosa-colonized patients with severe COPD. A therapeutic role for TNS can be strongly suggested in these particular conditions.