Bronchial microbiome of severe COPD patients colonised by Pseudomonas aeruginosa.

The bronchial microbiome in severe COPD during stability and exacerbation in patients chronically colonised by Pseudomonas aeruginosa (PA), has not been defined. Our objective was to determine the characteristics of the bronchial microbiome of severe COPD patients colonised and not colonised by P. aeruginosa and its changes during exacerbation. COPD patients with severe disease and frequent exacerbations were categorised according to chronic colonisation by P. aeruginosa. Sputum samples were obtained in stability and exacerbation, cultured, and analysed by 16S rRNA gene amplification and pyrosequencing. Sixteen patients were included, 5 of them showing chronic colonisation by P. aeruginosa. Pseudomonas genus had significantly higher relative abundance in stable colonised patients (p = 0.019), but no significant differences in biodiversity parameters were found between the two groups (Shannon, 3 (2-4) vs 3 (2-3), p = 0.699; Chao1, 124 (77-159) vs 140 (115-163), p = 0.364). In PA-colonised patients bronchial microbiome changed to a microbiome similar to non-PA-colonised patients during exacerbations. An increase in the relative abundance over 20 % during exacerbation was found for Streptococcus, Pseudomonas, Moraxella, Haemophilus, Neisseria, Achromobacter and Corynebacterium genera, which include recognised potentially pathogenic microorganisms, in 13 patients colonised and not colonised by P. aeruginosa with paired samples. These increases were not identified by culture in 5 out of 13 participants (38.5 %). Stable COPD patients with severe disease and PA-colonised showed a similar biodiversity to non-PA-colonised patients, with a higher relative abundance of Pseudomonas genus in bronchial secretions. Exacerbation in severe COPD patients showed the same microbial pattern, independently of previous colonisation by P. aeruginosa.

Effectiveness of omalizumab in non-allergic severe asthma.

Omalizumab is an effective drug for allergic asthma. The purpose of this study was to evaluate the effectiveness and tolerance of this drug in non-allergic GINA step V asthma patients. This study was single-centre, prospective, open-label, observational, naturalistic. Non-allergic asthma patients requiring a mean dose of oral prednisolone of at least 5 mg/day during greater than or equal to 1 year or an accumulated oral corticosteroid dose/year greater than or equal to 1500 mg were enrolled. At entry and the end of the 12-month follow-up we measured blood eosinophilia and IgE concentration; at every monthly visit a forced spirometry and exhaled fraction of nitric oxide (NO) were carried out. The subjects were seven adult patients (5 female), age range 37-63 years, with the following mean values: IgE: 226.7+/-176 IU/mL; FVC 74+/-18 percent; FEV1 57+/-11 percent; NO: 21.2+/-7 ppb. The study was approved by the IRB of the hospital. One patient decided to stop treatment after 12 weeks and was excluded from the evaluation. We did not observe changes in eosinophil count, spirometry or NO values. Three patients considered responders did not need prednisolone during the follow-up. The mean daily dose of prednisolone fell from 6.6+/-8.1 mg/day at entry to 1.5+/-2.3 mg/day (p less than 0.16) at the end of follow-up. The mean monthly accumulated dose fell from 92+/-112 to 12+/-26 mg/month (p=0.26). Total blood IgE increased 1.93-fold. Side effects were only local: treatment tolerance was excellent; three out of six patients seemed to slightly benefit from anti-IgE treatment; to date there is no evidence strong enough to systematically prescribe omalizumab in non-allergic asthma patients.