Microbiological airway colonization in COPD patients with severe emphysema undergoing endoscopic lung volume reduction

Meta-analysis and Systematic Review of Bronchoscopic Lung Volume Reduction Through Endobronchial Valves in Severe Emphysema

BACKGROUND

Pharmacologic therapeutics for advanced emphysema have limited benefit. Bronchoscopic lung volume reduction with endobronchial valves (EBVs) have reported improvements in lung function, breathlessness, and quality of life through randomized clinical trials, with less morbidity as comparted to Surgical Lung volume Reduction. We here present a Meta-analysis and systematic review of bronchoscopic lung volume reduction in advanced chronic obstructive lung disease patients.

METHODS

PubMed (NLM), Embase (Elsevier), and Web of Science (Clarivate Analytics) search was conducted using a combination of keywords and subject headings. The search was confined to the last 15 years and was completed on October 23, 2020. Only placebo-controlled randomized control trials of emphysema patients with EBV were included. Quality assessment was done by 2 independent reviewers.

RESULTS

Nine studies were included for the meta-analysis with a total number of 1383 patients of whom 888 received EBV and 495 standard of care (SOC) medications. Our Metanalysis show statistically significant improvement in forced expiratory volume in first second, percentage forced expiratory volume in first second, St. George's respiratory questionnaire, and 6-minute walk distance in EBV group compared with SOC. Residual volume had statistically significant reduction after EBV placement compared with SOC. These differences continued to be present during short-term (<=6 mo) and long-term follow-up (>=6 mo). These improvements were even higher when the EBV patients'. Collateral ventilation was negative/fissure was intact (CV-/FI >90%). The rate of hemoptysis and pneumothorax was higher in the EBV group compared with SOC, however, did not lead to increased fatal outcomes.

CONCLUSION

In conclusion, EBV has favorable effects on patients' outcomes in patients who have heterogeneous emphysema particularly with no collateral ventilation.

A Systematic Review and Meta-Analysis of the Prevalence and Impact of Pulmonary Bacterial Colonisation in Stable State Chronic Obstructive Pulmonary Disease (COPD)

Background: Half of acute exacerbations of COPD are due to bacterial infection, and the other half are likely influenced by microbial colonisation. The same organisms commonly cultured during acute exacerbations are often found in the sputum of patients during stability. A robust assessment of the prevalence of potentially pathogenic microorganisms (PPMs) in the sputum of stable COPD patients may help to inform the targeted prevention of exacerbation by these organisms. Methods: A systematic review and meta-analysis was carried out to determine the prevalence of PPMs in patients with COPD in the stable state. Meta-analysis of prevalence was carried out using the Freeman–Tukey double arcsine transformation random effects model, and sub-group analysis was performed for sputum modality. Prevalence of total and individual PPMs was calculated from patient-level data from individual studies. Results: Pooled prevalence of PPMs identified by sputum culture was found to be 41% (95% CI 36–47%). Significant heterogeneity was found across all studies, which can likely be attributed to inconsistent measuring and reporting of PPMs. The most commonly reported organisms were H. influenzae, M catarrhalis, S. pneumoniae, S. aureus, and P. aeruginosa. Declining lung function was weakly correlated with prevalence of PPMs. Conclusion: The airways of patients with COPD are colonised with PPMs during the stable state in almost half of patients. A complex relationship likely exists between the microbiome in the stable state and the phenotype of COPD patients. Targeted microbial therapy for preventing exacerbations of COPD should carefully consider the stable microbiome as well as the exacerbated.

Pulmonary emphysema is associated with fungal sensitization in asthma

Background

Fungal sensitization is a risk factor for severe asthma. Colonization in the lower respiratory tract is one of the forms of fungal exposure, and it is related to fungal sensitization. Pulmonary emphysema was recently reported to be an underlying disease of fungal colonization. The aim of study was to evaluate the prevalence of pulmonary emphysema in asthmatic patients with and without fungal sensitization.

Methods

We enrolled 108 patients with allergic asthma and divided them into the patients sensitized to Aspergillus and/or Candida (n=56) and those not sensitized to both Aspergillus and Candida (n=52). The presence of pulmonary emphysema on chest CT was evaluated retrospectively.

Results

The frequency of pulmonary emphysema was significantly higher in the patients sensitized to Aspergillus and/or Candida compared to the patients not sensitized to both fungi (P=0.0040). The frequency of pulmonary emphysema was also significantly higher in the patients sensitized to either Aspergillus or Candida compared to the patient not sensitized to the fungi (P=0.0398 and P=0.0198, respectively). A multivariate logistic regression analysis demonstrated that the presence of pulmonary emphysema was independently associated with the sensitization to Aspergillus and/or Candida (OR 7.84, 95% CI: 1.20–51.10).

Conclusions

Pulmonary emphysema is associated with sensitization to Aspergillus and/or Candida.