National Survey on the Management of Adult Bronchiectasis in Belgium

Insights into respiratory microbiome composition and systemic inflammatory biomarkers of bronchiectasis patients

The human microbiomes, including the ones present in the respiratory tract, are described and characterized in an increasing number of studies. However, the composition and the impact of the healthy and/or impaired microbiome on pulmonary health and its interaction with the host tissues remain enigmatic. In chronic airway diseases, bronchiectasis stands out as a progressive condition characterized by microbial colonization and infection. In this study, we aimed to investigate the microbiome of the lower airways and lungs of bronchiectasis patients together with their serum cytokine and chemokine content, and gain novel insights into the pathogenesis of bronchiectasis. The microbiome of 47 patients was analyzed by sequencing of full-length 16S rRNA gene using amplicon sequencing Oxford Nanopore technologies. Their serum inflammatory mediators content was quantified in parallel. Several divergently composed microbiome groups were identified and characterized, the majority of patients displayed one dominant bacterial species, whereas others had a more diverse microbiome. The analysis of systemic immune biomarkers revealed two distinct inflammatory response groups, i.e., low and high response groups, each associated with a specific array of clinical symptoms, microbial composition, and diversity. Moreover, we have identified some microbiome compositions associated with high inflammatory response, i.e., high levels of pro- and anti-inflammatory cytokines, whereas other microbiomes were in correlation with low inflammatory responses. Although bronchiectasis pathogenetic mechanisms remain to be elucidated, it is clear that addressing microbiome composition in the airways is a valuable resource not only for diagnosis but also for personalized disease management.

IMPORTANCE

The population of microorganisms on/in the human body resides in distinct local microbiomes, including the respiratory microbiome. It remains unclear what defines a healthy and a diseased respiratory microbiome. We investigated the respiratory microbiome in chronic pulmonary infectious disease, i.e., bronchiectasis, and researched correlations between microbiome composition, systemic inflammatory biomarkers, and disease characteristics. The bronchoalveolar microbiome of 47 patients was sequenced, and their serum inflammatory mediators were quantified. The microbiomes were grouped based on their content and diversity. In addition, patients were also grouped into low- and high-response groups according to their inflammatory biomarkers' levels. Certain microbiome compositions, mainly single-species dominated, were associated with high levels of inflammatory cytokines, whereas others correlated with low inflammatory response and remained diverse. We conclude that respiratory microbiome composition is a valuable resource for the diagnostics and personalized management of bronchiectasis, which may include preserving microbiome diversity and introducing possible probiotics.

Epidemiology of bronchiectasis

Bronchiectasis is a chronic respiratory disease characterised by permanent enlargement of the airways associated with cough, sputum production and a history of pulmonary exacerbations. In the past few years, incidence and prevalence of bronchiectasis have increased worldwide, possibly due to advances in imaging techniques and disease awareness, leading to increased socioeconomic burden and healthcare costs. Consistently, a mortality increase in bronchiectasis patient cohorts has been demonstrated in certain areas of the globe, with mortality rates of 16-24.8% over 4-5 years of follow-up. However, heterogeneity in epidemiological data is consistent, as reported prevalence in the general population ranges from 52.3 to more than 1000 per 100 000. Methodological flaws in the designs of available studies are likely to underestimate the proportion of people suffering from this condition worldwide and comparisons between different areas of the globe might be unreliable due to different assessment methods or local implementation of the same method in different contexts. Differences in disease severity associated with diverse geographical distribution of aetiologies, comorbidities and microbiology might explain an additional quota of heterogeneity. Finally, limited access to care in certain geographical areas is associated with both underestimation of the disease and increased severity and mortality. The aim of this review is to provide a snapshot of available real-world epidemiological data describing incidence and prevalence of bronchiectasis in the general population. Furthermore, data on mortality, healthcare burden and high-risk populations are provided. Finally, an analysis of the geographical distribution of determinants contributing to differences in bronchiectasis epidemiology is offered.

Australian airway clearance services for adults with chronic lung conditions: A national survey

BACKGROUND

Physiotherapy-led airway clearance interventions are indicated for some people with chronic lung conditions. This study describes Australian clinical models for the provision of adult airway clearance services.

METHODS

This cross-sectional national study recruited public and private health care providers (excluding cystic fibrosis-specific services) identified by a review of websites. Providers were invited to complete an electronic 61-item survey with questions about airway clearance service context, referral demographics, service provision and program metrics. Data were reported descriptively with differences between metropolitan and non-metropolitan services explored with chi-square tests.

RESULTS

Between October-December 2019, the survey was disseminated to 131 providers with 91 responses received (69% response rate; 87 (96%) public (34 metropolitan; 53 non-metropolitan) and 4 (4%) private). Intent (chronic condition self-management) and types of intervention provided (education, breathing techniques, exercise prescription) were common across all services. Geographic location was associated with differences in airway clearance service models (greater use of regular clinics, telephone/telehealth consultations and dedicated cardiorespiratory physiotherapists in metropolitan locations versus clients incurring service and device provision costs in non-metropolitan regions).

CONCLUSIONS

While similarities in airway clearance interventions exist, differences in service models may disadvantage people living with chronic lung conditions, especially in non-metropolitan regions of Australia.

Improving Care For People With Bronchiectasis: Opportunities And Challenges Highlighted From Service Evaluation

BACKGROUND AND AIM

Bronchiectasis is a serious, debilitating condition warranting specialist care. Our study aimed to determine if care provided in a tertiary hospital general respiratory clinic was guideline concordant and to validate the Bronchiectasis Severity Index (BSI) in the Australian context.

METHODS

A single centre ambispective study was conducted. The first stage involved a retrospective medical record audit between 1/01/2015 to 31/12/2016. All aspects of bronchiectasis management were reviewed. In the second prospective phase the cohort was followed for 4 years to determine survival and the validity of the BSI determined.

RESULTS

145 patients were included, with mean age of 65 years (SD=16.6). The aetiology of bronchiectasis was explicitly documented for fifty-eight (40%) patients, with potential causes identified in another thirty-seven patients. Post infectious aetiologies were described in 62 (43%). Most patients had lung function testing (n=142, 97%) and sputum culture results (n=120, 83%). Long-term antibiotics were prescribed to forty-nine (34%) patients. Only patients culturing Pseudomonas spp were prescribed inhaled antibiotics. Documentation regarding essential management recommendations was low, including airway clearance (46%), pneumococcal vaccination (27%) and written action plans (32%). Severe disease was common, with more than a third (34% to 48%) having BSI scores >9. One fifth of the cohort (21%) died during the 4 year follow up period. The BSI was significantly associated with mortality risk (OR 7.7, 95% CI=3.1-19.3, p<0.001).

CONCLUSION

Our cohort had a high proportion of patients with severe disease and significant mortality, some but not all aspects of recommended care were delivered. This article is protected by copyright. All rights reserved.

Criteria and definitions for the radiological and clinical diagnosis of bronchiectasis in adults for use in clinical trials: international consensus recommendations

Bronchiectasis refers to both a clinical disease and a radiological appearance that has multiple causes and can be associated with a range of conditions. Disease heterogeneity and the absence of standardised definitions have hampered clinical trials of treatments for bronchiectasis and are important challenges in clinical practice. In view of the need for new therapies for non-cystic fibrosis bronchiectasis to reduce the disease burden, we established an international taskforce of experts to develop recommendations and definitions for clinically significant bronchiectasis in adults to facilitate the standardisation of terminology for clinical trials. Systematic reviews were used to inform discussions, and Delphi processes were used to achieve expert consensus. We prioritised criteria for the radiological diagnosis of bronchiectasis and suggest recommendations on the use and central reading of chest CT scans to confirm the presence of bronchiectasis for clinical trials. Furthermore, we developed a set of consensus statements concerning the definitions of clinical bronchiectasis and its specific signs and symptoms, as well as definitions for chronic bacterial infection and sustained culture conversion. The diagnosis of clinically significant bronchiectasis requires both clinical and radiological criteria, and these expert recommendations and proposals should help to optimise patient recruitment into clinical trials and allow reliable comparisons of treatment effects among different interventions for bronchiectasis. Our consensus proposals should also provide a framework for future research to further refine definitions and establish definitive guidance on the diagnosis of bronchiectasis.