Additional important research priorities for bronchiectasis in China

To the Editor:

We highly appreciate the laudable desire of the European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC) [1] to provoke research interests and develop study protocols to investigate bronchiectasis, a disease which has not yet received sufficient attention worldwide, particularly in China. China is a major developing country with a large population; however, there is a lack of epidemiological investigations detailing the prevalence or incidence of bronchiectasis. While we totally concur with the recommendations from European experts, we feel that additional priorities in bronchiectasis should be highlighted for future research in China.

1) Regional distribution of bronchiectasis aetiology throughout China. The aetiological investigations published to date were mainly based in major cities such as Shanghai [2], Guangzhou [3], and Jinan [4]. The prevalence of pulmonary infections (e.g. tuberculosis, measles and pertussis) are expected to be significantly higher in rural areas because of the limited medical resources. Our understanding has been hampered by the lack of official documentation regarding regional distributions of bronchiectasis aetiologies in China. Future investigations are warranted to prioritise our national healthcare plan for disease control.

2) The role of traditional Chinese medicine in bronchiectasis patients. The long Chinese history has nurtured the development of traditional Chinese medicine, a delicate medical system which is still regarded as a tremendous treasure trove that is complementary to western medicine. In fact, a considerable number of bronchiectasis patients report that they have actively sought consultation from experts in traditional Chinese medicine. Patients had greater willingness to receive therapy with Chinese herbal compounds (typically for decoction) to minimise the potential adverse effects of western medicine (W.J. Guan and co-workers; unpublished data). To our knowledge, the efficacy of Chinese herbs for improving asthma control has been documented [5]. We strongly feel that Chinese herbs may have a role in future management of bronchiectasis, for instance, by reducing the frequency of bronchiectasis exacerbations. However, in light of the lack of evidence-based reports, well-designed randomised, double-blind clinical trials are needed to thoroughly validate the efficacy and safety of Chinese herbs for bronchiectasis.

3) The role of clinical phenotyping in improving management of bronchiectasis. The significant heterogeneity of clinical manifestations of bronchiectasis has been increasingly recognised. Clinical phenotyping using unsupervised learning techniques [6, 7] has provided researchers with an invaluable opportunity to personalise therapy. Despite the absence of “gold standard criteria” for classification of clusters, clinical phenotyping is complementary to disease severity assessment because it takes into account both the homogeneity and heterogeneity of bronchiectasis. To justify bronchiectasis phenotyping, it would be useful to investigate its added value to improve therapeutic outcomes and long-term prognosis.

4) The impact of bronchiectasis on fertility. Compared with Caucasians [6, 8, 9], Chinese bronchiectasis patients are significantly younger at enrolment [2–4, 7]. The mean age of our cohort was 44.5 years [6], and ∼62% of females were still of child-bearing age. Currently, no report documenting whether bronchiectasis decreased fertility has been published. Nonetheless, clinicians have been frequently confronted with fertility counselling for bronchiectasis patients. It has become increasingly urgent to solve this issue after the implementation of the two-child policy in China [10]. In our pilot study (W.J. Guan and co-workers; unpublished data), most female patients demonstrated varying magnitudes of concern about infertility associated with bronchiectasis, despite the fact that most females successfully gave birth to healthy infants. Concerns about infertility have cast a considerable shadow over patient's daily life, leading to the development of anxiety and/or depression. Addressing the impact of bronchiectasis on fertility may help advance future healthcare in terms of adding further evidence to genetic counselling and mitigating patient's anxiety or depression.

5) Pathophysiological pathways leading to bronchiectasis–chronic obstructive pulmonary disease (COPD) and bronchiectasis–asthma overlap syndrome. There are various aetiologies underlying the pathogenesis of bronchiectasis. In the British Thoracic Society guidelines [11], COPD or asthma should be considered as the underlying aetiology of bronchiectasis. It should also be recognised that the determination of aetiology is challenging in most patients, but the overlap of bronchiectasis with asthma or COPD can be assessed using simple tools such as lung function tests. Current knowledge indicates that bronchiectasis may have common pathways with asthma (e.g. eosinophilic and/or neutrophilic inflammation) and COPD (e.g. neutrophilic and/or macrophagic inflammation). Bronchiectasis can be readily identified in a considerable number of COPD and asthmatic patients using high-resolution chest computed tomography, particularly in those with a prolonged course of disease. How primary or secondary aetiologies stimulate exaggerated neutrophilic responses leading to relentless degradation of the matrices of bronchial mucosa remains an area of profound interest. Unravelling the most useful biomarkers (e.g. periostin or fractional exhaled nitric oxide) to classify the clinical clusters and predict prognosis would provide clinicians with practical tools for disease intervention and management.

These additional research priorities in China may have complementary significance to the statement from the EMBARC Clinical Research Collaboration [1]. Researchers from China keenly await collaboration with colleagues from western countries to collectively solve the unanswered questions associated with bronchiectasis management.

Disclosures