Table 2

Treatable traits in bronchiectasis

Diagnostic criteriaTreatmentExpected benefits of treatment
 Infection#Clinical features
Sputum characteristics
Inflammatory markers
Sputum culture
Airway clearance
Prompt treatment of exacerbations
Long-term oral or inhaled antibiotics
Reduce exacerbations
Improve QoL
 Chronic Pseudomonas infection≥2 culture isolates at least 3 months apart in 1 yearLong-term inhaled antibiotics
Long-term macrolides
Airway clearance
Eradication at first isolation
Reduce exacerbations
Improve QoL
Slow lung function decline
Prevent chronic infection
 Mucus hypersecretionVolume
Colour of sputum
Airway clearance
Airway adjunct devices
Mucoactive drugs
Reduce sputum volume
Reduce viscosity/increase ease of expectoration
 Mucus pluggingClinical features
CT scan
Airway clearance
Mucoactive drugs
Nebulised saline
Reduce sputum volume
Reduce viscosity/increase ease of expectoration
 Airflow obstructionFEV1/FVC <LLN
Fixed ratio spirometry
GLI equations, air trapping or increased airway resistance
Smoking cessation
Improved exercise capacity and functional status
 AsthmaBronchodilator reversibility
Peak expiratory flow variability
Elevated sputum or blood eosinophils
Systemic corticosteroids
Leukotriene receptor antagonists
Monoclonal antibody anti-IL-5, anti-IgE
Reduce exacerbations
 EosinophiliaElevated sputum or blood eosinophils
Exclude other causes of eosinophilia
Systemic corticosteroids
Treatment for underlying cause
Improve QoL and treatment response
 NTM pulmonary diseasePositive culture and clinical/radiological findingsLong-term antibioticImprove QoL and achieve remission
Aspergillus sensitisationElevated specific IgE/prick test positiveICS
Systemic corticosteroids
Reduce exacerbations
Reduce sputum production
Improved QoL
 Bronchial hyperreactivityChallenge testsICSReduce exacerbations
 Cough hypersensitivityClinical features
Search other potential extrapulmonary causes
Capsaicin cough challenge
Chest physiotherapy
Improve QoL
 Respiratory insufficiencyPaO2 <55 mmHg
PaCO2 >45 mmHg
Long-term oxygen and/or noninvasive ventilationImprove QoL
Improve survival
 Primary immunodeficienciesSerum immunoglobulins levels
Specific antibody levels
Refer to immunology specialist
Immunoglobulin replacement
Improve outcome
Improve QoL
Prevent lung damage
 CFClinical features
Sweat chloride testing, CFTR genetic analysis and/or CFTR physiological testing
Refer to CF clinic
CFTR modulators
Improve outcome
Improve QoL
Prevent lung damage
 PCDClinical features+
Nasal NO assay
Electron microscopy ciliary structure analysis or video recording ciliary function analysis
Genetic testing
Genetic counselling
Intensive airway clearance
Management of upper airway symptoms
Improve outcome
Improve QoL
Prevent lung damage
 ABPARaised specific IgE and/or positive prick skin test to fungi, raised total IgE
Other: eosinophilia, radiological features, raised specific IgG/precipitating antibodies against fungi
Systemic corticosteroids and/or antifungals
Monoclonal antibody anti-IgE
Improve outcome
Improve QoL
Prevent lung damage
 CTDClinical features
Serum antibodies
Refer to rheumatologist
Improve outcome
Improve QoL
Prevent lung damage
 IBDClinical features
Serological markers
Anatomopathological findings on gut biopsy
Refer to gastroenterologist
Improve outcome
Improve QoL
Prevent lung damage
Extrapulmonary (comorbidities)
Psychiatrist assessment
Anxiety management
Breathing retraining
Cognitive behavioural therapy
Support groups
Improve QoL
 Obesity/underweightBMINutritional evaluation
Regular physical activity
Improve QoL and outcome
 GORDClinical features
Gastric endoscopy
pH monitoring
Proton pump inhibitor H2-antagonist
Surgery (fundoplication)
Improve QoL
 Cardiovascular diseaseClinical features
Stress testing
ACE inhibitors
Refer to cardiologist
Improve QoL and outcome
 RhinosinusitisClinical features
Nasal steroids
Leukotriene receptor antagonists
Improve QoL
 Iron deficiency anaemiaFull blood count
Reticulocyte count
Serum iron tests
Exclude other causes
Oral iron supplements
Treatment of underlying cause
Improve QoL and exercise capacity
Environment and lifestyle
 SmokingPatient reported
Exhaled carbon monoxide
Tobacco cessation support
Nicotine replacement
Improve QoL, lung function, exercise capacity, response to treatment
 Lack of exercise/sedentarismCardiopulmonary exercise testing
6-min walk test
Exercise regularly
Pulmonary rehabilitation
Prescribed exercise programmes
Improve QoL and outcome
 AdherencePrescription refill rate
Patient feedback
Written instructions
Improve outcome
 Exposure to air pollutionPM10 and NO2 concentrationsReduce exposureReduce exacerbations

Some of the most common traits observed in clinical studies have been listed, but this list is not comprehensive. A different set of treatable traits may be applicable to children with bronchiectasis to include issues of growth and development. CT: computed tomography; FVC: forced vital capacity; LLN: lower limit of normal; GLI: Global Lung Function Initiative; QoL: quality of life; PaO2: arterial oxygen tension; PaCO2: arterial carbon dioxide tension; CTD: connective tissue disease; IBD: inflammatory bowel disease; GORD: gastro-oesophageal reflux disease; BNP: brain natriuretic peptide; ACE: angiotensin converting enzyme; PM10: particulate matter with a diameter smaller than 10 μm. #: the presence of airway infection itself may not be a treatable trait as such since better measures are required to differentiate infection from “colonisation” where the trait is not contributing directly to disease outcome. Additional measures such as bacterial load or microbiota characterisation may be needed to fully operationalise this trait. : could be aetiological or a complication of disease. +: recurrent upper and lower respiratory tract infections; recurrent otitis in childhood; infertility; and laterality disorders. Reproduced from [5] with permission.