What are the key diagnostic criteria for bronchiectasis in adults presenting with chronic cough and sputum production?

Key diagnostic criteria for bronchiectasis in adults presenting with chronic cough and sputum production include a combination of clinical features, imaging, and microbiological investigations. Clinically, a chronic productive cough with sputum production is a hallmark symptom, often accompanied by recurrent respiratory infections and sometimes breathlessness or wheeze. A thorough history and physical examination are essential to identify these symptoms and any underlying causes or risk factors ¹.

High-resolution computed tomography (HRCT) of the chest is the gold standard imaging modality to confirm the diagnosis of bronchiectasis, as it can demonstrate bronchial dilatation, lack of bronchial tapering, and bronchial wall thickening, which are characteristic features ¹. Chest X-rays are not recommended for diagnosis due to their limited sensitivity and specificity, especially in mild disease, but may be used initially to exclude other pathologies ¹.

Spirometry is used to assess lung function and typically shows airflow obstruction, although restrictive or mixed patterns can also be present. Reduced forced expiratory volume in 1 second (FEV1) or a reduced FEV1/forced vital capacity (FVC) ratio below 70% may be observed ¹.

Sputum culture is important to identify colonizing pathogens, which can guide management and indicate disease severity or risk of exacerbations. Persistent colonization with organisms such as Pseudomonas aeruginosa or methicillin-resistant Staphylococcus aureus (MRSA) is clinically significant ¹.

Additional investigations to identify underlying causes include testing for cystic fibrosis (especially in younger adults or those with suggestive features), immunoglobulin levels to screen for antibody deficiencies, and tests for allergic bronchopulmonary aspergillosis (total and specific IgE) ¹.

Recent literature emphasizes the importance of patient-managed interventions and the role of multidisciplinary care in bronchiectasis, highlighting that diagnosis should be followed by comprehensive assessment and tailored management plans (Spinou et al., 2024).