Diagnostics

• Confirm the diagnosis with imaging studies in patients with features suggestive of bronchiectasis.

  • Poor control or frequent exacerbations in patients with chronic pulmonary disease (e.g., COPD, asthma)

  • Chronic cough or recurrent pulmonary infections in patients with immunosuppression or conditions associated with bronchiectasis

  • Productive cough lasting > 8 weeks in otherwise healthy patients

• Identify the underlying etiology.

  • Routine laboratory studies, sputum culture and smear, and pulmonary function tests

  • Clinical suspicion for a specific etiology: Obtain additional studies based on individual evaluation.

In patients with suspected bronchiectasis, diagnosis is confirmed using imaging studies, preferably a HRCT scan. Additional diagnostic studies are useful to identify the underlying cause and possibly provide specific treatment.

• Imaging modalities

  • X-ray chest: best initial test (may not show mild disease)

  • High-resolution computed tomography (HRCT) chest: confirmatory test

• Findings

  • Bronchial dilation

    • Cylindrical or tubular (most common) : parallel tram track sign and signet ring sign

    • Varicose

    • Saccular or cystic (most severe form)

  • Thickened bronchial walls, mucus plugging, honeycombing (suggests late-stage bronchiectasis)

Studies to determine the underlying etiology of bronchiectasis are usually requested by a specialist. In many cases, it is not possible to reach a specific diagnosis and the disease may be classified as idiopathic.

Initial workup

Perform at the time of diagnosis to obtain baseline references. Sputum culture and smear, as well as spirometry, are also used for monitoring.

• CBC: Findings are variable and depend on the underlying etiology.

  • ↓ Hb

  • Variable leukocyte levels

  • ↑ Thrombocytes

• Consider ABG (e.g., in patients with ↓ SaO2 on room air): may show hypercapnia

• Quantitative measurement of serum immunoglobulins and electrophoresis (IgA, IgG, IgM, and IgG subclasses): to exclude immunodeficiencies [11]

• Aspergillus fumigatus IgG and IgE: to exclude ABPA

culture induced sputum or bronchoalveolar lavage for all of the following pathogens to detect infection or colonization

• Bacterial cultures: e.g., H. influenzae or P. aeruginosa

• Fungal cultures: Candida spp. or Aspergillus spp.

• Mycobacterial culture (with AFB smear microscopy): tuberculosis or nontuberculous mycobacteria

not needed to establish a diagnosis but useful to monitor disease progression [7][13]

• Mixed obstructive/restrictive pattern

• Restrictive pattern (i.e., ↓ FEV1 and FVC with normal or ↑ FEV1/FVC ratio)

• Obstructive pattern (i.e., ↓ FEV1/FVC ratio)

Additional diagnostics

These studies may be considered depending on clinical suspicion if the initial workup was not diagnostic.

• Laboratory studies

  • Specific antibodies (e.g., rheumatoid factor, ANAs, anti-CCP antibodies, ANCAs): suspected connective tissue or autoimmune diseases

  • Sweat chloride test and/or genetic testing for CFTR mutations: suspected CF

  • HIV testing , serum α1-antitrypsin levels , nasal nitric oxide testing for primary ciliary dyskinesia

• Further studies

  • Bronchoscopy

    • Indicated to visualize tumors, foreign bodies, or other lesions (most useful in patients with localized disease)

    • May also be used in combination with bronchoalveolar lavage (BAL) to obtain specimens for staining and culture

  • Upper GI studies (e.g., upper endoscopy, barium swallow, esophageal manometry): consider for suspected gastroesophageal reflux disease or recurrent pulmonary aspiration

  • Colonoscopy with biopsies: if associated inflammatory bowel disease is suspected (e.g., GI bleeding)

If the initial workup does not identify the underlying cause, perform further studies guided by the patient's clinical features and consider referral to a specialist.