Table 1

Basic investigations for the aetiology of bronchiectasis

Sweat test/cystic fibrosis geneticsExclude cystic fibrosis, diagnose non-classical cystic fibrosis
Immune function
  • White cell count

White cell differential
  • Total immunoglobulins

  • Antibody responses to vaccination, eg, tetanus, pneumococcus and Haemophilus influenzae B

Functional antibody problems
  • ±Mannose binding lectin, C3 and C4

Part of complement pathways
24 h pH study/impedence study
Barium mealGastro-oesophageal reflux
Flexible bronchoscopyForeign body, malacia, abnormal anatomy
Bronchoalveolar lavageMicrobiological investigations Fat laden macrophages – aspiration
Nasal nitric oxide±ciliary biopsyPrimary ciliary dyskinesia