ERS Guidelines for Bronchiectasis Etiologic Workup

ERS Minimum Etiological Testing Bundle

The European Respiratory Society recommends a minimum bundle of etiological tests for bronchiectasis, including differential blood count, serum immunoglobulins, and testing for allergic bronchopulmonary aspergillosis, with very low quality evidence 1, 2, 3
The European Respiratory Society suggests differential blood count to identify immune deficiency or haematological malignancy 1, 2
The European Respiratory Society recommends serum immunoglobulins to detect common variable immune deficiency, present in 2-8% of bronchiectasis patients, which is modifiable with immunoglobulin replacement 1, 2
The European Respiratory Society advises testing for ABPA because establishing this diagnosis alters management 1

The European Respiratory Society states that sputum culture is expected to be undertaken for monitoring purposes of bacterial infection, not as part of the etiological workup 1, 2, 3
The European Respiratory Society recommends initial diagnostic workup should include sputum culture for bacteria, mycobacteria, and fungi, but this appears in the context of comprehensive management rather than the minimum etiological bundle 4

The European Respiratory Society suggests fungal culture becomes relevant in specific clinical scenarios, such as when ABPA is suspected based on screening tests 1
The European Respiratory Society advises fungal culture in patients with clinical features suggesting fungal disease 2, 3
The European Respiratory Society recommends additional tests beyond the minimum bundle, including fungal culture, in patients with severe or rapidly progressive disease 1, 2

The European Respiratory Society acknowledges that no publications directly addressed whether routine aetiological investigation protocols provide benefit compared to clinically driven investigations 1, 2
The European Respiratory Society notes that the recommendation for the minimum bundle is based on very low quality evidence, with only observational studies showing that 7-37% of patients had management changes following aetiological investigation 1, 2