Comparison of bronchoscopy and bronchoalveolar lavage findings in three types of suppurative lung disease

Background: Endobronchial suppuration is present in children with protracted bacterial bronchitis (PBB), bronchiectasis, and cystic fibrosis (CF). However, no studies have directly compared bronchoscopy and bronchoalveolar lavage (BAL) findings across these conditions within a single center using the same techniques and with shared community pathogens.

Aim: To determine; (i) the bronchoscopic findings and BAL microbiology and cellularity among children with these conditions and; (ii) the relationship between bacterial pathogens, airway cellularity and aberrant macroscopic bronchoscopic findings. Methods: We retrospectively reviewed all bronchoscopy data (undertaken over 6.5-years) from our center in children (<6 years; n = 316) meeting definitions of PBB (n = 125), bronchiectasis (n = 138), and CF (n = 53).

Results: The children's median age was 26-months (Interquartile range (IQR) = 16-43). Children with PBB and bronchiectasis had higher rates of Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae infection, whereas children with CF had frequent Pseudomonas aeruginosa and Staphylococcus aureus infections. Novel findings include detection of cytomegalovirus and Epstein-Barr virus (EBV) (by polymerase chain reaction) in children with PBB (26%, 17%, respectively) and bronchiectasis (27%, 29%). Median airway neutrophil percentage was significantly higher in CF (68%; IQR = 42-83) compared to PBB (36%; IQR = 18-68) and bronchiectasis (22%; IQR = 8-64) (P < 0.0001), despite lower rates of infection. Presence of malacia did not significantly impact on infection or inflammation.

Conclusion: In this first study to directly compare bronchoscopic data among young children with PBB, bronchiectasis, and CF, microbiological patterns of airway infections and neutrophilia varied. Our findings of cytomegalovirus and EBV detection in children with PBB and bronchiectasis require confirmation and further evaluation.