Biofilm infections of endobronchial valves in COPD patients after endoscopic lung volume reduction: a pilot study with FISHseq

Endoscopic lung volume reduction (ELVR) using endobronchial valves (EBV) is a treatment option for a subset of patients with severe chronic obstructive pulmonary disease (COPD), suffering from emphysema and hyperinflation. In this pilot study, we aimed to determine the presence of bacterial biofilm infections on EBV and investigate their involvement in lack of clinical benefits, worsening symptomatology, and increased exacerbations that lead to the decision to remove EBVs. We analyzed ten COPD patients with ELVR who underwent EBV removal. Clinical data were compared to the microbiological findings from conventional EBV culture. In addition, EBV were analyzed by FISHseq, a combination of Fluorescence in situ hybridization (FISH) with PCR and sequencing, for visualization and identification of microorganisms and biofilms. All ten patients presented with clinical symptoms, including pneumonia and recurrent exacerbations. Microbiological cultures from EBV detected several microorganisms in all ten patients. FISHseq showed either mixed or monospecies colonization on the EBV, including oropharyngeal bacterial flora, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus spp., and Fusobacterium sp. On 5/10 EBV, FISHseq visualized biofilms, on 1/10 microbial microcolonies, on 3/10 single microorganisms, and on 1/10 no microorganisms. The results of the study demonstrate the presence of biofilms on EBV for the first time and its potential involvement in increased exacerbations and clinical worsening in patients with ELVR. However, further prospective studies are needed to evaluate the clinical relevance of biofilm formation on EBV and appropriate treatment options to avoid infections in patients with ELVR.