Characterization of Respiratory Pathogens in Contemporary Lung Transplant Recipients
The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation
Copyright © 2020. Published by Elsevier Inc. PURPOSE: This study assessed respiratory pathogens isolated in the first year post lung transplant in a recent multicenter cohort. Prior studies may not reflect current practices in antimicrobial prophylaxis and molecular diagnostics. METHODS: We examined 499 consecutive bronchoalveolar lavage (BAL) samples for microbial isolates in 82 lung transplant recipients (LTR) enrolled in the prospective Genomic Research Alliance for Transplantation from July 2015 to 2017. Isolates were examined for species, timing: early (0-1 months post-transplant (MPT), intermediate (1-6 MPT), and late (6-12 MPT), and associated lung function decline. RESULTS: 389 microbes were isolated in 499 BAL samples, representing 348 unique episodes, over a median of 196 days. Bacterial isolates were more common in the early and intermediate periods, and fungal and viral pathogens more common in the late period. In non-Cystic Fibrosis (CF) populations, the frequencies of most common bacterial isolates S. aureus, P. aeruginosa, and enteric Gram Negative Bacteria were 15.6%, 12.6%, 23.0%, compared to 28.0%, 30.0%, and 18.0% respectively, in CF LTRs. The most common viral pathogens were rhinovirus (60.6%), and enterovirus (12.7%). Non-invasive molds (Penicillium etc) comprised 73.3% of fungal isolates, with potentially invasive molds (Aspergillus, Mucor sp.) isolated in 12.9% of cases. Notably, there were only two isolates of Aspergillus fumigatus (2.0%). 48/389 isolates (12.3%) were associated with > 10% reduction in FEV1 at 90 days post isolation of which rhinovirus was the most frequent isolate (11/48). CONCLUSION: In a contemporary cohort, bacterial pathogens predominate in the early post-transplant period, while fungal and viral pathogens are more common later. Pseudomonas and Aspergillus sp. comprised a smaller proportion of total than previously described, and do not appear to associate with early lung function decline. Further studies are underway to determine the conditions in which select infections impact early lung function.
Bazemore, K.; Permpalung, N.; Rohly, M.; Timofte, I.; Brown, A.; Orens, J.; Iacono, A.; Nathan, S.; Avery, R.; Valentine, H.; Agbor-Enoh, S.; and Shah, P., "Characterization of Respiratory Pathogens in Contemporary Lung Transplant Recipients" (2020). Faculty Bibliography. 2691.