Nichols DP, Morgan SJ, Skalland M, Vo AT, Van Dalfsen JM, Singh SB, Ni W, Hoffman LR, McGeer K, Heltshe SL, Clancy JP, Rowe SM, Jorth PK, Singh PK. Pharmacologic improvement of CFTR function rapidly decreases sputum pathogen density but lung infections generally persist.
J Clin Invest 2023;
133:167957. [PMID:
36976651 PMCID:
PMC10178839 DOI:
10.1172/jci167957]
[Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/24/2023] [Indexed: 03/29/2023] Open
Abstract
BACKGROUND
Lung infections are among the most consequential manifestations of cystic fibrosis (CF) and are associated with reduced lung function and shortened survival. Drugs called CFTR modulators improve activity of dysfunctional cystic fibrosis transmembrane conductance regulator (CFTR) channels, which is the physiological defect causing CF. However, it is unclear how improved CFTR activity affects CF lung infections.
METHODS
We performed a prospective, multicenter, observational study to measure the effect of the newest and most effective CFTR modulator, elexacaftor/tezacaftor/ivacaftor (ETI) on CF lung infections. We studied sputum from 236 people with CF during their first 6 months of ETI using bacterial cultures, PCR and sequencing.
RESULTS
Mean sputum densities of Staphylococcus aureus, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Achromobacter and Burkholderia spp. decreased by 2-3 log10 CFU/ml after 1 month of ETI. However, most participants remained culture-positive for the pathogens cultured from their sputum before starting ETI. In those becoming culture-negative after ETI, the pathogens present before treatment were often still detectable by PCR months after sputum converted to culture-negative. Sequence-based analyses confirmed large reductions in CF pathogen genera, but other bacteria detected in sputum were largely unchanged. ETI treatment increased average sputum bacterial diversity and produced consistent shifts in sputum bacterial composition. However, these changes were caused by ETI-mediated decreases in CF pathogen abundance rather than changes in other bacteria.
CONCLUSIONS
Treatment with the most effective CFTR modulator currently available produced large and rapid reductions in traditional CF pathogens in sputum, but most participants remain infected with the pathogens present before modulator treatment.
TRIAL REGISTRATION
The trial registered at www.
CLINICALTRIALS
gov as NCT04038047.
FUNDING
This study was funded by the Cystic Fibtosis Foundation (PROMISE-MICRO18K1 and SINGH19R0) and NIH (R01HL148274).
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