Abstract
Background Although the lung clearance index (LCI) is a sensitive marker of small airway disease in individuals with cystic fibrosis (CF), less is known about longitudinal changes in LCI during routine clinical surveillance. Here, our objectives were to describe the longitudinal course of LCI in children with CF during routine clinical surveillance and assess influencing factors.
Methods Children with CF aged 3–18 years performed LCI measurements every 3 months as part of routine clinical care between 2011 and 2018. We recorded clinical data at every visit. We used a multilevel mixed effect model to determine changes in LCI over time and identify clinical factors that influence LCI course.
Results We collected LCI measurements from 1204 visits (3603 trials) in 78 participants, of which 907 visits had acceptable LCI data. The average unadjusted increase in LCI for the entire population was 0.29 (95% CI 0.20–0.38) LCI units·year−1. The increase in LCI was more pronounced in adolescence (0.41 (95% CI 0.27–0.54) LCI units·year−1). Colonisation with either Pseudomonas aeruginosa or Aspergillus fumigatus, pulmonary exacerbations, CF-related diabetes and bronchopulmonary aspergillosis were associated with a higher increase in LCI over time. Adjusting for clinical risk factors reduced the increase in LCI over time to 0.24 (95% CI 0.16–0.33) LCI units·year−1.
Conclusions LCI measured during routine clinical surveillance is associated with underlying disease progression in children with CF. An increased change in LCI over time should prompt further diagnostic intervention.
Abstract
The lung clearance index (LCI) is sensitive to assess lung disease progression in children with CF in routine clinical care. An increased change in LCI should prompt further diagnostic intervention to determine the underlying pathological process. https://bit.ly/3ae9Rhp
Footnotes
This article has an editorial commentary: https://doi.org/10.1183/13993003.00236-2021
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Data availability: Individual participant data that underlie the results reported in this article could be shared after de-identification. The study protocol and analytic code will be shared beginning 3 months and ending 36 months following article publication with investigators whose proposed use of the data has been approved by an independent review. Proposals should be directed to the corresponding author. Requestors will need to sign a data access agreement.
Author contributions: B.S. Frauchiger, K.A. Ramsey, S. Yammine and P. Latzin were responsible for the conception and design of this study. Data acquisition was conducted by B.S. Frauchiger, S. Binggeli, L. Krüger and S. Yammine. B.S. Frauchiger, K.A. Ramsey, P. Latzin and B. Spycher were responsible for data interpretation. B. Spycher supported the statistical analysis which was conducted by B.S. Frauchiger. B.S. Frauchiger, K.A. Ramsey and P. Latzin drafted the manuscript, and all authors revised and approved the manuscript for intellectual content before submission.
Conflict of interest: B.S. Frauchiger has nothing to disclose.
Conflict of interest: S. Binggeli has nothing to disclose.
Conflict of interest: S. Yammine reports grants from Swiss National Science Foundation, outside the submitted work.
Conflict of interest: B. Spycher reports grants from Swiss National Science Foundation and Swiss Cancer League, outside the submitted work.
Conflict of interest: L. Krüger has nothing to disclose.
Conflict of interest: K.A. Ramsey reports grants from Swiss National Science Foundation, outside the submitted work.
Conflict of interest: P. Latzin reports grants from Vertex, during the conduct of the study; personal fees from Vertex, Novartis, Roche, Polyphor, Vifor, Gilead, Schwabe, Zambon and Santhera, grants from Vertex, outside the submitted work.
Support statement: This project was funded by the Swiss National Science Foundation (grant numbers 182719 (P. Latzin), 168173 (K.A. Ramsey) and 179905 (S. Yammine)) and Vertex (IIS-2017-106193). Funding information for this article has been deposited with the Crossref Funder Registry.
- Received July 8, 2020.
- Accepted December 7, 2020.
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