P229 Do CFTR modulators interfere with microbiological diagnosis?
Abstract
Objectives: The widespread introduction of modulator therapies may force
us to reconsider our models of cystic fibrosis (CF) airway microbiology.
Indeed, by improving airway clearance, CFTR modulators are likely to lead
to substantial changes in the cyto-microbiological parameters of sputum
from people with CF (pwCF). Our aim was to assess the real impact of
modulators on the fundamentals of microbiological diagnosis.
Methods: During 2023, 13 French CF centers each prospectively collected
between 28 and 32 sputum samples from pwCF. For each sample, the
volume of sputum collected was recorded, along with the cytological
quality of the sputum and the results of microbiology. Routine microbial
cultures were performed according to the French standard operating
procedures. These data were compared according to the 2 groups: pwCF
with CFTR modulator treatment (M+) or not (M-).
Results: A total of 392 pwCF and samples were analysed. The mean age of
the cohort was 20.3 +/− 14.3 years, with 215 males and 177 females. Among
pwCF, 64.5% were M+, including 87% on Kaftrio®, and 35.5% were M-. The
median volume of sputum collected was 1 mL. Comparison of the two
patients’ groups identified no statistically significant difference in volume
collected, polynuclear count, or prevalence of the following pathogens:
Haemophilus influenzae, Staphylococcus aureus, Pseudomonas aeruginosa
(mucoid or not), Stenotrophomonas maltophilia, Achromobacter spp.
Enterobacterales, and Aspergillus fumigatus.
Conclusion: The lack of difference in the cyto-microbiological criteria
between M+ and M− patients seems to not reflect the lack of impact of CFTR
modulators, but rather the fact that the patients who continue to be
sampled correctly are the exacerbating pwCF in whom modulators do not
change drastically the airways microbiology. The number of patients for
whom sputum collection was not possible, making analysis impossible,
remains to be determined. The data will be analysed by age group.