Abstract
BACKGROUND: Elexacaftor/tezacaftor/ivacaftor (ETI) has impacted the ability for people with cystic fibrosis (PwCF) to spontaneously expectorate sputum, leading to lower respiratory sampling rates and infection detection challenges. Home sampling may permit a potential strategy for fungal detection in PwCF. METHODS: We conducted a prospective decentralised cohort study of PwCF to test the feasibility of home sputum collection and ambient temperature transport for Aspergillus fumigatus (Af) detection. Participants collected and shipped weekly sputum samples from home to the laboratory for fungal culture and completed electronic questionnaires. Descriptive statistics were calculated for patient factors, sputum characteristics and Af-positive cultures. We used a generalised estimating equations model to determine the association between highly effective modulator therapy (HEMT) and sputum volume. RESULTS: We enrolled 76 adults with cystic fibrosis (CF) with a median (interquartile range) forced expiratory volume in 1 s (FEV(1)) % predicted of 72.5% (53.8-86.3). 60 (79%) were on ETI and 44 (58%) had a history of Aspergillus. 70 (92%) successfully collected and shipped three or more sputum samples. Of 284 samples received, 83% arrived within one day. Sputum collection was reported as easy in 83 (29%) and somewhat easy in 114 (40%) collection events. Sputum volume from PwCF on HEMT was 36% lower than those not on HEMT (36%, 95% CI 3-58; p=0.03), adjusting for covariates. Af was detected in 205 (73%) of home sputum samples. CONCLUSION: Home sputum collection is feasible in adults with CF. Af was detected in remotely collected sputum samples. Further work to assess the validity of home sputum samples in PwCF is necessary to determine the value of remote specimens in clinical and research settings.