Olfactory dysfunction in cystic fibrosis: Impact of CFTR modulator therapy.

BACKGROUND: Elexacaftor-tezacaftor-ivacaftor (ETI) improves pulmonary health and chronic rhinosinusitis (CRS) for people with cystic fibrosis (PwCF), however its impact on olfaction has not been investigated. Olfactory dysfunction impairs quality-of-life (QOL). This study evaluated the impact of ETI on multiple olfactory metrics. METHODS: Adult PwCF/CRS with CF transmembrane conductance regulator genotype F508del/F508del or F508del/minimal function who clinically initiated ETI participated in a prospective, observational study. Endpoints included changes after 6 months of ETI in quantitative olfactory function (Smell Identification Test, SIT), olfactory QOL (Questionnaire of Olfactory Disorders, QOD) and percent olfactory cleft opacification (%OCO), representing superior nasal cavity inflammation where afferent olfactory neurons are concentrated. RESULTS: 30 PwCF/CRS met inclusion criteria; 25 completed the study. Mean ETI adherence was 93%. At baseline, participants were hyposmic (mean SIT 31.3), had significant %OCO (mean 65.6%), yet reported non-impaired olfactory QOL (mean QOD 6.1). At follow-up, mean SIT worsened mildly (p=0.009), mean %OCO remained stable (p=0.46), and mean QOD improved modestly (p=0.008). No outcomes were impacted by prior modulator use, genotype, nasal polyps, or CF-related diabetes. Prior sinus surgery was associated with QOD improvement (p=0.04). Increased (worse) baseline QOD scores and %OCO were associated with greater improvements (p<0.003), but not SIT (p=0.44). CONCLUSIONS: ETI was not associated with improvement in quantitative olfaction or olfactory cleft opacification after 6 months. PwCF/CRS have hyposmia but do not report impairment in olfactory QOL. Further study to investigate mechanisms explaining olfactory dysfunction and whether olfaction improves with greater duration of ETI or in younger age groups is warranted.

Impact of Cystic Fibrosis Transmembrane Conductance Regulator Therapy on Chronic Rhinosinusitis and Health Status: Deep Learning CT Analysis and Patient-reported Outcomes.

Rationale: Elexacaftor, tezacaftor, and ivacaftor (ETI) in triple combination improves pulmonary health for people with cystic fibrosis (PwCF). However, its impact on objective measures of sinus disease and health utility is unestablished. Objectives: To evaluate the impact of ETI on chronic rhinosinusitis (CRS) and general health status incorporating computed tomography (CT), quality-of-life (QOL) and productivity loss. Methods: Adult PwCF+CRS with CF transmembrane conductance regulator genotype F508del/F508del or F508del/minimal function who clinically initiated ETI participated in a prospective, observational study. The primary endpoint was change in percent sinus CT opacification (%SO) after 6 months of ETI assessed via deep learning-based methods. Secondary endpoints included changes in sinonasal QOL, health utility value and productivity loss, which were evaluated monthly via validated metrics. Results: 30 PwCF provided baseline data; 25 completed the study. At baseline, the cohort had substantial CRS, with mean 22-question SinoNasal Outcome Test (SNOT-22) score 33.1 and mean sinus CT %SO 63.7%. At 6-month follow-up, %SO improved by mean 22.9% (P < 0.001). %SO improvement trended toward greater magnitude for those naïve to prior modulator therapy (P = 0.09). Mean SNOT-22 scores and health utility improved by 15.3 and 0.068 [6.8%] (all P ⩽ 0.007). Presenteeism, activity impairment and overall productivity loss improved (all P ⩽ 0.049). Improvements in SNOT-22 scores and health utility occurred by one month and remained improved over the study. Conclusions: ETI is associated with substantial improvements in sinus CT opacification and productivity loss, and clinically meaningful improvements in sinonasal QOL and health utility. Most improvements were rapid, robust, and durable over the study.