Search

Multiple breath washout (MBW) has successfully assessed the silent lung zone particularly in cystic fibrosis lung disease, however, it is limited to the communicating lung only. There are a number of different pulmonary function methods that can assess what is commonly referred to as trapped air, with varying approaches and sensitivity. Twenty-five people with cystic fibrosis (pwCF) underwent MBW, spirometry, body plethysmography, and spirometry-controlled computed tomography (spiro-CT) on the same day. PwCF also performed extensions to MBW that evaluate air trapping, including our novel extension (MBW ShX ), which reveals the extent of underventilated lung units (UVLU). In addition, we used two previously established 5-breath methods that provide a volume of trapped gas (VTG). We used trapped air % from spiro-CT as the gold standard for comparison. UVLU derived from MBW ShX showed the best agreement with trapped air %, both in terms of correlation ( R S 0.89, P < 0.0001) and sensitivity (79%). Bland-Altman analysis demonstrated a significant underestimation of the VTG by both 5-breath methods (-249 mL [95% CI -10,796; 580 mL] and -203 mL [95% CI -997; 591 mL], respectively). Parameters from both spirometry and body plethysmography were suboptimal at assessing this pathophysiology. The parameters from MBW ShX demonstrated the best relationship with spiro-CT and had the best sensitivity compared with the other pulmonary function methods assessed in this study. MBW ShX shows promise to assess and monitor this critical pathophysiological feature, which has been shown to be a driver of lung disease progression in pwCF. NEW & NOTEWORTHY We consider the term "trapped air" either in the use of imaging or pulmonary function testing, something of a misnomer that can lead to an inaccurate assessment of an important physiological feature. Instead, we propose the term underventilated lung units (UVLU). Of the many pulmonary function methods we used in this study, we found that the use of multiple breath washout with short extension (MBW ShX ) to be the best nonimaging method.

Background: Factors associated with severe COVID-19 infection have been identified; however, the impact of infection on longer-term outcomes is unclear. The objective of this study was to examine the impact of COVID-19 infection on the trajectory of lung function and nutritional status in people with cystic fibrosis (pwCF)., Methods: This is a retrospective global cohort study of pwCF who had confirmed COVID-19 infection diagnosed between January 1, 2020 and December 31, 2021. Forced expiratory volume in one second percent predicted (ppFEV 1 ) and body mass index (BMI) twelve months prior to and following a diagnosis of COVID-19 were recorded. Change in mean ppFEV 1 and BMI were compared using a t-test. A linear mixed-effects model was used to estimate change over time and to compare the rate of change before and after infection., Results: A total of 6,500 cases of COVID-19 in pwCF from 33 countries were included for analysis. The mean difference in ppFEV 1 pre- and post-infection was 1.4 %, (95 % CI 1.1, 1.7). In those not on modulators, the difference in rate of change pre- and post-infection was 1.34 %, (95 % CI -0.88, 3.56) per year (p = 0.24) and -0.74 % (-1.89, 0.41) per year (p = 0.21) for those on elexacaftor/tezacaftor/ivacaftor. No clinically significant change was noted in BMI or BMI percentile before and after COVID-19 infection., Conclusions: No clinically meaningful impact on lung function and BMI trajectory in the year following infection with COVID-19 was identified. This work highlights the ability of the global CF community to unify and address critical issues facing pwCF., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors of this manuscript receive funding in the form of consulting fees or honoraria from Vertex Pharmaceuticals, Chiesi Pharmaceuticals, Enterprise Therapeutics, Gilead Sciences, GSK, Astra-Zeneca, Insmed, MSD, Sanofi, Viartis, Zambon, Limbic, Effrx Pharmaceuticals and Omron. Additionally, there is an author who serves on the Novartis Data and Safety Monitoring Board. There are several authors who are employed by the Cystic Fibrosis Foundation (CFF). The CFF, to advance drug development and search for a cure, have contracts with several companies to help fund the development of potential treatments and/or cures for cystic fibrosis. Pursuant to these contracts, CFF may receive milestone-based payments, equity interests, royalties on the net sales of therapies, and/or other forms of consideration. Resulting revenue received by CFF is used in support of our mission. See “How Drugs Get on the Pipeline” on the CFF website for more information. Additionally, CFF may license CFF Patient Registry data to some companies to monitor drug safety as part of the U.S. Food and Drug Administration's required Phase 4 clinical trials process and to encourage research aimed at improving the care of people with CF, while maintaining our obligation and commitment to protect the privacy of Registry participants. In connection with these licenses, and upon request, CFF may also assist company researchers in interpreting CFF Patient Registry data to aid in designing, analyzing, and interpreting real world studies in CF., (Copyright © 2024. Published by Elsevier B.V.)

Background: Good data quality is essential when rare disease registries are used as a data source for pharmacovigilance studies. This study investigated data quality of the Swiss cystic fibrosis (CF) registry in the frame of a European Cystic Fibrosis Society Patient Registry (ECFSPR) project aiming to implement measures to increase data reliability for registry-based research., Methods: All 20 pediatric and adult Swiss CF centers participated in a data quality audit between 2018 and 2020, and in a re-audit in 2022. Accuracy, consistency and completeness of variables and definitions were evaluated, and missing source data and informed consents (ICs) were assessed., Results: The first audit included 601 out of 997 Swiss people with CF (60.3 %). Data quality, as defined by data correctness ≥95 %, was high for most of the variables. Inconsistencies of specific variables were observed because of an incorrect application of the variable definition. The proportion of missing data was low with <5 % for almost all variables. A considerable number of missing source data occurred for CFTR variants. Availability of ICs varied largely between centers (10 centers had >5 % of missing documents). After providing feedback to the centers, availability of genetic source data and ICs improved., Conclusions: Data audits demonstrated an overall good data quality in the Swiss CF registry. Specific measures such as support of the participating sites, training of data managers and centralized data collection should be implemented in rare disease registries to optimize data quality and provide robust data for registry-based scientific research., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kathleen Jahn, Andreas Jung, Philipp Latzin, Alexander Moeller, Christian Murer, Lutz Naehrlich, Alain Sauty and Jakob Usemann have received honoraria from Vertex Pharmaceuticals. Andreas Jung has received consulting fees and honoraria from EffRx Pharmaceuticals and Viatris. Philipp Latzin has received honoraria from CSL Vifor., (Copyright © 2023. Published by Elsevier B.V.)

Rationale: Limited information is available on the clinical status of people with Cystic Fibrosis (pwCF) carrying 2 nonsense mutations (PTC/PTC). The main objective of this study was to compare disease severity between pwCF PTC/PTC, compound heterozygous for F508del and PTC (F508del/PTC) and homozygous for F508del (F508del+/+)., Methods: Based on the European CF Society Patient Registry clinical data of pwCF living in high and middle income European and neighboring countries, PTC/PTC (n = 657) were compared with F508del+/+ (n = 21,317) and F508del/PTC(n = 4254).CFTR mRNA and protein activity levels were assessed in primary human nasal epithelial (HNE) cells sampled from 22 PTC/PTC pwCF., Main Results: As compared to F508del+/+ pwCF; both PTC/PTC and F508del/PTC pwCF exhibited a significantly faster rate of decline in Forced Expiratory Volume in 1 s (FEV 1 ) from 7 years (-1.33 for F508del +/+, -1.59 for F508del/PTC; -1.65 for PTC/PTC, p < 0.001) until respectively 30 years (-1.05 for F508del +/+, -1.23 for PTC/PTC, p = 0.048) and 27 years (-1.12 for F508del +/+, -1.26 for F508del/PTC, p = 0.034). This resulted in lower FEV 1 values in adulthood. Mortality of pediatric pwCF with one or two PTC alleles was significantly higher than their F508del homozygous pairs. Infection with Pseudomonas aeruginosa was more frequent in PTC/PTC versus F508del+/+ and F508del/PTC pwCF. CFTR activity in PTC/PTC pwCF's HNE cells ranged between 0% to 3% of the wild-type level., Conclusions: Nonsense mutations decrease the survival and accelerate the course of respiratory disease in children and adolescents with Cystic Fibrosis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

This study explored the use of computed cardiopulmonography (CCP) to assess lung function in early-stage cystic fibrosis (CF). CCP has two components. The first is a particularly accurate technique for measuring gas exchange. The second is a computational cardiopulmonary model where patient-specific parameters can be estimated from the measurements of gas exchange. Twenty-five participants (14 healthy controls, 11 early-stage CF) were studied with CCP. They were also studied with a standard clinical protocol to measure the lung clearance index (LCI 2.5 ). Ventilation inhomogeneity, as quantified through CCP parameter σlnCl, was significantly greater ( P < 0.005) in CF than in controls, and anatomical deadspace relative to predicted functional residual capacity (DS/FRCpred) was significantly more variable ( P < 0.002). Participant-specific parameters were used with the CCP model to calculate idealized values for LCI 2.5 (iLCI 2.5 ) where extrapulmonary influences on the LCI 2.5 , such as breathing pattern, had all been standardized. Both LCI 2.5 and iLCI 2.5 distinguished clearly between CF and control participants. LCI 2.5 values were mostly higher than iLCI 2.5 values in a manner dependent on the participant's respiratory rate (r = 0.46, P < 0.05). The within-participant reproducibility for iLCI 2.5 appeared better than for LCI 2.5 , but this did not reach statistical significance ( F ratio = 2.2, P = 0.056). Both a sensitivity analysis on iLCI 2.5 and a regression analysis on LCI 2.5 revealed that these depended primarily on an interactive term between CCP parameters of the form σlnCL*(DS/FRC). In conclusion, the LCI 2.5 (or iLCI 2.5 ) probably reflects an amalgam of different underlying lung changes in early-stage CF that would require a multiparameter approach, such as potentially CCP, to resolve. NEW & NOTEWORTHY Computed cardiopulmonography is a new technique comprising a highly accurate sensor for measuring respiratory gas exchange coupled with a cardiopulmonary model that is used to identify a set of patient-specific characteristics of the lung. Here, we show that this technique can improve on a standard clinical approach for lung function testing in cystic fibrosis. Most particularly, an approach incorporating multiple model parameters can potentially separate different aspects of pathological change in this disease.

Rationale: The triple-combination regimen elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) was shown to be safe and efficacious in children aged 6 through 11 years with cystic fibrosis and at least one F508del-CFTR allele in a phase 3, open-label, single-arm study. Objectives: To further evaluate the efficacy and safety of ELX/TEZ/IVA in children 6 through 11 years of age with cystic fibrosis heterozygous for F508del and a minimal function CFTR mutation ( F /MF genotypes) in a randomized, double-blind, placebo-controlled phase 3b trial. Methods: Children were randomized to receive either ELX/TEZ/IVA ( n  = 60) or placebo ( n  = 61) during a 24-week treatment period. The dose of ELX/TEZ/IVA administered was based on weight at screening, with children <30 kg receiving ELX 100 mg once daily, TEZ 50 mg once daily, and IVA 75 mg every 12 hours, and children ⩾30 kg receiving ELX 200 mg once daily, TEZ 100 mg once daily, and IVA 150 mg every 12 hours (adult dose). Measurements and Main Results: The primary endpoint was absolute change in lung clearance index 2.5 from baseline through Week 24. Children given ELX/TEZ/IVA had a mean decrease in lung clearance index 2.5 of 2.29 units (95% confidence interval [CI], 1.97-2.60) compared with 0.02 units (95% CI, -0.29 to 0.34) in children given placebo (between-group treatment difference, -2.26 units; 95% CI, -2.71 to -1.81; P  < 0.0001). ELX/TEZ/IVA treatment also led to improvements in the secondary endpoint of sweat chloride concentration (between-group treatment difference, -51.2 mmol/L; 95% CI, -55.3 to -47.1) and in the other endpoints of percent predicted FEV 1 (between-group treatment difference, 11.0 percentage points; 95% CI, 6.9-15.1) and Cystic Fibrosis Questionnaire-Revised Respiratory domain score (between-group treatment difference, 5.5 points; 95% CI, 1.0-10.0) compared with placebo from baseline through Week 24. The most common adverse events in children receiving ELX/TEZ/IVA were headache and cough (30.0% and 23.3%, respectively); most adverse events were mild or moderate in severity. Conclusions: In this first randomized, controlled study of a cystic fibrosis transmembrane conductance regulator modulator conducted in children 6 through 11 years of age with F /MF genotypes, ELX/TEZ/IVA treatment led to significant improvements in lung function, as well as robust improvements in respiratory symptoms and cystic fibrosis transmembrane conductance regulator function. ELX/TEZ/IVA was generally safe and well tolerated in this pediatric population with no new safety findings.

Here, we present a standardized protocol for isolation, maintenance, and polarization of the respiratory epithelial primary cells from patient samples acquired from nasal brushing, polyp specimens, or lung explants. This protocol generates a clearly defined polarized layer of epithelial cells on filters, with a good number of ciliated cells and a thin layer of mucus. We detail the steps for samples prepared from patients with cystic fibrosis as well as from subjects without cystic fibrosis., Competing Interests: Damian Downey has received consultancy fees and/or grant support from Vertex pharmaceuticals, Proteostasis Therapeutics, Gilead, Chiesi, and Insmed. He is Director of the European CF Society – Clinical Trials Network and a member of the UK CF Trust Research Scientific Oversight Board of the Clinical Trials Accelerator Platform. Isabelle Sermet has received consultancy fees and/or grant support from Vertex Therapeutics, Eloxx, and PTC Therapeutics and is a Board Member of the European Cystic Fibrosis Society. Luis Galietta is a member of the Advisory Board of Enterprise Therapeutics., (© 2022 The Author(s).)

Background: Adding a slow vital capacity (SVC) to multiple breath washout (MBW) allows quantification of otherwise overlooked signal from under/un-ventilated lung units (UVLU) and may provide a more comprehensive assessment of airway disease than conventional lung clearance index (LCI 2.5 )., Methods: We conducted a pilot study on people undergoing MBW tests: 10 healthy controls (HC) and 43 cystic fibrosis (CF) subjects performed an SVC after the standard end of test. We term the new outcome LCI with Short extension (LCI ShX ). We assessed (i) CF/ HC differences, (ii) variability (iii) effect of pulmonary exacerbation (PEx)/treatment and (iv) relationship with CF computed tomography (CFCT) scores., Results: HC/ CF group differences were larger with LCI ShX than LCI 2.5 (P<0.001). Within the CF group UVLU was highly variable and when abnormal it did not correlate with corresponding LCI 2.5 . Signal showed little variability during clinical stability (n = 11 CF; 2 visits; median inter-test variability 2.6% LCI ShX, 2.5% LCI 2.5 ). PEx signal was significantly greater for LCI ShX both for onset and resolution. Both MBW parameters correlated significantly with total lung CT scores and hyperinflation but only LCI ShX correlated with mucus plugging., Conclusions: UVLU captured within the LCI ShX varies between individuals; the lack of relationship with LCI 2.5 demonstrates that new, additional information is being captured. LCI ShX repeatability during clinical stability combined with its larger signal around episodes of PEx may lend it superior sensitivity as an outcome measure. Further studies will build on this pilot data to fully establish its utility in monitoring disease status., Competing Interests: Declaration of Competing Interest Christopher Short, Clare Saunders, Dominic Hughes, Samantha Irving, Laura Gardener, Mark Rosenthal and Paul Robinson report no conflicts of interest. Thomas Semple reports speakers fees - Vertex Pharmaceuticals. Research grants – Chiesi Pharmaceuticals. Consultancy fees - Boehringer-Ingelheim and Calyx. Prof. Jane Davies has performed clinical trial leadership roles, educational and/ or advisory activities for the following: Abbvie, Algipharma AS, Bayer AG, Boehringer Ingelheim Pharma GmbH & Co. KG, Eloxx, Enterprise, Galapagos NV, ImevaX GmbH, Ionis, Nivalis Therapeutics, Inc., Novartis, ProQR Therapeutics III B.V., Proteostasis Therapeutics, INC., Pulmocide Raptor Pharmaceuticals, Inc, Vertex Pharmaceuticals., (Copyright © 2021. Published by Elsevier B.V.)

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in people with cystic fibrosis (pwCF) can lead to severe outcomes., Methods: In this observational study, the European Cystic Fibrosis Society Patient Registry collected data on pwCF and SARS-CoV-2 infection to estimate incidence, describe clinical presentation and investigate factors associated with severe outcomes using multivariable analysis., Results: Up to December 31, 2020, 26 countries reported information on 828 pwCF and SARS-CoV-2 infection. Incidence was 17.2 per 1000 pwCF (95% CI: 16.0-18.4). Median age was 24 years, 48.4% were male and 9.4% had lung transplants. SARS-CoV-2 incidence was higher in lung-transplanted (28.6; 95% CI: 22.7-35.5) versus non-lung-transplanted pwCF (16.6; 95% CI: 15.4-17.8) (p≤0.001).SARS-CoV-2 infection caused symptomatic illness in 75.7%. Factors associated with symptomatic SARS-CoV-2 infection were age >40 years, at least one F508del mutation and pancreatic insufficiency.Overall, 23.7% of pwCF were admitted to hospital, 2.5% of those to intensive care, and regretfully 11 (1.4%) died. Hospitalisation, oxygen therapy, intensive care, respiratory support and death were 2- to 6-fold more frequent in lung-transplanted versus non-lung-transplanted pwCF.Factors associated with hospitalisation and oxygen therapy were lung transplantation, cystic fibrosis-related diabetes (CFRD), moderate or severe lung disease and azithromycin use (often considered a surrogate marker for Pseudomonas aeruginosa infection and poorer lung function)., Conclusion: SARS-CoV-2 infection yielded high morbidity and hospitalisation in pwCF. PwCF with forced expiratory volume in 1 s <70% predicted, CFRD and those with lung transplants are at particular risk of more severe outcomes., Competing Interests: Conflict of interest: A. Jung has nothing to disclose. Conflict of interest: A. Orenti has nothing to disclose. Conflict of interest: F. Dunlevy reports support for the present manuscript from Chiesi Farmaceutici SpA. Conflict of interest: E. Aleksejeva has nothing to disclose. Conflict of interest: E. Bakkeheim has nothing to disclose. Conflict of interest: V. Bobrovnichy has nothing to disclose. Conflict of interest: S.B. Carr reports receiving speaker honoraria from Vertex and Chiesi, outside the submitted work; participation on a Data Safety Monitoring Board or Advisory Board for Vertex, Profile Pharma and Chiesi, outside the submitted work; leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid from UK CF Trust; PI for Pharmacovigilance study, payment to institution from Pharmaxis, outside the submitted work. Conflict of interest: C. Colombo has nothing to disclose. Conflict of interest: H. Corvol has nothing to disclose. Conflict of interest: R. Cosgrif declares outside the submitted work to be the director of the Cystic Fibrosis Trust. Conflict of interest: G. Daneau has nothing to disclose. Conflict of interest: D. Dogru has nothing to disclose. Conflict of interest: P. Drevinek reports grants or contracts from Ministry of Health, Czech Republic, outside the submitted work; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Vertex Pharmaceuticals and Actelion Pharmaceuticals, outside the submitted work; participation on a Data Safety Monitoring Board or Advisory Board for Vertex Pharmaceuticals, outside the submitted work; leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid from Society for Medical Microbiology, outside the submitted work. Conflict of interest: A.D. Vukic has nothing to disclose. Conflict of interest: I. Fajac reports grants or contracts from Boehringer Ingelheim, Celtaxsys, Corbus Pharmaceuticals, and Vertex Pharmaceuticals, outside the submitted work; consulting fees from Boehringer Ingelheim and Vertex Pharmaceuticals, outside the submitted work; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Vertex Pharmaceuticals and Boehringer Ingelheim, outside the submitted work; leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid for European Cystic Fibrosis Society. Conflict of interest: A. Fox support for the present manuscript from Chiesi Farmaceutici SpA. Conflict of interest: S. Fustik has nothing to disclose. Conflict of interest: V. Gulmans has nothing to disclose. Conflict of interest: S. Harutyunyan has nothing to disclose. Conflict of interest: E. Hatziagorou has nothing to disclose. Conflict of interest: I. Kasmi has nothing to disclose. Conflict of interest: H. Kayserová has nothing to disclose. Conflict of interest: E. Kondratyeva reports payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from All-Russian online school with international participation, outside the submitted work. Conflict of interest: U. Krivec has nothing to disclose. Conflict of interest: H. Makukh has nothing to disclose. Conflict of interest: K. Malakauskas has nothing to disclose. Conflict of interest: E.F. McKone reports grants or contracts from vertex, outside the submitted work; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Vertex Pharmaceuticals and Roche Pharmaceuticals, outside the submitted work; support for attending meetings and/or travel from A Menarini, outside the submitted work; participation on a Data Safety Monitoring Board or Advisory Board for Insmed and Janssen Pharmaceuticals, outside the submitted work. Conflict of interest: M. Mei-Zahav has nothing to disclose. Conflict of interest: I. de Monestrol reports grant from Vertex for an academic research study regarding gastrointestinal outcome in CF patients taking Orkambi medication, outside the submitted work; leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid from Swedish CF Registry and the Swedish Society of Medicine's CF working group. Conflict of interest: H.V. Olesen has nothing to disclose. Conflict of interest: R. Padoan has nothing to disclose. Conflict of interest: T. Parulava has nothing to disclose. Conflict of interest: M.D. Pastor-Vivero has nothing to disclose. Conflict of interest: L. Pereira has nothing to disclose. Conflict of interest: G. Petrova reports payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from TEVA Pharmaceuticals, Mylan and Alvogen, outside the submitted work. Conflict of interest: A. Pfleger has nothing to disclose. Conflict of interest: L. Pop has nothing to disclose. Conflict of interest: J.G. van Rens has nothing to disclose. Conflict of interest: M. Rodić has nothing to disclose. Conflict of interest: M. Schlesser has nothing to disclose. Conflict of interest: V. Storms has nothing to disclose. Conflict of interest: O. Turcu has nothing to disclose. Conflict of interest: L. Woźniacki has nothing to disclose. Conflict of interest: P. Yiallouros has nothing to disclose. Conflict of interest: A. Zolin has nothing to disclose. Conflict of interest: D.G. Downey has nothing to disclose. Conflict of interest: L. Naehrlich reports support for the present manuscript from Chiesi Farmaceutici SpA; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from ArticulateScience LLC, outside the submitted work; participation on a Data Safety Monitoring Board or Advisory Board for Trial Steering committee of CF Storm, outside the submitted work; leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid from Society for German CF Registry European CF Patient Registry, outside the submitted work; other financial or nonfinancial interests from Vertex Pharmaceuticals and Boehringer Ingelheim; Institutional fees for site participation (PI) in clinical trials from Vertex Pharmaceuticals and Boehringer Ingelheim., (Copyright ©The authors 2021.)

Background: People with cystic fibrosis (pwCF) are central in the development of patient-led assessment tools. Qualitative analysis of a frequently used CF-specific patient-reported outcome measure (PROM) sought patient recommendations for development of a new quality of life (QoL) tool., Methods: We performed an inventory of PROMs, symptom-report and QoL tools used in clinical trials within the European Cystic Fibrosis Society Clinical Trial Network (ECFS-CTN) and in routine clinical practice among Cystic Fibrosis Europe and ECFS members. A qualitative study using cognitive interviews with pwCF and their caregivers reviewed the Cystic Fibrosis Questionnaire (CFQ), the French initial form of the Cystic Fibrosis Questionnaire-Revised (CFQ-R)., Results: Survey results from 33 countries revealed over 70 tools used in routine clinical practice, utilized by clinical specialists (n=124), pwCF/parents/carers (n=49) and other allied health professionals (n=60). The CFQ-R was the main PROM used in clinical trials. The qualitative study enrolled 99 pwCF, 6 to 11 years (n=31); 12 to 18 years (n=38); >18 years (n=30) and 26 parents. Inductive thematic analysis based on the CFQ, revealed 19 key themes. Themes common across all cohorts included burden of treatment, impact of disease on day-to-day life, relationships/family, stress/mood, and nutrition. Themes unique to individual groups included, treatment when not symptomatic for the paediatric group; education/studies and planning for the future for adolescents, impact of anxiety and depression on day-to-day life for adults, and for parents, questions addressing anxiety and their role as carers., Conclusions: Patient-centeredness is paramount in development of an up-to-date PROM in the era of novel therapies., Competing Interests: Declaration of Competing Interest RC, AC, VBontemps, EL, EB, VB, MK, FC, MB, HdeK, PdeC, KH and IH have no conflicts of interest. ISG has received grants and personal fees from Vertex Pharmaceuticals, personal fees from Eloxx, and non-financial support from PTC Therapeutics; P-RB has received personal fees from Astra Zeneca, Boehringer-Ingelheim, Chiesi, GSK, Insmed, Novartis and Pfizer and grant from GSK; DH has received personal fees from Vertex; CM personal fees from Chiesi and Zambon., (Copyright © 2021. Published by Elsevier B.V.)

Background: Median survival for cystic fibrosis (CF) patients in Europe is unknown and is likely to be influenced by socioeconomic factors. Using the European CF Society Patient Registry (ECFSPR), median survival estimates were obtained for CF patients across Europe and the impact of socioeconomic status on survival was examined., Methods: CF subjects known to be alive and in the ECFSPR between 2010 and 2014 were included. Survival curves were estimated using the Kaplan-Meier method. Differences in the survival curves were assessed using the log-rank test. Cox regression was used to estimate the association between socioeconomic factors and the age-specific hazard of death, with adjustment for sex, age at diagnosis, CF transmembrane conductance regulator ( CFTR ) genotype and transplant status., Results: The final analysis included 13 countries with 31 987 subjects (135 833 person-years of follow-up) and 1435 deaths. Median survival age for these patients in the ECFSPR was 51.7 (95% CI 50.0-53.4) years. After adjusting for potential confounders age at diagnosis, sex, CFTR genotype and transplant status, there remained strong evidence of an association between socioeconomic factors and mortality (p<0.001). Countries in the highest third of healthcare spending had a 46% lower hazard of mortality (HR 0.54, 95% CI 0.45-0.64) than countries in the lowest third of healthcare spending., Conclusions: Median survival for patients with CF in Europe is comparable to that reported in other jurisdictions and differs by socioeconomic factors., Competing Interests: Conflict of interest: E.F. McKone reports grants and personal fees from Vertex Pharmaceuticals, personal fees from Novartis, nonfinancial support from A Menarini, and grants from Gilead, outside the submitted work. Conflict of interest: C. Ariti has nothing to disclose. Conflict of interest: A. Jackson has nothing to disclose. Conflict of interest: A. Zolin has nothing to disclose. Conflict of interest: S.B. Carr reports nonfinancial support and other from Chiesi Pharmaceuticals (Advisory Board fee), nonfinancial support and other from Vertex Pharmaceuticals (Advisory Board, lecture fee, travel, Steering Committee), other from Zambon Pharmaceuticals (Advisory Board fee), other from Insmed (Advisory Board fee), outside the submitted work. Conflict of interest: A. Orenti has nothing to disclose. Conflict of interest: J.G. van Rens has nothing to disclose. Conflict of interest: L. Lemonnier has nothing to disclose. Conflict of interest: M. Macek Jr has nothing to disclose. Conflict of interest: R.H. Keogh has nothing to disclose. Conflict of interest: L. Naehrlich reports that he has received institutional fees for site participation in clinical trials from Vertex Pharmaceuticals., (Copyright ©The authors 2021. For reproduction rights and permissions contact permissions@ersnet.org.)

With the advent of CFTR modulators, surrogate outcome parameters that accurately quantify the improvement in CFTR activity are needed. In vivo biomarkers that reflect CFTR ion transport and can serve as outcomes in the treatment of CFTR modulators are the sweat Cl - test (SCT), the nasal potential difference (NPD) measurement or the intestinal current measurement (ICM). This review focus on the SCT and NPD. The SCT displays a low intra-patient variability in contrast to the NPD. It has been used extensively as a biomarker of CFTR function in clinical trials of CFTR modulator therapies and provides evidence for change in the short term. The level of functional rescue in the NPD increases up to 40% of normal CFTR in patients with a Gly551Asp treated with ivacaftor monotherapy, while in F508del homozygous patients treated with ivacaftor-lumacaftor, activity increased on average up to ~20% of normal activity. While both tests provide evidence of the effect on CFTR activity, they cannot be used at an individual level to predict the response to any CFTR modulators. Nevertheless, their rapid modification, reflecting electrophysiological properties, highlight their potential use in proof-of-concept studies for CFTR modulators.

Background: Viral infections can cause significant morbidity in cystic fibrosis (CF). The current Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic could therefore have a serious impact on the health of people with CF (pwCF)., Methods: We used the 38-country European Cystic Fibrosis Society Patient Registry (ECFSPR) to collect case data about pwCF and SARS-CoV-2 infection., Results: Up to 30 June 2020, 16 countries reported 130 SARS-CoV-2 cases in people with CF, yielding an incidence of 2.70/1000 pwCF. Incidence was higher in lung-transplanted patients (n=23) versus non-transplanted patients (n=107) (8.43 versus 2.36 cases/1000). Incidence was higher in pwCF versus the age-matched general population in the age groups <15, 15-24, and 25-49 years (p<0.001), with similar trends for pwCF with and without lung transplant. Compared to the general population, pwCF (regardless of transplantation status) had significantly higher rates of admission to hospital for all age groups with available data, and higher rates of intensive care, although not statistically significant. Most pwCF recovered (96.2%), however 5 died, of whom 3 were lung transplant recipients. The case fatality rate for pwCF (3.85%, 95% CI: 1.26-8.75) was non-significantly lower than that of the general population (7.46%; p=0.133)., Conclusions: SARS-CoV-2 infection can result in severe illness and death for pwCF, even for younger patients and especially for lung transplant recipients. PwCF should continue to shield from infection and should be prioritized for vaccination., Competing Interests: Declaration of Competing Interest Dr. Naehrlich reports that he has received institutional fees for site participation in clinical trials from Vertex Pharmaceuticals and Boehringer Ingelheim; Dr. Orenti has nothing to disclose; Dr. Dunlevy reports institutional grants from Chiesi, during the conduct of the study; Dr. Kasmi has nothing to disclose; Dr. Harutyunyan has nothing to disclose; Dr. Pfleger has nothing to disclose; Dr. Bobrovnichy has nothing to disclose;Dr. Keegan has nothing to disclose; Dr. Daneau has nothing to disclose; Dr. Petrova has nothing to disclose; Dr. Bambir has nothing to disclose; Dr. Vukić Dugac has nothing to disclose; Dr. Tješić-Drinković has nothing to disclose; Dr. Yiallouros has nothing to disclose; Dr. Drevinek reports personal fees from Vertex Pharmaceuticals, outside the submitted work; Prof. Milan Macek reports grants from Vertex Pharmaceuticals,  outside the submitted workr r; Mrs. Bilkova has nothing to disclose; Dr. Olesen has nothing to disclose; Dr. Burgel reports personal fees from Astra-Zeneca, personal fees from Boehringer Ingelheim, personal fees from Chiesi, personal fees from GSK, personal fees from Insmed, personal fees from Novartis, personal fees from Pfizer, grants and personal fees from Vertex, personal fees from Zambon, outside the submitted work; Dr. Corvol has nothing to disclose; Ms. Lemmonier has nothing to disclose; Dr. Parulava has nothing to disclose; Dr. Hatziagorou has nothing to disclose; Dr. Diamantea has nothing to disclose; Dr. Párniczky has nothing to disclose; G. Fletcher has nothing to disclose; Prof. McKone reports travel support from A Menarini, speaker fees from Roche Pharmaceuticals, consultancy fees from Insmed, consultancy fees from Janssen Pharmaceuticals, grants to institution and consultancy fees from Vertex, outside the submitted work; Dr. Mei-Zahav has nothing to disclose; Dr. Padoan has nothing to disclose; Dr. Salvatore has nothing to disclose; Dr. Colombo has nothing to disclose; Dr. Aleksejeva has nothing to disclose; Dr. Malakauskas has nothing to disclose; Dr. Schlesser has nothing to disclose; Dr. Fustik has nothing to disclose; Dr. Turcu has nothing to disclose; V. Gulmans has nothing to disclose; D. Zomer-van Ommen has nothing to disclose; Dr. Wathne has nothing to disclose; Dr. Bakkeheim has nothing to disclose; Dr. Wozniacki has nothing to disclose; Dr. Pereira has nothing to disclose; Dr. Pop has nothing to disclose; Dr. Kondratyeva has nothing to disclose; Dr. Amelina has nothing to disclose; Dr. Zhekaite has nothing to disclose; Dr. O. Simonova has nothing to disclose; Dr. Kashirskaya has nothing to disclose; Dr. Rodic has nothing to disclose; Dr. Kayserova has nothing to disclose; Dr. Krivec has nothing to disclose; Dr. Mondejar-Lopez has nothing to disclose; Dr. Pastor-Vivero has nothing to disclose; Dr. de Monestrol reports grants from Vertex, outside the submitted work; Dr. Lindblad has nothing to disclose; Dr. Dogru has nothing to disclose; Dr. Gokdemir has nothing to disclose; Dr. Pekcan has nothing to disclose; Dr. Makukh has nothing to disclose; Dr. Brownlee has nothing to disclose; Ms. Cosgriff has nothing to disclose; Mr. McClenaghan has nothing to disclose; Dr. Carr reports personal fees from Chiesi Pharmaceuticals, personal fees and non-financial support from Vertex, personal fees from Zambon, personal fees from Insmed, outside the submitted work; Dr. Lammertyn has nothing to disclose; Dr. Zolin has nothing to disclose; Ms.. Fox reports grants from ECFS, during the conduct of the study; Mr Krasnyk has nothing to disclose; Mrs. Van Rens has nothing to disclose; Dr. van Koningsbruggen-Rietschel reports grants and personal fees from Algipharma (HORIZON2020), personal fees from Deutsches Zentrum für Infektionsforschung, personal fees from Antabio, personal fees from Proteostasis, personal fees from Roche, personal fees from Vertex, outside the submitted work; Dr. Jung reports grants from Chiesi Pharmaceuticals, during the conduct of the study., (Copyright © 2021. Published by Elsevier B.V.)

Knowledge on the mechanisms of acid and base secretion in airways has progressed recently. The aim of this review is to summarize the known mechanisms of airway surface liquid (ASL) pH regulation and their implication in lung diseases. Normal ASL is slightly acidic relative to the interstitium, and defects in ASL pH regulation are associated with various respiratory diseases, such as cystic fibrosis. Basolateral bicarbonate (HCO 3 - ) entry occurs via the electrogenic, coupled transport of sodium (Na + ) and HCO 3 - , and, together with carbonic anhydrase enzymatic activity, provides HCO 3 - for apical secretion. The latter mainly involves CFTR, the apical chloride/bicarbonate exchanger pendrin and paracellular transport. Proton (H + ) secretion into ASL is crucial to maintain its relative acidity compared to the blood. This is enabled by H + apical secretion, mainly involving H + /K + ATPase and vacuolar H + -ATPase that carry H + against the electrochemical potential gradient. Paracellular HCO 3 - transport, the direction of which depends on the ASL pH value, acts as an ASL protective buffering mechanism. How the transepithelial transport of H + and HCO 3 - is coordinated to tightly regulate ASL pH remains poorly understood, and should be the focus of new studies.

Cystic fibrosis (CF) is the most frequent life-limiting autosomal recessive disorder in the Caucasian population. It is due to mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. Current symptomatic CF therapies, which treat the downstream consequences of CFTR mutations, have increased survival. Better knowledge of the CFTR protein has enabled pharmacologic therapy aiming to restore mutated CFTR expression and function. These CFTR "modulators" have revolutionised the CF therapeutic landscape, with the potential to transform prognosis for a considerable number of patients. This review provides a brief summary of their mechanism of action and presents a thorough review of the results obtained from clinical trials of CFTR modulators., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Rationale: Ivacaftor's clinical effects in the residual function mutations 3849 + 10kb C→T and D1152H warrant further characterization. Objectives: To evaluate ivacaftor's effect in people with cystic fibrosis aged ≥6 years with 3849 + 10kb C→T or D1152H residual function mutations and to explore the correlation between ivacaftor-induced organoid-based cystic fibrosis transmembrane conductance regulator function measurements and clinical response to ivacaftor. Methods: Participants were randomized (1:1) in this placebo-controlled crossover study; each treatment sequence included two 8-week treatments with an 8-week washout period. The primary endpoint was absolute change in lung clearance index 2.5 from baseline through Week 8. Additional endpoints included lung function, patient-reported outcomes, and in vitro intestinal organoid-based measurements of ivacaftor-induced cystic fibrosis transmembrane conductance regulator function. Results: Of 38 participants, 37 completed the study. The primary endpoint was met; the Bayesian posterior probability of improvement in lung clearance index 2.5 with ivacaftor versus placebo was >99%. Additional endpoints improved with ivacaftor. Safety findings were consistent with ivacaftor's known safety profile. Dose-dependent swelling was observed in 23 of 25 viable organoid cultures with ivacaftor treatment. Correlations between ivacaftor-induced organoid swelling and clinical endpoints were negligible to low. Conclusions: In people with cystic fibrosis aged ≥6 years with a 3849 + 10kb C→T or D1152H mutation, ivacaftor treatment improved clinical endpoints compared with placebo; however, there was no correlation between organoid swelling and change in clinical endpoints. The organoid assay may assist in identification of ivacaftor-responsive mutations but in this study did not predict magnitude of clinical benefit for individual people with cystic fibrosis with these two mutations.Clinical trial registered with ClinicalTrials.gov (NCT03068312).

Addressing concerns with use of the Exhalyzer D multiple breath washout device http://bit.ly/2ug0fAi., Competing Interests: Conflict of interest: K.J. Bayfield has nothing to disclose. Conflict of interest: E. Alton has nothing to disclose. Conflict of interest: S. Irving has nothing to disclose. Conflict of interest: A. Bush has nothing to disclose. Conflict of interest: J.C. Davies reports grants from the European Cystic Fibrosis Clinical Trials Network and personal fees from pharmaceutical advisory boards during the conduct of the study., (Copyright ©ERS 2020.)

Multiple-breath washout (MBW) can be performed with different gases (sulfur hexafluoride (SF 6- ) and nitrogen (N 2 )) and different devices, all of which give discrepant results. This study aimed to confirm previously reported differences and explore factors influencing discrepant results; equipment factors or the physical properties of gases used., Methods: Healthy controls (HCs) and participants with cystic fibrosis (CF) completed MBW trials on two commercially available devices (Exhalyzer D (N 2 ) and Innocor (SF 6 )). Simultaneous washout of both gases at the same time on the commercial equipment and simultaneous washouts using a respiratory mass spectrometer (RMS) were completed in subsets. Primary outcomes were lung clearance index (LCI), breath number and time required to washout., Results: Breath number was higher with N 2 washout than SF 6 in both HCs and patients with CF, whether washouts were completed individually or simultaneously. The difference was greater in more advanced disease, largely caused by differences in the final part of the washout. Results from commercial devices were similar to those obtained with the RMS., Conclusions: N 2 MBW results were higher than SF 6 MBW, with some of the largest differences reported to date being observed. The biggest impact was at the end of the washout and this was even the case when gases were washed out simultaneously. N 2 and SF 6 MBW results are inherently different and should be considered as independent measurements., Competing Interests: Conflict of interest: K.J. Bayfield has nothing to disclose. Conflict of interest: A. Horsley reports personal fees from pharmaceutical advisory boards during the conduct of the study. Conflict of interest: E. Alton has nothing to disclose. Conflict of interest: S. Irving has nothing to disclose. Conflict of interest: A. Bush has nothing to disclose. Conflict of interest: J.C. Davies reports grants from the European Cystic Fibrosis Clinical Trials Network and personal fees from pharmaceutical advisory boards, during the conduct of the study., (Copyright ©ERS 2019.)

Background: Long-term effect of enteral tube feeding (ETF) in cystic fibrosis (CF) remains equivocal., Methods: A Belgian CF registry based, retrospective, longitudinal study, evaluated the pre- and post- ETF (n = 113) clinical evolution and compared each patient with 2 age, gender, pancreatic status and genotype class-matched controls., Results: At baseline ETF had a worse BMI z-score (p < 0.0001) and FEV1% (p < 0.0001) compared to controls. Patients eventually receiving ETF, had already a significant worse nutritional status and pulmonary function at first entry in the registry. Both parameters displayed a significant decline before ETF-introduction. ETF had more hospitalization and intravenous antibiotic (IVAB) treatment days (p < 0.0001). After ETF introduction hospitalizations and IVAB decreased significantly. After ETF-introduction BMI z-score recuperated towards the original curve before the decline, but remained below the controls. Starting ETF had no effect on rate of height gain in children. The pre-index FEV1 decline (-1.52%/year (p = 0.002)) stabilized to +0.39%/year afterwards. Controls displayed decline of -0.48%/year (p < 0.0001)., Conclusion: ETF introduction improved BMI z-score and stabilized FEV1, associated with less hospitalizations and IVAB treatments. Higher mortality and transplantation in the ETF cases, leading to drop-outs, made determination of the effect size difficult., (Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)