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Objective: Glycans attached to the Fc region of IgG antibodies influence their pro- or anti-inflammatory effector function. We aimed to explore the interrelation of the Fc glycosylation profile and disease transition, disease activity, and outcome in patients with suspected and confirmed primary Sjögren disease (SjD)., Methods: IgG Fc sialylation and IgG Fc galactosylation serum levels were determined in 300 patients from the Belgian Sjögren's Syndrome Transition Trial. This cohort includes both suspected and confirmed patients with SjD meeting the 2016 American College of Rheumatology/EULAR criteria. Salivary gland involvement was evaluated through ultrasonography (Hocevar score 0-48) and histopathology (focus score). The relative amount of sialylated and galactosylated IgG was determined by capillary electrophoresis after using the endoglycosidase S-based assay., Results: Patients with SjD exhibited significantly lower sialylation and galactosylation levels versus asymptomatic carriers of anti-SSA and patients with sicca. Lower sialylation and galactosylation levels were significantly associated with an increase in B cell activation markers and distinct autoantibody profiles, particularly with multiple autoantibody reactivities. They were also linked to histopathological salivary gland alterations, higher Hocevar scores, and, importantly, risk factors for non-Hodgkin lymphoma (NHL) development. In contrast, patients with SjD who were mono-anti-Ro60 positive and those who were anti-SSA negative had normal IgG Fc glycosylation., Conclusion: This study points to a novel role of IgG Fc glycosylation in patients with SjD in predicting disease transition, monitoring disease activity, and stratifying risk of NHL development., (© 2024 American College of Rheumatology.)

Background: Diagnosing cystic fibrosis (CF) is not always straightforward, in particular when sweat chloride concentration (SCC) is intermediate and <2 CF-causing CFTR variants are identified. The physiological CFTR assays proposed in the guidelines, nasal potential difference and intestinal current measurement, are not readily available nor feasible at all ages. Rectal organoid morphology analysis (ROMA) was previously shown to discriminate between organoids from subjects with and without CF based on a distinct phenotypical difference: compared with non-CF organoids, CF organoids have an irregular shape and lack a visible lumen. The current study serves to further explore the role of ROMA when a CF diagnosis is inconclusive., Methods: Organoid morphology was analysed using the previously established ROMA protocol. Two indices were calculated: the circularity index to quantify the roundness of organoids and the intensity ratio as a measure of the presence of a central lumen., Results: Rectal organoids from 116 subjects were cultured and analysed together with the 189 subjects from the previous study. ROMA almost completely discriminated between CF and non-CF. ROMA indices correlated with SCC, pancreatic status and genetics, demonstrating convergent validity. For cases with an inconclusive diagnosis according to current guidelines, ROMA provided additional diagnostic information, with a diagnostic ROMA classification for 18 of 24 (75%)., Discussion: ROMA provides additional information to support a CF diagnosis when SCC and genetics are insufficient for diagnostic classification. ROMA is standardised and can be centralised, allowing future inclusion in the diagnostic work-up as first-choice physiological assay in case of an unclear diagnosis., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

This is the third paper in the series providing updated information and recommendations for people with cystic fibrosis transmembrane conductance regulator (CFTR)-related disorder (CFTR-RD). This paper covers the individual disorders, including the established conditions - congenital absence of the vas deferens (CAVD), diffuse bronchiectasis and chronic or acute recurrent pancreatitis - and also other conditions which might be considered a CFTR-RD, including allergic bronchopulmonary aspergillosis, chronic rhinosinusitis, primary sclerosing cholangitis and aquagenic wrinkling. The CFTR functional and genetic evidence in support of the condition being a CFTR-RD are discussed and guidance for reaching the diagnosis, including alternative conditions to consider and management recommendations, is provided. Gaps in our knowledge, particularly of the emerging conditions, and future areas of research, including the role of CFTR modulators, are highlighted., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: NJS reports consulting fees and/or honoraria from Vertex, Chiesi, Gilead and Menarini. KDB reports consulting fees and/or honoraria from Vertex, ELoxx, Splisense and Arcturus. JGM reports honoraria from Vertex, Chiesi, Abbvie and Viatris. PGM reports consulting fees and/or honoraria from Vertex, AstraZenica, Limbic and MedEd. CS reports consulting fees and/or honoraria from Vertex, Chiesi, TFF and Pfizer. JC reports consulting fees for Astrazeneca, Boehringer Ingelheim, Grifols, Gilead sciences, Insmed, Genentech, Glaxosmithkline, Antabio, Zambon and Trudell. OCY reports consulting fees and honoraria from Vertex. DGD reports consulting fees and/or honoraria from Chiesi, Insmed and Vertex. DP reports payments for educational talks. DVD reports consulting fees for Arcturus, Arrevus, BiomX, Clarametyx, CFF, Enbiotix, Microbion, Pyros, Respirion and Zambon. ISG reports honoraria from Vertex. KWS, FB, VV, EDW, MW, EB, DD, PE, EG, GH, AK, DN, JAN, CR, IS, MDW report no personal fees/honoraria, (Copyright © 2024. Published by Elsevier B.V.)

Background: The pneumococcal antibody response after vaccination with unconjugated pneumococcal vaccine can be evaluated as part of the diagnostic work-up of children with recurrent respiratory tract infections to detect an underlying polysaccharide antibody deficiency. Little is known about the prevalence of polysaccharide antibody deficiency in this population and its therapeutic consequences., Objectives: This study aimed to investigate the prevalence of polysaccharide antibody deficiency in children with recurrent respiratory tract infections and to correlate polysaccharide responsiveness with clinical severity. In addition, we aimed to evaluate differences in the immunoglobulin (Ig)G2/IgG ratio, IgA level, and age in relation to the number of deficient serotype-specific antibody responses., Methods: Polysaccharide antibody titers for pneumococcal serotypes 8, 9N, and 15B; clinical characteristics; and immunoglobulin levels of 103 children with recurrent respiratory tract infections were retrospectively assessed. American Academy of Allergy, Asthma, and Immunology guidelines were used for the interpretation of the polysaccharide antibody response., Results: Overall, 28 children (27.2 %) were diagnosed with polysaccharide antibody deficiency. No correlation was found between the number of deficient serotype-specific antibody responses and clinical severity. The study participants with a normal response to all three serotypes had a higher IgG2/IgG ratio than those with one or more deficient responses (p < 0.003). No significant correlation between IgA levels and polysaccharide responsiveness was found. The median age of children with normal polysaccharide responsiveness for the three tested serotypes was higher than that of children with a deficient response to one or more serotypes (p < 0.0025)., Conclusion: For a large group of children (18.4 %) with recurrent respiratory tract infections, an underlying mechanism for their susceptibility was defined thanks to diagnostic unconjugated pneumococcal polysaccharide vaccination. Further research is needed to formulate age-specific normal values for polysaccharide responsiveness and to investigate the usefulness of the IgG2/IgG ratio in determining the need for diagnostic unconjugated pneumococcal polysaccharide vaccination., Competing Interests: Declaration of competing interest None., (Copyright © 2024 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.)

Background: The forskolin-induced swelling (FIS) assay measures CFTR function on patient-derived intestinal organoids (PDIOs) and may guide treatment selection for individuals with Cystic Fibrosis (CF). The aim of this study is to demonstrate the repeatability and reproducibility of the FIS assay following a detailed Standard Operating Procedure (SOP), thus advancing the validation of the assay for precision medicine (theranostic) applications., Methods: Over a 2-year period, FIS responses to CFTR modulators were measured in four European labs. PDIOs from six subjects with CF carrying different CFTR genotypes were used to assess the repeatability and reproducibility across the dynamic range of the assay., Results: Technical, intra-assay repeatability was high (Lin's concordance correlation coefficient (CCC) 0.95-0.98). Experimental, within-subject repeatability was also high within each lab (CCCs all >0.9). Longer-term repeatability (>1 year) showed more variability (CCCs from 0.67 to 0.95). The reproducibility between labs was also high (CCC ranging from 0.92 to 0.97). Exploratory analysis also found that between-lab percentage of agreement of dichotomized CFTR modulator outcomes for predefined FIS thresholds ranged between 78 and 100 %., Conclusions: The observed repeatability and reproducibility of the FIS assay within and across different labs is high and support the use of FIS as biomarker of CFTR function in the presence or absence 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 © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective: Intestinal inflammation with contradictory data on faecal calprotectin (fCP) levels is documented in patients with cystic fibrosis (CF). The aim of this study was to longitudinally evaluate fCP in a cohort of children with CF and their relationship with clinical variables., Design: Prospective observational study to assess evolution of fCP levels, primary aimed at improving fat absorption. Along 1.5 years of follow-up (November 2016-May 2018) with four study visits pertaining to a pilot study (two of four) and to a clinical trial (two of four), the study outcomes were measured., Setting: Six European CF centres in the context of MyCyFAPP Project., Subjects: Children with CF and pancreatic insufficiency (2-18 years old)., Main Outcome Measurements: fCP levels, pulmonary function (percentage of forced expiratory volume in 1 s (FEV 1 %)) and coefficient of fat absorption (CFA). Additionally, in the last two visits, gastrointestinal (GI) symptoms were evaluated through the PedsQL-GI Questionnaire. Linear mixed regression models were applied to assess association between fCP and FEV 1 , CFA and GI symptoms., Results: Twenty-nine children with CF and pancreatic insufficiency were included. fCP levels were inversely associated with total modified specific PedsQL-GI score (p=0.04) and positively associated with diarrhoea (p=0.03), but not with CFA. Along the four study visits, fCP significantly increased (from 62 to 256 µg/g) and pulmonary function decreased (from 97% to 87%), with a significant inverse association between the two study outcomes (p<0.001)., Conclusions: In children with CF, fCP levels are inversely associated with pulmonary function and thus the specificity of fCP as a marker of intestinal inflammation in paediatric patients with CF warrants further investigation., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

After three publications defining an updated guidance on the diagnostic criteria for people with cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (pwCFTR-RDs), establishing its relationship to CFTR-dysfunction and describing the individual disorders, this fourth and last paper in the series addresses some critical challenges facing health care providers and pwCFTR-RD. Topics included are: 1) benefits and obstacles to collect data from pwCFTR-RD are discussed, together with the opportunity to integrate them into established CF-registries; 2) the potential of infants designated CRMS/CFSPID to develop a CFTR-RD and how to communicate this information; 3) a description of the challenges in genetic counseling, with particular regard to phenotypic variability, unknown long-term evolution, CFTR testing and pregnancy termination 4) a proposal for the assessment of potential barriers to the implementation and dissemination of the produced documents to health care professionals involved in the care of pwCFTR-RD and a process to monitor the implementation of the CFTR-RD recommendations; 5) clinical trials investigating the efficacy of CFTR modulators in CFTR-RD and how endpoints and outcomes might be adapted to the heterogeneity of these disorders., 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 © 2024 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

This is the second in a series of four papers updating the European Cystic Fibrosis Society (ECFS) standards for the care of people with CF. This paper focuses on establishing and maintaining health. The guidance is produced using an evidence-based framework and with wide stakeholder engagement, including people from the CF community. Authors provided a narrative description of their topic and statements, which were more directive. These statements were reviewed by a Delphi exercise, achieving good levels of agreement from a wide group for all statements. This guidance reinforces the importance of a multi-disciplinary CF team, but also describes developing models of care including virtual consultations. The framework for health is reinforced, including the need for a physically active lifestyle and the strict avoidance of all recreational inhalations, including e-cigarettes. Progress with cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy is reviewed, including emerging adverse events and advice for dose reduction and interruption. This paper contains guidance that is pertinent to all people with CF regardless of age and eligibility for and access to modulator therapy., Competing Interests: Declaration of competing interest KWS has no competing interests. See supplementary materials for full CoI statements for all authors., (Copyright © 2023. Published by Elsevier B.V.)

Cystic fibrosis is a multiorgan disease caused by impaired function of the cystic fibrosis transmembrane conductance regulator (CFTR). Since the introduction of the CFTR modulator combination elexacaftor-tezacaftor-ivacaftor (ETI), which acts directly on mutant CFTR to enhance its activity, most people with cystic fibrosis (pwCF) have seen pronounced reductions in symptoms, and studies project marked increases in life expectancy for pwCF who are eligible for ETI. However, modulator therapy has not cured cystic fibrosis and the success of CFTR modulators has resulted in immediate questions about the new state of cystic fibrosis disease and clinical challenges in the care of pwCF. In this Series paper, we summarise key questions about cystic fibrosis disease in the era of modulator therapy, highlighting state-of-the-art research and clinical practices, knowledge gaps, new challenges faced by pwCF and the potential for future health-care challenges, and the pressing need for additional therapies to treat the underlying genetic or molecular causes of cystic fibrosis., Competing Interests: Declaration of interests KBH reports funding from the National Institutes of Health (NIH) National Heart, Lung, and Blood Institute (NHLBI) and the Cystic Fibrosis Foundation (CFF), outside of the submitted work. SEB reports funding from NIH NHLBI and CFF, outside of the submitted work. DGD reports funding from Chiesi Farmaceutici and CFF to Queen's University Belfast; consulting fees from Vertex and Insmed; honoraria from Chiesi and Gilead; support for travel from the European Cystic Fibrosis Society (ECFS) and CFF; and participation on data and safety monitoring boards (DSMBs) for Nomab trial and CSL Behring, outside of the submitted work. DGD is Director of the ECFS Clinical Trials Network. JFE reports funding from NIH NHLBI and the National Institute of Diabetes and Digestive Kidney Diseases (R01 HL165404, RC2 DK124207, and NHLBI Contract 75N92019C00010) paid to the University of Iowa, outside of the submitted work. IF reports funding from AbbVie, Bayer, Boehringer Ingelheim, Insmed, Vertex, and ECFS to AP-HP-Université Paris Cité; and honoraria from AbbVie, Boehringer Ingelheim, Vertex, and Kither Biotech, outside of the submitted work. RDG reports honoraria for lectures from Vertex, outside of the submitted work. NM-H reports funding from CFF, NIH, and the Food and Drug Administration to Seattle Children's Research Institute, University of Washington; consulting fees from Enterprise Therapeutics; and honoraria for NIH DSMB participation, outside of the submitted work. CEW reports editorial support from Articulate Science outside of the submitted work; income on a per-patient basis to the University of Queensland for participation in pharmaceutical studies; participating on steering committees and international advisory boards for Vertex; and participation as a consultant and presenter at several medical education events sponsored by Vertex, outside of the submitted work. CEW has served as an Associate Editor for Respirology and Associate Editor for Thorax. KDB reports consulting fees from Arcturus, Splisense, Translate Bio, and Vertex; and honoraria from Vertex, outside of the submitted work. JPC, MEL-S, PT, and KLT declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objectives: Salivary gland lymphocytic infiltrates are a hallmark of primary SS (pSS), but traditional biopsy techniques hold several disadvantages. Ultrasound-guided core needle (US-guided CN) parotid gland biopsy is minimally invasive and reliable for diagnosis of lymphoma in pSS. This proof-of-concept study aimed to explore this technique in the diagnostic work-up of pSS and is the first to address its value in a consecutive cohort independently of the presence of salivary gland swelling., Methods: Combined incisional and US-guided CN parotid biopsy was performed in 20 patients with suspected or confirmed pSS from the Belgian Sjögren's Syndrome Transition Trial (BeSSTT). Surface area and presence of a focus score (FS) of at least one, germinal centres and lymphoepithelial lesions were recorded., Results: Salivary gland tissue was interpretable in 19 patients. Fourteen patients had ≥4 mm2 salivary gland tissue by both techniques, in four US-guided CN biopsies salivary gland tissue was <4 mm2. Paired biopsies ≥4 mm2 displayed a concordance of 90% for FS ≥ 1. Presence of lymphoepithelial lesions and germinal centres showed absolute concordance. Of four US-guided CN biopsies <4 mm2, three interpretable incisional biopsies were available, 2/3 with perfect concordance. When including biopsies of <4 mm2 salivary gland tissue, presence of FS ≥ 1 or germinal centres gave a sensitivity of 70% in incisional and of 69% in US-guided CN biopsy., Conclusions: US-guided CN biopsy of the parotid gland is at least equivalent to incisional biopsy of the parotid gland in the diagnostic work-up of pSS., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Aim: To examine the trajectory of forced expiratory volume in 1 s (FEV 1 ) using data from the European Cystic Fibrosis Society patient registry (ECFPR) collected from 2008 to 2016, i.e. the era before highly effective modulator therapy (HEMT). We evaluated risk factors for FEV 1 decline., Methods: The study population included patients with a confirmed diagnosis of cystic fibrosis recorded in the ECFPR (2008-2016). The evolution of FEV 1 % predicted (%FEV 1 ) with age, and the yearly change in %FEV 1 were evaluated. Risk factors considered were cystic fibrosis transmembrane conductance regulator ( -CFTR ) mutation class, gender, age at diagnosis, neonatal screening, meconium ileus, sweat chloride concentration at diagnosis and country's income level., Results: We used 199 604 FEV 1 recordings from 38 734 patients. The fastest decline was seen during puberty and in patients diagnosed before the age of 10 years. Males had a higher %FEV 1 , but a higher yearly %FEV 1 loss between the ages of 15 and 25 years. We showed stabilisation and even improvement in %FEV 1 over age in adults with a class III CFTR mutation, but a steady decline in patients homozygous for F508del or with both mutations of classes I/II. A faster decline in %FEV 1 was found in patients from low-income countries compared to a similar %FEV 1 evolution in patients from middle- and high-income countries., Conclusions: These longitudinal FEV 1 data reflect the reality of cystic fibrosis across Europe in the era pre-HEMT, and can serve as baseline for comparison with the post-HEMT era. The similar evolution in middle- and high-income countries underlines opportunities for low-income countries., Competing Interests: Conflict of interest: The authors declare no conflict of interest., (Copyright ©The authors 2023.)

Background: Newly developed quantitative chest computed tomography (CT) outcomes designed specifically to assess structural abnormalities related to cystic fibrosis (CF) lung disease are now available. CFTR modulators potentially can reduce some structural lung abnormalities. We aimed to investigate the effect of CFTR modulators on structural lung disease progression using different quantitative CT analysis methods specific for people with CF (PwCF). Methods: PwCF with a gating mutation (Ivacaftor) or two Phe508del alleles (lumacaftor-ivacaftor) provided clinical data and underwent chest CT scans. Chest CTs were performed before and after initiation of CFTR modulator treatment. Structural lung abnormalities on CT were assessed using the Perth Rotterdam Annotated Grid Morphometric Analysis for CF (PRAGMA-CF), airway-artery dimensions (AA), and CF-CT methods. Lung disease progression (0-3 years) in exposed and matched unexposed subjects was compared using analysis of covariance. To investigate the effect of treatment in early lung disease, subgroup analyses were performed on data of children and adolescents aged <18 years. Results: We included 16 modulator exposed PwCF and 25 unexposed PwCF. Median (range) age at the baseline visit was 12.55 (4.25-36.49) years and 8.34 (3.47-38.29) years, respectively. The change in PRAGMA-CF %Airway disease (-2.88 (-4.46, -1.30), p = 0.001) and %Bronchiectasis extent (-2.07 (-3.13, -1.02), p < 0.001) improved in exposed PwCF compared to unexposed. Subgroup analysis of paediatric data showed that only PRAGMA-CF %Bronchiectasis (-0.88 (-1.70, -0.07), p = 0.035) improved in exposed PwCF compared to unexposed. Conclusion: In this preliminary real-life retrospective study CFTR modulators improve several quantitative CT outcomes. A follow-up study with a large cohort and standardization of CT scanning is needed to confirm our findings., Competing Interests: HT reports a part time position as chief medical officer for Thirona, functions as vice chair and faculty for the Advance course sponsored by Vertex, and owns no shares. Erasmus MC and Telethon Kids Institute have licensed the use of PRAGMA-CF to Thirona and Resonance Health. SS is employed by Telethon Kids Institute that has licensing agreements for use of PRAGMA-CF with Thirona and Resonance Health to develop an automated scoring system. All other authors declare no competing interests., (Copyright © 2023 Mok, Garcia-Uceda, Cooper, Kemner-Van De Corput, De Bruijne, Feyaerts, Rosenow, De Boeck, Stick and Tiddens.)

Objectives: Autoantibody detection is an essential step in pSS diagnosis. However, the value of separate anti-Ro52, anti-Ro60 and anti-SSB/La detection in pSS diagnosis and phenotyping has not been extensively studied. This study aimed to explore disease characteristics of anti-SSA/Ro positive, suspected and definite pSS patients, in relation to serological profiles based on anti-Ro52, anti-Ro60 and anti-SSB/La reactivity., Methods: Of 187 anti-SSA/Ro positive patients included in the Belgian Sjögren's Syndrome Transition Trial (BeSSTT), 155 were considered definite pSS patients, due to fulfilment of the 2016 ACR-EULAR classification criteria, and 32 suspected, due to reactivity against SSA/Ro without presence of other criteria. None of the patients met any of the ACR-EULAR exclusion criteria for pSS. Patients were grouped based on the presence of anti-Ro52, anti-Ro60 and anti-SSB/La antibodies., Results: Mono-reactivity against Ro60 or Ro52, double reactivity against Ro52/Ro60 and triple reactivity against Ro52/Ro60 and SSB was detected in respectively 30, 23, 70 and 60 patients. Mono-anti-Ro60 positive patients showed the least pSS features. Mono-anti-Ro52 positive patients reported a significantly higher dryness burden (p=0.016) and tended toward more salivary gland ultrasound (SGUS) abnormalities (p=0.054) than mono-anti-Ro60 positives. Double positive patients showed similar characteristics as mono-anti-Ro52 positive patients, whereas triple positive patients showed lowest unstimulated salivary flow rates (p=0.002) and Schirmer tests (p=0.002), highest ocular staining scores (p<0.001), most positive labial salivary gland biopsies (p=0.039), most laboratory abnormalities compatible with B-cell hyperactivity and highest SGUS scores (p<0.001) compared to other patient groups., Conclusions: These data indicate that separate detection of anti-Ro52, anti-Ro60 and anti-SSB/La reactivity is not only relevant towards pSS diagnosis, but markedly aids in patient stratification and evaluation of disease burden. Our results suggest a stepwise model in which mono-reactivity against Ro60 displayed the least objective and subjective glandular pSS features, whereas glandular abnormalities and signs of B-cell hyperactivity were most present in patients showing triple reactivity against Ro60, Ro52 and SSB/La.

This paper is the first in a series providing updated guidance on the definition, evaluation and management of people with a Cystic Fibrosis Transmembrane conductance Regulator (CFTR)-Related Disorder (CFTR-RD). The need for this update relates to more precise characterisation of CFTR gene variants and improved assessment of CFTR protein dysfunction. The exercise is co-ordinated by the European CF Society Standards of Care Committee and Diagnostic Network Working Group and involves stakeholder engagement. This first paper was produced by a core group using an extensive literature review and papers graded for their quality. Subsequent wider stakeholder agreement was achieved. The definition of a CFTR-RD remains "a clinical condition with evidence of CFTR protein dysfunction that does not fulfil the diagnostic criteria for CF". Clearer guidance on CFTR dysfunction and relevant CFTR variants will be provided. Thresholds for clinical presentations are presented and the paradigm that pathobiological processes may be evident in more than one organ is agreed. In this paper we reflect on the early patient journey, highlighting that CF specialists as well as other relevant specialists should be involved in the care of people with a CFTR-RD., Competing Interests: Declaration of Competing Interest Carlo Castellani reports payments of honoraria for presentations from Vertex Pharmaceuticals and Chiesi and participation to Advisory Boards of Vertex Pharmaceuticals. Mylan, Actelion and Chiesi. Kris De Boeck reports consulting fees from Vertex Pharmaceuticals, Arcturus, Splisense, Translate Bio and Chiesi and honoraria for lectures from Vertex Pharmaceuticals. Elke De Wachter reports that her Institution received fundings from Vertex for her participation in an Advisory Board and for a presentation. Isabelle Sermet-Gaudelus reports funding for academic research from Vertex Therapeutics and participation to Scientific Boards of Vertex Therapeutics and Eliox; support for attending conferences by Vertex Therapeutics. Nicholas Simmonds reports payment of honoraria for lectures from Vertex, Chiesi, Gilead and Teva; participation to Advisory Boards of Vertex, Chiesi, Gilead and Menarini. Kevin Southern reports no competing interests, (Copyright © 2022. Published by Elsevier B.V.)

Objectives: Salivary gland ultrasound (SGUS) is emerging as essential tool in primary Sjögren's Syndrome (pSS), but its link to symptom-based endotypes is unknown. Therefore, we explored SGUS outcomes in relation to endotypes in patients with definite and suspected pSS., Methods: Definite pSS patients (n = 171) fulfilling the 2016 ACR/EULAR classification criteria, and suspected pSS patients (n = 119), positive for at least one criterion, were included in the Belgian Sjögren's Syndrome Transition Trial (BeSSTT). Stratification into endotypes according to the Newcastle Sjögren's Stratification Tool resulted in low symptom burden (LSB), pain dominant with fatigue (PDF), dryness dominant with fatigue (DDF) and high symptom burden (HSB). SGUS was assessed with Hocevar score (0-48). The dataset was randomly divided into a discovery (n = 203) and replication (n = 87) cohort., Results: SGUS had strong discriminative power for pSS classification (AUC=0.74), especially in DDF (AUC=0.89). In definite pSS, Hocevar scores in DDF were high compared to other endotypes (38 (20-44) versus 18 (9-33); p < 0.001). Patients with highest SGUS-scores showed more sicca and laboratory abnormalities. Moreover, a subset of young, anti-SSA/Ro positive patients not fulfilling classification criteria showed clear SGUS abnormalities. Replication showed similar results., Conclusions: SGUS-scores were significantly higher in definite pSS with DDF endotype, providing the first evidence of imaging abnormalities in salivary glands matching distinct biological profiles ascribed to pSS endotypes. Additionally, a subset of patients with potential early disease was detected based on presence of anti-SSA antibodies and high SGUS-scores. These results underscore the role of SGUS as powerful tool both in pSS classification and stratification., Competing Interests: Declaration of Competing Interest Competing interests: L.D., H.A., K.D.B., E.G., W.B., D.R., F.D., D.C. and A.S.D.C. report no competing interests. F.Vd.B. has received consultancy fee honoraria from Abbvie, Amgen, Eli Lilly, Galapagos, Gilead, Janssen, Merck, Moonlake, Novartis, Pfizer and UCB. D.E. has received consultancy fee honoraria from Abbvie, Amgen, Eli Lilly, Galapagos, Gilead, Janssen, Merck, Novartis, Pfizer and UCB. I.P. has received consultancy and/or speaker fee honoraria from Amgen, Argenx, Galapagos and Novartis; and participated in advisory boards for Astra-Zeneca, Amgen, GSK, Argenx, BMS, Galapagos, UCB and Novartis., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: In cystic fibrosis (CF), genotype-phenotype correlation is complicated by the large number of CFTR variants, the influence of modifier genes, environmental effects, and the existence of complex alleles. We document the importance of complex alleles, in particular the F508C variant present in cis with the S1251N disease-causing variant, by detailed analysis of a patient with CF, with the [S1251N;F508]/G542X genotype and a very mild phenotype, contrasting it to that of four subjects with the [S1251N;F508C]/F508del genotype and classical CF presentation., Methods: Genetic differences were identified by Sanger sequencing and CFTR function was quantified using rectal organoids in rectal organoid morphology analysis (ROMA) and forskolin-induced swelling (FIS) assays. CFTR variants were further characterised in CF bronchial epithelial (CFBE) cell lines. The impact of involved amino acid changes in the CFTR 3D protein structure was evaluated., Results: Organoids of the patient [S1251N;F508] with mild CF phenotype confirmed the CF diagnosis but showed higher residual CFTR function compared to the four others [S1251N;F508C]. CFBE cell lines showed a decrease in [S1251N;F508C]-CFTR function but not in processing when compared to [S1251N;F508]-CFTR. Analysis of the 3D CFTR structure suggested an additive deleterious effect of the combined presence of S1251N and F508C with respect to NBD1-2 dimerisation., Conclusions: In vitro and in silico data show that the presence of F508C in cis with S1251N decreases CFTR function without affecting processing. Complex CFTR alleles play a role in clinical phenotype and their identification is relevant in the context of personalised medicine for each patient with CF., 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 © 2022. Published by Elsevier B.V.)

Objectives: Cystic fibrosis transmembrane conductance regulator (CFTR) modulators, Kalydeco® (ivacaftor), Orkambi® (lumacaftor/ivacaftor) and Symkevi® (tezacaftor/ivacaftor), have substantially improved patients' lives yet significantly burden healthcare budgets. This analysis aims to compare pricing and reimbursement of aforementioned cystic fibrosis medicines, across European countries. Methods: Clinical trial registries, national databases, health technology assessment reports and grey literature of Austria, Belgium, Denmark, France, Germany, Ireland, Poland, Spain, Sweden, Switzerland, Netherlands, the United Kingdom were consulted. Publicly available prices, reimbursement statuses, economic evaluations, budget impact analyses and managed entry agreements of CFTR modulators were examined. Results: In Belgium, lowest list prices were observed for Kalydeco® (ivacaftor) and Symkevi® (tezacaftor/ivacaftor) at €417 per defined daily dose (DDD) and €372 per average daily dose (ADD), respectively. Whereas, Switzerland had the lowest price for Orkambi® (lumacaftor/ivacaftor) listed at €309 per DDD. Spain had the highest prices for Kalydeco® (ivacaftor) and Symkevi® (tezacaftor/ivacaftor) at €850 per DDD and €761 per ADD, whereas Orkambi® (lumacaftor/ivacaftor) was most expensive in Poland at €983 per DDD. However, list prices were subject to confidential discounts and likely varied from actual costs. In all countries, these treatments were deemed not to be cost-effective. The annual budget impact of the CFTR modulators varied between countries and depended on factors such as local product prices, size of target population, scope of costs and discounting. However, all modulators were fully reimbursed in ten of the evaluated countries except for Sweden and Poland that, respectively, granted reimbursement to one and none of the therapies. Managed entry agreements were confidential but commonly adopted to address financial uncertainties. Conclusion: Discrepancies concerning prices, reimbursement and access were detected for Kalydeco® (ivacaftor), Orkambi® (lumacaftor/ivacaftor) and Symkevi® (tezacaftor/ivacaftor) across European countries., Competing Interests: SS has previously conducted research about market access of orphan medicines sponsored by the Belgian Health Care Knowledge Centre and by Genzyme (now Sanofi), and he has participated in an orphan medicine roundtable sponsored by Celgene. SS is a member of the ISPOR Rare Disease Special Interest Group’s Challenges in Research and Health Technology Assessment of Rare Disease Technologies Working Group, the International Working Group on Orphan Drugs, and the Innoval Working Group on Ultra-Rare Disorders. KDB has been principal investigator in several clinical trials conducted by Vertex Pharmaceuticals and for which her institution has received funding. She or her institution has received fees for participation in advisory boards, satellite symposia or specific projects. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Abdallah, De Boeck, Dooms and Simoens.)

Diagnosing cystic fibrosis (CF) when sweat chloride is not in the CF range and less than 2 disease-causing CFTR mutations are found requires physiological CFTR assays, which are not always feasible or available. We developed a new physiological CFTR assay based on the morphological differences between rectal organoids from subjects with and without CF. In organoids from 167 subjects with and 22 without CF, two parameters derived from a semi-automated image analysis protocol (rectal organoid morphology analysis, ROMA) fully discriminated CF subjects with two disease-causing mutations from non-CF subjects (p<0.001). ROMA, feasible at all ages, can be centralised to improve standardisation., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Despite massive progress in vaccine coverage globally, the region of sub-Saharan Africa is lagging behind for Sustainable Development Goal 3 by 2030. Sub-national under-immunisation is part of the problem. In order to reverse the current immunisation system's (IMS) underperformance, a conceptual model is proposed that captures the complexity of IMSs in low- and middle-income countries (LMICs) and offers directions for sustainable redesign. The IMS model was constructed based on literature and stakeholder interaction in Rwanda and Kenya. The model assembles the paradigms of planned and emergency immunisation in one system and emphasises the synchronised flows of vaccinee, vaccinator and vaccine. Six feedback loops capture the main mechanisms governing the system. Sustainability and resilience are assessed based on loop dominance and dependency on exogenous factors. The diagram invites stakeholders to share their mental models and. The framework provides a systems approach for problem structuring and policy design., Competing Interests: No potential conflict of interest was reported by the authors., (© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

Background: Patients with cystic fibrosis (CF) and pancreatic insufficiency need pancreatic enzyme replacement therapy (PERT) for dietary lipids digestion. There is limited evidence for recommending the adequate PERT dose for every meal, and controlling steatorrhea remains a challenge. This study aimed to evaluate a new PERT dosing method supported by a self-management mobile-app., Methods: Children with CF recruited from 6 European centres were instructed to use the app, including an algorithm for optimal PERT dosing based on in vitro digestion studies for every type of food. At baseline, a 24h self-selected diet was registered in the app, and usual PERT doses were taken by the patient. After 1 month, the same diet was followed, but PERT doses were indicated by the app. Change in faecal fat and coefficient of fat absorption (CFA) were determined., Results: 58 patients (median age 8.1 years) participated. Baseline fat absorption was high: median CFA 96.9%, median 2.4g faecal fat). After intervention CFA did not significantly change, but range of PERT doses was reduced: interquartile ranges narrowing from 1447-3070 at baseline to 1783-2495 LU/g fat when using the app. Patients with a low baseline fat absorption (CFA<90%, n=12) experienced significant improvement in CFA after adhering to the recommended PERT dose (from 86.3 to 94.0%, p=0.031)., Conclusion: the use of a novel evidence-based PERT dosing method, based on in vitro fat digestion studies incorporating food characteristics, was effective in increasing CFA in patients with poor baseline fat absorption and could safely be implemented in clinical practice., (Copyright © 2020. Published by Elsevier B.V.)

Background: Immunization directly impacts health (SDG3) and brings a contribution to 14 out of the 17 Sustainable Development Goals (SDGs), such as ending poverty, reducing hunger, and reducing inequalities. Therefore, immunization is recognized to play a central role in reaching the SDGs, especially in low- and middle-income countries (LMICs). Despite continuous interventions to strengthen immunization systems and to adequately respond to emergency immunization during epidemics, the immunization-related indicators for SDG3 lag behind in sub-Saharan Africa. Especially taking into account the current Covid19 pandemic, the current performance on the connected SDGs is both a cause and a result of this., Methods: We conduct a literature review through a keyword search strategy complemented with handpicking and snowballing from earlier reviews. After title and abstract screening, we conducted a qualitative analysis of key insights and categorized them according to showing the impact of immunization on SDGs, sustainability challenges, and model-based solutions to these challenges., Results: We reveal the leveraging mechanisms triggered by immunization and position them vis-à-vis the SDGs, within the framework of Public Health and Planetary Health. Several challenges for sustainable control of vaccine-preventable diseases are identified: access to immunization services, global vaccine availability to LMICs, context-dependent vaccine effectiveness, safe and affordable vaccines, local/regional vaccine production, public-private partnerships, and immunization capacity/capability building. Model-based approaches that support SDG-promoting interventions concerning immunization systems are analyzed in light of the strategic priorities of the Immunization Agenda 2030., Conclusions: In general terms, it can be concluded that relevant future research requires (i) design for system resilience, (ii) transdisciplinary modeling, (iii) connecting interventions in immunization with SDG outcomes, (iv) designing interventions and their implementation simultaneously, (v) offering tailored solutions, and (vi) model coordination and integration of services and partnerships. The research and health community is called upon to join forces to activate existing knowledge, generate new insights and develop decision-supporting tools for Low-and Middle-Income Countries' health authorities and communities to leverage immunization in its transformational role toward successfully meeting the SDGs in 2030., (© 2021. The Author(s).)

Activation of the Ca 2+ activated Cl - channel TMEM16A is proposed as a treatment in inflammatory airway disease. It is assumed that activation of TMEM16A will induce electrolyte secretion, and thus reduce airway mucus plugging and improve mucociliary clearance. A benefit of activation of TMEM16A was shown in vitro and in studies in sheep, but others reported an increase in mucus production and airway contraction by activation of TMEM16A. We analyzed expression of TMEM16A in healthy and inflamed human and mouse airways and examined the consequences of activation or inhibition of TMEM16A in asthmatic mice. TMEM16A was found to be upregulated in the lungs of patients with asthma or cystic fibrosis, as well as in the airways of asthmatic mice. Activation or potentiation of TMEM16A by the compounds Eact or brevenal, respectively, induced acute mucus release from airway goblet cells and induced bronchoconstriction in mice in vivo. In contrast, niclosamide, an inhibitor of TMEM16A, blocked mucus production and mucus secretion in vivo and in vitro. Treatment of airway epithelial cells with niclosamide strongly inhibited expression of the essential transcription factor of Th2-dependent inflammation and goblet cell differentiation, SAM pointed domain-containing ETS-like factor (SPDEF). Activation of TMEM16A in people with inflammatory airway diseases is likely to induce mucus secretion along with airway constriction. In contrast, inhibitors of TMEM16A may suppress pulmonary Th2 inflammation, goblet cell metaplasia, mucus production, and bronchoconstriction, partially by inhibiting expression of SPDEF.

Background: Tezacaftor-ivacaftor is an approved cystic fibrosis transmembrane conductance regulator (CFTR) modulator shown to be efficacious and generally safe and well tolerated over 8-24 weeks in phase 3 clinical studies in participants aged 12 years or older with cystic fibrosis homozygous for the Phe508del CFTR mutation (F/F; study 661-106 [EVOLVE]) or heterozygous for the Phe508del CFTR mutation and a residual function mutation (F/RF; study 661-108 [EXPAND]). Longer-term (>24 weeks) safety and efficacy of tezacaftor-ivacaftor has not been assessed in clinical studies. Here, we present results of study 661-110 (EXTEND), a 96-week open-label extension study that assessed long-term safety, tolerability, and efficacy of tezacaftor-ivacaftor in participants aged 12 years or older with cystic fibrosis who were homozygous or heterozygous for the Phe508del CFTR mutation., Methods: Study 661-110 was a 96-week, phase 3, multicentre, open-label study at 170 clinical research sites in Australia, Europe, Israel, and North America. Participants were aged 12 years or older, had cystic fibrosis, were homozygous or heterozygous for Phe508del CFTR, and completed one of six parent studies of tezacaftor-ivacaftor: studies 661-103, 661-106, 661-107, 661-108, 661-109, and 661-111. Participants received oral tezacaftor 100 mg once daily and oral ivacaftor 150 mg once every 12 h for up to 96 weeks. The primary endpoint was safety and tolerability. Secondary endpoints were changes in lung function, nutritional parameters, and respiratory symptom scores; pulmonary exacerbations; and pharmacokinetic parameters. A post-hoc analysis assessed the rate of lung function decline in F/F participants who received up to 120 weeks of tezacaftor-ivacaftor in studies 661-106 (F/F) and/or 661-110 compared with a matched cohort of CFTR modulator-untreated historical F/F controls from the Cystic Fibrosis Foundation Patient Registry. Primary safety analyses were done in all participants from all six parent studies who received at least one dose of study drug during this study. This study was registered at ClinicalTrials.gov (NCT02565914)., Findings: Between Aug 31, 2015, to May 31, 2019, 1044 participants were enrolled in study 661-110 from the six parent studies of whom 1042 participants received at least one dose of study drug and were included in the safety set. 995 (95%) participants had at least one TEAE; 22 (2%) had TEAEs leading to discontinuation; and 351 (34%) had serious TEAEs. No deaths occurred during the treatment-emergent period; after the treatment-emergent period, two deaths occurred, which were both deemed unrelated to study drug. F/F (106/110; n=459) and F/RF (108/110; n=226) participants beginning tezacaftor-ivacaftor in study 661-110 had improvements in efficacy endpoints consistent with parent studies; improvements in lung function and nutritional parameters and reductions in pulmonary exacerbations observed in the tezacaftor-ivacaftor groups in the parent studies were generally maintained in study 661-110 for an additional 96 weeks. Pharmacokinetic parameters were also similar to those in the parent studies. The annualised rate of lung function decline was 61·5% (95% CI 35·8 to 86·1) lower in tezacaftor-ivacaftor-treated F/F participants versus untreated matched historical controls., Interpretation: Tezacaftor-ivacaftor was generally safe, well tolerated, and efficacious for up to 120 weeks, and the safety profile of tezacaftor-ivacaftor in study 661-110 was consistent with cystic fibrosis manifestations and with the safety profiles of the parent studies. The rate of lung function decline was significantly reduced in F/F participants, consistent with cystic fibrosis disease modification. Our results support the clinical benefit of long-term tezacaftor-ivacaftor treatment for people aged 12 years or older with cystic fibrosis with F/F or F/RF genotypes., Funding: Vertex Pharmaceuticals Incorporated., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: In patients with normal renal function or early stage CKD, the risk-benefit profile of direct oral anticoagulants (DOACs) is superior to that of vitamin K antagonists (VKAs). In patients on hemodialysis, the comparative efficacy and safety of DOACs versus VKAs are unknown., Methods: In the Valkyrie study, 132 patients on hemodialysis with atrial fibrillation were randomized to a VKA with a target INR of 2-3, 10 mg rivaroxaban daily, or rivaroxaban and vitamin K2 for 18 months. Patients continued the originally assigned treatment and follow-up was extended for at least an additional 18 months. The primary efficacy end point was a composite of fatal and nonfatal cardiovascular events. Secondary efficacy end points were individual components of the composite outcome and all-cause death. Safety end points were life-threatening, major, and minor bleeding., Results: Median (IQR) follow-up was 1.88 (1.01-3.38) years. Premature, permanent discontinuation of anticoagulation occurred in 25% of patients. The primary end point occurred at a rate of 63.8 per 100 person-years in the VKA group, 26.2 per 100 person-years in the rivaroxaban group, and 21.4 per 100 person-years in the rivaroxaban and vitamin K2 group. The estimated competing risk-adjusted hazard ratio for the primary end point was 0.41 (95% CI, 0.25 to 0.68; P =0.0006) in the rivaroxaban group and 0.34 (95% CI, 0.19 to 0.61; P =0.0003) in the rivaroxaban and vitamin K2 group, compared with the VKA group. Death from any cause, cardiac death, and risk of stroke were not different between the treatment arms, but symptomatic limb ischemia occurred significantly less frequently with rivaroxaban than with VKA. After adjustment for competing risk of death, the hazard ratio for life-threatening and major bleeding compared with the VKA group was 0.39 (95% CI, 0.17 to 0.90; P =0.03) in the rivaroxaban group, 0.48 (95% CI, 0.22 to 1.08; P =0.08) in the rivaroxaban and vitamin K2 group and 0.44 (95% CI, 0.23 to 0.85; P =0.02) in the pooled rivaroxaban groups., Conclusions: In patients on hemodialysis with atrial fibrillation, a reduced dose of rivaroxaban significantly decreased the composite outcome of fatal and nonfatal cardiovascular events and major bleeding complications compared with VKA., Clinical Trial Registry Name and Registration Number: Oral Anticoagulation in Hemodialysis, NCT03799822., (Copyright © 2021 by the American Society of Nephrology.)

Cystic Fibrosis (CF) is a life-long genetic disease, causing increased energy needs and a healthy diet with a specific nutrient distribution. Nutritional status is an indicator of disease prognosis and survival. This study aimed at assessing the effectiveness of a self-management mobile app in supporting patients with CF to achieve the dietary goals set by the CF nutrition guidelines. A clinical trial was conducted in pancreatic insufficient children with CF, followed in six European CF centres, where the self-management app developed within the MyCyFAPP project was used for six months. To assess secondary outcomes, three-day food records were compiled in the app at baseline and after 3 and 6 months of use. Eighty-four subjects (mean 7.8 years old) were enrolled. Compared to baseline, macronutrient distribution better approximated the guidelines, with protein and lipid increasing by 1.0 and 2.1% of the total energy intake, respectively, by the end of the study. Consequently, carbohydrate intake of the total energy intake decreased significantly (-2.9%), along with simple carbohydrate intake (-2.4%). Regarding food groups, a decrease in ultra-processed foods was documented, with a concomitant increase in meat and dairy. The use of a self-management mobile app to self-monitor dietary intake could become a useful tool to achieve adherence to guideline recommendations, if validated during a longer period of time or against a control group.

In previous work, participants with a G970R mutation in cystic fibrosis transmembrane conductance regulator (CFTR) (c.2908G>C) had numerically lower sweat chloride responses during ivacaftor treatment than participants with other CFTR gating mutations. The objective of this substudy was to characterize the molecular defect of the G970R mutation in vitro and assess the benefit of ivacaftor in participants with this mutation. This substudy assessed sweat chloride, spirometry findings, and nasal potential difference on and off ivacaftor treatment in three participants with a G970R/F508del genotype. Intestinal organoids derived from rectal biopsy specimens were used to assess ivacaftor response ex vivo and conduct messenger RNA splice and protein analyses. No consistent or meaningful trends were observed between on-treatment and off-treatment clinical assessments. Organoids did not respond to ivacaftor in forskolin-induced swelling assays; no mature CFTR protein was detected in Western blots. Organoid RNA analysis demonstrated that 3 novel splice variants were created by G970R-CFTR: exon 17 truncation, exons 13-15 and 17 skipping, and intron 17 retention. Functional and molecular analyses indicated that the c.2908G>C mutation caused a cryptic splicing defect. Organoids lacked an ex vivo response with ivacaftor and supported identification of the mechanism underlying the CFTR defect caused by c.2908G>C. Analysis of CFTR mutations indicated that cryptic splicing was a rare cause of mutation misclassification in engineered cell lines. This substudy used organoids as an alternative in vitro model for mutations, such as cryptic splice mutations that cannot be fully assessed using cDNA expressed in recombinant cell systems., (© 2020 The Authors. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Rationale: Given the vast number of cystic fibrosis transmembrane conductance regulator ( CFTR ) mutations, biomarkers predicting benefit from CFTR modulator therapies are needed for subjects with cystic fibrosis (CF)., Objectives: To study CFTR function in organoids of subjects with common and rare CFTR mutations and evaluate correlations between CFTR function and clinical data., Methods: Intestinal organoids were grown from rectal biopsies in a cohort of 97 subjects with CF. Residual CFTR function was measured by quantifying organoid swelling induced by forskolin and response to modulators by quantifying organoid swelling induced by CFTR correctors, potentiator and their combination. Organoid data were correlated with clinical data from the literature., Results: Across 28 genotypes, residual CFTR function correlated (r 2 =0.87) with sweat chloride values. When studying the same genotypes, CFTR function rescue by CFTR modulators in organoids correlated tightly with mean improvement in lung function (r 2 =0.90) and sweat chloride (r 2 =0.95) reported in clinical trials. We identified candidate genotypes for modulator therapy, such as E92K, Q237E, R334W and L159S. Based on organoid results, two subjects started modulator treatment: one homozygous for complex allele Q359K&#95;T360K, and the second with mutation E60K. Both subjects had major clinical benefit., Conclusions: Measurements of residual CFTR function and rescue of function by CFTR modulators in intestinal organoids correlate closely with clinical data. Our results for reference genotypes concur with previous results. CFTR function measured in organoids can be used to guide precision medicine in patients with CF, positioning organoids as a potential in vitro model to bring treatment to patients carrying rare CFTR mutations., Competing Interests: Conflict of interest: A.S. Ramalho has nothing to disclose. Conflict of interest: E. Fürstová has nothing to disclose. Conflict of interest: A.M. Vonk has nothing to disclose. Conflict of interest: M. Ferrante reports grants and personal fees from Amgen, grants, personal fees and non-financial support from Biogen, Janssen, Pfizer and Takeda, personal fees and non-financial support from Boehringer Ingelheim, MSD, Falk and Ferring, personal fees from Sandoz, Lamepro, and Mylan, outside the submitted work. Conflict of interest: C. Verfaillie has nothing to disclose. Conflict of interest: L. Dupont has nothing to disclose. Conflict of interest: M. Boon is a member of the European Reference Network for Rare Respiratory Diseases (ERN-LUNG) – Project ID number 739546. Conflict of interest: M. Proesmans has nothing to disclose. Conflict of interest: J.M. Beekman reports personal fees from various industries (Vertex, Proteostasis, Teva, others) for costs related to conference presentations, outside the submitted work; and has a patent WO2013093812A3 with royalties paid by Hubrecht Organoid Technology. Conflict of interest: I. Sarouk has nothing to disclose. Conflict of interest: C. Vazquez Cordero has nothing to disclose. Conflict of interest: F. Vermeulen has nothing to disclose. Conflict of interest: K. De Boeck has provided consultancy for Boehringer, Protalix, Raptor, Novabiotics, Eloxx and Chiesi, has been member of steering committees/advisory boards and been PI in studies for Vertex, has provided consultancy and been PI in studies for Galapagos, and has received speaker fees from Teva, outside the submitted work., (Copyright ©ERS 2021.)

Background: Despite treatment with pancreatic enzyme replacement therapy (PERT), patients with cystic fibrosis (CF) can still suffer from fat malabsorption. A cause could be low intestinal pH disabling PERT. The aim of this study was to assess the association between faecal pH (as intestinal pH surrogate) and coefficient of fat absorption (CFA). Additionally, faecal free fatty acids (FFAs) were quantified to determine the amount of digested, but unabsorbed fat., Methods: In a 24-h pilot study, CF patients followed a standardised diet with fixed PERT doses, corresponding to theoretical optimal doses determined by an in vitro digestion model. Study variables were faecal pH, fat and FFA excretion, CFA and transit time. Linear mixed regression models were applied to explore associations., Results: In 43 patients, median (1st, 3rd quartile) faecal pH and CFA were 6.1% (5.8, 6.4) and 90% (84, 94), and they were positively associated (p < 0.001). An inverse relationship was found between faecal pH and total fat excretion (p < 0.01), as well as total FFA (p = 0.048). Higher faecal pH was associated with longer intestinal transit time (p = 0.049) and the use of proton pump inhibitors (p = 0.009)., Conclusions: Although the clinical significance of faecal pH is not fully defined, its usefulness as a surrogate biomarker for intestinal pH should be further explored., Impact: Faecal pH is a physiological parameter that may be related to intestinal pH and may provide important physiopathological information on CF-related pancreatic insufficiency. Faecal pH is correlated with fat absorption, and this may explain why pancreatic enzyme replacement therapy is not effective in all patients with malabsorption related to CF. Use of proton pump inhibitors is associated to higher values of faecal pH. Faecal pH could be used as a surrogate biomarker to routinely monitor the efficacy of pancreatic enzyme replacement therapy in clinical practice. Strategies to increase intestinal pH in children with cystic fibrosis should be targeted.

Synonymous single nucleotide polymorphisms (sSNPs), which change a nucleotide, but not the encoded amino acid, are perceived as neutral to protein function and thus, classified as benign. We report a patient who was diagnosed with cystic fibrosis (CF) at an advanced age and presented very mild CF symptoms. The sequencing of the whole cystic fibrosis transmembrane conductance regulator ( CFTR ) gene locus revealed that the patient lacks known CF-causing mutations. We found a homozygous sSNP (c.1584G>A) at the end of exon 11 in the CFTR gene. Using sensitive molecular methods, we report that the c.1584G>A sSNP causes cognate exon skipping and retention of a sequence from the downstream intron, both of which, however, occur at a relatively low frequency. In addition, we found two other sSNPs (c.2562T>G (p.Thr854=) and c.4389G>A (p.Gln1463=)), for which the patient is also homozygous. These two sSNPs stabilize the CFTR protein expression, compensating, at least in part, for the c.1584G>A-triggered inefficient splicing. Our data highlight the importance of considering sSNPs when assessing the effect(s) of complex CFTR alleles. sSNPs may epistatically modulate mRNA and protein expression levels and consequently influence disease phenotype and progression.

Introduction: Mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR) affect the quantity and/or function of CFTR protein reaching the cell surface. Ivacaftor, a CFTR potentiator that enhances chloride transport, increases the channel-open probability of normal and dysfunctional CFTR. Initially approved for people with CF (pwCF) with G551D-CFTR gating mutations, ivacaftor demonstrated clinical benefit in pwCF with other gating mutations and certain residual function mutations, including R117H-CFTR, in clinical studies. We evaluated the long-term safety and efficacy of ivacaftor in pwCF aged 6 years and older with non-G551D-CFTR ivacaftor-responsive mutations., Methods: Efficacy and safety data from a phase 3, multicenter, open-label, extension study for participants from Study 110 (R117H-CFTR mutations), Study 111 (non-G551D-CFTR gating mutations), and Study 113 (n-of-1 pilot study in participants with residual CFTR function) were analyzed. Following washout from the randomized parent study, participants received oral ivacaftor 150 mg once every 12 h for 104 weeks., Results: Forty-one of 121 participants completed treatment through 104 weeks; 59 participants who did not complete the extension study continued treatment with commercial ivacaftor. The most common adverse events were pulmonary exacerbation (46.3%) and cough (33.9%). Most treatment-emergent adverse events were mild/moderate in severity and consistent with manifestations of CF or the ivacaftor safety profile. Rapid, durable improvement occurred across all efficacy endpoints., Conclusions: Ivacaftor was generally safe and well tolerated with no new safety concerns for up to 104 weeks in pwCF with ivacaftor-responsive mutations. The pattern of improvement across efficacy endpoints was durable and generally consistent with parent-study outcomes., Trial Registration: NCT01707290.

CFTR modulators associated with substantial clinical benefit are expected to rapidly improve the baseline condition of people with cystic fibrosis (PWCF) as well as decrease the rate of lung function decline, the occurrence of pulmonary exacerbations and likely even other disease complications. These changes in clinical status of PWCF introduced by clinically effective modulator therapy will have major repercussions on modalities of future CF drug development. As part of its 'Strategic Plan to speed up Access to new Drugs', the European Cystic Fibrosis Society (ECFS) convened a meeting in Brussels on November 27 th 2019 with relevant stakeholders (CF researchers and clinicians, patient organization and pharmaceutical company representatives, regulators, health technology assessors; see Acknowledgments for list of attendees) to discuss the future of clinical trials in cystic fibrosis (CF) in the context of HEMT entering the clinical arena. The following is the conclusion of the presentations and discussions. It is hoped that these concepts will be considered in future regulatory guidelines and may provide rationale and support for alternative trial designs., (Copyright © 2020. Published by Elsevier B.V.)

As CFTR modulator therapy transforms the landscape of cystic fibrosis (CF) care, its lack of uniform access across the globe combined with the shift towards a new standard of care creates unique challenges for the development of future CF therapies. The advancement of a full and promising CF therapeutics pipeline remains a necessary priority to ensure maximal clinical benefits for all people with CF. It is through collaboration across the global CF community that we can optimize the evaluation and approval process of new therapies. To this end, we must identify areas for which harmonization is lacking and for which efficiencies can be gained to promote ethical, feasible, and credible study designs amidst the changing CF care landscape. This article summarizes the counsel from core advisors across multiple international regions and clinical trial networks, developed during a one-day workshop in October 2019. The goal of the workshop was to identify, in consideration of the highly transitional era of CFTR modulator availability, the drug development areas for which global alignment is currently uncertain, and paths forward that will enable advancement of CF therapeutic development., Competing Interests: Declaration of Competing Interest NMH serves as a consultant through her institution in her role as Executive Director of the CF Therapeutics Development Network Coordinating Center (CF TDNCC) and has received personal consulting fees from Kala Pharmaceuticals and Calithera. She has received grant funding from the Cystic Fibrosis Foundation (CFF) and National Institutes of Health (NIH). SvKR has received personal consulting fees from Antabio, Proteostasis Therapeutics (PTI), and Vertex Pharmaceuticals (VRTX). She has received grant support to her institution for her participation in the European Union HORIZON 2020 work. DPN serves as a consultant through his institution in his role as Medical Director of CF TDNCC. He has received grant support to his Institution from the CFF and Gilead Sciences. DRV has received personal consulting fees from AbbVie, Albumedix, AN2, Aradigm, Armata, Arrevus, Calithera, Chiesi USA, Cipla, Corbus, CFF, Eloxx, Enbiotix, Eveo, Galephar, Horizon, IBF, ICON clinical sciences, Ionis, Kala, Merck, Microbion, NDA, Protalix, PTC, Pulmocide, Recida, Savara, Vast, and VRTX. JCD has received other support from Aligipharma AS, Bayer AG, BI, Galapagos NV, ImevaX GmbH, Nivalis Therapeutics, ProQR Therapeutics, PTI, Raptor Pharamceuticals, VRTX, Enterprise, Novartis, Pulmocide, Flately and Teva for advisory board and educational activities. She has received grant support from the CF Trust. TL has received personal fees from Alan Boyd Consultants, Ltd for his participation in DSMB activities. FAR has received personal consulting fees from Novartis, Bayer, Roche, and Genentech for participation in CF related consulting activities. He has received grant support to his institution from VRTX for his participation as site PI in multicenter trials which they have funded as well as personal consulting fees. MWK has received personal consulting fees for advisory board participation, grant support to his institution for clinical trial participation, and non-financial support from VRTX, Savara, Laurent, Corbus Pharmaceuticals, PTC, and AzurRx. He has received personal consulting fees and non-financial support from Chiesi, Celtaxsys, Merck, and Kala. Personal consulting fees were received from Albumedix, Paranta, Protalix, Santhera, pH Pharma, Novartis, Ionis, the Italian Cystic Fibrosis Foundation, and the Food and Drug Administration. Grant support was provided to his Institution by NIH. Grant support was provided to his Institution by Anthera as well as personal consulting fees. SCB has received support from VRTX, Galapagos, and AbbVie for his participation in advisory boards and as site PI in multicenter trials which they have funded. JLTC has received personal consulting fees from Gilead Sciences, Protalix, and Santhera for participation in advisory board activities. She has received grant support to her institution from PTI, Celtaxsys, and VRTX as well as personal consulting fees for advisory activities. Grant support to her institution for her participation as site PI in a multicenter trial which they have funded from Eloxx. KDB has received consulting fees from Boehringer-Ingelheim (BI), Protalix Biotherapeutics, Raptor Pharmaceuticals, Novabiotics, Eloxx Pharmaceutics, Galapagos, and Chiesi. She has received speaker fees from Teva Pharmaceutical Industries and serves on the Steering Committee and Advisory Board for VRTX. DGD has received consulting fees from VRTX and consulting fees as well as grant support from PTI and Chiesi. PAF has received personal consulting fees from the Food and Drug Administration, Polyphor, and Santhera. He has received personal consulting fees and grant support from CFF, PTI, Savara, and VRTX. He has received grant support from NIH, Novartis, Novoteris, and Sound Pharmaceuticals. PD has received personal consulting fees from VRTX, PTI, and Actelion Pharmaceuticals. He has also received support for his participation as site PI in multicenter trials funded by Corbus Pharmaceuticals and VRTX. CHG has received grant funding from CFF, NIH, the European Commission and the Food and Drug Administration. He has also received honoraria from Gilead Sciences for grant reviews, honoraria from VRTX and Mylan for invited talks, and BI for participation as a PI in a multicenter trial in CF that they have funded. IF has received consulting fees and support from PTI, VRTX and BI for her participation in advisory boards as well as site PI in multicenter trials which they have funded. She has received support from Corbus Pharmaceuticals for participation as site PI in multicenter trials which they have funded ASM has received grant support to her Institution from CFF. BSQ has received grant support to his institution from the Cystic Fibrosis Canada, CFF, Michael Smith Foundation for Health Research, BC Lung Association, and Gilead Sciences. GZRB's institution has received support from the CFF, NIH and VRTX. for his participation as site PI in multicenter trials which they have funded. AGD, KP, JPC, SHD, SMS, and JMVD have nothing to disclose., (Copyright © 2020. Published by Elsevier B.V.)

Background: Most patients with cystic fibrosis (CF) suffer from pancreatic insufficiency (PI), leading to fat malabsorption, malnutrition, abdominal discomfort and impaired growth. Pancreatic enzyme replacement therapy (PERT) is effective, but evidence based guidelines for dose adjustment are lacking. A mobile app for self-management of PERT was developed in the context of the HORIZON 2020 project MyCyFAPP. It contains an algorithm to calculate individual PERT-doses for optimal fat digestion, based on in vitro and in vivo studies carried out in the same project. In addition, the app includes a symptoms diary, educational material, and it is linked to a web tool allowing health care professionals to evaluate patient's data and provide feedback., Methods: A 6-month open label prospective multicenter interventional clinical trial was performed to assess effects of using the app on gastro-intestinal related quality of life (GI QOL), measured by the CF-PedsQL-GI (shortened, CF specific version of the Pediatric Quality of Life Inventory, Gastrointestinal Symptoms Module)., Results: One hundred and seventy-one patients with CF and PI between 2 and 18 years were recruited at 6 European CF centers. Self-reported CF-PedsQL-GI improved significantly from month 0 (M0) (84.3, 76.4-90.3) to month 6 (M6) (89.4, 80.35-93.5) (p< 0.0001). Similar improvements were reported by parents. Lower baseline CF-PedsQL-GI was associated with a greater improvement at M6 (p < 0.001)., Conclusions: The results suggest that the MyCyFAPP may improve GI QOL for children with CF. This tool may help patients to improve self-management of PERT, especially those with considerable GI symptoms., Competing Interests: Declaration of competing interest All authors report grants from the European Commission Horizon 2020 during the conduct of the study. Dr. Mainz reports grants and personal fees from Vertex Corp.,  during the conduct of the study; Dr. Janssens reports grants from Vectura, personal fees from Vertex, outside the submitted work; Dr. Boon reports grants from University Hospital Leuven, outside the submitted work; Dr. De Boeck reports other financial support from Boehringer, Protalix, Raptor, Teva, Novabiotics, Eloxx, Vertex, Galapagos, Chiesi, outside the submitted work. Several authors of this publication are member of the European Reference Network for Rare Respiratory Diseases (ERN-LUNG) - Project ID No 739546., (Copyright © 2020 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background: 5T polymorphism is a CFTR mutation with unclear clinical consequences: the phenotype varies from healthy individuals to Cystic Fibrosis (CF). The aim of this study was to evaluate if nasal potential difference (NPD) and sweat testing correlate with symptoms and CF diagnosis in 5T patients., Methods: 86 patients with 5T who had undergone NPD measurement, were included (6 homozygous (5T/5T), 41 with a PI-CF causing mutation in trans (5T/PI-CF), 11 with a PS-CF causing mutation in trans (5T/PS-CF) and 28 without a known mutation in trans (5T/?). Data including age, phenotype, sweat chloride and follow up were collected., Results: 33% of the 5T/5T patients had abnormal NPD results, compared to 70% in 5T/PI-CF; 33% in 5T/PS-CF and 29% in 5T/?. The percentage of high or borderline sweat chloride was highest in 5T/PI-CF, and 5T/?, compared to 5T/5T and 5T/PS-CF (91, 96, 80, and 63%, respectively). TGm (number of TG repeats in intron 8) analysis was performed in 21 5T/PI-CF patients. TG11 was associated with lower sweat chloride, lower percentage of abnormal NPD and less progression of symptoms compared to TG12 and TG13., Conclusion: There is much variation in clinical status among 5T patients. All patients in this study with 5T/PS CF, all patients with both normal NPD and sweat test, and most patients with TG11 were stable or improving over time. Therefore, NPD measurement and TGm status aid to assess if a patient is at high risk for developing CF or CFTR-related disease and if specific follow up in a CF center is required., (Copyright © 2019 European Cystic Fibrosis Society. All rights reserved.)

Background: Ataluren was developed for potential treatment of nonsense-mutation cystic fibrosis (CF). A previous phase 3 ataluren study failed to meet its primary efficacy endpoint, but post-hoc analyses suggested that aminoglycosides may have interfered with ataluren's action. Thus, this subsequent trial (NCT02139306) was designed to assess the efficacy and safety of ataluren in patients with nonsense-mutation CF not receiving aminoglycosides., Methods: Eligible subjects with nonsense-mutation CF (aged ≥6 years; percent predicted (pp) FEV 1 ≥40 and ≤90) from 75 sites in 16 countries were randomly assigned in double-blinded fashion to receive oral ataluren or matching placebo thrice daily for 48 weeks. The primary endpoint was absolute change in average ppFEV 1 from baseline to the average of Weeks 40 and 48., Findings: 279 subjects were enrolled; 138 subjects in the ataluren arm and 136 in the placebo arm were evaluable for efficacy. Absolute ppFEV 1 change from baseline did not differ significantly between the ataluren and placebo groups at Week 40 (-0.8 vs -1.8) or Week 48 (-1.7 vs -2.4). Average ppFEV 1 treatment difference from baseline to Weeks 40 and 48 was 0.6 (95% CI -1.3, 2.5; p = 0.54). Pulmonary exacerbation rate per 48 weeks was not significantly different (ataluren 0.95 vs placebo 1.13; rate ratio p = 0.40). Safety was similar between groups. No life-threatening adverse events or deaths were reported., Interpretation: Neither ppFEV 1 change nor pulmonary exacerbation rate over 48 weeks were statistically different between ataluren and placebo groups. Development of a nonsense-mutation CF therapy remains elusive., Competing Interests: Declaration of Competing Interest JM is an employee of PTC Therapeutics, the funder of this clinical trial, and holds financial interests in the company. MWK, SMR, and DRV received compensation for consultant services from PTC Therapeutics prior to and/or during this study. EK, MW, IS-G, and KDB received compensation for travel expenses for meetings related to the study. All other authors declare no competing interests., (Copyright © 2020. Published by Elsevier B.V.)

This protocol describes the isolation, handling, culture of, and experiments with human colon stem cell organoids in the context of cystic fibrosis (CF). In human colon organoids, the function of cystic fibrosis transmembrane conductance regulator (CFTR) protein and its rescue by CFTR modulators can be quantified using the forskolin-induced swelling assay. Implementation procedures and validation experiments are described for six CF human colon organoid lines, and representative CFTR genotypes are tested for basal CFTR function and response to CFTR-modulating drugs. For complete details on the use and execution of this protocol, please refer to Dekkers et al (2016) and Berkers and van Mourik (2019)., Competing Interests: J.F.D. is an inventor on a patent related to the organoid technology. M.A.A. reports grants from Gilead Pharmaceuticals, Vertex Pharmceuticals, Proteostasis Therapeutics and personal fees from Vertex Pharmceuticals and PTC Pharmaceuticals outside the submitted work. K.B. reports consultancy work for CHIESI, grants from VERTEX, advisory board meetings for PROTEOSTASIS and ELOXX, grants from and advisory board meetings for GALAPAGOS, and advisory board meetings for TRANSLATE BIO outside the submitted work. R.V. is CEO of Hubrecht Organoid Technology, which provides organoid services to companies. C.K.E. reports grants from GSK, Nutricia, TEVA, Gilead, Vertex, ProQR, Proteostasis, Galapagos NV, and Eloxx outside the submitted work and has a patent 10006904 with royalties paid. J.M.B. is inventor on a patent related to CFTR function measurements in organoids and has received financial royalties. He also participates in industry-sponsored clinical trials (Galapagos NV, Vertex Pharmaceuticals, Proteostasis, Eloxx Pharmaceuticals) and has received travel reimbursements and speaker’s fees. The other authors have nothing to disclose., (© 2020 The Authors.)

The autosomal recessive disease cystic fibrosis (CF) was once untreatable and deadly in childhood, but now most patients survive to adulthood. Many countries have instituted CF newborn screening because early diagnosis improves outcome. CF research has greatly intensified following the discovery of the CF transmembrane conductance regulator (CFTR) gene, which has more than 2000 different mutations. For patients with common mutations like F508del, CFTR modulators are life transforming and may even prevent major complications if started early in childhood. For some patients with rare CFTR mutations, a treatment path still needs to be developed. Conclusion: This review provides a general update on CF, including screening and current and future treatment., (© 2020 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Background: Increased abundance of Enterobacteriaceae(EB) in the respiratory microbiome of young CF patients was reported to precede Pseudomonas aeruginosa(PA) colonisation. We explored whether impending PA colonisation can be predicted by growth of EB in routine airway cultures and whether EB contribute to CF lung disease severity., Methods: We retrospectively studied the records of 62 children with CF for growth of EB and PA during the first 5 years of life and subsequent best lung function at ages 5-7 and 9-11 years., Results: At least one EB positive month occurred in 36/62 (58%) patients. Median (IQR) age at first EB isolation was 0.4 (0.2-0.8) years. PA isolation before age 5 was more frequent in the EB positive (23/36, 54%) than in EB negative children (10/26, 38%; p = 0.048). EB isolation preceded PA isolation in 19/23 (83%) cases (p = 0.003). Median (IQRf) FEV 1 at age 5 to 7 years was 105% (94-117) in the EB positive group and 108% (102-115) in the EB negative group (p = 0.154). At age 9-11, FEV 1 was lower in EB positive children (99%(88-105) vs 105%(96-110); p = 0.035). Only PA isolation (p = 0.002) before age 5 years was a significant predictor of FEV 1 at age 5-7 years. Both EB isolation (p = 0.033) and PA isolation (p = 0.023) were predictors of the FEV 1 at age 9-11 years., Conclusion: In preschool children with CF, EB were isolated in just over half of the children. In that subgroup PA isolation was more common. Both EB and PA isolation are associated with worse lung function at later age., Competing Interests: Declaration of Competing Interest Prof. F. Vermeulen, Prof. M. Proesmans, Dr. M. Vermaelen have nothing to disclose. Prof. K. De Boeck reports other from Boehringer, Protalix, Raptor, Teva, Novabiotics, Elox, Vertex, Galapagos, outside the submitted work. Prof. M. Boon reports grants from MyCyFAPP, outside the submitted work., (Copyright © 2019. Published by Elsevier B.V.)

Background: Monitoring changes in the epidemiology of cystic fibrosis (CF) pathogens is essential for clinical research, quality improvement, and clinical management., Methods: We analyzed data reported to the European Cystic Fibrosis Society Patient Registry (ECFSPR) from 2011 to 2016 to determine the overall and the age-specific annual prevalence and incidence of selected CF pathogens and their trends during these years. The ECFSPR collects data on three chronic infections: Pseudomonas aeruginosa (PsA), Burkholderia cepacia complex Species (BCC) and Staphylococcus aureus (SA), as well as on the occurrence of non-tuberculous mycobacteria (NTM) and Stenotrophomonas maltophilia (SM). The same analyses were performed for different country groups, according to their gross national income (GNI)., Results: The pathogens with the highest prevalence were SA and PsA, with prevalence, in 2016, equal to 38.3% and 29.8% respectively, followed by SM (8.1%). The pathogens with the lowest prevalence were NTM (3.3%) and BCC (3.1%). The overall prevalence and incidence significantly decreased for PsA; they also decreased for BCC, while they increased significantly for SA. The overall prevalence of NTM and SM increased significantly. The most considerable prevalence changes were observed for PsA, which decreased across all income country groups and all age strata (with the exception of 0-1 years) The prevalence and incidence of pathogens differed significantly according to GNI., Conclusions: The epidemiology of CF pathogens in Europe has changed; epidemiologic data differ significantly among countries with different socio-economic status. The causes of these observations are multifactorial and include improvements in clinical care and infection control., Competing Interests: Declaration of Competing Interest None., (Copyright © 2019 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Background. The most common CFTR mutation, F508del, presents with multiple cellular defects. However, the possible multiple defects caused by many rarer CFTR mutations are not well studied. We investigated four rare CFTR mutations E60K, G85E, E92K and A455E against well-characterized mutations, F508del and G551D, and their responses to corrector VX-809 and/or potentiator VX-770. Methods. Using complementary assays in HEK293T stable cell lines, we determined maturation by Western blotting, trafficking by flow cytometry using extracellular 3HA-tagged CFTR, and function by halide-sensitive YFP quenching. In the forskolin-induced swelling assay in intestinal organoids, we validated the effect of tagged versus endogenous CFTR. Results. Treatment with VX-809 significantly restored maturation, PM localization and function of both E60K and E92K. Mechanistically, VX-809 not only raised the total amount of CFTR, but significantly increased the traffic efficiency, which was not the case for A455E. G85E was refractory to VX-809 and VX-770 treatment. Conclusions. Since no single model or assay allows deciphering all defects at once, we propose a combination of phenotypic assays to collect rapid and early insights into the multiple defects of CFTR variants.

Background: Vitamin K antagonists (VKAs), although commonly used to reduce thromboembolic risk in atrial fibrillation, have been incriminated as probable cause of accelerated vascular calcification (VC) in patients on hemodialysis. Functional vitamin K deficiency may further contribute to their susceptibility for VC. We investigated the effect of vitamin K status on VC progression in 132 patients on hemodialysis with atrial fibrillation treated with VKAs or qualifying for anticoagulation., Methods: Patients were randomized to VKAs with target INR 2-3, rivaroxaban 10 mg daily, or rivaroxaban 10 mg daily plus vitamin K2 2000 µ g thrice weekly during 18 months. Systemic dp-ucMGP levels were quantified to assess vascular vitamin K status. Cardiac and thoracic aorta calcium scores and pulse wave velocity were measured to evaluate VC progression., Results: Baseline dp-ucMGP was severely elevated in all groups. Initiation or continuation of VKAs further increased dp-ucMGP, whereas levels decreased in the rivaroxaban group and to a larger extent in the rivaroxaban+vitamin K2 group, but remained nevertheless elevated. Changes in coronary artery, thoracic aorta, and cardiac valve calcium scores and pulse wave velocity were not significantly different among the treatment arms. All cause death, stroke, and cardiovascular event rates were similar between the groups. Bleeding outcomes were not significantly different, except for a lower number of life-threatening and major bleeding episodes in the rivaroxaban arms versus the VKA arm., Conclusions: Withdrawal of VKAs and high-dose vitamin K2 improve vitamin K status in patients on hemodialysis, but have no significant favorable effect on VC progression. Severe bleeding complications may be lower with rivaroxaban than with VKAs., (Copyright © 2020 by the American Society of Nephrology.)

Background: Eluforsen is an antisense oligonucleotide designed to bind to the mRNA region around the F508-encoding deletion and restore the cystic fibrosis transmembrane conductance regulator (CFTR) protein function in the airway epithelium. We assessed the safety and tolerability, pharmacokinetics and exploratory measures of efficacy of inhaled eluforsen in cystic fibrosis (CF) patients homozygous for the F508del-CFTR mutation., Methods: This randomised, double-blind, placebo-controlled, dose escalation 1b study recruited adult CF subjects with a FEV 1  > 70% predicted in four single ascending dose cohorts and four multiple ascending dose cohorts. Primary objectives were safety and tolerability. Secondary endpoints included pharmacokinetics, percent predicted forced expiratory volume in 1 s (ppFEV 1 ), and Cystic Fibrosis Questionnaire-Revised (CFQ-R) Respiratory Symptom Score (RSS)., Results: Single and multiple doses of inhaled eluforsen up to 50 mg were safe and well tolerated. A maximum tolerated dose was not established. Systemic exposure was low in all cohorts and lung function remained stable throughout the study. Three of four eluforsen-treated groups in the MAD study demonstrated an improvement in CFQ-R RSS at end of treatment with adjusted mean change from baseline values ranging from 6.4 to 12.7 points. In comparison, there was a mean decrease of 6.5 points in the placebo group from baseline to end of treatment., Conclusions: Inhaled eluforsen up to 50 mg dosed 3 times per week for 4 weeks was safe and well tolerated, showed low systemic exposure, and demonstrated improvement in CFQ-R RSS, a relevant measure of clinical benefit in CF patients., Competing Interests: Conflict of interest statement WdH, JP and NT are full-time employees of ProQR Therapeutics. NP-L and NH were full-time employees of ProQR Therapeutics during design development, execution and reporting of this study, and SM was full-time employee of ProQR Therapeutics during execution and reporting of this study. FB and MB are or were statistical consultants paid by ProQR Therapeutics. KDB report grants related to the submitted work. KDB and JSE report grants outside the submitted work. KDB and JSE report activity on advisory boards during the conduct of the study and outside the submitted work. PD, KDB and JSE received fees for consultancy. CS, MC and TP have no disclosures., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: The correlation between different methods for the detection of pneumococcal polysaccharide vaccine (PPV) responses to diagnose specific polysaccharide antibody deficiency (SAD) is poor and the criteria for defining a normal response lack consensus. We previously proposed fifth percentile (p5) values of PPV responses as a new cutoff for SAD., Objective: To analyze the association of SAD (determined by either World Health Organization (WHO)-standardized ELISA or multiplex bead-based assay) with abnormal response to Salmonella (S.) typhi Vi vaccination in a cohort of patients with recurrent infections., Methods: Ninety-four patients with a clinical history suggestive of antibody deficiency received PPV and S. typhi Vi vaccines. Polysaccharide responses to either 3 or 18 pneumococcal serotypes were measured by either the WHO ELISA or a multiplex in-house bead-based assay. Anti-S. typhi Vi IgG were measured by a commercial ELISA kit. Allohemagglutinins (AHA) were measured by agglutination method., Results: Based on the American Academy of Allergy, Asthma and Immunology (AAAAI) criteria for WHO ELISA, 18/94 patients were diagnosed with SAD and 22/93 based on serotype-specific p5 cutoffs for bead-based assay. The association between the two methods was significant, with 10 subjects showing abnormal response according to both techniques. Abnormal response to S. typhi Vi vaccination was found in 7 patients, 6 of which had SAD. No correlation was found between polysaccharide response and AHA, age, or clinical phenotype., Conclusion: The lack of evidence-based gold standards for the diagnosis of SAD represents a challenge in clinical practice. In our cohort, we confirmed the insufficient correlation between different methods of specific PPV response measurement, and showed that the S. typhi Vi response was not contributive. Caution in the interpretation of results is warranted until more reliable diagnostic methods can be validated.

Background: Most patients with cystic fibrosis (CF) suffer from pancreatic insufficiency, leading to fat malabsorption, malnutrition and abdominal discomfort. Until recently, no specific tool was available for assessing gastro-intestinal related quality of life (GI QOL) in patients with CF. As the Horizon2020 project MyCyFAPP aims to improve GI QOL by using a newly designed mobile application, a sensitive and reliable outcome measure was needed. We aimed to study the applicability of the existing child-specific Pediatric Quality of Life Inventory, Gastrointestinal Symptoms Scales and Module (PedsQL GI) in children with CF., Methods: A multicenter, prospective observational study was performed in 6 European centers to validate the PedsQL GI in children with CF during 3 months., Results: In total, 248 children and their parents were included. Within-patient variability of PedsQL GI was low (24.11), and there was reasonable agreement between children and parents (ICC 0.681). Nine of 14 subscales were informative (no ceiling effect). The PedsQL GI and the median scores for 4 subscales were significantly lower in patients compared to healthy controls. Positive associations were found between PedsQL GI and age (OR = 1.044, p = 0.004) and between PedsQL GI and BMI z-score (OR = 1.127, p = 0.036). PedsQL GI correlated with most CFQ-R subscales (r 0.268 to 0.623) and with a Visual Analogue Scale (r = 0.20)., Conclusions: PedsQL GI is a valid and applicable instrument to assess GI QOL in children with CF. Future research efforts should examine the responsiveness of the CF PedsQL GI to change in the context of clinical interventions and trials., Competing Interests: The authors have declared that no competing interests exist.

Bronchopulmonary dysplasia (BPD) is one of the most important sequelae of premature birth. There is concern that in some patients, lung injuries early in life may have lifelong consequences. In this retrospective observational cohort study, lung function evolution in children with BPD was investigated from childhood to young adulthood. Data from 355 pulmonary function tests (PFT) in 24 patients were analyzed, with a median age at first PFT of 7.6 years and at last PFT 18.2 years. FEV 1 and FEV 1 /FVC were below the 5th percentile in respectively 18 and 13/24 patients. Comparing first and last measurement, there was significant worsening in FEV 1 from a mean of 71.3% pred (SD 18.3) to 66.7% pred (SD 21.7) (p < 0.05) and in FEV 1 /FVC from 85.4% pred (SD 15.2) to 79.8% pred (SD 17.3) (p = 0.01). Evaluation of the individual lung function changes with linear regression showed deterioration in FEV 1 , FVC, and FEV 1 /FVC in respectively 17, 13, and 17/24 patients. Total group analysis showed significant deterioration in FEV 1 (- 0.7%/year, p = 0.002) and FEV 1 /FVC (- 0.5%/year, p = 0.01). None of the 11 patients born up to 1990 improved in FEV 1 vs 7 of the 13 patients born after 1990 (p = 0.006).Conclusion: This points out to further deterioration of the lung function during childhood in this selected group of children with BPD.What is Known:• Data on longitudinal changes in lung function in children with BPD are scarce.What is New:• In children with BPD at the severe end of the disease spectrum, lung function does not improve over time. On the contrary, in two-thirds of the subjects studied FEV 1 and FEV 1 /FVC worsen over time.• Lung function evolution towards adulthood was somewhat more favorable in children born after 1990 compared with those born earlier, probably reflecting improvements in neonatal care in subjects with new type BPD.

Detailed knowledge of how mutations in the cystic fibrosis transmembrane conductance regulator ( CFTR ) gene disturb the trafficking or function of the CFTR protein and the use of high-throughput drug screens have allowed novel therapeutic strategies for cystic fibrosis (CF). The main goal of treatment is slowly but surely shifting from symptomatic management to targeting the underlying CFTR defect to halt disease progression and even to prevent occurrence of CF complications. CFTR potentiators for patients with class III mutations, mutation R117H (and in United States also for patients with specific residual function mutations) and the combination of a CFTR modulator plus a potentiator for patients homozygous for F508del, are the two classes of modulators that are in use in the clinic. Approval of these therapeutics has progressively expanded to include both younger patients and a wider range of CFTR mutations. For a significant proportion of patients with CF, current treatment is however still insufficient or unavailable.This review provides an overview of the clinical trial results and the real-life efficacy data of approved CFTR modulators. In addition, we discuss the entire pipeline of CFTR modulators: novel potentiators and correctors, amplifiers, stabilizers, and read-through agents. Furthermore, we discuss other strategies to improve CFTR function like nonsense-mediated decay inhibitors, modified transfer ribonucleic acids, antisense oligonucleotides, and genetic therapies.CFTR modulators are already changing the face of CF and the pipeline of new therapies continues to be exciting., Competing Interests: None declared., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

The last decade has witnessed developments in the CF drug pipeline which are both exciting and unprecedented, bringing with them previously unconsidered challenges. The Task Force group came together to consider these challenges and possible strategies to address them. Over the last 18 months, we have discussed internally and gathered views from a broad range of individuals representing patient organizations, clinical and research teams, the pharmaceutical industry and regulatory agencies. In this and the accompanying article, we discuss two main areas of focus: i) optimising trial design and delivery for speed/efficiency; ii) drug development for patients with rare CFTR mutations. We propose some strategies to tackle the challenges ahead and highlight areas where further thought is needed. We see this as the start of a process rather than the end and hope herewith to engage the wider community in seeking solutions to improved treatments for all patients with CF., (Copyright © 2019. Published by Elsevier B.V.)