ECFS standards of care on CFTR-related disorders: Towards a comprehensive program for affected individuals.

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.

CFTR biomarkers: time for promotion to surrogate end-point.

In patients with cystic fibrosis, cystic fibrosis transmembrane conductance regulator (CFTR) biomarkers, such as sweat chloride concentration and/or nasal potential difference, are used as end-points of efficacy in phase-III clinical trials with the disease modifying drugs ivacaftor (VX-770), VX809 and ataluren. The aim of this project was to review the literature on reliability, validity and responsiveness of nasal potential difference, sweat chloride and intestinal current measurement in patients with cystic fibrosis. Data on clinimetric properties were collected for each biomarker and reviewed by an international team of experts. Data on reliability, validity and responsiveness were tabulated. In addition, narrative answers to four key questions were discussed and agreed by the team of experts. The data collected demonstrated the reliability, validity and responsiveness of nasal potential difference. Fewer data were found on reliability of sweat chloride concentration; however, validity and responsiveness were demonstrated. Validity was demonstrated for intestinal current measurement, but further information is required on reliability and responsiveness. For all three end-points, normal values were collected and further research requirements were proposed. This body of work adds useful information to support the promotion of CFTR biomarkers to surrogate end-points and to guide further research in the area.

Pseudomonas aeruginosa induces vascular endothelial growth factor synthesis in airway epithelium in vitro and in vivo.

Pseudomonas aeruginosa (PA) airway infection and bronchial blood vessel proliferation are features of bronchiectasis. Because vascular endothelial growth factor (VEGF)-A regulates angiogenesis, we hypothesised that PA infection induces VEGF synthesis in epithelium and peribronchial angiogenesis. Because epidermal growth factor receptor (EGFR) activation regulates VEGF synthesis in cancer, we also evaluated the roles of EGFR. Airway epithelial cells were incubated for 24 h with PA supernatants and VEGF concentrations were measured in culture medium by ELISA. C57BL/6N mice were instilled intratracheally with sterile agarose beads or with agarose beads coated with the PA strain PAO1 (mean ± sem 6 × 10(5) ± 3 × 10(5) cfu · animal(-1)), with or without the EGFR inhibitor AG1478 (12.5 mg · kg(-1) · day(-1) intraperitoneally). Epithelial immunostaining for VEGF and phosphorylated EGFR, and peribronchial vascularity, were quantified using morphometric analysis. VEGF expression was further assessed by western blot in mouse lung homogenates. PA supernatants induced dose-dependent VEGF synthesis in cultured airway epithelial cells, effects which were prevented by EGFR antagonists. In mice, persistent PAO1 infection increased immunostaining for VEGF and phosphorylated EGFR in airway epithelium, and resulted in increased peribronchial vascularity within 7 days. These effects were reduced by EGFR inhibition. Persistent PA infection induced VEGF synthesis in airway epithelium and peribronchial angiogenesis, at least in part via EGFR-dependent mechanisms.

Non-classic cystic fibrosis associated with D1152H CFTR mutation.

BACKGROUND: Limited knowledge exists on phenotypes associated with the D1152H cystic fibrosis transmembrane conductance regulator (CFTR) mutation. METHODS: Subjects with a D1152H allele in trans with another CFTR mutation were identified using the French Cystic Fibrosis Registry. Phenotypic characteristics were compared with those of pancreatic insufficient (PI) and pancreatic sufficient (PS) cystic fibrosis (CF) subjects in the Registry (CF cohort). RESULTS: Forty-two subjects with D1152H alleles were identified. Features leading to diagnosis included chronic sinopulmonary disease (n = 25), congenital absence of the vas deferens (n = 11), systematic neonatal screening (n = 4), and genetic counseling (n = 2). Median age at diagnosis was 33 [interquartile range (IQR, 24-41)] years in D1152H subjects. Median sweat chloride concentrations were 43.5 (39-63) mmol/l in D1152H subjects and were markedly lower than in PI and PS CF subjects (p < 0.05). Bronchiectasis was present in 67% of D1152H subjects, but Pseudomonas aeruginosa colonization and pancreatic insufficiency were present in <30% of subjects. Estimated rates of decline in forced expiratory volume in 1 s (FEV(1)) were lower in D1152H subjects vs PI CF subjects (p < 0.05). None of the D1152H subjects identified since 1999 had died or required lung transplantation. CONCLUSIONS: When present in trans with a CF-causing mutation, D1152H causes significant pulmonary disease, but all subjects had prolonged survival.

Genomically-guided therapies: A new era for cystic fibrosis.

Since the cloning of the CFTR gene 30 years ago, research aiming at understanding how CFTR mutations translate to abnormal synthesis or function of the CFTR protein has opened the way to genomically-guided therapy to improve CFTR function. A CFTR potentiator to enhance CFTR channel function has been approved in 2012 for specific and quite rare mutations. Subsequently, combinations of a corrector to increase CFTR expression at the cell membrane, plus a potentiator, have been approved for patients homozygous for the p.Phe508del mutation. To obtain robust correction of CFTR, new combinations of drugs are being studied. A triple combination associating two correctors and one potentiator is very promising and if data of clinical trials are confirmed, it could be a robust and well tolerated CFTR modulator for patients bearing at least one p.Phe508del mutation. Many other strategies are also in development to make these genomically-guided treatments available to all patients with CF. © 2020 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.

Cystic fibrosis drug trial design in the era of CFTR modulators associated with substantial clinical benefit: stakeholders' consensus view.

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 27th 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.

Building global development strategies for cf therapeutics during a transitional cftr modulator era.

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.

[The diagnosis of cystic fibrosis in adults: lessons from a family story]. / Le diagnostic de mucoviscidose chez l'adulte: les enseignements d'une histoire de famille!

INTRODUCTION: Cystic fibrosis is usually diagnosed during the first years of life. Diagnosis may be achieved in adults with milder forms of the disease at any age. CASE REPORTS: We report the diagnosis of cystic fibrosis in three adults within the same family. A 39 yr old man, was diagnosed with congenital absence of the vas deferens; the diagnosis of cystic fibrosis was achieved based on a positive chloride sweat test and the identification of two mutations in the CFTR gene. His mother experienced repeated bronchial infections that began when she was 12 years old. The diagnosis of cystic fibrosis was considered at the age of 74 yr after her son was diagnosed with this disease. Sweat test showed normal chloride concentrations and cystic fibrosis was suspected based on elevated basal transepithelial nasal potential difference. Genetic testing for the 33 most frequent mutations in the CFTR gene showed only one mutation. A second rare mutation was identified by complete sequencing of the CFTR gene, confirming the diagnosis of cystic fibrosis. A third case of pauci-symptomatic cystic fibrosis was diagnosed in a brother of the index case. CONCLUSION: These observations illustrate the challenge of diagnosing milder forms of cystic fibrosis in adult subjects. The recognition of this diagnosis may lead to improvement in patient's care and to genetic counselling.

[Cystic fibrosis: how to use pulmonary function tests]. / Mucoviscidose: du bon usage des explorations fonctionnelles respiratoires.

INTRODUCTION: Neonatal screening for cystic fibrosis (CF) leads to early dedicated specialist care for all patients. BACKGROUND: Pulmonary function tests (PFT) are mandatory for routine monitoring of CF patients. The aim of this article is to review the current guidelines for PFTs in CF, particularly the type of test, the age and the clinical status of the patient. VIEWPOINT: The regular use of spirometry is generally accepted. Many other tests are used but their clinical value in the routine follow-up of CF patients remains to be established. CONCLUSION: Further efforts should be made to evaluate the value of PFTs in CF, particularly in very young children.

Reduced exhaled NO is related to impaired nasal potential difference in patients with cystic fibrosis.

Nitric oxide (NO) plays a central role in many airway physiological functions, and its production appears to be related with progression of lung disease in patients with cystic fibrosis (CF). However, underlying mechanisms which specifically link NO and CF-related lung disease remain unclear. Following in vitro and animal studies suggesting a role for NO in ion transport in various epithelia, this work investigates the relationship between transepithelial baseline potential difference (BPD), an index of airway ion transport, and exhaled NO in the airways of adult patients with CF. Association with other phenotypic traits, lung function tests and CFTR genotype was also assessed. Using simple linear regression, F(E)NO and transepithelial BPD values were significantly inversely correlated (p<0.001, r=-0.53). Polynomial analysis evidenced an asymptotic relationship between F(E)NO and BPD values, yielding a plateau for absolute BPD values above 50 mV. This relation was not altered by adjustment for clinical and genetic characteristics of the patients. The relationship between exhaled NO and transepithelial BPD suggests that low NO concentrations likely worsens airway ion transport impairment resulting from CFTR defect. These results fit with experimental studies that suggest the inhibitory effect of NO on sodium absorption, which is the main determinant of airway basal transepithelial conductance.

Sugar-mediated uptake of glycosylated polylysines and gene transfer into normal and cystic fibrosis airway epithelial cells.

We have examined the membrane lectin expressed by immortalized normal and cystic fibrosis (CF) airway epithelial cells, using fluorescein-labeled neoglycoproteins; the uptake of plasmid DNA using fluoresceinylated glycoplexes (plasmid/glycosylated polylysine complexes); and the efficiency of gene transfer when glycosylated polylysines and glycosylated, partially gluconoylated polylysines were used as vectors. The most efficient uptake of neoglycoproteins by normal and CF cells was obtained with mannosylated BSA (bovine serum albumin). Similarly, the most efficient uptake of plasmid DNA was obtained with glycoplexes bearing alpha-D-Man residues. Surprisingly, glycoplexes bearing alpha-D-Man residues were poorly efficient for gene transfer into normal and CF cells. The highest luciferase activity was achieved with lactosylated polylysine- and beta-D-GlcNAc-substituted gluconoylated polylysine as vectors. Gene transfer efficiency obtained with gluconoylated polylysine bearing beta-D-GlcNAc residues was similar to that observed with polyethylenimine (PEI; 25 and 800 kDa) and 10-fold higher than that observed with lipofectin and LipofectAMINE. These results suggest that the transfection efficiency with glycoplexes is not determined only by the specificity of the lectin expressed at the cell surface membrane but also by intracellular trafficking of the glycoplexes, which could be mediated by lectins present inside the cells.

Pulmonary Hodgkin's disease in HIV-infected patient. Diagnosis by bronchoalveolar lavage.

We report herein the pulmonary recurrence of Hodgkin's disease coincidental with a marked decrease in the peripheral blood CD4 lymphocyte count in an HIV-seropositive patient with alveolar consolidation on chest roentgenogram. The diagnosis of lung parenchyma involvement was made by bronchoalveolar lavage cell analysis and illustrates the reliability of Reed-Sternberg cell identification in bronchoalveolar lavage for the diagnosis of pulmonary localization of Hodgkin's disease.

Recombinant Escherichia coli as a gene delivery vector into airway epithelial cells.

To transfer genes into airway epithelial cells, we have generated auxotrophic dap Escherichia coli BM2710 mutant that expresses the invasin of Yersinia pseudotuberculosis and the listeriolysin of Listeria monocytogenes. E. coli BM2710 harboring a plasmid carrying the gfp gene was incubated with immortalized normal or cystic fibrosis (CF) airway epithelial cells or with primary bronchial epithelial cells grown as an explant-outgrowth cell culture model. Approximately 2% of immortalized cells expressed GFP. Few primary cells were transfected that were always poorly differentiated and located at the edge of the outgrowth. This was consistent with the expression of beta1-integrins only on these cells and with the required interaction for cell entry of E. coli expressing the invasin with beta1-integrins. The subsequent intracellular trafficking of E. coli BM2710 studied by confocal and electronic microscopy showed that the E. coli-containing phagosomes rapidly matured into phagolysosomes. This is the first demonstration that recombinant bacteria are able to transfer genes into primary airway epithelial cells, provided that they are able to invade the cells.

Increased nitric oxide in exhaled air in patients with systemic sclerosis.

OBJECTIVE: To assess the lung production of nitric oxide (NO) in patients with systemic sclerosis. METHODS: The NO concentration and its rate of production by the lungs were measured in the exhaled air in 14 patients with systemic sclerosis and in 12 healthy control subjects using the chemiluminescent method. RESULTS: The NO concentration and its rate of production were significantly increased in scleroderma patients (mean +/- SEM, 18.7 +/- 1.7 ppb and 5.8 +/- 0.5 nmol/min, respectively), as compared with control subjects (11.2 +/- 0.8 ppb and 4.3 +/- 0.4 nmol/min, p < 0.01 and p < 0.05, respectively). CONCLUSION: The pulmonary production of NO is increased in scleroderma patients, which might reflect and contribute to the inflammatory processes of the lungs in systemic sclerosis.

[Neuropeptides of the nasal innervation and allergic rhinitis]. / Neuropeptides de l'innervation nasale et rhinite allergique.

In the last decade, several neuropeptides have been localized in sensory, sympathetic and parasympathetic neurons of the upper and lower airways in animals and man. Tachykinins are sensory neuropeptides: after nasal allergen challenge in patients with allergic rhinitis, substance P is locally released and induces nasal obstruction. Like neurokinin A, another tachykinin of sensory C fibers, substance P induces an increase in vascular permeability and a recruitment of inflammatory cells. Thus, tachykinins partially mimic nasal response to antigen. Calcitonin gene-related peptide (CGRP) is another sensory neuropeptide and vasoactive intestinal peptide (VIP) is a neuropeptide localized to parasympathetic fibers. The distributions of CGRP and VIP fibers and of their binding sites, as well as their physiological effects described in other tissues, are consistent with a vasodilator effect. On the other hand, neuropeptide Y (NPY), a sympathetic neuropeptide, would seem to be a potent vasoconstrictor. Thus, nasal neuropeptides, and above all sensory neuropeptides, could play a role in the pathophysiology of allergic rhinitis.

[Bronchial hyperreactivity: neurogenic factors]. / Hyperréactivité bronchique: facteurs neurogènes.

Over the last fifty years, the role of neurogenic factors in asthma and bronchial hyperreactivity has been intensively investigated. The roles of the cholinergic and adrenergic nervous systems have been clarified and several sub-types of muscarinic receptors identified. The localisation and functions of both muscarinic and adrenergic receptors have been further specified. It has also been shown that afferent nerve fibers as well as sympathetic and parasympathetic nerve fibers secrete various neuropeptides. The physiological role of these peptides is not yet known but it appears that they have a powerful effect on bronchial smooth muscle tone, microvascular permeability, mucus secretion and secretion of mediators by inflammatory cells. The results of numerous studies suggest that there are several abnormalities in the adrenergic and cholinergic nervous systems of asthmatic patients, but that these abnormalities are not themselves the cause of bronchial hyperreactivity. They may however contribute to enhance it. The role of the various newly identified neuropeptides in the genesis and maintenance of bronchial hyperreactivity remains to be determined.

[Diagnosis of cystic fibrosis in adults]. / Diagnostic de la mucoviscidose chez l'adulte.

Cystic fibrosis is a genetic recessive disorder caused by mutations in the gene that encodes the CFTR protein. The diagnosis of cystic fibrosis is usually established in early childhood but it is now being made in an increasing number of adults. Many of them present with mild or atypical cystic fibrosis clinical features, mostly lung disease. In addition, some adults with congenital bilateral absence of vas deferens or idiopathic chronic pancreatitis may be assigned a diagnosis of cystic fibrosis. The diagnosis of cystic fibrosis in adults should be based on the presence of one or more characteristic clinical features, a history of cystic fibrosis in a sibling, plus evidence of defective CFTR function as documented by elevated sweat chloride concentrations or abnormal ion transport across the nasal epithelium, or identification of mutations on both CFTR genes.

[Airway neuropeptides--what is their role in physiopathology?]. / Neuropeptides dans les voies aériennes quel est leur rôle en physiopathologie?

Research work over the last ten years has identified a nonadrenergic, non cholinergic innervation in the upper and lower airways, in man and other animals. This innervation has two components: An excitatory bronchoconstrictor component, of which the neurotransmitters are peptides, substance P, neurokinin A, CGRP and gastrin-releasing peptide. A bronchodilating component known as inhibitor, of which the neurotransmitters are the vasoactive intestinal peptide and nitric oxide. Those neurotransmitters effect all the systems that are involved in allergic respiratory diseases, asthma and allergic rhinitis. They may therefore have a role to play in the physiopathology of these diseases.