Case Report: When cystic fibrosis, elexacaftor/tezacaftor/ivacaftor therapy, and alpha1 antitrypsin deficiency get together.

In the last 10 years, the care of patients with cystic fibrosis (CF) has been revolutionized with the introduction of cystic fibrosis transmembrane conductance regulator (CFTR) modulator drugs, with a major impact on symptoms and life expectancy, especially considering the newest and highly effective elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) therapy. Conversely, adverse effects are relatively frequent, with some being life-threatening, such as severe hepatitis. Clinical trials on children starting CFTR modulators have reported transaminase elevations >3× upper limit of the norm in 10%-20% of patients, whereas real-life studies have reported discontinuation rates three times higher than those observed in phase 3 trials. We report the case of a 10-year-old boy with CF who developed severe acute hepatitis 2 weeks after starting ELX/TEZ/IVA therapy. An extensive screening for potential causes led to the identification of heterozygous alpha1-antitrypsin (AAT) deficiency with genotype MZ. The Z allele of SERPINA1 gene, encoding AAT, is known as a risk factor for CF liver disease. We hypothesized that it may act as a risk factor for drug-induced liver injury from CFTR modulators, notably ELX/TEZ/IVA. Therefore, checking AAT before starting CFTR modulator therapy can be suggested, in particular for children with previous, even transient, liver disease.

Phenotypes of cough in children: A latent class analysis.

INTRODUCTION: Distinguishing phenotypes among children with cough helps understand underlying causes. Using a statistical data-driven approach, we aimed to identify and validate cough phenotypes based on measurable traits, physician diagnoses, and prognosis. METHODS: We used data from the Swiss Paediatric Airway Cohort and included 531 children aged 5-16 years seen in outpatient clinics since 2017. We included children with any parent-reported cough (i.e. cough without a cold, cough at night, cough more than other children, or cough longer than 4 weeks) without current wheeze. We applied latent class analysis to identify phenotypes using nine symptoms and characteristics and selected the best model using the Akaike information criterion. We assigned children to the most likely phenotype and compared the resulting groups for parental atopy history, comorbidities, spirometry, fractional exhaled nitric oxide (FeNO), skin prick tests and specific IgE, physician diagnoses, and 1-year prognosis. RESULTS: We identified four cough phenotypes: non-specific cough (26%); non-allergic infectious and night cough with snoring and otitis (4%); chronic allergic dry night cough with snoring (9%); and allergic non-infectious cough with rhino-conjunctivitis (61%). Children with the allergic phenotype often had family or personal history of atopy and asthma diagnosis. FeNO was highest for the allergic phenotype [median 17.9 parts per billion (ppb)] and lowest for the non-allergic infectious phenotype [median 7.0 parts per billion (ppb)]. Positive allergy test results differed across phenotypes (p < .001) and were most common among the allergic (70%) and least common among the non-specific cough (31%) phenotypes. Subsequent wheeze was more common among the allergic than the non-specific phenotype. CONCLUSION: We identified four clinically relevant cough phenotypes with different prognoses. Although we excluded children with current wheeze, most children with cough belonged to allergy-related phenotypes.

[Where we stand with asthma: optimized medical care and biologic therapy for children]. / Le point sur l'asthme en pédiatrie : optimisation de la prise en charge et thérapies biologiques.

Asthma recommendations are in constant evolution. Salbutamol exclusivity as the historical reference treatment for asthma exacerbations is now questioned. In case of light to moderate crisis, budesonide/formoterol, combining an inhaled corticosteroid and a fast acting long lasting beta2 agonist, can now be proposed as first line as needed treatment, for adolescents older than 12 years old. In addition, progress in fundamental research revealed the heterogeneous nature of asthma and allowed for the emergence of new-targeted therapies.

La prise en charge de l'asthme est en constante évolution. L'exclusivité du salbutamol, traitement historique de référence des exacerbations aiguës, même légères, est remise en question depuis plusieurs années. En cas de symptômes ou crise légère à modérée, le budésonide/formotérol, combiné de corticostéroïde inhalé et bronchodilatateur (ß2-agoniste) d'action rapide et prolongée, peut dorénavant être proposé en première intention, à la demande, y compris en pédiatrie, notamment à partir de 12 ans. De plus, les progrès en recherche fondamentale ont permis de révéler la nature hétérogène de l'asthme et de faire émerger de nouvelles cibles thérapeutiques. En particulier, les patients asthmatiques peuvent bénéficier de l'entrée des biologiques dans l'arsenal thérapeutique.

[Phage therapy for respiratory infections]. / Phagothérapie pour traiter les infections respiratoires.

The crisis of antibiotic resistance represents a global public health challenge, affecting particularly patients with respiratory infections. The use of (bacterio)phages for the treatment of bacterial infections (phage therapy) seems safe but its effectiveness has not yet been proven by controlled clinical trials. Nevertheless, phage therapy is regaining interest, encouraged by published cases treated successfully with personalized phage combinations as well as significant advances at a preclinical level. Standardized approaches in phage production and treatment administration, as well as future translational studies, are needed to improve our understanding and explore the potential of phage therapy.

La crise de l'antibiorésistance représente un enjeu considérable en santé publique, touchant particulièrement les patients avec des infections respiratoires. L'utilisation des (bactério)phages pour le traitement des infections bactériennes semble sécuritaire mais son efficacité n'a pas encore été formellement démontrée dans des essais cliniques contrôlés. La phagothérapie regagne de l'intérêt comme traitement personnalisé pour les patients qui ne répondent pas aux traitements standards, comme en témoignent les multiples cas publiés ainsi que des découvertes significatives au niveau préclinique. Des approches standardisées concernant la production et l'administration des phages ainsi que des études translationnelles sont nécessaires afin d'améliorer notre compréhension et d'explorer le potentiel de la phagothérapie.

Phage therapy for pulmonary infections: lessons from clinical experiences and key considerations.

Lower respiratory tract infections lead to significant morbidity and mortality. They are increasingly caused by multidrug-resistant pathogens, notably in individuals with cystic fibrosis, hospital-acquired pneumonia and lung transplantation. The use of bacteriophages (phages) to treat bacterial infections is gaining growing attention, with numerous published cases of compassionate treatment over the last few years. Although the use of phages appears safe, the lack of standardisation, the significant heterogeneity of published studies and the paucity of robust efficacy data, alongside regulatory hurdles arising from the existing pharmaceutical legislation, are just some of the challenges phage therapy has to overcome. In this review, we discuss the lessons learned from recent clinical experiences of phage therapy for the treatment of pulmonary infections. We review the key aspects, opportunities and challenges of phage therapy regarding formulations and administration routes, interactions with antibiotics and the immune system, and phage resistance. Building upon the current knowledge base, future pre-clinical studies using emerging technologies and carefully designed clinical trials are expected to enhance our understanding and explore the therapeutic potential of phage therapy.

Therapeutic Drug Monitoring of Ivacaftor, Lumacaftor, Tezacaftor, and Elexacaftor in Cystic Fibrosis: Where Are We Now?

Drugs modulating the cystic fibrosis transmembrane conductance regulator (CFTR) protein, namely ivacaftor, lumacaftor, tezacaftor, and elexacaftor, are currently revolutionizing the management of patients with cystic fibrosis (CF), particularly those with at least one F508del variant (up to 85% of patients). These "caftor" drugs are mainly metabolized by cytochromes P450 3A, whose enzymatic activity is influenced by environmental factors, and are sensitive to inhibition and induction. Hence, CFTR modulators are characterized by an important interindividual pharmacokinetic variability and are also prone to drug-drug interactions. However, these CFTR modulators are given at standardized dosages, while they meet all criteria for a formal therapeutic drug monitoring (TDM) program that should be considered in cases of clinical toxicity, less-than-expected clinical response, drug or food interactions, distinct patient subgroups (i.e., pediatrics), and for monitoring short-term adherence. While the information on CFTR drug exposure-clinical response relationships is still limited, we review the current evidence of the potential interest in the TDM of caftor drugs in real-life settings.

[Respiratory issues in children with severe neurological impairment]. / Atteinte respiratoire chez l'enfant en situation de polyhandicap sévère.

Respiratory problems have a significant impact on morbidity and mortality in children with severe neurological impairment. In particular, impaired airway clearance, recurrent respiratory infections, bronchial hyper reactivity can lead to acute decompensation and, with time, to chronic respiratory failure. Multiple coexisting and interacting factors that influence the respiratory status of these children should be recognized and effectively addressed to reduce respiratory morbidity and mortality. An accurate assessment involving a multidisciplinary approach and relatively simple interventions can lead to significant improvements in the quality of life of children as well as their parents and carers.

Les complications respiratoires ont un impact significatif sur la morbidité et la mortalité chez les enfants en situation de polyhandicap sévère. En particulier l'encombrement bronchique, les infections respiratoires récurrentes et l'hyperréactivité bronchique peuvent conduire à des décompensations aiguës et, avec le temps, à une insuffisance respiratoire chronique. De multiples facteurs coexistant et interagissant qui influencent l'état respiratoire de ces enfants doivent être reconnus et traités efficacement afin de réduire la morbidité et la mortalité respiratoires. Une évaluation précise impliquant une approche multidisciplinaire et des interventions relativement simples peuvent conduire à une amélioration significative de la qualité de vie de ces enfants ainsi que de leurs parents et tuteurs.

Diagnosis of primary ciliary dyskinesia: discrepancy according to different algorithms.

BACKGROUND: Diagnosis of primary ciliary dyskinesia (PCD) is challenging since there is no gold standard test. The European Respiratory (ERS) and American Thoracic (ATS) Societies developed evidence-based diagnostic guidelines with considerable differences. OBJECTIVE: We aimed to compare the algorithms published by the ERS and the ATS with each other and with our own PCD-UNIBE algorithm in a clinical setting. Our algorithm is similar to the ERS algorithm with additional immunofluorescence staining. Agreement (Cohen's κ) and concordance between the three algorithms were assessed in patients with suspicion of PCD referred to our diagnostic centre. RESULTS: In 46 out of 54 patients (85%) the final diagnosis was concordant between all three algorithms (30 PCD negative, 16 PCD positive). In eight patients (15%) PCD diagnosis differed between the algorithms. Five patients (9%) were diagnosed as PCD only by the ATS, one (2%) only by the ERS and PCD-UNIBE, one (2%) only by the ATS and PCD-UNIBE, and one (2%) only by the PCD-UNIBE algorithm. Agreement was substantial between the ERS and the ATS (κ=0.72, 95% CI 0.53-0.92) and the ATS and the PCD-UNIBE (κ=0.73, 95% CI 0.53-0.92) and almost perfect between the ERS and the PCD-UNIBE algorithms (κ=0.92, 95% CI 0.80-1.00). CONCLUSION: The different diagnostic algorithms lead to a contradictory diagnosis in a considerable proportion of patients. Thus, an updated, internationally harmonised and standardised PCD diagnostic algorithm is needed to improve diagnostics for these discordant cases.

A Comprehensive Approach for the Diagnosis of Primary Ciliary Dyskinesia-Experiences from the First 100 Patients of the PCD-UNIBE Diagnostic Center.

Primary ciliary dyskinesia (PCD) is a rare genetic disease characterized by dyskinetic cilia. Respiratory symptoms usually start at birth. The lack of diagnostic gold standard tests is challenging, as PCD diagnostics requires different methods with high expertise. We founded PCD-UNIBE as the first comprehensive PCD diagnostic center in Switzerland. Our diagnostic approach includes nasal brushing and cell culture with analysis of ciliary motility via high-speed-videomicroscopy (HSVM) and immunofluorescence labeling (IF) of structural proteins. Selected patients undergo electron microscopy (TEM) of ciliary ultrastructure and genetics. We report here on the first 100 patients assessed by PCD-UNIBE. All patients received HSVM fresh, IF, and cell culture (success rate of 90%). We repeated the HSVM with cell cultures and conducted TEM in 30 patients and genetics in 31 patients. Results from cell cultures were much clearer compared to fresh samples. For 80 patients, we found no evidence of PCD, 17 were diagnosed with PCD, two remained inconclusive, and one case is ongoing. HSVM was diagnostic in 12, IF in 14, TEM in five and genetics in 11 cases. None of the methods was able to diagnose all 17 PCD cases, highlighting that a comprehensive approach is essential for an accurate diagnosis of PCD.

Diagnostic tools and CFTR functional assays in cystic fibrosis: utility and availability in Switzerland.

Cystic fibrosis (CF) is a genetic disease caused by a bi-allelic mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. When the diagnosis cannot be confirmed by a positive sweat test or/and the identification of two CF-causing variants, international guidelines recommend the use of CFTR functional assays. These tests assess whether CFTR activity is normal or diminished/absent through measurement of CFTR-mediated chloride secretion/absorption. CFTR functional assays are not only useful for diagnostic purposes but can also serve as a surrogate outcome for clinical trials of CFTR modulators, which are emerging therapeutic agents designed to correct the malfunctioning protein. In the near future they could also be used as precision-medicine techniques, to help guidance and optimisation of treatment. Until now, sweat testing has been the only CFTR functional assay available in Switzerland. Since 2020, the Centre Hospitalier Universitaire Vaudois (CHUV) at Lausanne and the Lucerne Children’s Hospital perform nasal potential difference measurement. Moreover, The Ecole Polytechnique Fédérale de Lausanne (EPFL) established a reliable procedure to generate adult intestinal organoids, i.e., stem cell-derived in-vitro grown mini tissues, extracted from rectal biopsies, which can be used to assess CFTR function in vitro. This narrative review describes the most popular CFTR functional assays, as well as their indications, limitations and availability in Switzerland.

Factors Associated with Asthma Severity in Children: Data from the French COBRAPed Cohort.

BACKGROUND: Severe asthma (SA) in children is a complex, heterogeneous disease, associated with a considerable burden. However, factors influencing asthma severity are poorly described and may differ according to age. OBJECTIVE: To determine whether factors associated with asthma severity differ between preschoolers with severe recurrent wheeze (SRW) and school-age children with SA. METHODS: Data from the French multicenter prospective observational cohort of preschool (3-6 years) children with SRW and nonsevere recurrent wheeze (NSRW) and school-age (7-11 years) children with SA and nonsevere asthma (NSA) (Pediatric Cohort of Bronchial Obstruction and Asthma) were analyzed. RESULTS: A total of 131 preschool children (92 SRW and 49 NSRW) and 207 school-age children (92 SA and 115 NSA) were included. In both univariable and multivariable analysis, SRW was associated with second-hand smoke exposure (multivariable analysis: odds ratio [95% CI], 29.8 [3.57-3910]) and exposure to mold/dampness at home (multivariable analysis: odds ratio [95% CI], 4.22 [1.25-18.2]) compared with NSRW. At school-age, history of atopic dermatitis and food allergy was more frequent in children with SA than in those with NSA. Multivariable analysis confirmed that SA was associated with a history of food allergy (odds ratio [95% CI], 5.01 [2.23-11.9]). CONCLUSIONS: Our data suggest that factors influencing asthma severity may differ according to age. In preschool children with SRW, second-hand smoke and exposure to mold are predominant, whereas associated allergic disorders are mainly involved in SA at school-age.

[Revolution in the treatment of cystic fibrosis]. / Révolution dans le traitement de la mucoviscidose.

Cystic Fibrosis is a genetic disorder resulting in the absence or dysfunction of the CFTR protein, a chloride channel present on the surface of epithelia, particularly respiratory. Until recently, treatments only concerned the consequences of the disease. But a new type of molecules called «â€…modulators ¼, is already available to some patients and targets the origin of the disease. «â€…Modulators ¼ are divided into «â€…potentiators ¼, which improve the transport of chloride by the CFTR protein, and «â€…correctors ¼, increasing the amount of CFTR proteins. An oral triple therapy combining a potentiator and two correctors has just been approved in the USA and will treat 85 % of patients. The clinical benefit of «â€…modulators ¼ is remarkable, and these drugs are revolutionizing the treatment of Cystic Fibrosis.

La mucoviscidose est une maladie génétique entraînant une absence ou des dysfonctions de la protéine Cystic Fibrosis Transmembrane Conductance Regulator (CFTR), un canal chlore présent à la surface des épithélia, notamment respiratoire. Jusqu'à récemment, les traitements ne concernaient que les conséquences de la maladie. Mais un nouveau type de molécules appelées «â€…modulateurs ¼ est déjà à la disposition de certains patients et cible l'origine de la maladie. Les «â€…modulateurs ¼ sont divisés en «â€…potentiateurs ¼, permettant d'améliorer le transport du chlore par la protéine CFTR, et en «â€…correcteurs ¼, augmentant la quantité de protéines CFTR. Une trithérapie orale combinant un potentiateur et deux correcteurs vient d'être approuvée aux États-Unis et permettra de traiter 85 % des patients. Le bénéfice clinique des «â€…modulateurs ¼ est remarquable et ces médicaments bouleversent le traitement de la mucoviscidose.