Cystic fibrosis in the year 2020: A disease with a new face

Drug Hypersensitivity Reactions in Patients with Cystic Fibrosis: Potential Value of the Lymphocyte Toxicity Assay to Assess Risk

BACKGROUND

Cystic fibrosis (CF) is a genetic disease characterized by multi-system dysfunction resulting in recurrent lung infections and progressive pulmonary disease. CF patients are at a higher risk for drug hypersensitivity reactions (DHRs) compared to the general population, which has been attributed to the recurrent need for antibiotics and the inflammation associated with CF disease. In vitro toxicity tests such as the lymphocyte toxicity assay (LTA) offer the potential for risk assessment for DHRs. In the current study, we investigated the utility of the LTA test for diagnosis of DHRs in a cohort of CF patients.

METHOD

Twenty CF patients with suspected DHRs to sulfamethoxazole, penicillins, cephalosporins, meropenem, vancomycin, rifampicin, and tobramycin were recruited to this study and tested using the LTA test along with 20 healthy control volunteers. Demographic data of the patients, including age, sex, and medical history, were obtained. Blood samples were withdrawn from patients and healthy volunteers, and the LTA test was performed on isolated peripheral blood monocytes (PBMCs) from those individuals.

RESULTS

Cells from CF patients with DHRs displayed a significant (p < 0.0001) concentration-dependent enhanced cell death upon incubation with the culprit drug compared to cells from healthy volunteers. The positivity rate of the LTA test was over 80% in patients with a medical history and clinical presentation consistent with DHRs.

CONCLUSION

This study is the first to evaluate the use of the LTA test for diagnosis of DHRs in CF patients. According to our results, the LTA test may be a useful tool for diagnosis and management of DHRs in CF patients. Identifying the culprit drug is essential for optimal healthcare for CF patients in the setting of a suspected DHR. The data also provide evidence that accumulation of toxic reactive metabolites could be an important component in the cascade of events leading to the development of DHRs in CF patients. A larger-scale study is needed to confirm the data.

The Epithelial Sodium Channel-An Underestimated Drug Target

Epithelial sodium channels (ENaC) are part of a complex network of interacting biochemical pathways and as such are involved in several disease states. Dependent on site and type of mutation, gain- or loss-of-function generated symptoms occur which span from asymptomatic to life-threatening disorders such as Liddle syndrome, cystic fibrosis or generalized pseudohypoaldosteronism type 1. Variants of ENaC which are implicated in disease assist further understanding of their molecular mechanisms in order to create models for specific pharmacological targeting. Identification and characterization of ENaC modifiers not only furthers our basic understanding of how these regulatory processes interact, but also enables discovery of new therapeutic targets for the disease conditions caused by ENaC dysfunction. Numerous test compounds have revealed encouraging results in vitro and in animal models but less in clinical settings. The EMA- and FDA-designated orphan drug solnatide is currently being tested in phase 2 clinical trials in the setting of acute respiratory distress syndrome, and the NOX1/ NOX4 inhibitor setanaxib is undergoing clinical phase 2 and 3 trials for therapy of primary biliary cholangitis, liver stiffness, and carcinoma. The established ENaC blocker amiloride is mainly used as an add-on drug in the therapy of resistant hypertension and is being studied in ongoing clinical phase 3 and 4 trials for special applications. This review focuses on discussing some recent developments in the search for novel therapeutic agents.

Easy-to-Build and Reusable Microfluidic Device for the Dynamic Culture of Human Bronchial Cystic Fibrosis Epithelia

Cystic fibrosis (CF) is one of the most frequent genetic diseases, caused by dysfunction of the CF transmembrane conductance regulator (CFTR) chloride channel. CF particularly affects the epithelium of the respiratory system. Therapies aim at rescuing CFTR defects in the epithelium, but CF genetic heterogeneity hinders the finding of a single and generally effective treatment. Therefore, in vitro models have been developed to study CF and guide patient therapy. Here, we show a CF model on-chip by coupling the feasibility of the human bronchial epithelium differentiated in vitro at the air-liquid interface and the innovation of microfluidics. We demonstrate that the dynamic flow enhanced cilia distribution and increased mucus quantity, thus promoting tissue differentiation in a short time. The microfluidic devices highlighted differences between CF and non-CF epithelia, as shown by electrophysiological measures, mucus quantity, viscosity, and the analysis of ciliary beat frequency. The described model on-chip may be a handy instrument for studying CF and setting up therapies. As a proof of principle, we administrated the corrector VX-809 on-chip and observed a decrease in mucus thickness and viscosity.

Antimicrobial Strategies for Cystic Fibrosis

Lung infection is the leading cause of death in cystic fibrosis (CF), and antimicrobial therapies are the backbone of infection management. While many different strategies may be applied, rigorous microbiological surveillance, intensive eradication therapy, and long-term maintenance therapy based on inhaled antibiotics may be considered the main strategy for infection control in individuals with CF. While most of the existing evidence is based on infection with Pseudomonas aeruginosa, other important pathogens causing lung inflammation and deterioration exist and should be treated despite the evidence gap. In this chapter, we describe the approaches to the antimicrobial treatment of the most important pathogens in CF and the evidence behind.

Cystic fibrosis and primary ciliary dyskinesia: Similarities and differences

Cystic fibrosis (CF) and Primary ciliary dyskinesia (PCD) are both rare chronic diseases, inherited disorders associated with multiple complications, namely respiratory complications, due to impaired mucociliary clearance that affect severely patients' lives. Although both are classified as rare diseases, PCD has a much lower prevalence than CF, particularly among Caucasians. As a result, CF is well studied, better recognized by clinicians, and with some therapeutic approaches already available. Whereas PCD is still largely unknown, and thus the approach is based on consensus guidelines, expert opinion, and extrapolation from the larger evidence base available for patients with CF. Both diseases have some clinical similarities but are very different, necessitating different treatment by specialists who are familiar with the complexities of each disease.This review aims to provide an overview of the knowledge about the two diseases with a focus on the similarities and differences between both in terms of disease mechanisms, common clinical manifestations, genetics and the most relevant therapeutic options. We hoped to raise clinical awareness about PCD, what it is, how it differs from CF, and how much information is still lacking. Furthermore, this review emphasises the fact that both diseases require ongoing research to find better treatments and, in particular for PCD, to fill the medical and scientific gaps.

Nontuberculous Mycobacteria in Cystic Fibrosis in the Era of Cystic Fibrosis Transmembrane Regulator Modulators

Nontuberculous mycobacteria (NTM) are a group of mycobacteria which represent opportunistic pathogens that are of increasing concern in people with cystic fibrosis (pwCF). The acquisition has been traditionally though to be from environmental sources, though recent work has suggested clustered clonal infections do occur and transmission potential demonstrated among pwCF attending CF specialist centers. Guidelines for the screening, diagnosis, and identification of NTM and management of pwCF have been published. The emergence of CF-specific therapies, in particular cystic fibrosis transmembrane regulator (CFTR) modulator drugs, have led to significant improvement in the health and well-being of pwCF and may lead to challenges in sampling the lower respiratory tract including to screen for NTM. This review highlights the epidemiology, modes of acquisition, screening and diagnosis, therapeutic approaches in the context of improved clinical status for pwCF, and the clinical application of CFTR modulator therapies.

Advances in Cystic Fibrosis Research in Qatar: A Commentary

Cystic fibrosis is a genetic disorder caused by a Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene defect. Many across the globe suffer the debilitating symptoms. The aim of this commentary is to briefly cover various aspects related to the disease in the Arab world and then in Qatar.

Lessons from other fields of medicine, Part 2: Cystic fibrosis

Cystic fibrosis (CF), first described in 1938, is a common, life-limiting monogenetic disease. The discovery of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 1989 was crucial in advancing our understanding of disease pathogenesis and paving the road for treatment aimed at the fundamental molecular defect. With the delineation of over 2000 variations in the CFTR gene, a sound understanding of the individual variations in cell biology, and electrophysiological abnormalities conferred by the most common defects propelled the advent of targeted disease-modifying therapeutics beginning in 2012. Since then, CF care has transformed beyond just symptomatic treatment to include a variety of small-molecule therapies that address the basic electrophysiologic defect and cause profound improvements in physiology, clinical manifestations, and long-term outcomes, designed to differentially address six genetic/molecular subtypes. This chapter illustrates the progress made toward how fundamental science and translational initiatives enabled personalized, mutation specific treatment. We highlight the importance of preclinical assays and mechanistically-driven development strategies that were coupled with sensitive biomarkers and a clinical trial cooperative to provide a platform for successful drug development. This convergence of academic and private partnerships, and formation of multidisciplinary care teams directed by evidence-based initiatives provide a seminal example of addressing the needs of individuals with a rare, but fatal genetic disease.

The Role of MMPs in the Era of CFTR Modulators: An Additional Target for Cystic Fibrosis Patients?

Cystic fibrosis (CF) is a high-prevalence disease characterized by significant lung remodeling, responsible for high morbidity and mortality worldwide. The lung structural changes are partly due to proteolytic activity associated with inflammatory cells such as neutrophils and macrophages. Matrix metalloproteases (MMPs) are the major proteases involved in CF, and recent literature data focused on their potential role in the pathogenesis of the disease. In fact, an imbalance of proteases and antiproteases was observed in CF patients, resulting in dysfunction of protease activity and loss of lung homeostasis. Currently, many steps forward have been moved in the field of pharmacological treatment with the recent introduction of triple-combination therapy targeting the CFTR channel. Despite CFTR modulator therapy potentially being effective in up to 90% of patients with CF, there are still patients who are not eligible for the available therapies. Here, we introduce experimental drugs to provide updates on therapy evolution regarding a proportion of CF non-responder patients to current treatment, and we summarize the role of MMPs in pathogenesis and as future therapeutic targets of CF.

Clearing up the smoke: Physical and mental health considerations regarding cannabis use in adolescents with cystic fibrosis

The cannabis plant is the most used federally illegal drug in the United States and is widely used by adolescents. Cannabis has complex effects on the body and mind. All health professionals who take care of adolescents with cystic fibrosis (CF) should be aware of the factors impacting cannabis use in CF. Given limited evidence regarding the benefits of cannabis and the significant risks, clinicians have the responsibility to identify risk of cannabis use early, counsel patients about the risks, provide a safe space for ongoing conversations about cannabis use in the context of CF care, and deliver evidence-based interventions.

Importance of Vitamin D Status and Nerve Conduction in Pediatric Cystic Fibrosis Patients

Cystic fibrosis is one of the most common inherited diseases. It presents with recurrent respiratory infections, pancreatic insufficiency, and growth retardation. Neurological involvement becomes more common as life expectancy increases. Chronic hypoxia, impaired glucose intolerance, autoimmune mechanisms, vasculitis changes, and micronutrient deficiencies seem to cause neuropathy in cystic fibrosis. This study was aimed to investigate peripheral neuropathy in pediatric cystic fibrosis patients. Twenty-one cystic fibrosis patients and 19 healthy control subjects between the ages of 7 and 17 years were included. Their nerve conduction study results and laboratory investigations were analyzed. Participants were classified into four groups; 1. Cystic fibrosis with vitamin D deficiency, 2. Cystic fibrosis with normal vitamin D levels, 3. Healthy subjects with vitamin D deficiency, 4. Healthy subjects with normal vitamin D levels. We found statistically significantly lower sensory median nerve sensorial nerve action potential, sensorial sural nerve conduction velocity, and motor peroneal nerve compound motor action potential in cystic fibrosis patients with vitamin D deficiency than in other cases. We also found that the main difference between cystic fibrosis and control groups was especially in patients with low vitamin D levels. Nerve damage starts at an early age, especially in cystic fibrosis patients especially those with vitamin D deficiency. Electrophysiological evaluation to assess neuropathy is important even in asymptomatic patients. Prevention of hypovitaminosis D is important to prevent neuropathy in cystic fibrosis patients.

Antibiotic Resistance in Patients with Cystic Fibrosis: Past, Present, and Future

Patients with cystic fibrosis (CF) are repeatedly exposed to antibiotics, especially during the pulmonary exacerbations of the disease. However, the available therapeutic strategies are frequently inadequate to eradicate the involved pathogens and most importantly, facilitate the development of antimicrobial resistance (AMR). The evaluation of AMR is demanding; conventional culture-based susceptibility-testing techniques cannot account for the lung microenvironment and/or the adaptive mechanisms developed by the pathogens, such as biofilm formation. Moreover, features linked to modified pharmaco-kinetics and pulmonary parenchyma penetration make the dosing of antibiotics even more challenging. In this review, we present the existing knowledge regarding AMR in CF, we shortly review the existing therapeutic strategies, and we discuss the future directions of antimicrobial stewardship. Due to the increasing difficulty in eradicating strains that develop AMR, the appropriate management should rely on targeting the underlying resistance mechanisms; thus, the interest in novel, molecular-based diagnostic tools, such as metagenomic sequencing and next-generation transcriptomics, has increased exponentially. Moreover, since the development of new antibiotics has a slow pace, the design of effective treatment strategies to eradicate persistent infections represents an urgency that requires consorted work. In this regard, both the management and monitoring of antibiotics usage are obligatory and more relevant than ever.

Recent Advancements in Ion-Pair Receptors

Over the past two decades, non-covalent chemistry has introduced various promising artificial receptors and revolutionized the host-guest chemistry. These versatile receptors have particularly been entertained in sensing and recognizing of diverse neutral molecules and/or ionic entities (e. g. anions, cations and ion-pair) of particular interest. Notably, supramolecular chemistry had given birth to a plethora of important molecules, explored in the chemical, biological, environmental, and pharmacological world to resolve the critical issues related to the human health while keeping environmental concerns in mind. Amongst the various types of supramolecular monotopic receptors (anions, cations, and neutral molecules), heteroditopic receptors (ion-pair receptors) consisting of distinct binding sites in one system for both cation and anion, have gained much interest from the scientific community in recent past because of their unique binding abilities. Interestingly, these promising artificial receptors have shown potential applications in sensing, recognition, transport and extraction processes besides their uses in salt/waste purification. Bearing the importance of these systems in mind, we intended to report the recent developments in ion-pair chemistry. Herein, we divided the whole document into three main sections; first one describes the introduction and history of the ion-pairs receptors. The second portion highlights the synthesis and applications of ion-pair receptors in sensing, recognition, molecular machines, photoswitching behaviour, extraction and transport properties, whereas the last part of this manuscript provides concluding remarks as well as future prospects of ion-pair receptors. We hope that this manuscript will be helpful to stimulating researchers around the globe to find out the hidden opportunities in this and related areas.

What Can RNA-Based Therapy Do for Monogenic Diseases?

The use of RNA-based approaches to treat monogenic diseases (i.e., hereditary disorders caused by mutations in single genes) has been developed on different fronts. One approach uses small antisense oligonucleotides (ASOs) to modulate RNA processing at various stages; namely, to enhance correct splicing, to stimulate exon skipping (to exclude premature termination codon variants), to avoid undesired messenger RNA (mRNA) transcript degradation via the nonsense-mediated decay (NMD) pathway, or to induce mRNA degradation where they encode toxic proteins (e.g., in dominant diseases). Another approach consists in administering mRNA, which, like gene therapy, is a mutation-agnostic approach with potential application to any recessive monogenic disease. This is simpler than gene therapy because instead of requiring targeting of the nucleus, the mRNA only needs to be delivered to the cytoplasm. Although very promising (as demonstrated by COVID-19 vaccines), these approaches still have potential for optimisation, namely regarding delivery efficiency, adverse drug reactions and toxicity.

Bisphosphonates for osteoporosis in people with cystic fibrosis

BACKGROUND

Osteoporosis is a disorder of bone mineralisation occurring in about one third of adults with cystic fibrosis. Bisphosphonates can increase bone mineral density and decrease the risk of new fractures in post-menopausal women and people receiving long-term oral corticosteroids. This is an updated version of a previous review.

OBJECTIVES

To assess the effects of bisphosphonates on the frequency of fractures, bone mineral density, quality of life, adverse events, trial withdrawals, and survival in people with cystic fibrosis.

SEARCH METHODS

We searched the Cystic Fibrosis and Genetic Disorders Group's Trials Register of references (identified from electronic database searches and hand searches of journals and abstract books) on 5 May 2022. We performed additional searches of PubMed, clinicaltrials.gov and the WHO ICTRP (International Clinical Trials Registry Platform) on 5 May 2022.

SELECTION CRITERIA

Randomised controlled trials of at least six months duration studying bisphosphonates in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Authors independently selected trials, extracted data and assessed risk of bias in included studies. Trial investigators were contacted to obtain missing data. We judged the certainty of the evidence using GRADE.

MAIN RESULTS

We included nine trials with a total of 385 participants (272 adults and 113 children (aged five to 18 years)). Trial durations ranged from six months to two years. Only two of the studies were considered to have a low risk of bias for all the domains.  Bisphosphonates compared to control in people with cystic fibrosis who have not had a lung transplant Seven trials included only adult participants without lung transplants, one trial included both adults and children without lung transplantation (total of 238 adults and 113 children). We analysed adults (n = 238) and children (n = 113) separately. Adults Three trials assessed intravenous bisphosphonates (one assessed pamidronate and two assessed zoledronate) and five trials assessed oral bisphosphonates (one assessed risedronate and four assessed alendronate). Bisphosphonates were compared to either placebo or calcium (with or without additional vitamin D). Data showed no difference between treatment or control groups in new vertebral fractures at 12 months (odds ratio (OR) 0.22, 95% confidence interval (CI) 0.02 to 2.09; 5 trials, 142 participants; very low-certainty evidence) and two trials (44 participants) reported no vertebral fractures at 24 months. There was no difference in non-vertebral fractures at 12 months (OR 2.11, 95% CI 0.18 to 25.35; 4 trials, 95 participants; very low-certainty evidence) and again two trials (44 participants) reported no non-vertebral fractures at 24 months. There was no difference in total fractures between groups at 12 months (OR 0.57, 95% CI 0.13 to 2.50; 5 trials, 142 participants) and no fractures were reported in two trials (44 participants) at 24 months. At 12 months, bisphosphonates may increase bone mineral density at the lumbar spine (mean difference (MD) 6.31, 95% CI 5.39 to 7.22; 6 trials, 171 participants; low-certainty evidence) and at the hip or femur (MD 4.41, 95% 3.44 to 5.37; 5 trials, 155 participants; low-certainty evidence). There was no clear difference in quality of life scores at 12 months (1 trial, 47 participants; low-certainty evidence), but bisphosphonates probably led to more adverse events (bone pain) at 12 months (OR 8.49, 95% CI 3.20 to 22.56; 7 trials, 206 participants; moderate-certainty evidence). Children The single trial in 113 children compared oral alendronate to placebo. We graded all evidence as low certainty. At 12 months we found no difference between treatment and placebo in new vertebral fractures (OR 0.32, 95% CI 0.03 to 3.13; 1 trial, 113 participants) and non-vertebral fractures (OR 0.19, 95% CI 0.01 to 4.04; 1 trial, 113 participants). There was also no difference in total fractures (OR 0.18, 95% CI 0.02 to 1.61; 1 trial, 113 participants). Bisphosphonates may increase bone mineral density at the lumbar spine at 12 months (MD 14.50, 95% CI 12.91 to 16.09). There was no difference in bone or muscle pain (MD 3.00, 95% CI 0.12 to 75.22), fever (MD 3.00, 95% CI 0.12 to 75.22) or gastrointestinal adverse events (OR 0.67, 95% CI 0.20 to 2.26). The trial did not measure bone mineral density at the hip/femur or report on quality of life.  Bisphosphonates compared to control in people with cystic fibrosis who have had a lung transplant One trial of 34 adults who had undergone lung transplantation compared intravenous pamidronate to no bisphosphonate treatment. It did not report at 12 months and we report the 24-month data (not assessed by GRADE). There was no difference in the number of fractures, either vertebral or non-vertebral. However, bone mineral density increased with treatment at the lumbar spine (MD 6.20, 95% CI 4.28 to 8.12) and femur (MD 7.90, 95% CI 5.78 to 10.02). No participants in either group reported either bone pain or fever. The trial did not measure quality of life.

AUTHORS' CONCLUSIONS

Oral and intravenous bisphosphonates may increase bone mineral density in people with cystic fibrosis, but there are insufficient data to determine whether treatment reduces fractures. Severe bone pain and flu-like symptoms may occur with intravenous bisphosphonates. Before any firm conclusions can be drawn, trials in larger populations, including children, and of longer duration are needed to determine effects on fracture rate and survival. Additional trials are needed to determine if bone pain is more common or severe (or both) with the more potent zoledronate and if corticosteroids can ameliorate or prevent these adverse events. Future trials should also assess gastrointestinal adverse effects associated with oral bisphosphonates.

Antibacterial Activity of a Natural Clay Mineral against Burkholderia cepacia Complex and Other Bacterial Pathogens Isolated from People with Cystic Fibrosis

There is an impending crisis in healthcare brought about by a new era of untreatable infections caused by bacteria resistant to all available antibiotics. Thus, there is an urgent need to identify novel antimicrobial agents to counter the continuing threat posed by formerly treatable infections. We previously reported that a natural mineral clay known as Kisameet clay (KC) is a potent inhibitor of the organisms responsible for acute infections. Chronic bacterial infections present another major challenge to treatment by antimicrobials, due to their prolonged nature, which results in repeated exposure to antibiotics and a constant selection for antimicrobial resistance. A prime example is bacteria belonging to the Burkholderia cepacia complex (Bcc), which particularly causes some of the most serious chronic lung infections in patients with cystic fibrosis (CF) associated with unpredictable clinical outcomes, poor prognosis, and high mortality rates. Eradication of these organisms from CF patients with limited effective antimicrobial options is a major challenge. Novel therapeutic approaches are urgently required. Here, we report the in vitro antibacterial activity of KC aqueous suspensions (1-10% w/v) and its aqueous extract (L100) against a collection of extensively and multi-drug resistant clinical isolates of Bcc, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia isolated from patients with CF. These findings present a potential novel therapy for further investigation in the clinic.

Cystic Fibrosis: Back to the Basics

Cystic fibrosis (CF) is the most common genetic disorder in Caucasian individuals, with an incidence of 1/2,500-3,500 live births. When CF was first described in 1938, most children died in infancy. Currently, the average lifespan is 28-47.7 years. Although new breakthroughs have occurred, CF is still incurable. Both early diagnosis and treatment by multidisciplinary teams are essential to optimize short- and long-term outcomes. It is imperative for neonatal clinicians to keep up to date on the most current research, treatment, and management of CF to provide the best outcomes. This article offers clinicians an updated review of the pathophysiology and clinical manifestations of CF, as well as current evidence-based diagnostics and treatment regimens.

Pulmonary drug delivery technology enables anakinra repurposing in cystic fibrosis

Inflammation is a key pathological driver in cystic fibrosis (CF). Current therapies are ineffective in treating and preventing the escalation of inflammatory events often exacerbated by superimposed infection. In this work, we propose a novel treatment based on the pulmonary administration of anakinra, a non-glycosylated recombinant form of IL-1Ra. An inhalable dry powder of anakinra was successfully developed to meet the specific needs of lung drug delivery. The new formulation was investigated in vitro for aerodynamic performances and activity and in vivo for its pharmacological profile, including the pharmacokinetics, treatment schedule, antimicrobial and anti-inflammatory activity and systemic toxicity. The protein was structurally preserved inside the formulation and retained its pharmacological activity in vitro immediately after preparation and over time when stored at ambient conditions. Anakinra when delivered to the lungs showed an improved and extended therapeutic efficacy in CF models in vivo as well as higher potency compared to systemic delivery. Peripheral side effects were significantly reduced and correlated with lower serum levels compared to systemic treatment. These findings provide proof-of-concept demonstration for anakinra repurposing in CF through the pulmonary route.

Facilitators and barriers to empowerment in children and young people with cystic fibrosis: a meta-synthesis of the qualitative literature

PURPOSE

Patient empowerment may be particularly important in children and young people (CYP) with CF, due to high treatment burden and limited peer support opportunities. This review aimed to meta-synthesize the qualitative literature pertaining to empowerment in CYP with CF.

MATERIALS AND METHODS

This work was guided by the ENTREQ framework, with a search strategy based on the SPIDER framework. A systematic search of PsycInfo, Medline, CINAHL and ASSIA databases was conducted. Identified studies were quality assessed and data analysed using thematic synthesis. PROSPERO registration: CRD42019154014.

RESULTS

Seventeen studies met inclusion criteria, though none explicitly explored empowerment. Thematic synthesis identified six analytic themes: relational support, information and understanding and feeling heard and respected appeared to facilitate empowerment, while prejudices and assumptions were identified as potential barriers. Mastery and competence and Navigating being different appeared to be components of empowerment.

CONCLUSIONS

The findings provide an initial understanding of patient empowerment in CYP with CF. Potential clinical implications include the need for more CYP-friendly information, more shared decision making and more opportunities to experience mastery. The need for further research is highlighted, particularly relating to developmental influences and factors unique to CF, which are not adequately addressed in existing patient empowerment models.Implications for rehabilitationEmpowerment in children and young people with cystic fibrosis can be facilitated by supportive and respectful relationships with family, friends and clinical teams, that enable them to feel heard and understood.It can be further supported by providing developmentally appropriate information and opportunities for children and young people to experience mastery and competency in typical childhood activities.Prejudices and assumptions about the capabilities of children and young people with CF, even when based in good intentions, can act as a barrier to empowerment.Empowerment can shape (and be shaped by) the way the children and young people navigate differences associated with living with CF.

Emerging strategies in nanotechnology to treat respiratory tract infections: realizing current trends for future clinical perspectives

A boom in respiratory tract infection cases has inflicted a socio-economic burden on the healthcare system worldwide, especially in developing countries. Limited alternative therapeutic options have posed a major threat to human health. Nanotechnology has brought an immense breakthrough in the pharmaceutical industry in a jiffy. The vast applications of nanotechnology ranging from early diagnosis to treatment strategies are employed for respiratory tract infections. The research avenues explored a multitude of nanosystems for effective drug delivery to the target site and combating the issues laid through multidrug resistance and protective niches of the bacteria. In this review a brief introduction to respiratory diseases and multifaceted barriers imposed by bacterial infections are enlightened. The manuscript reviewed different nanosystems, i.e. liposomes, solid lipid nanoparticles, polymeric nanoparticles, dendrimers, nanogels, and metallic (gold and silver) which enhanced bactericidal effects, prevented biofilm formation, improved mucus penetration, and site-specific delivery. Moreover, most of the nanotechnology-based recent research is in a preclinical and clinical experimental stage and safety assessment is still challenging.

Toward a Broader Understanding of Cystic Fibrosis Epidemiology and Its Impact on Clinical Manifestations

The incidence of cystic fibrosis remains constant in North America and Western Europe is 1 in 3500 live births, but survival and quality of life have improved. The cystic fibrosis population has shifted toward the adult age range with a concomitant shift in the spectrum of complications. Survival increased because of aggressive symptomatic therapy, earlier diagnosis by newborn screening, and the introduction of modulators of the cystic fibrosis transmembrane conductance regulator, so that predicted median survival age is now about 50 years. In the United States, members of low socioeconomic status populations or members of racial or ethnic minorities have benefitted less from these advances.

Cathepsin S (CTSS) activity in health and disease - A treasure trove of untapped clinical potential

Amongst the lysosomal cysteine cathepsin family of proteases, cathepsin S (CTSS) holds particular interest due to distinctive properties including a normal restricted expression profile, inducible upregulation and activity at a broad pH range. Consequently, while CTSS is well-established as a member of the proteolytic cocktail within the lysosome, degrading unwanted and damaged proteins, it has increasingly been shown to mediate a number of distinct, more selective roles including antigen processing and antigen presentation, and cleavage of substrates both intra and extracellularly. Increasingly, aberrant CTSS expression has been demonstrated in a variety of conditions and disease states, marking it out as both a biomarker and potential therapeutic target. This review seeks to contextualise CTSS within the cysteine cathepsin family before providing an overview of the broad range of pathologies in which roles for CTSS have been identified. Additionally, current clinical progress towards specific inhibitors is detailed, updating the position of the field in exploiting this most unique of proteases.

Identification of and discrimination between the Mycobacterium abscessus complex and Mycobacterium avium complex directly from sputum using quadruplex real-time PCR

Introduction. Cystic fibrosis (CF) is a serious disease with multisystemic clinical signs that is easily and frequently complicated by bacterial infection. Recently, the prevalence of nontuberculous mycobacteria as secondary contaminants of CF has increased, with the Mycobacterium avium complex (MAC) and Mycobacterium abscessus complex (MABSC) being the most frequently identified. The MABSC includes subspecies of significant clinical importance, mainly due to their resistance to antibiotics.Gap statement. Sensitive method for early detection and differentiation of MABSC members and MAC complex for use in routine clinical laboratories is lacking. A method based on direct DNA isolation from sputum, using standard equipment in clinical laboratories and allowing uncovering of possible sample inhibition (false negative results) would be required. The availability of such a method would allow accurate and accelerated time detection of MABSC members and their timely and targeted treatment.Aim. To develop a real time multiplex assay for rapid and sensitive identification and discrimination of MABSC members and MAC complex.Methodology. The method of DNA isolation directly from the sputum of patients followed by quadruplex real-time quantitative PCR (qPCR) detection was developed and optimised. The sensitivity and limit of detection (LOD) of the qPCR was determined using human sputum samples artificially spiked with a known amount of M. abscessus subsp. massiliense (MAM).Results. The method can distinguish between MAC and MABSC members and, at the same time, to differentiate between M. abscessus subsp. abscessus/subsp. bolletii (MAAb/MAB) and MAM. The system was verified using 61 culture isolates and sputum samples from CF and non-CF patients showing 29.5 % MAAb/MAB, 14.7 % MAM and 26.2 % MAC. The LOD was determined to be 1 490 MAM cells in the sputum sample with the efficiency of DNA isolation being 95.4 %. Verification of the qPCR results with sequencing showed 100 % homology.Conclusions. The developed quadruplex qPCR assay, which is preceded by DNA extraction directly from patients' sputum without the need for culturing, significantly improves and speeds up the entire process of diagnosing CF patients and is therefore particularly suitable for use in routine laboratories.

Polymicrobial Infections and Biofilms: Clinical Significance and Eradication Strategies

Biofilms are population of cells growing in a coordinated manner and exhibiting resistance towards hostile environments. The infections associated with biofilms are difficult to control owing to the chronicity of infections and the emergence of antibiotic resistance. Most microbial infections are contributed by polymicrobial or mixed species interactions, such as those observed in chronic wound infections, otitis media, dental caries, and cystic fibrosis. This review focuses on the polymicrobial interactions among bacterial-bacterial, bacterial-fungal, and fungal-fungal aggregations based on in vitro and in vivo models and different therapeutic interventions available for polymicrobial biofilms. Deciphering the mechanisms of polymicrobial interactions and microbial diversity in chronic infections is very helpful in anti-microbial research. Together, we have discussed the role of metagenomic approaches in studying polymicrobial biofilms. The outstanding progress made in polymicrobial research, especially the model systems and application of metagenomics for detecting, preventing, and controlling infections, are reviewed.

Clinical and Genetic Characterisation of Cystic Fibrosis Patients in Latvia: A Twenty-Five-Year Experience

Cystic fibrosis (CF) is the most common life-limiting genetic disorder in European descent populations. It is caused by pathogenic variants in the CFTR gene, and inheritance is autosomal recessive. This study provides an up-to-date, comprehensive estimation of the distribution of CFTR pathogenic variants in Latvia and their phenotypic characteristics. It also reports the first results of the CF newborn screening programme following its implementation in 2019. We analysed the clinical and molecular data of CF patients treated at the only tertiary hospital in Latvia providing specialised healthcare for the disorder. Between 1997 and 2022, 66 CF patients from 62 families were diagnosed based on symptoms or a molecular confirmation (six patients were diagnosed through the CF newborn screening programme). F508del was identified in 70.5% of all CF chromosomes. Known variants were identified in more than one family: dele2,3, R1006H, L1335P, W57R, R553X, 2143delT and 3849+10kb C>T (legacy names used). Furthermore, two novel variants were identified, namely, c.503C>A p.(Ser168Ter) and c.(743+1_744-1)_(1584+1_1585-1)del p.(?). The available follow-up results indicated that Latvian CF patients demonstrated similar tendencies to CF patients worldwide. The oldest age at diagnosis prior to the implementation of the CF newborn screening programme was 14 years. We provide here, for the first time, a comprehensive description of Latvian CF patients. An improvement in the healthcare of CF patients over time, including access to diagnosis, is evident. Two novel CF-causing variants are reported, and F508del is the most frequently occurring variant in the population, thus suggesting that F508del screening should be followed by the testing of the full CFTR gene.

Personalized Selection of a CFTR Modulator for a Patient with a Complex Allele [L467F;F508del]

The presence of complex alleles in the CFTR gene can lead to difficulties in diagnosing cystic fibrosis and cause resistance to therapy with CFTR modulators. Tezacaftor/ivacaftor therapy for 8 months in a patient with the initially established F508del/F508del genotype did not lead to an improvement in her condition—there was no change in spirometry and an increase in the patient’s weight, while there was only a slight decrease in NaCl values, measured by a sweat test. The intestinal current measurements of the patient’s rectal biopsy showed no positive dynamics in the rescue of CFTR function while taking tezacaftor/ivacaftor. The assumption that the patient had an additional mutation in the cis position was confirmed by sequencing the CFTR gene, and the complex allele [L467F;F508del] was identified. Based on the rescue of CFTR function by elexacaftor/tezacaftor/ivacaftor obtained using forskolin-induced swelling on intestinal organoids, the patient was prescribed therapy with this targeted drug. The use of elexacaftor/tezacaftor/ivacaftor for 7 months resulted in a significant improvement in the patient’s clinical condition.

Complementary Dual Approach for In Silico Target Identification of Potential Pharmaceutical Compounds in Cystic Fibrosis

Cystic fibrosis is a genetic disease caused by mutation of the CFTR gene, which encodes a chloride and bicarbonate transporter in epithelial cells. Due to the vast range of geno- and phenotypes, it is difficult to find causative treatments; however, small-molecule therapeutics have been clinically approved in the last decade. Still, the search for novel therapeutics is ongoing, and thousands of compounds are being tested in different assays, often leaving their mechanism of action unknown. Here, we bring together a CFTR-specific compound database (CandActCFTR) and systems biology model (CFTR Lifecycle Map) to identify the targets of the most promising compounds. We use a dual inverse screening approach, where we employ target- and ligand-based methods to suggest targets of 309 active compounds in the database amongst 90 protein targets from the systems biology model. Overall, we identified 1038 potential target–compound pairings and were able to suggest targets for all 309 active compounds in the database.

A pilot study investigating the effects of a manuka honey sinus rinse compared to a standard sinus rinse on sino-nasal outcome test scores in cystic fibrosis patients

Background

People with cystic fibrosis (CF) are prone to bacterial respiratory infections; these are often antibiotic resistant, are difficult to treat, and impact on the quality of life and lung function. The upper respiratory tract can act as a reservoir for these pathogens, and as part of clinical care, sinus rinses are used to alleviate symptoms in the upper airway. We have developed a sinus rinse containing manuka honey, to identify whether it can help improve symptoms or reduce the bacterial load.

Methods

We will undertake a randomised controlled trial where 30 adults with CF will be recruited and randomised to either the control or intervention group. Both groups will follow a sinus rinse protocol for 30 days (± 7 days); the control group will use the standard of care rinse, and the intervention group will use a manuka honey rinse. Both groups will provide samples at day 0 and day 30. The primary outcome measure will be a change in the 22-item Sino-Nasal Outcome Test (SNOT-22) score. Secondary outcomes will include changes to quality of life (questionnaire), bacterial load/community composition, and sputum viscosity.

Discussion

This trial will look at the use of a manuka honey-infused sinus rinse solution on patients diagnosed with cystic fibrosis (CF) suffering with sinusitis; it will allow us to determine the efficacy of the manuka honey sinus rinse compared to standard rinse and will allow us to determine if molecular bacterial diversity analysis will provide in-depth information beyond the usual conventional microbiological. It will allow us to determine the feasibility of recruiting participants to this type of trial, allow us to check participant compliance with the protocol, and inform future studies.

Trial registration

Approval was obtained from the Research Ethics Committee Wales REC7 reference 18/WA/0319. Results of this study will be published at international conferences and in peer-reviewed journals; they will also be presented to the relevant stakeholders and research networks.

Trial registration number: ClinicalTrials.gov Identifier NCT04589897 (retrospectively registered)

Individual Genetic Heterogeneity

Genetic variation has been widely covered in literature, however, not from the perspective of an individual in any species. Here, a synthesis of genetic concepts and variations relevant for individual genetic constitution is provided. All the different levels of genetic information and variation are covered, ranging from whether an organism is unmixed or hybrid, has variations in genome, chromosomes, and more locally in DNA regions, to epigenetic variants or alterations in selfish genetic elements. Genetic constitution and heterogeneity of microbiota are highly relevant for health and wellbeing of an individual. Mutation rates vary widely for variation types, e.g., due to the sequence context. Genetic information guides numerous aspects in organisms. Types of inheritance, whether Mendelian or non-Mendelian, zygosity, sexual reproduction, and sex determination are covered. Functions of DNA and functional effects of variations are introduced, along with mechanism that reduce and modulate functional effects, including TARAR countermeasures and intraindividual genetic conflict. TARAR countermeasures for tolerance, avoidance, repair, attenuation, and resistance are essential for life, integrity of genetic information, and gene expression. The genetic composition, effects of variations, and their expression are considered also in diseases and personalized medicine. The text synthesizes knowledge and insight on individual genetic heterogeneity and organizes and systematizes the central concepts.

Reporting Two Novel Mutations in Two Iranian Families with Cystic Fibrosis, Molecular and Bioinformatic Analysis

Background

Cystic fibrosis (CF) is the most common heredity disease among the Caucasian population. More than 350 known pathogenic variations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene (NM_000492.4) cause CF. Herein, we report the outcome of our investigation in two unrelated Iranian families with CF patients.

Methods

We conducted phenotypic examination, segregation, linkage analysis, and CFTR gene sequencing to define causative mutations.

Results

We found two novel mutations in the present study. The first one was a deletion causing frameshift, c.299delT p.(Leu100Profs*7), and the second one was a missense mutation, c.1857G>T, at nucleotide binding domain 1 of the CFTR protein. Haplotype segregation data supported our new mutation findings.

Conclusion

Findings of this study expand the spectrum of CFTR pathogenic variations and can improve prenatal diagnosis and genetic counseling for CF.

Chloride channels in the lung: Challenges and perspectives for viral infections, pulmonary arterial hypertension, and cystic fibrosis

Fine control over chloride homeostasis in the lung is required to maintain membrane excitability, transepithelial transport as well as intra- and extracellular ion and water homeostasis. Over the last decades, a growing number of chloride channels and transporters have been identified in the cells of the pulmonary vasculature and the respiratory tract. The importance of these proteins is underpinned by the fact that impairment of their physiological function is associated with functional dysregulation, structural remodeling, or hereditary diseases of the lung. This paper reviews the field of chloride channels and transporters in the lung and discusses chloride channels in disease processes such as viral infections including SARS-CoV- 2, pulmonary arterial hypertension, cystic fibrosis and asthma. Although chloride channels have become a hot research topic in recent years, remarkably few of them have been targeted by pharmacological agents. As such, we complement the putative pathophysiological role of chloride channels here with a summary of their therapeutic potential.

Understanding motivation for Australian adolescents and young adults with cystic fibrosis: Modifiable factors to support self-management

Cystic fibrosis (CF) is Australia's most common life limiting genetic condition, characterised by declining health and quality of life (QoL) over time. Despite improvements in treatment, there remains no cure. Adolescents and young adults (AYAs) with CF experience broad impacts to psychosocial functioning and QoL, as well as major transitions in care, all at a time of significant developmental change. The importance of developmentally tailored approaches to youth health care and self-management for young people with CF are well understood. However, to date, models of youth specific self-management have been lacking and motivation for young people with CF has not been well explored. This qualitative study, based on a social constructionist epistemological framework, addresses this gap. A total of 21 AYAs aged 15-30 years were recruited through one paediatric and one adult Australian CF centre. Demographic, clinical and distress data were captured to describe health complexity. Semi-structured interviews were audio-recorded, transcribed and analysed using thematic analysis. Participants were representative of Australian AYAs with CF by demography and clinical status. Alarmingly, over a third reported clinically significant distress. Two themes emerged. The first Identified impacts to motivation and self-management resulting from the challenges of managing CF, life and care. These included time and competing priorities, changing health statis, mental health, social factors, unmet needs and health system complexity. The second identified factors that support motivation including: achievement, meaning and purpose; consequence avoidance; and accountability. These results illustrate the importance of AYA specific, theoretically founded, holistic self-management models which extend beyond current theoretical approaches that aim to understand behaviour change or address barriers, in isolation from motivation. Improved approaches to care based on these findings are essential to foster positive behavioural change, support self-management and foster the best health outcomes for young people living with CF.

Self-reported dental attendance, oral hygiene habits, and dietary habits of adults with cystic fibrosis

AIMS

To evaluate the dental attendance, oral hygiene habits, and dietary habits of adults with Cystic Fibrosis in the Republic of Ireland.

METHODS AND RESULTS

A cross-sectional study was carried out using a structured anonymous questionnaire. A total of 71 adults with Cystic Fibrosis responded. While the majority of respondents (66.2%) saw a dentist in the preceding year, 15.5% had not attended a dentist for over 2 years. Smoking and alcohol consumption levels were low. 63.4% brushed twice or more daily, with 70.4% using a Fluoride containing toothpaste. 62% did not use any interdental cleaning aid. 5.6% changed their toothbrush at least once a month, but for 22.5% it was over 6 months. 70.4% used fluoride toothpaste. 38% snacked three or more times daily and 29.5% consumed fizzy drinks at least once daily.

CONCLUSIONS

The alcohol and tobacco consumption in this study group was low. However, a large proportion frequently consumed sugar-rich foods, and they did not change their toothbrush, brush their teeth, or attend the dentist as regularly as is advised. More targeted advice may be necessary to improve the oral hygiene habits of adults with Cystic Fibrosis.

Cystic Fibrosis and Oxidative Stress: The Role of CFTR

There is substantial evidence in the literature that patients with cystic fibrosis (CF) have higher oxidative stress than patients with other diseases or healthy subjects. This results in an increase in reactive oxygen species (ROS) and in a deficit of antioxidant molecules and plays a fundamental role in the progression of chronic lung damage. Although it is known that recurrent infection–inflammation cycles in CF patients generate a highly oxidative environment, numerous clinical and preclinical studies suggest that the airways of a patient with CF present an inherently abnormal proinflammatory milieu due to elevated oxidative stress and abnormal lipid metabolism even before they become infected. This could be directly related to cystic fibrosis transmembrane conductance regulator (CFTR) deficiency, which appears to produce a redox imbalance in epithelial cells and extracellular fluids. This review aims to summarize the main mechanism by which CFTR deficiency is intrinsically responsible for the proinflammatory environment that characterizes the lung of a patient with CF.

Emerging Concepts in Defective Macrophage Phagocytosis in Cystic Fibrosis

Cystic fibrosis (CF) is caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Chronic inflammation and decline in lung function are major reasons for morbidity in CF. Mutant CFTR expressed in phagocytic cells such as macrophages contributes to persistent infection, inflammation, and lung disease in CF. Macrophages play a central role in innate immunity by eliminating pathogenic microbes by a process called phagocytosis. Phagocytosis is required for tissue homeostasis, balancing inflammation, and crosstalk with the adaptive immune system for antigen presentation. This review focused on (1) current understandings of the signaling underlying phagocytic mechanisms; (2) existing evidence for phagocytic dysregulation in CF; and (3) the emerging role of CFTR modulators in influencing CF phagocytic function. Alterations in CF macrophages from receptor initiation to phagosome formation are linked to disease progression in CF. A deeper understanding of macrophages in the context of CFTR and phagocytosis proteins at each step of phagosome formation might contribute to the new therapeutic development of dysregulated innate immunity in CF. Therefore, the review also indicates future areas of research in the context of CFTR and macrophages.

Lung Organoids—The Ultimate Tool to Dissect Pulmonary Diseases?

Organoids are complex multicellular three-dimensional (3D) in vitro models that are designed to allow accurate studies of the molecular processes and pathologies of human organs. Organoids can be derived from a variety of cell types, such as human primary progenitor cells, pluripotent stem cells, or tumor-derived cells and can be co-cultured with immune or microbial cells to further mimic the tissue niche. Here, we focus on the development of 3D lung organoids and their use as disease models and drug screening tools. We introduce the various experimental approaches used to model complex human diseases and analyze their advantages and disadvantages. We also discuss validation of the organoids and their physiological relevance to the study of lung diseases. Furthermore, we summarize the current use of lung organoids as models of host-pathogen interactions and human lung diseases such as cystic fibrosis, chronic obstructive pulmonary disease, or SARS-CoV-2 infection. Moreover, we discuss the use of lung organoids derived from tumor cells as lung cancer models and their application in personalized cancer medicine research. Finally, we outline the future of research in the field of human induced pluripotent stem cell-derived organoids.

Development of excipients free inhalable co-spray-dried tobramycin and diclofenac formulations for cystic fibrosis using two and three fluid nozzles

This study aims to investigate the effect of physicochemical properties and aerosol performance of two (2FN) and three-fluid nozzles (3FN) on the inhalable co-formulation of tobramycin and diclofenac dry powders. Combination formulations of tobramycin and diclofenac at 2:1 and 4:1 w/w ratios were prepared at a laboratory scale using a spray dryer in conjunction with a 2FN or 3FN. Powder size, morphology, solid-state characteristics, and aerodynamic and dissolution properties were characterised. The nozzle types and the formulation composition influenced the yield, particle size, solid-state properties, aerosolization behaviour and dissolution of the co-spray dried formulations. In particular, using the 2FN the co-spray dried formulation of tobramycin and diclofenac at 2:1 w/w showed smaller particle size (D50, 3.01 ± 0.06 μm), high fine particle fractions (FPF) (61.1 ± 3.6% for tobramycin and 65.92 ± 3 for diclofenac) and faster dissolution with approx. 70% diclofenac released within 3 h and approx. 90% tobramycin was released within 45 min. However, the 3FN for the co-spray dried formulation of tobramycin and diclofenac at a 2:1 w/w ratio showed a larger particle size (D50, 3.42 ± 0.02 μm), lower FPF (40.6 ± 3.4% for tobramycin and 36.9 ± 0.84 for diclofenac) and comparative slower dissolution with approx. 60% diclofenac was released within 3 h and 80% tobramycin was released within 45 min. A similar trend was observed when the tobramycin to diclofenac ratio was increased to 4:1 w/w. Overall results suggest that spray drying with 2FN showed a superior and viable approach to producing excipients-free inhalable co-spray dried formulations of tobramycin and diclofenac. However, the formulation produced using the 3FN showed higher enrichment of hydrophobic diclofenac and an ability to control the tobramycin drug release in vitro.

Analysis of the genotypic profile and its relationship with the clinical manifestations in people with cystic fibrosis: study from a rare disease registry

Background

Cystic fibrosis (CF) has a vast and heterogeneous mutational spectrum in Europe. This variability has also been described in Spain, and there are numerous studies linking CFTR variants with the symptoms of the disease. Most of the studies analysed determinate clinical manifestations or specific sequence variants in patients from clinical units. Others used registry data without addressing the genotype–phenotype relationship. Therefore, the objective of this study is to describe the genetic and clinical characteristics of people with CF and to analyse the relationship between both using data from the rare disease registry of a region in southeastern Spain.

Methods

A cross-sectional study was carried out in people with a confirmed diagnosis of CF registered in the Rare Diseases Information System (SIER) of the Region of Murcia (Spain). The patients were classified into two genotypes according to the functional consequence that the genetic variants had on the CFTR protein.

Results

There were 192 people diagnosed with CF reported in the Region of Murcia as of 31 December 2018. Seventy-six genotypes and 49 different variants were described, with c.1521_1523delCTT (p. Phe508del) being the most common in 58.3% of the CF patients and 37.0% of the alleles. In addition, 67% of the patients were classified as a high-risk genotype, which was associated with a lower percentage of FEV₁ (OR: 5.3; 95% CI: 1.2, 24.4), an increased risk of colonization by Pseudomonas aeruginosa (OR: 7.5; 95% CI: 1.7, 33.0) and the presence of pancreatic insufficiency (OR: 28.1; 95% CI: 9.3, 84.4) compared to those with a low-risk genotype.

Conclusions

This is the first study in Spain that describes the mutational spectrum and its association with clinical manifestations in patients with CF using data from a rare disease registry. The results obtained allow planning for the health resources needed by people with this disease, thus contributing to the development of personalized medicine that helps to optimize health care in CF patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02373-y.

Impact of illness on mothers of children with cystic fibrosis in Tunisia: A qualitative interview study: Impact of cystic fibrosis on Tunisian mothers

BACKGROUND

Caring for a child with cystic fibrosis (CF) is challenging and stressful and even more so in a country with limited resources. Our aim was to study the impact of CF on the daily life of mothers with children who have CF in Tunisia, emphasizing the difficulties encountered.

METHODS

Overall, 20 participants were interviewed about their experiences of being caregivers and mothers of children with CF, including their knowledge about the condition, their attitude toward it, the impact of CF on their daily lives, the main difficulties they had faced, and their concerns and wishes about CF management.

RESULTS

The median age of the interviewees was 39 years. None of the mothers had known about CF before; 14 of them had difficulty accepting it at first, with suicidal thoughts in one case. Six hid the illness from the close family for fear of negative prejudices. Three mothers decided to stop having children despite availability of prenatal screening. CF also influenced the mothers' social activities (n = 13) and interfered with their jobs (n = 5). It was responsible for additional expenses in all cases. Chest physiotherapy represented a daily source of coping for all participants. Hospitalization related to Pseudomonas aeruginosa infection was considered stressful and constraining by 12 mothers. The mothers' main concern was the child's life expectancy (n = 7). Their main wish was to administer a curative treatment (n = 17).

CONCLUSION

CF was found to have deeply affected the mothers' psychosocial life stressing the need for the involvement of qualified psychologists and social workers together with the medical staff.

One Size Does Not Fit All: The Past, Present and Future of Cystic Fibrosis Causal Therapies

Cystic fibrosis (CF) is the most common monogenic disorder, caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Over the last 30 years, tremendous progress has been made in understanding the molecular basis of CF and the development of treatments that target the underlying defects in CF. Currently, a highly effective CFTR modulator treatment (Kalydeco™/Trikafta™) is available for 90% of people with CF. In this review, we will give an extensive overview of past and ongoing efforts in the development of therapies targeting the molecular defects in CF. We will discuss strategies targeting the CFTR protein (i.e., CFTR modulators such as correctors and potentiators), its cellular environment (i.e., proteostasis modulation, stabilization at the plasma membrane), the CFTR mRNA (i.e., amplifiers, nonsense mediated mRNA decay suppressors, translational readthrough inducing drugs) or the CFTR gene (gene therapies). Finally, we will focus on how these efforts can be applied to the 15% of people with CF for whom no causal therapy is available yet.

New drugs in cystic fibrosis: what has changed in the last decade?

Cystic fibrosis (CF), a life-limiting chronic disease caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) gene, affects more than 90,000 people worldwide. Until recently, the only available treatments were directed to symptom control, but they failed to change the course of the disease. New drugs developed in the last decade have the potential to change the expression, function, and stability of CFTR protein, targeting the basic molecular defect. The authors seek to provide an update on the new drugs, with a special focus on the most promising clinical trials that have been carried out to date. These newly approved drugs that target specific CFTR mutations are mainly divided into two main groups of CFTR modulators: potentiators and correctors. New therapies have opened the door for potentially disease-modifying, personalized treatments for patients with CF.

Surface Hydration Protects Cystic Fibrosis Airways from Infection by Restoring Junctional Networks

Defective hydration of airway surface mucosa is associated with recurrent lung infection in cystic fibrosis (CF), a disease caused by CF transmembrane conductance regulator (CFTR) gene mutations. Whether the composition and/or presence of an airway surface liquid (ASL) is sufficient to prevent infection remains unclear. The susceptibility to infection of polarized wild type and CFTR knockdown (CFTR-KD) airway epithelial cells was determined in the presence or absence of a healthy ASL or physiological saline. CFTR-KD epithelia exhibited strong ASL volume reduction, enhanced susceptibility to infection, and reduced junctional integrity. Interestingly, the presence of an apical physiological saline alleviated disruption of the airway epithelial barrier by stimulating essential junctional protein expression. Thus, rehydrated CFTR-KD cells were protected from infection despite normally intense bacterial growth. This study indicates that an epithelial integrity gatekeeper is modulated by the presence of an apical liquid volume, irrespective of the liquid's composition and of expression of a functional CFTR.

Sputum Metabolites Associated with Nontuberculous Mycobacterial Infection in Cystic Fibrosis

Nontuberculous mycobacterial (NTM) pulmonary infections in people with cystic fibrosis (CF) are associated with significant morbidity and mortality and are increasing in prevalence. Host risk factors for NTM infection in CF are largely unknown. We hypothesize that the airway microbiota represents a host risk factor for NTM infection. In this study, 69 sputum samples were collected from 59 people with CF; 42 samples from 32 subjects with NTM infection (14 samples collected before incident NTM infection and 28 samples collected following incident NTM infection) were compared to 27 samples from 27 subjects without NTM infection. Sputum samples were analyzed with 16S rRNA gene sequencing and metabolomics. A supervised classification and correlation analysis framework (sparse partial least-squares discriminant analysis [sPLS-DA]) was used to identify correlations between the microbial and metabolomic profiles of the NTM cases compared to the NTM-negative controls. Several metabolites significantly differed in the NTM cases compared to controls, including decreased levels of tryptophan-associated and branched-chain amino acid metabolites, while compounds involved in phospholipid metabolism displayed increased levels. When the metabolome and microbiome data were integrated by sPLS-DA, the models and component ordinations showed separation between the NTM and control samples. While this study could not determine if the observed differences in sputum metabolites between the cohorts reflect metabolic changes that occurred as a result of the NTM infection or metabolic features that contributed to NTM acquisition, it is hypothesis generating for future work to investigate host and bacterial community factors that may contribute to NTM infection risk in CF.

IMPORTANCE Host risk factors for nontuberculous mycobacterial (NTM) infection in people with cystic fibrosis (CF) are largely unclear. The goal of this study was to help identify potential host and bacterial community risk factors for NTM infection in people with CF, using microbiome and metabolome data from CF sputum samples. The data obtained in this study identified several metabolic profile differences in sputum associated with NTM infection in CF, including 2-methylcitrate/homocitrate and selected ceramides. These findings represent potential risk factors and therapeutic targets for preventing and/or treating NTM infections in people with CF.

CFTR Modulator Therapies: Potential Impact on Airway Infections in Cystic Fibrosis

Cystic Fibrosis (CF) is an autosomal recessive disease caused by mutations in the gene encoding for the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) protein, expressed on the apical surface of epithelial cells. CFTR absence/dysfunction results in ion imbalance and airway surface dehydration that severely compromise the CF airway microenvironment, increasing infection susceptibility. Recently, novel therapies aimed at correcting the basic CFTR defect have become available, leading to substantial clinical improvement of CF patients. The restoration or increase of CFTR function affects the airway microenvironment, improving local defence mechanisms. CFTR modulator drugs might therefore affect the development of chronic airway infections and/or improve the status of existing infections in CF. Thus far, however, the full extent of these effects of CFTR-modulators, especially in the long-term remains still unknown. This review aims to provide an overview of current evidence on the potential impact of CFTR modulators on airway infections in CF. Their role in affecting CF microbiology, the susceptibility to infections as well as the potential efficacy of their use in preventing/decreasing the development of chronic lung infections and the recurrent acute exacerbations in CF will be critically analysed.

The changing landscape of pediatric lung transplantation

There has been a shift over decades in the diagnostic indications for lung transplantation in children; in particular, there has been a reduction in the proportion of pediatric cystic fibrosis (CF) patients undergoing lung transplantation early in life, and more transplants occurring in other diagnostic groups. Here, we examine trends in pediatric lung transplantation with regards to indication by analyzing data from the United Network of Organ Sharing, the International Society for Heart and Lung Transplantation Thoracic Transplant Registry, and other sources. Over the past two years, there has been a precipitous decline in both the number of transplants due to CF and the proportion of CF cases relative to the total number of transplants, likely not solely due to the COVID-19 pandemic. In 2020, primary pulmonary arterial hypertension for the first time surpassed CF as main indication for pediatric lung transplantation in the United States, a finding that is also reflected in international data. We discuss the effect of novel CFTR modulator therapies as a major factor leading to this shifting landscape. Based on our trending, pulmonary hypertension-related diagnoses and pediatric interstitial lung diseases are rising indications, for which we suggest adjustments of consensus guidelines around candidate selection criteria. This article is protected by copyright. All rights reserved.

Pediatric population with cystic fibrosis in the centre of Portugal: candidates for new therapies

OBJECTIVES

Cystic fibrosis (CF) is a severe autosomal recessive disease that results from mutations in a gene encoding the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, a chloride channel. This study aims to characterize the clinical and genetic features of a cohort of pediatric people with CF (PwCF) in the center of Portugal and to determine which ones are candidates for the new drugs modulating the CFTR channel.

METHODS

A review of the demographic, genetic and clinical characteristics of PwCF undergoing follow-up at a CF reference center was carried out.

RESULTS

Twenty-three PwCF (12 male), with a median age of 12 years, were followed up. All patients carry the F508del mutation in at least one allele. Fifteen PwCF were F508del-homozygous, median BMI z-score was -0.13, all are pancreatic insufficient and median FEV1 value was 78.1%. These PwCF are eligible for dual therapy (lumacaftor/tezacaftor+ivacaftor) and for triple therapy (tezacaftor+ivacaftor+elexacaftor). PwCF with 711 +1G->T (n = 2), 2184insA (n = 1) mutations and a novel mutation c.3321dup (n = 1) have minimal function mutation and patients with a residual function mutation: R334W (n = 3) and P5L (n = 1) have a less severe phenotype. All these patients, because they also carry F508del mutation, are elegible to triple therapy.

CONCLUSIONS

Genetic and molecular characterization of PwCF poses an important step not just for CF diagnosis and prognosis which is tightly correlated with the clinical phenotype, but also for the eligibility of CFTR modulator drugs.