Persistence and evolution of Pseudomonas aeruginosa following initiation of highly effective modulator therapy in cystic fibrosis.

Today, more than 90% of people with cystic fibrosis (pwCF) are eligible for the highly effective cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy called elexacaftor/tezacaftor/ivacaftor (ETI) and its use is widespread. Given the drastic respiratory symptom improvement experienced by many post-ETI, clinical studies are already underway to reduce the number of respiratory therapies, including antibiotic regimens, that pwCF historically relied on to combat lung disease progression. Early studies suggest that bacterial burden in the lungs is reduced post-ETI, yet it is unknown how chronic Pseudomonas aeruginosa populations are impacted by ETI. We found that pwCF remain infected throughout their upper and lower respiratory tract with their same strain of P. aeruginosa post-ETI, and these strains continue to evolve in response to the newly CFTR-corrected airway. Our work underscores the continued importance of CF airway microbiology in the new era of highly effective CFTR modulator therapy. IMPORTANCE: The highly effective cystic fibrosis transmembrane conductance regulator modulator therapy Elexakaftor/Tezacaftor/Ivacaftor (ETI) has changed cystic fibrosis (CF) disease for many people with cystic fibrosis. While respiratory symptoms are improved by ETI, we found that people with CF remain infected with Pseudomonas aeruginosa. How these persistent and evolving bacterial populations will impact the clinical manifestations of CF in the coming years remains to be seen, but the role and potentially changing face of infection in CF should not be discounted in the era of highly effective modulator therapy.

Glycemic Variability and the Thickness of Retinal Layers in Cystic Fibrosis Patients with and without Cystic Fibrosis Related Diabetes.

PURPOSE: Patients with cystic fibrosis (CF) are at risk to develop CF related diabetes (CFRD) and subsequently even diabetic neuro- and/or vasculopathy. We sought to determine if there are typical signs of diabetes-related retinal alterations present in CF patients with preserved and impaired glycemic control. METHODS: During routine annual examination CF patients were offered an additional 7-day period of real time continuous glucose monitoring (rtCGM) and an ophthalmological examination including retinal optical coherence tomography (OCT). Patients were categorized according to the glycemic control, i.e. the results of an oral glucose tolerance test (OGTT) and rtCGM were taken into consideration. OCT data was analyzed by our previously published visual analysis software generating dedicated and spatially resolved deviation maps for visualization and quantification of differences in total retinal thickness and thickness of retinal nerve fiber layer (RNFL) as well as ganglion cell layer (GCL) in comparison to age-matched healthy controls and patients with either type 1 or type 2 diabetes mellitus. RESULTS: Results of the rtCGM and/or OGTT enabled discrimination between patients with normal glycemic control (CFNG; n = 6), with abnormal glycemic control (CFAG; n = 6) and overt CFRD (n = 4). OCT data indicates gradually increasing retinal thinning in all 3 groups, depending on the degree of glucose metabolism disorder compared to healthy controls. At the foveal region total retinal thickness and GCL thickness were significantly thinner in CFRD patients compared to CFNG patients (total retinal thickness: 260.4 µm (239.3-270.8) vs. 275.4 µm (254.3-289.5); GCL: 11.82 µm (11.16-15.25) vs. 17.30 µm (13.95-19.82); each p < 0.05). CONCLUSION: Although we investigated a rather small number of patients, we obtained evidence that intraretinal neurodegenerative changes occur in each of our subgroups (CFNG, CFAG, CFRD). Beyond this, our results favor the detrimental role of additional diabetes, as the deviations from healthy controls were most pronounced in the CFRD group and are similar to those seen in patients suffering from type 1 or type 2 diabetes.

Prevalence, stability, and clinical significance of an isolated low FEV1 spirometry pattern in children.

OBJECTIVES: In adults, an isolated low FEV1 pattern (an FEV1 below the lower limit of normal with a preserved FVC and FEV1/FVC) has been associated with the risk of developing airway obstruction. Our objective was to examine the prevalence, stability, and clinical significance of an isolated low FEV1 pattern in the pediatric population. METHODS: We conducted a retrospective study of spirometries from children ages 6-21 years and categorized tests into spirometry patterns according to published guidelines and recent literature. In a subgroup of tests with an isolated low FEV1 pattern, we evaluated spirometry technique. We also examined the association of having a test with an isolated low FEV1 pattern with clinical markers of disease severity in a subgroup of children with cystic fibrosis (CF). RESULTS: The isolated low FEV1 pattern was uncommon across the 29,979 tests included (n = 645 [2%]). In the 263 children with an isolated low FEV1 pattern who had a follow-up test performed, the most frequent spirometry pattern at last test was normal (n = 123 [47%]). A primary diagnosis of CF was associated with increased odds of having at least one test with an isolated low FEV1 pattern (OR = 8.37, 95% CI = 4.70-15.96, p < .001). The spirometry quality in a subgroup of tests with an isolated low FEV1 pattern (n = 50) was satisfactory. In the subgroup of children with CF (n = 102), those who had a test with an isolated low FEV1 pattern had higher odds of using oral antibiotics in the last 12 months than those who had a normal pattern (OR = 3.50, 95% CI = 1.15-10.63, p = .03). CONCLUSIONS: The isolated low FEV1 pattern can occur repeatedly over time, usually transitions to a normal pattern, is not due to a poor spirometry technique, and could be clinically relevant in children with chronic lung diseases.

Effect of Elexacaftor/Tezacaftor/Ivacaftor on Pseudomonas aeruginosa Acquisition and Chronic Infection at a Single Pediatric Cystic Fibrosis Care Center.

OBJECTIVES: As cystic fibrosis (CF) lung disease progresses, the airways become infected with opportunistic pathogens, such as Pseudomonas aeruginosa (PA). In October 2019, the US Food and Drug Administration approved elexacaftor/tezacaftor/ivacaftor (ETI), a highly effective modulator therapy (HEMT), for individuals 12 years and older with 1 copy of the F508del cystic fibrosis transmembrane conductance regulator (CFTR) mutation. ETI increases the amount of and function of CFTR in the respiratory epithelium, improving mucociliary clearance and reducing static airway mucus, a major trigger for chronic infection and inflammation. METHODS: A retrospective analysis of inhaled tobramycin (iTOB) prescriptions between January 1, 2016, and December 31, 2021, was performed. This captured data before and after ETI approval at Children's Mercy Kansas City (CMKC). The number of individuals with new PA acquisition and individuals considered -chronically infected was analyzed. RESULTS: The number of eradication prescriptions declined in 2020 and 2021, with 15 (7%) and 12 (5%) -individuals prescribed therapy for those years, respectively. A similar pattern was observed for -prescriptions for chronic infection. A reduction was seen in 2020 and 2021, with 28 (13%) and 20 (9%) individuals -prescribed therapy for the respective years. CONCLUSIONS: The CMKC experienced a decrease in the number of courses of iTOB prescribed during the last 6 years. The reasons for this are likely multifactorial and may include the implementation of standardized PA surveillance and eradication protocols, the effect of HEMT on mucociliary clearance and airway microbiology, and the poorly understood effects of the SARS-CoV-2 pandemic on the epidemiology of respiratory infections.

Identification of an ultra-rare Alu insertion in the CFTR gene: Pitfalls and challenges in genetic test interpretation.

Cystic fibrosis (CF) is a life-limiting genetic disorder characterized by defective chloride ion transport due to mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Early detection through newborn screening programs significantly improves outcomes for individuals with CF by enabling timely intervention. Here, we report the identification of an Alu element insertion within the exon 15 of CFTR gene, initially overlooked in standard next-generation sequencing analyses. However, using traditional molecular techniques, based on polymerase chain reaction and Sanger sequencing, allowed the identification of the Alu element and the reporting of a correct diagnosis. Our analysis, based on bioinformatics tools and molecular techniques, revealed that the Alu element insertion severely affects the gene expression, splicing patterns, and structure of CFTR protein. In conclusion, this study emphasizes the importance of how the integration of human expertise and modern technologies represents a pivotal step forward in genomic medicine, ensuring the delivery of precision healthcare to individuals affected by genetic diseases.

Attitudes to cross infection, nebuliser hygiene and antimicrobial resistance in people with cystic fibrosis: Results of an international survey.

BACKGROUND: Respiratory infection is a major cause of disease severity in people with cystic fibrosis (PwCF). This project aimed to establish the CF community's opinion regarding cross infection (CI), nebuliser hygiene, antimicrobial resistance, personal impact of microbiological findings and the role of the microbiology laboratory. METHODS: A questionnaire was completed anonymously (n = 280; PwCF (n = 128), parents (n = 123); friends/family/carers/charity personnel (n = 29)) from 13 countries. Readability scores (Flesch Reading Ease (FRE), Flesch Kincaid Grade Level (FKGL)) were determined for CI/IP&C information from six national CF charities and 21 scientific abstracts. RESULTS: Respondents (72.5%) indicated knowledge of laboratory aspects of CF microbiology was important, however implications of microbiological findings on personal health/well-being were of higher importance (p < 0.0001). Cross infection/infection prevention & control (CI/IP&C) was of highest importance (95.6% respondents) with 27.3% indicating they were not given adequate information, particularly in older respondents (50 y+) (p = 0.006) versus young adults (16-29 y) and respondents from the Middle East versus N. America (p = 0.022) and Europe (p = 0.045). Responses highlighted how CI/IP&C health literacy could be enhanced. Respondents (77.3%), particularly females (p < 0.0001), indicated they would increase the frequency of nebuliser disinfection following guidance on infection risks/best practice, therefore an educational video was prepared. CI/IP&C readability scores (mean ± sd) from CF charities (FRE 52.5 ± 10.8; FKGL 9.7 ± 2.3) were more readable (p < 0.0001) than scientific abstracts (FRE 13.3 ± 11.1; FKGL 16.9 ± 2.3), however not meeting the targets (FRE≥60 and FKGL≤8). CONCLUSION: There is a requirement for further CI/IP&C evidence-based guidance, policies/guidelines, education awareness, best practice in the home environment and multi-modal communication, enabling the CF community to make informed choices on lifestyle behaviours.

Impact of pseudomonas aeruginosa on resource utilization and costs in patients with exacerbated non-cystic fibrosis bronchiectasis.

Aims Non-cystic fibrosis bronchiectasis (NCFB) is a chronic progressive respiratory disorder occurring at a rate ranging from 4.2 to 278.1 cases per 100,000 persons, depending on age, in the United States. For many patients with NCFB, the presence of Pseudomonas aeruginosa (PA) makes treatment more complicated and typically has worse outcomes. Management of NCFB can be challenging, warranting a better understanding of the burden of illness for NCFB, treatments applied, healthcare resources used, and subsequent treatment costs. Comparing patients diagnosed with exacerbated NCFB, with or without PA on antibiotic utilization, treatments, and healthcare resources utilization and costs, was the purpose of this study.Materials and Methods This was a retrospective cohort study of commercial claims from IQVIA's PharMetrics Plus database (01/01/2006-12/31/2020). Study patients with a diagnosis of NCFB were stratified into two groups based on presence or absence of PA, then followed to identify demographic characteristics, comorbid conditions, antibiotic treatment regimen prescribed, healthcare resources utilized, and costs of care.Results The results showed that patients with exacerbated NCFB who were PA+ had significantly more oral antibiotic fills per patient per year, more inpatient admissions with a longer length of stay, and more outpatient encounters than those who were PA-. For costs, PA+ patients also had significantly greater total healthcare costs per patient when compared to those who were PA-.Conclusion Exacerbated NCFB with PA+ was associated with increased antibiotic usage, greater resource utilization, and increased costs. The major contributor to the cost differences was the use of inpatient services. Treatment strategies aimed at reducing the need for inpatient treatment could lessen the disparities observed in patients with NCFB.

Cystic fibrosis in Iceland and the high prevalence of the N1303K variant.

BACKGROUND: Cystic fibrosis (CF) is most common in populations of Northern European ancestry where the F508del variant predominates. In 2020, Iceland became a member of the European Cystic Fibrosis Society Patient Registry, and we launched an epidemiological study of CF in Iceland. The study aimed to determine the prevalence and the genetic variants present in the country. Furthermore, we aimed to describe the previous and the current situation regarding lung function, infections, complications, treatment, and follow-up to understand the strengths and weaknesses of CF care in Iceland. METHODS: This retrospective study included all individuals in Iceland with a confirmed CF diagnosis between 1955 and 2021. We conducted a medical records search for CF diagnosis codes and found 30 people with CF who were included in the study. Two hundred sixteen clinical variables were registered. A descriptive analysis of these was performed. RESULTS: The prevalence of CF in Iceland is 0.372:10,000 inhabitants. The F508del is the most common CF transmembrane conductance regulator (CFTR) variant (46.4%), closely followed by N1303K (44.6%). Staphylococcus aureus was the most common airway pathogen, followed by Pseudomonas aeruginosa. Nasal polyps and CF-related diabetes were the most common complications. Modern CF medications, including the recent CFTR modulators, are available. CONCLUSION: Even though Iceland has a relatively low prevalence of CF, it holds the highest known prevalence of the N1303K variant in Europe. Access to necessary treatment is satisfactory, but improvements are advisable for some aspects of the routine assessments by best practice guidelines.

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OBJECTIVES: To investigate the nutritional status of children with cystic fibrosis (CF) and understand the correlation between malnutrition and clinical characteristics as well as lung function. METHODS: A retrospective analysis was performed on clinical data of CF children admitted from January 2016 to June 2023. Clinical characteristics of CF children with different nutritional statuses were compared, and the correlation between malnutrition and lung function was analyzed. RESULTS: A total of 52 CF children were included, comprising 25 boys (48%) and 27 girls (52%), aged between 7 months and 17 years. Respiratory symptoms were the predominant clinical manifestations (96%, 50/52). The prevalence of malnutrition was 65% (34/52), with moderate/severe malnutrition being the most common (65%, 22/34). The malnutrition group had a longer duration of illness, higher proportion of digestive system symptoms, and lower levels of serum albumin (P<0.05). Pulmonary function parameters, including forced expiratory volume in one second as a percentage of the predicted value, ratio of forced expiratory volume in one second to forced vital capacity, forced expiratory flow at 25% of forced vital capacity exhaled, forced expiratory flow at 50% of forced vital capacity exhaled, forced expiratory flow at 75% of forced vital capacity exhaled, and maximum mid-expiratory flow as a percentage of the predicted value, were lower in the malnutrition group compared to the normal nutrition group (P<0.05). Correlation analysis showed body mass index Z-score was positively correlated with the above six pulmonary function parameters (P<0.05). CONCLUSIONS: The prevalence of malnutrition is high in CF children and is associated with decreased lung function. CF children with higher body mass index have better lung function. Therefore, screening and evaluation of nutritional status as well as appropriate nutritional intervention should be emphasized in CF children.

Genome-scale model of Rothia mucilaginosa predicts gene essentialities and reveals metabolic capabilities.

Cystic fibrosis (CF), an inherited genetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator gene, results in sticky and thick mucosal fluids. This environment facilitates the colonization of various microorganisms, some of which can cause acute and chronic lung infections, while others may positively impact the disease. Rothia mucilaginosa, an oral commensal, is relatively abundant in the lungs of CF patients. Recent studies have unveiled its anti-inflammatory properties using in vitro three-dimensional lung epithelial cell cultures and in vivo mouse models relevant to chronic lung diseases. Apart from this, R. mucilaginosa has been associated with severe infections. However, its metabolic capabilities and genotype-phenotype relationships remain largely unknown. To gain insights into its cellular metabolism and genetic content, we developed the first manually curated genome-scale metabolic model, iRM23NL. Through growth kinetics and high-throughput phenotypic microarray testings, we defined its complete catabolic phenome. Subsequently, we assessed the model's effectiveness in accurately predicting growth behaviors and utilizing multiple substrates. We used constraint-based modeling techniques to formulate novel hypotheses that could expedite the development of antimicrobial strategies. More specifically, we detected putative essential genes and assessed their effect on metabolism under varying nutritional conditions. These predictions could offer novel potential antimicrobial targets without laborious large-scale screening of knockouts and mutant transposon libraries. Overall, iRM23NL demonstrates a solid capability to predict cellular phenotypes and holds immense potential as a valuable resource for accurate predictions in advancing antimicrobial therapies. Moreover, it can guide metabolic engineering to tailor R. mucilaginosa's metabolism for desired performance.IMPORTANCECystic fibrosis (CF) is a genetic disorder characterized by thick mucosal secretions, leading to chronic lung infections. Rothia mucilaginosa is a common bacterium found in various parts of the human body, acting as a normal part of the flora. In people with weakened immune systems, it can become an opportunistic pathogen, while it is prevalent and active in CF airways. Recent studies have highlighted its anti-inflammatory properties in the lower pulmonary system, indicating the intricate relationship between microbes and human health. Herein, we have developed the first manually curated metabolic model of R. mucilaginosa. Our study examined the previously unknown relationships between the bacterium's genotype and phenotype and identified essential genes that impact the metabolism under various conditions. With this, we opt for paving the way for developing new strategies in antimicrobial therapy and metabolic engineering, leading to enhanced therapeutic outcomes in cystic fibrosis and related conditions.

The prevalence of developmental defects of enamel in people with cystic fibrosis: a systematic review.

BACKGROUND: Oral health impacts systemic health, individual well-being, and quality of life. It is important to identify conditions that may exacerbate oral disease to aid public health and policy development and promote targeted patient treatment strategies. Developmental defects can increase an individual's risk of dental caries, hypersensitivity, premature tooth wear, erosion, and poor aesthetics. As part of an ongoing study assessing oral health in adults with cystic fibrosis at Cork University Dental School and Hospital, a systematic review of available literature was conducted to assess the prevalence of enamel defects in people with cystic fibrosis. AIMS: To critically evaluate the literature to determine if the prevalence of developmental defects of enamel is higher in people with cystic fibrosis (PwCF). METHODS: Data Sources: Three online databases were searched Embase, Scopus, and Web of Science Core Collection. Studies that examined an association between cystic fibrosis and developmental defects of enamel were included in this systematic review. RESULTS: The initial search identified 116 publications from the following databases Embase, Web of Science Core Collection, and Scopus. Eleven studies were included for qualitative analysis. Nine studies concluded that PwCF had a higher prevalence of enamel defects than control people and one study found no difference in cystic fibrosis (CF) status. All studies had a risk of bias that may influence study results and their interpretation. CONCLUSIONS: The results of the systematic review show a consistent pattern that PwCF have a higher prevalence of DDE than people without CF. Genetic dysfunction, chronic systemic infections, and long-term antibiotic use are possible aetiological causes. This review highlights the need for future studies to investigate if DDEs are caused by the underlying CFTR mutation or as a consequence of disease manifestations and/or management.

Elevated Prostaglandin E2 Synthesis Is Associated with Clinical and Radiological Disease Severity in Cystic Fibrosis.

Background: Previous studies found high but very variable levels of tetranor-PGEM and PGDM (urine metabolites of prostaglandin (PG) E2 and PGD2, respectively) in persons with cystic fibrosis (pwCF). This study aims to assess the role of cyclooxygenase COX-1 and COX-2 genetic polymorphisms in PG production and of PG metabolites as potential markers of symptoms' severity and imaging findings. Methods: A total of 30 healthy subjects and 103 pwCF were included in this study. Clinical and radiological CF severity was evaluated using clinical scoring methods and chest computed tomography (CT), respectively. Urine metabolites were measured using liquid chromatography/tandem mass spectrometry. Variants in the COX-1 gene (PTGS1 639 C>A, PTGS1 762+14delA and COX-2 gene: PTGS2-899G>C (-765G>C) and PTGS2 (8473T>C) were also analyzed. Results: PGE-M and PGD-M urine concentrations were significantly higher in pwCF than in controls. There were also statistically significant differences between clinically mild and moderate disease and severe disease. Patients with bronchiectasis and/or air trapping had higher PGE-M levels than patients without these complications. The four polymorphisms did not associate with clinical severity, air trapping, bronchiectasis, or urinary PG levels. Conclusions: These results suggest that urinary PG level testing can be used as a biomarker of CF severity. COX genetic polymorphisms are not involved in the variability of PG production.

Diagnosing Cystic Fibrosis in the 21st Century-A Complex and Challenging Task.

Cystic fibrosis (CF) is a chronic and potentially life-threatening condition, wherein timely diagnosis assumes paramount significance for the prompt initiation of therapeutic interventions, thereby ameliorating pulmonary function, addressing nutritional deficits, averting complications, mitigating morbidity, and ultimately enhancing the quality of life and extending longevity. This review aims to amalgamate existing knowledge to provide a comprehensive appraisal of contemporary diagnostic modalities pertinent to CF in the 21st century. Deliberations encompass discrete delineations of each diagnostic modality and the elucidation of potential diagnostic quandaries encountered in select instances, as well as the delineation of genotype-phenotype correlations germane to genetic counseling endeavors. The synthesis underscores that, notwithstanding the availability and strides in diagnostic methodologies, including genetic assays, the sweat test (ST) retains its position as the preeminent diagnostic standard for CF, serving as a robust surrogate for CFTR functionality. Prospective clinical investigations in the realm of CF should be orchestrated with the objective of discerning novel diagnostic modalities endowed with heightened specificity and sensitivity.

Insights into the Adolescent Cystic Fibrosis Airway Microbiome Using Shotgun Metagenomics.

Cystic fibrosis (CF) is an inherited genetic disorder which manifests primarily in airway disease. Recent advances in molecular technologies have unearthed the diverse polymicrobial nature of the CF airway. Numerous studies have characterised the genus-level composition of this airway community using targeted 16S rDNA sequencing. Here, we employed whole-genome shotgun metagenomics to provide a more comprehensive understanding of the early CF airway microbiome. We collected 48 sputum samples from 11 adolescents and children with CF over a 12-month period and performed shotgun metagenomics on the Illumina NextSeq platform. We carried out functional and taxonomic analysis of the lung microbiome at the species and strain levels. Correlations between microbial diversity measures and independent demographic and clinical variables were performed. Shotgun metagenomics detected a greater diversity of bacteria than culture-based methods. A large proportion of the top 25 most-dominant species were anaerobes. Samples dominated by Staphylococcus aureus and Prevotella melaninogenica had significantly higher microbiome diversity, while no CF pathogen was associated with reduced microbial diversity. There was a diverse resistome present in all samples in this study, with 57.8% agreement between shotgun metagenomics and culture-based methods for detection of resistance. Pathogenic sequence types (STs) of S. aureus, Pseudomonas aeruginosa, Haemophilus influenzae and Stenotrophomonas maltophilia were observed to persist in young CF patients, while STs of S. aureus were both persistent and shared between patients. This study provides new insight into the temporal changes in strain level composition of the microbiome and the landscape of the resistome in young people with CF. Shotgun metagenomics could provide a very useful one-stop assay for detecting pathogens, emergence of resistance and conversion to persistent colonisation in early CF disease.

Lipoxygenases at the Intersection of Infection and Carcinogenesis.

The persisting presence of opportunistic pathogens like Pseudomonas aeruginosa poses a significant threat to many immunocompromised cancer patients with pulmonary infections. This review highlights the complexity of interactions in the host's defensive eicosanoid signaling network and its hijacking by pathogenic bacteria to their own advantage. Human lipoxygenases (ALOXs) and their mouse counterparts are integral elements of the innate immune system, mostly operating in the pro-inflammatory mode. Taking into account the indispensable role of inflammation in carcinogenesis, lipoxygenases have counteracting roles in this process. In addition to describing the structure-function of lipoxygenases in this review, we discuss their roles in such critical processes as cancer cell signaling, metastases, death of cancer and immune cells through ferroptosis, as well as the roles of ALOXs in carcinogenesis promoted by pathogenic infections. Finally, we discuss perspectives of novel oncotherapeutic approaches to harness lipoxygenase signaling in tumors.

CFTR pathogenic variants spectrum in a cohort of Mexican patients with cystic fibrosis.

Background: Molecular diagnosis of cystic fibrosis (CF) is challenging in Mexico due to the population's high genetic heterogeneity. To date, 46 pathogenic variants (PVs) have been reported, yielding a detection rate of 77%. We updated the spectrum and frequency of PVs responsible for this disease in mexican patients. Methods: We extracted genomic DNA from peripheral blood lymphocytes obtained from 297 CF patients and their parents. First, we analyzed the five most frequent PVs in the Mexican population using PCR-mediated site-directed mutagenesis. In patients with at least one identified allele, CFTR sequencing was performed using next-generation sequencing tools and multiplex ligation-dependent probe amplification. For variants not previously classified as pathogenic, we used a combination of in silico prediction, CFTR modeling, and clinical characteristics to determine a genotype-phenotype correlation. Results: We identified 95 PVs, increasing the detection rate to 87.04%. The most frequent variants were p.(PheF508del) (42.7%), followed by p.(Gly542*) (5.6%), p.(Ser945Leu) (2.9%), p.(Trp1204*) and p.(Ser549Asn) (2.5%), and CFTRdel25-26 and p.(Asn386Ilefs*3) (2.3%). The remaining variants had frequencies of <2.0%, and some were exclusive to one family. We identified 10 novel PVs localized in different exons (frequency range: 0.1-0.8%), all of which produced structural changes, deletions, or duplications in different domains of the protein, resulting in dysfunctional ion flow. The use of different in silico software and American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) criteria allowed us to assume that all of these PVs were pathogenic, causing a severe phenotype. Conclusions: In a highly heterogeneous population, combinations of different tools are needed to identify the variants responsible for CF and enable the establishment of appropriate strategies for CF diagnosis, prevention, and treatment.

The effect of respiratory muscle training on children and adolescents with cystic fibrosis: a systematic review and meta-analysis.

BACKGROUND: Cystic fibrosis is a chronic genetic disease that can affect the function of the respiratory system. Previous reviews of the effects of respiratory muscle training in people with cystic fibrosis are uncertain and do not consider the effect of age on disease progression. This systematic review aims to determine the effectiveness of respiratory muscle training in the clinical outcomes of children and adolescents with cystic fibrosis. METHODS: Up to July 2023, electronic databases and clinical trial registries were searched. Controlled clinical trials comparing respiratory muscle training with sham intervention or no intervention in children and adolescents with cystic fibrosis. The primary outcomes were respiratory muscle strength, respiratory muscle endurance, lung function, and cough. Secondary outcomes included exercise capacity, quality of life and adverse events. Two review authors independently extracted data and assessed study quality using the Cochrane Risk of Bias Tool 2. The certainty of the evidence was assessed according to the GRADE approach. Meta-analyses where possible; otherwise, take a qualitative approach. RESULTS: Six studies with a total of 151 participants met the inclusion criteria for this review. Two of the six included studies were published in abstract form only, limiting the available information. Four studies were parallel studies and two were cross-over designs. There were significant differences in the methods and quality of the methodology included in the studies. The pooled data showed no difference in respiratory muscle strength, lung function, and exercise capacity between the treatment and control groups. However, subgroup analyses suggest that inspiratory muscle training is beneficial in increasing maximal inspiratory pressure, and qualitative analyses suggest that respiratory muscle training may benefit respiratory muscle endurance without any adverse effects. CONCLUSIONS: This systematic review and meta-analysis indicate that although the level of evidence indicating the benefits of respiratory muscle training is low, its clinical significance suggests that we further study the methodological quality to determine the effectiveness of training. TRIAL REGISTRATION: The protocol for this review was recorded in the International Prospective Register of Systematic Reviews (PROSPERO) under registration number CRD42023441829.

Concentrations of dehydroepiandrosterone-sulphate (DHEA-S) in people with cystic fibrosis on and off elexacaftor-tezacaftor-ivacaftor.

BACKGROUND: Levels of sulfated Dehydroepiandrosterone (DHEA-S) are unknown in people with Cystic Fibrosis (pwCF). DHEA-S is reported to have an inverse association with inflammation and warrants evaluation in pwCF. METHODS: We compared differences in DHEA-S and other hormones between pwCF (n = 180) and without CF (n = 180) and DHEA-S association with percent predicted forced expiratory volume in one second (ppFEV1). We also evaluated DHEA-S levels in people with CF on elexacaftor-tezacaftor-ivacaftor (ETI) (n = 145). RESULTS: PwCF (not on ETI) had lower DHEA-S levels compared to healthy non-CF controls. DHEA-S levels in individuals with CF on ETI were similar to those without CF. Lower DHEA-S levels were associated with lower ppFEV1. CONCLUSIONS: PwCF (not on ETI) have lower levels of DHEA-S than people without CF or people with CF on ETI. Additional studies are needed to investigate the impact of DHEA-S on the health of pwCF and mechanisms involved.