Cystic Fibrosis Disease Research Articles

Neutrophil extracellular traps are associated with airways inflammation and increased severity of lung disease in Cystic Fibrosis

BackgroundCystic Fibrosis (CF) is characterised by inflammatory lung disease and large numbers of airways neutrophils. In health, neutrophils undergo apoptosis and removal from the airway. Since CF neutrophils are known to engage in apoptosis less efficiently, we wanted to assess whether alternative forms of neutrophil clearance such as NETosis were prominent in the CF airway.MethodsSputum and blood were collected from 45 CF and 15 healthy control (HC) participants. Neutrophil morphology and biochemical properties were assessed in CF and HC sputum. Neutrophil Extracellular Traps (NETs) were measured by a novel histone-calprotectin ELISA. NET levels were compared to established measurements of airway inflammation. CF participants were followed up for one year and number of exacerbations recorded. Neutrophil and macrophage co-culture experiments were undertaken with cells from CF and HC.ResultsNeutrophil numbers were significantly higher in CF and associated with abnormal morphology. Several inflammatory mediators were elevated in CF sputum, as was cell-free DNA. This was highly correlated with sputum calprotectin, a known NET associated protein. Using a Histone/Calprotectin NETs ELISA, we demonstrated higher levels of NETs in the CF airway. CF participants treated with DNase had less sputum NETs, and in neutrophil/macrophage co-culture experiments, DNase effectively attenuated the pro-inflammatory potential of NETs, suggesting a previously unrecognised anti-inflammatory role for this treatment.ConclusionsNETs in the CF airway are associated with increased levels of inflammatory mediators and more severe lung disease. NETs effects on macrophages can be blocked by DNase, suggesting an anti-inflammatory role for this treatment in CF.

Telemedicine and home spirometry in cystic fibrosis: A prospective multicenter study.

Telehealth and home spirometry feasibility for children has been established, but their impact on cystic fibrosis (CF) disease progression remains unassessed. We aimed to evaluate the effects of telehealth and home spirometry on CF disease progression and care. Children with CF aged 5-17 years from all Swedish CF centers were provided with home spirometers. A minimum of two in-person visits were replaced with telemedicine visits and participants were instructed to conduct home spirometry before visits. Linear mixed-effects models were used to compare annual CF disease trajectories during the intervention period and prepandemic period (1 January 2019 to 28 February 2020). Participants and caregivers completed study questionnaires. A total of 59 individuals completed the study over a mean (SD) period of 6.8 (1.4) months, made 3.1 (1.0) physical visits and 2.2 (0.6) telehealth visits per patient year during the study period. The mean difference (95% CI) between the intervention and prepandemic period progression rate for FEV1%, lung clearance index and BMI were -0.4 (-1.3 to 0.5, p = 0.39), 0.11 (-0.07 to 0.28, p = 0.25) and -0.02 (-0.13 to 0.08, p = 0.70), respectively. There were no major shifts in the incidence of airway pathogens, sputum cultures, or antibiotics use between the periods (p > 0.05). The intervention did not increase stress. Almost all participants and caregivers expressed a desire to continue with home spirometry and telemedicine. Combining telehealth and physical visits with access to home spirometry demonstrated comparable effectiveness as exclusively in-person care with enhanced flexibility and personalization of CF care.

Comparative sensitivity of early cystic fibrosis lung disease detection tools in school aged children

BackgroundEffective detection of early lung disease in cystic fibrosis (CF) is critical to understanding early pathogenesis and evaluating early intervention strategies. We aimed to compare ability of several proposed sensitive functional tools to detect early CF lung disease as defined by CT structural disease in school aged children. Methods50 CF subjects (mean±SD 11.2 ± 3.5y, range 5–18y) with early lung disease (FEV1≥70 % predicted: 95.7 ± 11.8 %) performed spirometry, Multiple breath washout (MBW, including trapped gas assessment), oscillometry, cardiopulmonary exercise testing (CPET) and simultaneous spirometer-directed low-dose CT imaging. CT data were analysed using well-evaluated fully quantitative software for bronchiectasis and air trapping (AT). ResultsCT bronchiectasis and AT occurred in 24 % and 58 % of patients, respectively. Of the functional tools, MBW detected the highest rates of abnormality: Scond 82 %, MBWTG RV 78 %, LCI 74 %, MBWTG IC 68 % and Sacin 51 %. CPET VO2peak detected slightly higher rates of abnormality (9 %) than spirometry-based FEV1 (2 %). For oscillometry AX (14 %) performed better than Rrs (2 %) whereas Xrs and R5-19 failed to detect any abnormality. LCI and Scond correlated with bronchiectasis (r = 0.55–0.64, p < 0.001) and AT (r = 0.73–0.74, p < 0.001). MBW-assessed trapped gas was detectable in 92 % of subjects and concordant with CT-assessed AT in 74 %. ConclusionsSignificant structural and functional deficits occur in early CF lung disease, as detected by CT and MBW. For MBW, additional utility, beyond that offered by LCI, was suggested for Scond and MBW-assessed gas trapping. Our study reinforces the complementary nature of these tools and the limited utility of conventional oscillometry and CPET in this setting.

Cystic fibrosis cell models for high-throughput analysis and drug screening

Cystic fibrosis (CF) is a single-gene disorder that affects the lung, digestive system, and other organs. Mutations in the CF transmembrane conductance regulator (CFTR) gene are classified into several classes based on their pathogenic mechanism and clinical severity. The distinct and heterogeneous clinical behavior of each CF class and the respective CFTR mutations have made the development of a durable therapy for all CF patients extremely challenging. While the FDA-approved drug elexacaftor/tezacaftor/ivacaftor (Trikafta) benefits CF patients carrying at least one F508del mutation in CFTR, it's not effective for many CF patients carrying a variety of other CFTR mutations. To establish a better understanding of CF pathophysiology and aid the development of novel therapeutics for different classes of CF patients, we have created four CF-mutation-specific cell models that recapitulate respectively four distinct CF classes and disease phenotypes, as confirmed by sequencing, CFTR mRNA and protein quantification. The channel function of each cell model was first validated using a well-established FLIPR (Fluorescent Imaging Plate Reader) membrane potential assay and then assessed by the YFP-based functional assay. Integrated with a halide-sensitive fluorescent reporter, these CF cell models can be used for high-throughput drug screening, as demonstrated by a proof-of-concept study using Trikafta. These cell models have the potential to advance CFTR mutation-specific therapies thus addressing the unmet needs of CF patients with rare mutations.

Disease-specific transcriptional programs govern airway goblet cell metaplasia

Hypersecretion of airway mucus caused by goblet cell metaplasia is a characteristic of chronic pulmonary inflammatory diseases including asthma, cystic fibrosis (CF), and chronic obstructive pulmonary disease (COPD). Goblet cells originate from airway progenitor club cells. However, the molecular mechanisms and features of goblet cell metaplasia in lung disease are poorly understood. Herein, public single-cell RNA sequencing datasets of human lungs were reanalyzed to explore the transitional phase as club cells differentiate into goblet cells in asthma, CF, and COPD. We found that changes in club and goblet cells during pathogenesis and cellular transition were associated with signalling pathways related to immune response, oxidative stress, and apoptosis. Moreover, other key drivers of goblet cell specification appeared to be pathologically specific, with interleukin (IL)-13 and hypoxia inducible factor 1 (HIF-1)-induced genetic changes in asthma, cystic fibrosis transmembrane conductance regulator (CFTR) mutation being present in CF, and interactions with CD8+ T cells, mitophagy, and mitochondria-induced apoptosis in COPD. In conclusion, this study revealed the similarities and differences in goblet cell metaplasia in asthma, CF, and COPD at the transcriptome level, thereby providing insights into possible novel therapeutic approaches for these diseases.

Highly branched poly β-amino ester/CpG-depleted CFTR plasmid nanoparticles for non-viral gene therapy in lung cystic fibrosis disease

Highly branched poly β-amino ester/CpG-depleted CFTR plasmid nanoparticles for non-viral gene therapy in lung cystic fibrosis disease

Analysis of CFTR mRNA and Protein in Peripheral Blood Mononuclear Cells via Quantitative Real-Time PCR and Western Blot.

The Cystic Fibrosis Conductance Transmembrane Regulator gene encodes for the CFTR ion channel, which is responsible for the transport of chloride and bicarbonate across the plasma membrane. Mutations in the gene result in impaired ion transport, subsequently leading to perturbed secretion in all exocrine glands and, therefore, the multi-organ disease cystic fibrosis (CF). In recent years, several studies have reported on CFTR expression in immune cells as demonstrated by immunofluorescence, flow cytometry, and immunoblotting. However, these data are mainly restricted to single-cell populations and show significant variation depending on the methodology used. Here, we investigated CFTR transcription and protein expression using standardized protocols in a comprehensive panel of immune cells. Methods: We applied a high-resolution Western blot protocol using a combination of highly specific monoclonal CFTR antibodies that have been optimized for the detection of CFTR in epithelial cells and healthy primary immune cell subpopulations sorted by flow cytometry and used immortalized cell lines as controls. The specificity of CFTR protein detection was controlled by peptide competition and enzymatic Peptide-N-Glycosidase-F (PNGase) digest. CFTR transcripts were analyzed using quantitative real-time PCR and normalized to the level of epithelial T84 cells as a reference. Results: CFTR mRNA expression could be shown for primary CD4+ T cells, NK cells, as well as differentiated THP-1 and Jurkat T cells. In contrast, we failed to detect CFTR transcripts for CD14+ monocytes and undifferentiated THP-1 cells, as well as for B cells and CD8+ T cells. Prominent immunoreactive bands were detectable by immunoblotting with the combination of four CFTR antibodies targeting different epitopes of the CFTR protein. However, in biosamples of non-epithelial origin, these CFTR-like protein bands could be unmasked as false positives through peptide competition or PNGase digest, meaning that the observed mRNA transcripts were not necessarily translated into CFTR proteins, which could be detected via immunoblotting. Our results confirm that mRNA expression in immune cells is many times lower than in that cells of epithelial origin. The immunoreactive signals in immune cells turned out to be false positives, and may be provoked by the presence of a high-affinity protein with a similar epitope. Non-specific binding (e.g., Fab-interaction with glycosyl branches) might also contribute to false positive signals. Our findings highlight the necessity of accurate controls, such as CFTR-negative cells, as well as peptide competition and glycolytic digest in order to identify genuine CFTR protein by immunoblotting. Our data suggest, furthermore, that CFTR protein expression data from techniques such as histology, for which the absence of a molecular weight or other independent control prevents the unmasking of false positive immunoreactive signals, must be interpreted carefully as well.

Microbial community organization designates distinct pulmonary exacerbation types and predicts treatment outcome in cystic fibrosis

Polymicrobial infection of the airways is a hallmark of obstructive lung diseases such as cystic fibrosis (CF), non-CF bronchiectasis, and chronic obstructive pulmonary disease. Pulmonary exacerbations (PEx) in these conditions are associated with accelerated lung function decline and higher mortality rates. Understanding PEx ecology is challenged by high inter-patient variability in airway microbial community profiles. We analyze bacterial communities in 880 CF sputum samples collected during an observational prospective cohort study and develop microbiome descriptors to model community reorganization prior to and during 18 PEx. We identify two microbial dysbiosis regimes with opposing ecology and dynamics. Pathogen-governed PEx show hierarchical community reorganization and reduced diversity, whereas anaerobic bloom PEx display stochasticity and increased diversity. A simulation of antimicrobial treatment predicts better efficacy for hierarchically organized communities. This link between PEx, microbiome organization, and treatment success advances the development of personalized clinical management in CF and, potentially, other obstructive lung diseases.

The Use of Expanded Carrier Screening in Reproductive Medicine: Scientific Impact Paper No. 74.

Expanded carrier screening (ECS) is a genetic screening test carried out by analysing a blood sample. This screen can be used to detect whether the individual unknowingly carries gene variants associated with common genetic conditions, such as cystic fibrosis, that may be passed on to their children. It is typically performed in reproductive medicine for those who are considering having a family either naturally or via fertility treatment. Many donor sperm and egg banks, particularly in the USA and Europe, also perform blanket ECS testing on all their prospective sperm and egg donors. ECS is not currently routine practice in the UK, but a growing number of patients are requesting it before treatment. All of us carry gene variants of some sort that may cause autosomal recessive disease in their children if their partner or donor also carry a variant in the same gene. An autosomal recessive disease means two copies of an abnormal gene must be present in order for the disease or trait (such as cystic fibrosis or sickle cell disease) to develop. One copy of the variant means the person is a carrier but does not have the condition. Two copies, i.e. from the mother and father, means the child has a 25% chance of having the genetic disease. Carrying a gene variant does not mean that the individual would necessarily have any symptoms of the disease or any features of the condition. Genetic tests for specific conditions are currently available either before or during pregnancy for prospective parents who have a family or personal history of a genetic condition, or for those from ethnic backgrounds where certain conditions - such as haemoglobinopathies (blood disorders) - are common, prompting referral to a clinical genetics department. Expanded carrier screens may test for more than 100 genetic conditions. The list of conditions screened for is called a panel. Common panels are 250 or 600 genes. Not all expanded carrier screens that are available analyse the same genes. Some may test for genes that do not cause serious disease, or cause diseases that occur in later life; others test for genes that cause severe conditions in childhood. There is no agreement as to which panel of genes should be tested for in an ECS. Understanding the screening that is being offered, and the meaning of any results, is complicated and requires support from appropriately trained professionals to best inform the prospective parent or parents.

EPS7.08 Improved diagnosis of early aspergillus lung disease in cystic fibrosis (IDEAL)

EPS7.08 Improved diagnosis of early aspergillus lung disease in cystic fibrosis (IDEAL)

P280 Rapid review of the outcome measures and endpoints used to measure gastrointestinal disease in cystic fibrosis (CARDS-CF study)

P280 Rapid review of the outcome measures and endpoints used to measure gastrointestinal disease in cystic fibrosis (CARDS-CF study)

P303 Prevalence and clinical presentation of inflammatory bowel disease (IBD) in a large adult cystic fibrosis (CF) Unit

P303 Prevalence and clinical presentation of inflammatory bowel disease (IBD) in a large adult cystic fibrosis (CF) Unit

P315 Association of cystic fibrosis disease and the menstrual period?

P315 Association of cystic fibrosis disease and the menstrual period?

Mutation of hmgA, encoding homogentisate 1,2-dioxygenase, is responsible for pyomelanin production but does not impact the virulence of Burkholderia cenocepacia in a chronic granulomatous disease mouse lung infection.

The Burkholderia cepacia complex (Bcc) is a group of Gram-negative opportunistic bacteria often associated with fatal pulmonary infections in patients with impaired immunity, particularly those with cystic fibrosis (CF) and chronic granulomatous disease (CGD). Some Bcc strains are known to naturally produce pyomelanin, a brown melanin-like pigment known for scavenging free radicals; pigment production has been reported to enable Bcc strains to overcome the host cell oxidative burst. In this work, we investigated the role of pyomelanin in resistance to oxidative stress and virulence in strains J2315 and K56-2, two epidemic CF isolates belonging to the Burkholderia cenocepacia ET-12 lineage. We previously reported that a single amino acid change from glycine to arginine at residue 378 in homogentisate 1,2-dioxygenase (HmgA) affects the pigment production phenotype: pigmented J2315 has an arginine at position 378, while non-pigmented K56-2 has a glycine at this position. Herein, we performed allelic exchange to generate isogenic non-pigmented and pigmented strains of J2315 and K56-2, respectively, and tested these to determine whether pyomelanin contributes to the protection against oxidative stress in vitro as well as in a respiratory infection in CGD mice in vivo. Our results indicate that the altered pigment phenotype does not significantly impact these strains' ability to resist oxidative stress with H2O2 and NO in vitro and did not change the virulence and infection outcome in CGD mice in vivo suggesting that other factors besides pyomelanin are contributing to the pathophysiology of these strains.IMPORTANCEThe Burkholderia cepacia complex (Bcc) is a group of Gram-negative opportunistic bacteria that are often associated with fatal pulmonary infections in patients with impaired immunity, particularly those with cystic fibrosis and chronic granulomatous disease (CGD). Some Bcc strains are known to naturally produce pyomelanin, a brown melanin-like pigment known for scavenging free radicals and overcoming the host cell oxidative burst. We investigated the role of pyomelanin in Burkholderia cenocepacia strains J2315 (pigmented) and K56-2 (non-pigmented) and performed allelic exchange to generate isogenic non-pigmented and pigmented strains, respectively. Our results indicate that the altered pigment phenotype does not significantly impact these strains' ability to resist H2O2 or NO in vitro and did not alter the outcome of a respiratory infection in CGD mice in vivo. These results suggest that pyomelanin may not always constitute a virulence factor and suggest that other features are contributing to the pathophysiology of these strains.

Bronchoscopy-guided antimicrobial therapy for cystic fibrosis.

Bronchoscopy-guided antimicrobial therapy for cystic fibrosis.

A rare case of urinary tract infection by Burkholderia cepacia

Burkholderia cepacia is a motile, aerobic, non-fermentative, gram-negative bacillus and has been widely documented as a lung pathogen in patients with cystic fibrosis and chronic granulomatous disease. It is documented as an important emerging cause of multi-drug resistant nosocomial infections, and an important cause of morbidity and mortality. A 64-year-old male patient visited the Nikea Primary Healthcare Center, Piraeus, Greece, referred by the family doctor (GP), for follow-up due a history of prostate cancer (patient on immunosuppression) and recurrent UTIs with subsequent admission to the hospital. Patient history revealed diabetes mellitus type 2, arterial hypertension, hypercholesterolemia, hypertriglyceridemia, history of recurrent UTIs, with 4 hospitalizations in a tertiary hospital during the last 2 years, prostatic hypertrophy, 2 episodes of prostatitis before the diagnosis of prostate cancer Gleason score 6, at the end of 2019, with subsequent total prostatectomy, and radiotherapy. Patient history also revealed dysuria, frequent urination, pain and burning sensation during urination and erectile dysfunction. Urinalysis showed intense pyuria, abundance of micro-organisms and abundance of red blood cells. The urine culture grew monomicrobial Burkholderia cepacia 105 CFU/ml. The bacterium was identified by the RapID™ REMEL ONE identification system (Thermo Fisher Scientific). Antimicrobial susceptibility testing revealed susceptibility to antibiotics such as, Ceftazidime, Ciprofloxacin, Norfloxacin, Levofloxacin and Imipenem.The patient received treatment with Levofloxacin. Burkholderia cepacia infections outside the respiratory system are rare. Moreover, recurrent UTIs with B. cepacia is a rare finding, which highlights the importance of our study. UTIs with B. cepacia have been associated with bladder irrigation or use of contaminated hospital objects and liquids. B. cepacia is one of the most antimicrobial-resistant organisms and treatment options are limited. The patient was treated with Levofloxacin (3rd generation fluoroquinolone — Tavanic) 500 mg daily per os for 2 weeks, due to his history.

Gastrointestinal Pathologies in Pediatric Patients With Cystic Fibrosis Undergoing Endoscopy: A Single-Center Retrospective Review Over 15 Years.

Introduction Previous studies have demonstrated an increased incidence of gastrointestinal (GI) pathologies, specifically celiac disease (CD) and eosinophilic esophagitis (EoE), in patients with cystic fibrosis (CF). However, there is minimal data available regarding endoscopic findings in pediatric patients with CF and GI mucosal disease. Methods A retrospective chart review was performed on patients with CF under 18 years of age who underwent esophagogastroduodenoscopy (EGD) or colonoscopy with biopsy over a 15-year period at our institution. Patient characteristics including assigned sex at birth, CF genetic mutations (if identified), and cystic fibrosis transmembrane conductance regulator (CFTR) modulator use were recorded.Data obtained at the time of biopsy included body mass index (BMI), indication for the procedure, exocrine pancreatic status, visual endoscopic findings, and histologic findings. Results A total of 72 patients with CF were included in the study. 24% (n=17) were found to have abnormal endoscopic biopsy results. EoE (13% of all patients, n=9) and CD (6% of all patients, n=4) were the most common GI diagnoses present on endoscopic biopsy. All 3 patients taking CFTR modulator medications at the time of endoscopy had normal biopsy results. Of the 17 patients found to have abnormal pathology results, 14 (82%) were taking proton-pump inhibitor (PPI) medication at the time of endoscopy. Conclusion This study highlights the probable increased frequency of GI disease in the pediatric CF population. These findings underscore the importance of maintaining a broad differential diagnosis while considering utilization of endoscopy with biopsy in pediatric patients with CF who have GI symptoms.

Newborn screening in France: news and perspectives

Newborn screening is a major public health concern. In France, it was established in 1972 with systematic screening for phenylketonuria. Subsequently, other screenings, including congenital hypothyroidism, congenital adrenal hyperplasia, cystic fibrosis, and sickle cell disease, were added. The introduction of tandem mass spectrometry in screening laboratories in 2020 enabled the inclusion of eight additional inherited metabolic diseases: aminoacidopathies (tyrosinemia type I, maple syrup urine disease, and homocystinuria), organic acidurias (isovaleric and glutaric type I acidurias), and disorders of fatty acid metabolism (MCADD, long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD), and primary carnitine deficiency). We briefly present these newly added diseases, of which public awareness is still incomplete.

A role for the stringent response in ciprofloxacin resistance in Pseudomonas aeruginosa

Pseudomonas aeruginosa is a major cause of nosocomial infections and the leading cause of chronic lung infections in cystic fibrosis and chronic obstructive pulmonary disease patients. Antibiotic treatment remains challenging because P. aeruginosa is resistant to high concentrations of antibiotics and has a remarkable ability to acquire mutations conferring resistance to multiple groups of antimicrobial agents. Here we report that when P. aeruginosa is plated on ciprofloxacin (cipro) plates, the majority of cipro-resistant (ciproR) colonies observed at and after 48 h of incubation carry mutations in genes related to the Stringent Response (SR). Mutations in one of the major SR components, spoT, were present in approximately 40% of the ciproR isolates. Compared to the wild-type strain, most of these isolates had decreased growth rate, longer lag phase and altered intracellular ppGpp content. Also, 75% of all sequenced mutations were insertions and deletions, with short deletions being the most frequently occurring mutation type. We present evidence that most of the observed mutations are induced on the selective plates in a subpopulation of cells that are not instantly killed by cipro. Our results suggests that the SR may be an important contributor to antibiotic resistance acquisition in P. aeruginosa.

Neutrophil Elastase Degrades Histone Deacetylases and Sirtuin 1 in Primary Human Monocyte Derived Macrophages.

Neutrophil elastase (NE) is taken up by macrophages, retains intracellular protease activity, and induces a pro-inflammatory phenotype. However, the mechanism of NE-induced pro-inflammatory polarization of macrophages is not well understood. We hypothesized that intracellular NE degrades histone deacetylases (HDAC) and Sirtuins, disrupting the balance of lysine acetylation and deacetylation and resulting in nuclear to cytoplasmic translocation of a major alarmin, High Mobility Group Box 1 (HMGB1), a pro-inflammatory response in macrophages. Human blood monocytes were obtained from healthy donors or from subjects with cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD). Monocytes were differentiated into blood monocyte derived macrophages (BMDMs) in vitro. Human BMDMs were exposed to NE or control vehicle, and the abundance of HDACs and Sirtuins was determined by Western blotting of total cell lysates or nuclear extracts or determined by ELISA. HDAC, Sirtuin, and Histone acetyltransferase (HAT) activities were measured. NE degraded most HDACs and Sirtuin (Sirt)1, resulting in decreased HDAC and sirtuin activities, with minimal change in HAT activity. We then evaluated whether the NE-induced loss of Sirt activity or loss of HDAC activities would alter the cellular localization of HMGB1. NE treatment or treatment with Trichostatin A (TSA), a global HDAC inhibitor, both increased HMGB1 translocation from the nucleus to the cytoplasm, consistent with HMGB1 activation. NE significantly degraded Class I and II HDAC family members and Sirt 1, which shifted BMDMs to a pro-inflammatory phenotype.