Cystic Fibrosis Pulmonary Disease Research Articles

Effect of Trikafta on bone density, body composition and exercise capacity in CF: A pilot study.

While the positive effect of Trikafta on cystic fibrosis (CF) pulmonary disease is well established, there is limited data about its effect on bone mineral density (BMD), body composition and exercise capacity. A pilot single center study. BMD and body composition were measured three months after the initiation of Trikafta (study group) and compared to values obtained 2 years earlier. CF patients not treated with Trikafta, for whom BMD was measured 2 years apart, served as controls. Spirometry, lung clearance index (LCI), sweat test, six-minwalk test (6MWT) and cardio-pulmonary exercise test (CPET) were performed before and three months after the initiation of Trikafta. Nine study patients, aged 18.6 ± 4.7 years, and nine controls. For the study group, BMI and hip and spine BMD increased significantly (19.4 ± 2.6 to 20.3 ± 2.19 BMI, p = 0.05; 0.73 ± 0.098 to 0.81 ± 0.12 gr/cm2 hip, p = 0.017; 0.76 ± 0.14 to 0.82 ± 0.14 gr/cm2 spine, p = 0.025). For the control group, there was no difference in hip or spine BMD. Lean body mass, %fat z-score and fat mass/height2 z-score increased significantly (34770.23 ± 10521.21 to 37430.16 ± 10330.09gr, p = 0.017; -0.8 ± 0.75 to 0.46 ± 0.58, p = 0.012; and -0.98 ± 0.66 to -0.04 ± 0.51, p = 0.025, respectively). 6MWT improved from 541.1 ± 48.9 to 592.9 ± 54.5 m (p = 0.046). As expected, FEV1%pred increased (p = 0.008) and sweat chloride decreased significantly (p = 0.017). In CPET, VE/VCO2 improved, indicating better ventilatory efficiency. To the best of our knowledge, this is the first study evaluating the metabolic effects of Trikafta. The results are encouraging and offer hope beyond the well-established effect on pulmonary disease. Larger long-term studies are warranted to unpin the underlying physiological mechanisms.

Specific circulating neutrophils subsets are present in clinically stable adults with cystic fibrosis and are further modulated by pulmonary exacerbations

The progressive lung destruction in cystic fibrosis (CF) is tightly associated with chronic bacterial infection and neutrophil-dominated airway inflammation. CF pulmonary disease is complicated by episodes of acute exacerbations, contributing to irreversible lung damage. We hypothesized that circulating subsets of neutrophils from clinically stable adults with CF present some phenotypic specificities that could amplify their activation during an infectious episode. The aim of the present study was to examine the different neutrophil subsets in whole blood and in the low density neutrophils (LDN) that co-purify with peripheral blood mononuclear cells (PBMC) in clinically stable adults with CF and in CF adults during pulmonary exacerbations compared to healthy donors. Blood samples were obtained from 22 adults with CF (16 in stable state and 6 during pulmonary exacerbations) and from 20 healthy donors. Flow cytometry analysis of 13 different markers related to lineage (CD45, CD15), maturity (CD16, CD10, and CD33), activation (CD62L, CD11b, CD66b, and CD114), metabolism (GLUT-1, LOX1) and immunosuppression (PD1, PD-L1) was carried out within whole blood and within the LDN fraction. Unsupervised analysis of flow cytometry data was performed using visual t-distributed stochastic neighbor embedding (vi-tSNE). A significant increase in the CD11b expression in neutrophils from CF patients during exacerbations was observed compared to neutrophils from stable CF patients or to healthy donors, indicative of a circulating activation state due to an infectious status. The percentage of LDN was not increased in stable CF patients but increased during exacerbations. Analysis of neutrophil subsets using the double CD16/CD62L labeling revealed a significant increase in the CD16high/CD62Llow subset in all CF patients compared to healthy donors. In contrast, an increase in the CD16low/CD62Lhigh subset was observed only in CF patients during exacerbations. Unsupervised analysis identified a PD-L1high/CD114high population that was present in stable CF patients and as well as in CF patients during exacerbations.

Modulator Combination Improves In Vitro the Microrheological Properties of the Airway Surface Liquid of Cystic Fibrosis Airway Epithelia.

Cystic fibrosis (CF) is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a plasma membrane protein expressed on the apical surface of secretory epithelia of the airways. In the airways, defective or absent function of the CFTR protein determines abnormalities of chloride and bicarbonate secretion and, in general, of the transepithelial homeostasis that lead to alterations of airway surface liquid (ASL) composition and properties. The reduction of ASL volume impairs ciliary beating with the consequent accumulation of a sticky mucus. This situation prevents normal mucociliary clearance, favoring the survival and proliferation of bacteria and contributing to the genesis of the CF pulmonary disease. We explored the potential of some CFTR modulators, namely ivacaftor, tezacaftor, elexacaftor and their combination KaftrioTM, capable of partially recovering the basic defects of the CFTR protein, to ameliorate the transepithelial fluid transport and the viscoelastic properties of the mucus when used singly or in combination. Primary human bronchial epithelial cells obtained from CF and non-CF patients were differentiated into a mucociliated epithelia in order to assess the effects of correctors tezacaftor, elexacaftor and their combination with potentiator ivacaftor on the key properties of ASL, such as fluid reabsorption, viscosity, protein content and pH. The treatment of airway epithelia bearing the deletion of a phenylalanine at position 508 (F508del) in the CFTR gene with tezacaftor and elexacaftor significantly improved the pericilial fluid composition, reducing the fluid reabsorption, correcting the ASL pH and reducing the viscosity of the mucus. KaftrioTM was more effective than single modulators in improving all the evaluated parameters, demonstrating once more that this combination recently approved for patients 6 years and older with cystic fibrosis who have at least one F508del mutation in the CFTR gene represents a valuable tool to defeat CF.

Global burden of nontuberculous mycobacteria in the cystic fibrosis population: a systematic review and meta-analysis.

People living with cystic fibrosis have an increased risk of lung infection with nontuberculous mycobacteria (NTM), the prevalence of which is reportedly increasing. We conducted a systematic review of the literature to estimate the burden (prevalence and incidence) of NTM in the cystic fibrosis population. Electronic databases, registries and grey literature sources were searched for cohort and cross-sectional studies reporting epidemiological measures (incidence and prevalence) of NTM infection or NTM pulmonary disease in cystic fibrosis. The last search was conducted in September 2021; we included reports published since database creation and registry reports published since 2010. The methodological quality of studies was appraised with the Joanna Briggs Institute tool. A random effects meta-analysis was conducted to summarise the prevalence of NTM infection, and the remaining results are presented in a narrative synthesis. This review included 95 studies. All 95 studies reported on NTM infection, and 14 of these also reported on NTM pulmonary disease. The pooled estimate for the point prevalence of NTM infection was 7.9% (95% CI 5.1-12.0%). In meta-regression, sample size and geographical location of the study modified the estimate. Longitudinal analysis of registry reports showed an increasing trend in NTM infection prevalence between 2010 and 2019. The overall prevalence of NTM infection in cystic fibrosis is 7.9% and is increasing over time based on international registry reports. Future studies should report screening frequency, microbial identification methods and incidence rates of progression from NTM infection to pulmonary disease.

Effects of Mucin and DNA Concentrations in Airway Mucus on Pseudomonas aeruginosa Biofilm Recalcitrance.

ABSTRACTThe pathological properties of airway mucus in cystic fibrosis (CF) are dictated by mucus concentration and composition, with mucins and DNA being responsible for mucus viscoelastic properties. As CF pulmonary disease progresses, the concentrations of mucins and DNA increase and are associated with increased mucus viscoelasticity and decreased transport. Similarly, the biophysical properties of bacterial biofilms are heavily influenced by the composition of their extracellular polymeric substances (EPS). While the roles of polymer concentration and composition in mucus and biofilm mechanical properties have been evaluated independently, the relationship between mucus concentration and composition and the biophysical properties of biofilms grown therein remains unknown. Pseudomonas aeruginosa biofilms were grown in airway mucus as a function of overall concentration and DNA concentration to mimic healthy, and CF pathophysiology and biophysical properties were evaluated with macro- and microrheology. Biofilms were also characterized after exposure to DNase or DTT to examine the effects of DNA and mucin degradation, respectively. Identifying critical targets in biofilms for disrupting mechanical stability in highly concentrated mucus may lead to the development of efficacious biofilm therapies and ultimately improve CF patient outcomes. Overall mucus concentration was the predominant contributor to biofilm viscoelasticity and both DNA degradation and mucin reduction resulted in compromised biofilm mechanical strength.IMPORTANCE Pathological mucus in cystic fibrosis (CF) is highly concentrated and insufficiently cleared from the airway, causing chronic inflammation and infection. Pseudomonas aeruginosa establishes chronic infection in the form of biofilms within mucus, and this study determined that biofilms formed in more concentrated mucus were more robust and less susceptible to mechanical and chemical challenges compared to biofilms grown in lower concentrated mucus. Neither DNA degradation nor disulfide bond reduction was sufficient to fully degrade biofilms. Mucus rehydration should remain a priority for treating CF pulmonary disease with concomitant multimechanistic biofilm degradation agents and antibiotics to clear chronic infection.

Routine spirometry in cystic fibrosis patients: impact on pulmonary exacerbation diagnosis and FEV1 decline.

ABSTRACTObjective:Pulmonary disease in cystic fibrosis (CF) is characterised by recurrent episodes of pulmonary exacerbations (PExs), with acute and long-term declines in lung function (FEV1). The study sought to determine whether routine spirometry increases the frequency of PEx diagnosis, resulting in benefits to long-term pulmonary function. Methods:CF patients in the 5- to 18-year age bracket were followed for 1 year, during which they underwent spirometry before every medical visit. The main variables were the frequency of PEx diagnosis and use of antibiotics; the use of spirometry as a criterion for PEx diagnosis (a decline ≥ 10% in baseline FEV1); and median percent predicted FEV1 over time. The data were compared with those for the previous 24-month period, when spirometry was performed electively every 6 months. Results:The study included 80 CF patients. PExs were diagnosed in 27.5% of the visits, with a mean frequency of 1.44 PExs per patient/year in 2014 vs. 0.88 PExs per patient/year in 2012 (p = 0.0001) and 1.15 PExs per patient/year in 2013 (p = 0.05). FEV1 was used as a diagnostic feature in 83.5% of PExs. In 21.9% of PExs, the decision to initiate antibiotics was solely based on an acute decline in FEV1. The median percent predicted FEV1 during the follow-up year was 85.7%, being 78.5% in 2013 and 76.8% in 2012 (p > 0.05). The median percent predicted FEV1 remained above 80% during the two years after the study. Conclusions:Routine spirometry is associated with higher rates of diagnosis and treatment of PExs, possibly impacting long-term pulmonary function.

Children With Cystic Fibrosis Have Elevated Levels of Fecal Chitinase-3-like-1.

Although chitinase-3-like-1 (CHI3L1), predominately produced by epithelial cells and macrophages, is relevant to pulmonary disease in cystic fibrosis (CF), fecal levels have not yet been assessed in children with CF. Fecal CHI3L1 was measured with a commercial immunoassay using fecal samples provided by children with CF and healthy control (HC) children. Higher median (interquartile range) fecal CHI3L1 levels were seen in the 52 children with CF than in the 35 controls: 15.97 (3.34-50.53) ng/g versus 2.93 (2.13-9.27) ng/g ( P = 0.001). Fecal CHI3LI did not differ according to sex. In the children with CF, fecal CHI3L1 levels did not correlate with growth parameters nor were the levels affected by pancreatic insufficiency. Children with CF had higher fecal CHI3L1 levels, suggesting underlying gut inflammation. Further work is required to confirm the current findings and to ascertain the longer-term significance of elevated CHI3L1.

Changes in Glucose Breath Test in Cystic Fibrosis Patients Treated With 1 Month of Lumacaftor/Ivacaftor.

Alteration of the airway microbiota is a hallmark of cystic fibrosis (CF) pulmonary disease. Dysfunction of cystic fibrosis transmembrane regulator (CFTR) in the intestine also promotes changes in local microbiota such as small intestinal bacterial overgrowth (SIBO), which is common in CF. We evaluated whether therapy with the CFTR modulator combination lumacaftor/ivacaftor (luma/iva) has a beneficial impact on SIBO as measured by breath testing (BT). A multicenter longitudinal study of CFTR-dependent disease profiling (NCT02477319) included a prospective evaluation for SIBO by BT. Tidal breath samples were collected after fasting and 15, 30, 45, 60, 90, and 120 minutes after ingestion of glucose, before and 1 month after subjects initiated luma + iva. Forty-two subjects enrolled in the sub-study (mean age = 23.3 years; 51% female; 9.5% Latinx); 38 completed a hydrogen BT at both time points, of which 73.7% had a positive BT before luma/iva (baseline) and 65.8% had a positive test after luma/iva ( P = 0.44); shifts from negative to positive were also seen. Use of azithromycin (63.1%) and inhaled antibiotics (60.5%) were not associated with positive BT. Acid-blocking medications were taken by 73% of those with a negative BT at baseline and by 35% with a positive baseline BT ( P = 0.04). We found a high rate of positive hydrogen breath tests in individuals with CF, confirming that SIBO is common. One month of luma/iva did not significantly change the proportion of those with positive breath hydrogen measurements.

Alginate oligosaccharides enhance diffusion and activity of colistin in a mucin-rich environment

In a number of chronic respiratory diseases e.g. cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD), the production of viscous mucin reduces pulmonary function and represents an effective barrier to diffusion of inhaled therapies e.g. antibiotics. Here, a 2-compartment Transwell model was developed to study impaired diffusion of the antibiotic colistin across an artificial sputum (AS) matrix/medium and to quantify its antimicrobial activity against Pseudomonas aeruginosa NH57388A biofilms (alone and in combination with mucolytic therapy). High-performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) revealed that the presence of AS medium significantly reduced the rate of colistin diffusion (> 85% at 48 h; p < 0.05). Addition of alginate oligosaccharide (OligoG CF-5/20) significantly improved colistin diffusion by 3.7 times through mucin-rich AS medium (at 48 h; p < 0.05). Increased diffusion of colistin with OligoG CF-5/20 was shown (using confocal laser scanning microscopy and COMSTAT image analysis) to be associated with significantly increased bacterial killing (p < 0.05). These data support the use of this model to study drug and small molecule delivery across clinically-relevant diffusion barriers. The findings indicate the significant loss of colistin and reduced effectiveness that occurs with mucin binding, and support the use of mucolytics to improve antimicrobial efficacy and lower antibiotic exposure.

Sustained effectiveness of elexacaftor-tezacaftor-ivacaftor in lung transplant candidates with cystic fibrosis

BackgroundElexacaftor-tezacaftor-ivacaftor induces rapid clinical improvement in patients with cystic fibrosis (CF) and advanced pulmonary disease, often leading to suspend the indication for lung transplantation. Yet no long-term data is available in lung transplant candidates. MethodsLung transplant candidates (defined as being waitlisted for lung transplantation or considered for listing within 3 months) who have initiated elexacaftor-tezacaftor-ivacaftor were identified in the French cohort of patients with CF and advanced pulmonary disease. Patients were prospectively followed to evaluate treatment safety and effectiveness from initiation to July 20th, 2021. ResultsAmong the 331 patients with advanced CF pulmonary disease who initiated elexacaftor-tezacaftor-ivacaftor, 65 were lung transplant candidates (17 listed for transplantation, 48 considered for listing within 3 months). Median [IQR] follow-up time was 363 [329; 377] days. At the end of the follow-up period, two patients were transplanted five and 11 days following treatment initiation, two were listed for transplantation, and 61 no longer met transplantation criteria. Improvement in percent predicted forced expiratory volume in 1 s (ppFEV1) at one month was +13.4% (95% confidence interval, 10.3%-16.5%; P < 0.0001) and remained stable thereafter. Treatment burden decreased substantially, with an 86% decrease in the need for intravenous antibiotics, 59% for oxygen therapy and 62% for non-invasive ventilation. ConclusionIn lung transplant candidates eligible for elexacaftor-tezacaftor-ivacaftor, the rapid improvement following initiation of treatment persisted over one year with a reduction in treatment burden and lung transplantation could be safely deferred in most patients.

Clinical characteristics of people with cystic fibrosis and frequent fungal infection.

BackgroundIndividuals with cystic fibrosis (CF) and fungal airway infection may present with fungal bronchitis, allergic bronchopulmonary aspergillosis (ABPA) or may appear unaffected despite fungal detection. We sought to characterize people with CF with frequent detection of fungi from airway samples and determine clinical outcomes.MethodsThis retrospective study included individuals with CF with ≥4 lower airway cultures over a 2‐year baseline period and ≥2 years of follow‐up. We defined two groups: ≤1 positive fungus culture (rare) or ≥2 positive cultures during baseline (frequent). Clinical characteristics and outcomes were determined.ResultsBetween 2004 and 2016, 294 individuals met inclusion with 62% classified as rare and 38% as frequent fungi during baseline. Median follow‐up was 6 years (range: 2–9 years). Aspergillus fumigatus was the most common fungal species detected. Individuals with frequent fungi were older (13.7 vs. 11.7 years, p = .02) and more likely to have Stenotrophomonas maltophilia (35% vs. 17%, p < .001) at baseline, but did not differ in lung function or ABPA diagnosis. During follow‐up, those with frequent fungi were more likely to have chronic Pseudomonas aeruginosa and S. maltophilia. Individuals with ABPA and frequent fungi had the highest rates of co‐infection and co‐morbidities, and a trend towards more rapid lung function decline.DiscussionFungal infection in CF was associated with frequent P. aeruginosa and S. maltophilia co‐infection even in those without ABPA. Individuals with frequent fungi and ABPA had worse outcomes, highlighting the potential contribution of fungi to CF pulmonary disease.

An initial evaluation of the safety of a disposable oscillating positive expiratory pressure device in patients with chronic obstructive pulmonary disease: a short-term pilot study

BackgroundHandheld oscillating positive expiratory pressure (OPEP) devices have been a mainstay of treatment for patients with hypersecretory conditions such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) since the 1970s. Current devices are reusable and require regular cleaning and disinfection to prevent harbouring potentially pathogenic organisms. Adherence to cleaning regimens for respiratory devices is often poor and in response to this, a prototype disposable OPEP device—the ‘UL-OPEP’ (University of Limerick—Oscillating Positive Expiratory Pressure device)—was developed to mitigate the risk of contamination by pathogens. The device was previously evaluated successfully in a group of paediatric CF patients. The aim of the current study was to initially evaluate the safety of the prototype in patients with COPD over a period of 1 month to ensure no adverse events, negative impacts on lung function, exercise tolerance, or quality of life. Data on user experience of the device were also collected during post-study follow-up.MethodsA sample of 50 volunteer participants were recruited from pulmonary rehabilitation clinics within the local hospital network. The patients were clinically stable, productive, and not current or previous users of OPEP devices. Participants were invited to use a prototype disposable OPEP device daily for a period of 1 month. Pre- and post-study lung function was assessed with standard spirometry, and exercise tolerance with the 6-min-walk-test (6MWT). Quality of life was assessed using the St. George’s Respiratory Questionnaire (SGRQ), and user experience of the prototype device evaluated using a post-study questionnaire.Results24 Participants completed the study: 9 were female. Overall median age was 67.5 years, range 53–85 years. Lung function, 6-min walk test, and SGRQ scores showed no significant change post-study. User feedback was positive overall.ConclusionsThe results indicate that the UL-OPEP is safe to use in patients with COPD. No adverse events were recorded during the study or in the follow-up period of 2 weeks. The device did not negatively impact patients’ lung function, exercise tolerance, or quality of life during short term use (1 month), and usability feedback received was generally positive. Larger, longer duration studies will be required to evaluate efficacy.Registration The study was approved as a Clinical Investigation by the Irish Health Products Regulatory Authority (CRN-2209025-CI0085).

Антибиопленочные эффекты муколитических лекарственных средств

Муколитические лекарственные средства обладают способностью нарушать структуру матрикса и разрушать сформированные бактериальные биопленки. Наиболее изученным является N-ацетилцистеин. Впервые антибиопленочная активность N-ацетилцистеина была продемонстрирована Ciro Pérez-Giraldo и соавт. в 1997 году. Они показали, что вещество оказывает ингибирующее действие на рост бактерий и способствует диспергированию биопленок, образованных бактериями Staphylococcus epidermidis. В настоящее время установлено, что N-ацетилцистеин обладает выраженной активностью, направленной против биопленок, сформированных различными грамположительными и грамотрицательными бактериями, в том числе и антибиотикорезистентными бактериальными штаммами метициллинрезистентного золотистого стафилококка и хинолонрезистентных синегнойных палочек. N-ацетилцистеин способствует проникновению пенициллинов, полимиксинов, фторхинолонов в самые глубокие слои биопленки, преодолевая антибио­тикорезистентность причинно-значимых бактериальных агентов. N-ацетилцистеин может применяться как антибиопленочное лекарственное средство при хронических бактериально-ассоциированных заболеваниях, в частности при эпизодах респираторных инфекций у больных муковисцидозом, хроническом бронхите, хронической обструктивной болезни легких. Полагают, что N-ацетилцистеин обладает превосходным профилем безопасности и эффективности при лечении заболеваний, которые сопровождаются образованием бактериальных биопленок. N-ацетилцистеин и нанотехнологические лекарственные средства, в которых его молекулы скомбинированы с частицами галлия или серебра, могут стать средствами выбора, диспергирующими биопленки и усиливающими эффективность антибактериальной терапии, особенно при заболеваниях, вызванных антибиотикорезистентными штаммами микроорганизмов.

Pancreas transplantation for cystic fibrosis: A frequently missed opportunity.

Cystic fibrosis (CF) is an inherited autosomal recessive disorder. Despite optimized therapy, the majority of affected individuals ultimately die of respiratory failure. As patients with CF are living longer, extra-pulmonary manifestations may develop including pancreatic failure, which manifests as exocrine insufficiency, and CF-related diabetes (CFRD). Both of these can be managed through pancreas transplantation. Pancreas transplantation is usually performed in combination with another organ, most often with a kidney transplant for end-stage diabetic nephropathy. In the CF patient population, the two settings where inclusion of a pancreas transplant should be considered would be in combination with a lung transplant for CF pulmonary disease, or in combination with a liver for CF-related liver disease with cirrhosis. This report will discuss this topic in detail, including a review of the literature regarding combinations of lung/pancreas and liver/pancreas transplant.

Cystic fibrosis year in review 2020: Section 2 pulmonary disease, infections, and inflammation.

The outlook for those with cystic fibrosis (CF) has never been brighter with ever increasing life expectancy and the approval of the highly effective CFTR modulators, such as elexacaftor/tezacaftor/ivacaftor. With that being said, the progressive pulmonary decline and importance of lung health, infection, and inflammation in CF remains. This review is the second part in a three-part CF Year in Review 2020. Part one focused on the literature related to CFTR modulators while part three will feature the multisystem effects related to CF. This review focuses on articles from Pediatric Pulmonology, including articles from other journals that are of particular interest to clinicians. Herein, we highlight studies published during 2020 related to CF pulmonary disease, infection, treatment, and diagnostics.

Cystic fibrosis year in review 2019: Section 3 multisystem-based care and research.

During the year 2019, numerous research studies and other reports were published that are interesting and instructive to professionals who care for people with cystic fibrosis (CF) and their families. This report is the third of 3 CF year in review articles and focuses on the multisystem manifestations of CF care. Previous articles have addressed cystic fibrosis transmembrane regulator modulators and reports on CF pulmonary disease and airway infections. It is an exciting time to be involved in care and research that aims to improve care for people with CF and their families.

Low-Avidity Autoantibodies against Bactericidal/Permeability-Increasing Protein Occur in Gram-Negative and Gram-Positive Bacteremia.

Antibody autoreactivity against bactericidal/permeability-increasing protein (BPI) is strongly associated with Pseudomonas aeruginosa infection in cystic fibrosis (CF), non-CF bronchiectasis (BE), and chronic obstructive pulmonary disease (COPD). We examined the pathogen-specific nature of this autoreactivity by examining antibodies to BPI in bacteremia patients. Antibodies to BPI and bacterial antigens were measured in sera by ELISA from five patient cohorts (n = 214). Antibody avidity was investigated. Bacteremic patient sera (n = 32) exhibited IgG antibody autoreactivity against BPI in 64.7% and 46.7% of patients with positive blood cultures for P. aeruginosa and Escherichia coli, respectively. Autoantibody titers correlated with IgG responses to bacterial extracts and lipopolysaccharide (LPS). A prospective cohort of bacteremic patient sera exhibited anti-BPI IgG responses in 23/154 (14.9%) patients with autoreactivity present at the time of positive blood cultures in patients with Gram-negative and Gram-positive bacteria, including 8/60 (13.3%) patients with Staphylococcus aureus Chronic tissue infection with S. aureus was associated with BPI antibody autoreactivity in 2/15 patients (13.3%). Previously, we demonstrated that BPI autoreactivity in CF patient sera exhibits high avidity. Here, a similar pattern was seen in BE patient sera. In contrast, sera from patients with bacteremia exhibited low avidity. These data indicate that low-avidity IgG responses to BPI can arise acutely in response to bacteremia and that this association is not limited to P. aeruginosa This is to be contrasted with chronic respiratory infection with P. aeruginosa, suggesting that either the chronicity or the site of infection selects for the generation of high-avidity responses, with biologic consequences for airway immunity.

Analysis of airway microbiota in adults from a Brazilian cystic fibrosis center.

The application of next-generation sequencing tools revealed that the cystic fibrosis respiratory tract is a polymicrobial environment. We have characterized the airway bacterial microbiota of five adult patients with cystic fibrosis during a 14-month period by 16S rRNA tag sequencing using the Illumina technology. Microbial diversity, estimated by the Shannon index, varied among patient samples collected throughout the follow-up period. The beta diversity analysis revealed that the composition of the airway microbiota was highly specific for each patient, showing little variation among the samples of each patient analyzed over time. The composition of the bacterial microbiota did not reveal any emerging pathogen predictor of pulmonary disease in cystic fibrosis or of its unfavorable clinical progress, except for unveiling the presence of anaerobic microorganisms, even without any established clinical association. Our results could potentialy help us to translate and develop strategies in response to the pathobiology of this disease, particularly because it represents an innovative approach for CF centers in Brazil.

The Microbiome in Cystic Fibrosis Pulmonary Disease.

Cystic fibrosis (CF) is a genetic disease with mutational changes leading to profound dysbiosis, both pulmonary and intestinal, from a very young age. This dysbiosis plays an important role in clinical manifestations, particularly in the lungs, affected by chronic infection. The range of microbiological tools has recently been enriched by metagenomics based on next-generation sequencing (NGS). Currently applied essentially in a gene-targeted manner, metagenomics has enabled very exhaustive description of bacterial communities in the CF lung niche and, to a lesser extent, the fungi. Aided by progress in bioinformatics, this now makes it possible to envisage shotgun sequencing and opens the door to other areas of the microbial world, the virome, and the archaeome, for which almost everything remains to be described in cystic fibrosis. Paradoxically, applying NGS in microbiology has seen a rebirth of bacterial culture, but in an extended manner (culturomics), which has proved to be a perfectly complementary approach to NGS. Animal models have also proved indispensable for validating microbiome pathophysiological hypotheses. Description of pathological microbiomes and correlation with clinical status and therapeutics (antibiotic therapy, cystic fibrosis transmembrane conductance regulator (CFTR) modulators) revealed the richness of microbiome data, enabling description of predictive and follow-up biomarkers. Although monogenic, CF is a multifactorial disease, and both genotype and microbiome profiles are crucial interconnected factors in disease progression. Microbiome-genome interactions are thus important to decipher.

Specific Inhibition of the NLRP3 Inflammasome as an Antiinflammatory Strategy in Cystic Fibrosis

Rationale: Cystic fibrosis (CF) pulmonary disease is characterized by chronic infection with Pseudomonas aeruginosa and sustained neutrophil-dominant inflammation. The lack of effective antiinflammatory therapies for people with CF (PWCF) represents a significant challenge.Objectives: To identify altered immunometabolism in the CF neutrophil and investigate the feasibility of specific inhibition of the NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) inflammasome as a CF antiinflammatory strategy in vivo.Methods: Key markers of increased aerobic glycolysis, known as a Warburg effect, including cytosolic PKM2 (pyruvate kinase M2), phosphorylated PKM2, succinate, HIF-1α (hypoxia-inducible factor-1α), lactate, and the IL-1β precursor pro-IL-1β, as well as caspase-1 activity and processing of pro-IL-1β to IL-1β by the NLRP3 inflammasome, were measured in neutrophils from blood and airway secretions from healthy control subjects (n = 12), PWCF (n = 16), and PWCF after double-lung transplantation (n = 6). The effects of specific inhibition of NLRP3 on airway inflammation and bacterial clearance in a murine CF model were subsequently assessed in vivo.Measurements and Main Results: CF neutrophils display increased aerobic glycolysis in the systemic circulation. This effect is driven by low-level endotoxemia, unaffected by CFTR (cystic fibrosis transmembrane conductance regulator) modulation, and resolves after transplant. The increased pro-IL-1β produced is processed to its mature active form in the LPS-rich CF lung by the NLRP3 inflammasome via caspase-1. Specific NLRP3 inhibition in vivo with MCC950 inhibited IL-1β in the lungs of CF mice (P < 0.0001), resulting in significantly reduced airway inflammation and improved Pseudomonas clearance (P < 0.0001).Conclusions: CF neutrophil immunometabolism is altered in response to inflammation. NLRP3 inflammasome inhibition may have an antiinflammatory and anti-infective role in CF.