The Rapid Reduction of Infection-Related Visits and Antibiotic Use Among People With Cystic Fibrosis After Starting Elexacaftor-Tezacaftor-Ivacaftor

Phosphatidylinositol 5-Phosphate-Loaded Apoptotic Body-Like Liposomes for Mycobacterium abscessus Infection Management in Patients With Cystic Fibrosis

The study investigates therapeutic strategies for managing chronic Mycobacterium abscessus infections, particularly in people with cystic fibrosis (PWCF) who are ineligible for standard elexacaftor, tezacaftor, ivakaftor (ETI) treatments. Apoptotic body-like liposomes loaded with phosphatidylinositol 5-phosphate (ABL/PI5P) were tested in vitro in M. abscessus-infected macrophages from PWCF as potential treatment. ABL/PI5P reduced intracellular bacterial viability and showed enhanced effects on a M. abscessus clinical strain when combined with amikacin. Notably, ABL/PI5P was effective on macrophages from PWCF not receiving ETI therapy. The findings suggest ABL/PI5P liposomes as a promising alternative or adjunct therapy, especially for those who cannot access ETI treatment, warranting further clinical investigation.

Real-Life in Cystic Fibrosis Pediatric Patients Treated With Kaftrio: A Descriptive Observational Study

In 2020, Kaftrio, a combination of Elexacaftor, Tezacaftor, and Ivacaftor, gained approval for treating cystic fibrosis (CF) in patients from the age of 12 years. This study aims to analyze 1 year of treatment with Kaftrio in pediatric patients, comparing their clinical characteristics with pre-treatment data. This is an observational, descriptive, and longitudinal study in patients with CF older than 12 years with at least 1 F508del mutation treated with Kaftrio for 1 year. Forced expiratory volume in 1 second (FEV1) z-score increased by +1.1 (95% confidence interval [CI] = 0.55 to 1.64), forced vital capacity (FVC) by +0.56 (95% CI = 0.10 to 1.04), and maximal mid-expiratory flow (MMEF) 25/75 improved by +1.53 (95% CI = 0.59 to 2.47). In addition, a reduction of 25.50 points (95% CI = -37.95 to -13.06) in sweat chloride levels was observed. Body mass index (BMI)-for-age z-score (WHO 2006/2007) increased +0.39 (95% CI = 0.02 to 0.77). A transient increase in cough and secretions was noted in 61.53% after starting treatment. Kaftrio improves lung function and BMI and also reduces respiratory exacerbations and sweat chloride levels.

Elexacaftor/Tezacaftor/Ivacaftor for Cystic Fibrosis: Impact on Hospitalizations and Health Care Resource Utilization in a Universal Health Care Setting

INTRODUCTION

Elexacaftor/tezacaftor/ivacaftor (ETI) has been shown to substantially improve clinical outcomes among people living with cystic fibrosis (pwCF). The impact of ETI on health care resource utilization in the context of universal health care is largely unknown. We aimed to assess the impact of ETI on hospital and non-hospital health care resource utilization in a national cohort of pwCF up to 2 years after ETI initiation.

METHODS

We included all pwCF aged 12 years or older in the Danish Cystic Fibrosis Cohort initiating ETI therapy between 1 September 2020 and 31 December 2022. The following health care contacts were reported: acute and elective hospitalizations, acute and elective outpatient contacts, general practitioner (GP) visits, other specialist visits, physiotherapist/chiropractor visits, pharmacy visits, and blood sampling appointments. Pre- and post-ETI data were analyzed using logistic and linear regression models estimating number of visits, days in hospital, and odds ratios (ORs) for one monthly contact.

RESULTS

A total of 283 pwCF initiated ETI in the study period. At 24 months post-ETI, utilization of the following health care resources was reduced: elective hospitalizations [OR 0.20 (95% CI: 0.08; 0.50)], elective outpatient hospital contacts [0.70 (0.57; 0.86)], pharmacy visits [0.56 (0.45; 0.71)], and blood sampling appointments [0.61 (0.49; 0.77)]. Number of contacts per month was reduced for the aforementioned outcomes, as well as number of days in hospital for elective hospitalizations. A downward but not statistically significant trend was observed for acute hospitalizations. No significant change was observed for acute outpatient visits, GP visits, other specialist visits, or visits to a physiotherapist/chiropractor.

CONCLUSION

In a national cohort of pwCF, ETI was associated with substantial reductions in elective hospitalizations, elective outpatient contacts, duration of elective hospitalizations, pharmacy visits, and blood sampling appointments, sustained 2 years post-ETI initiation. These findings highlight the real-world effectiveness of ETI in the context of a universal health care system.

Impact of elexacaftor/tezacaftor/ivacaftor on utilization of routine therapies in cystic fibrosis: Danish nationwide register study

BACKGROUND

Elexacaftor/tezacaftor/ivacaftor (ETI) has been effective in improving several outcomes in people living with cystic fibrosis (pwCF). Although clinical guidance regarding maintenance therapies has not changed, staff reports indicate that individuals reduce some therapies. This study aimed to evaluate ETI's effect on utilization of routine therapies among pwCF in Denmark.

METHODS

We included all pwCF initiating ETI between 1 September 2020 and 31 October 2022. Utilization of routine therapies was analysed by drug class (e.g., gastrointestinal medications) and individual treatments (e.g., pancreatic enzymes) before and after ETI initiation using national registry data. Odds ratios (ORs) for prescription redemptions pre- and post-ETI were calculated to assess ETIs impact on the use of routine therapies.

RESULTS

The study population consisted of 351 individuals. Median age was 23 years (IQR 14-32) and mean ppFEV1 was 76 (SD 22) at index. Two-year follow-up was available for 205 individuals. Two years post ETI initiation, the one-year prevalence was reduced for airway medications, (89.5 % to 75.1 %) and inhaled antibiotics (59.5 % to 42.9 %.). OR for redeeming a prescription two years post-ETI initiation (95 % CI) was reduced for four out of five drug classes: airway medications (OR: 0.24 [0.19; 0.29]), inhaled antibiotics (OR: 0.28 [0.2; 0.39]), oral antibiotics (OR: 0.49 [0.41; 0.58]), gastrointestinal medications (OR: 0.66 [0.57; 0.77]).

CONCLUSION

Two years after ETI initiation, reductions in the use of several routine therapies were observed in a national cohort of pwCF, with the largest declines in airway medications and antibiotics. These findings highlight ETI's real-world impact beyond conventional clinical metrics.

Real-world impact of Elexacaftor-Tezacaftor-Ivacaftor treatment in young people with Cystic Fibrosis: A longitudinal study

BACKGROUND

Elexacaftor, Tezacaftor, Ivacaftor (ETI) became available in the UK in August 2020 to treat people with Cystic Fibrosis (CF) aged >12 years. We report a real-world study of clinical outcomes in young people treated with ETI at our CF centre within the first two years of its availability.

METHODS

Participants aged 12-17 were identified within our clinic, with demographic data supplemented by the UK CF registry. Comprehensive outcome data spanning two years pre- and two years post-initiation of CFTR modulators were compiled from various local sources, including patient records, medication delivery logs, and clinical notes.

RESULTS

Of the 62 patients started on ETI (32 male, mean age 13.3 years), most (76 %) were homozygous for the F508del mutation. Three discontinuations occurred: one pregnancy, two related to side effects. Adherence was high (Proportion of Days covered >90 % both years). Following ETI initiation there was a significant increase in mean FEV1% (+11.7 units; 95 % CI 7.4-15.6), sustained throughout the two-year treatment period. There was no association between baseline lung function and the degree of improvement or rate of decline post-treatment. Improvements were similar for all treatable genotypes. BMI z-score increased by 0.25 units after four months of treatment, returning to baseline by 24 months. Intravenous antibiotic use decreased by 88 % (median IV days/year reduced from 32 to 4 days, p < 0.01).

CONCLUSIONS

ETI use in adolescents in a real-world setting led to sustained improvements in health outcomes, consistent with those seen in open trial extension studies.

Gene expression responses of CF airway epithelial cells exposed to elexacaftor/tezacaftor/ivacaftor suggest benefits beyond improved CFTR channel function

The combination of elexacaftor/tezacaftor/ivacaftor (ETI, Trikafta) reverses the primary defect in cystic fibrosis (CF) by improving CFTR-mediated Cl- and HCO3- secretion by airway epithelial cells (AECs), leading to improved lung function and less frequent exacerbations and hospitalizations. However, studies have shown that CFTR modulators like ivacaftor, a component of ETI, have numerous effects on CF cells beyond improved CFTR channel function. Because little is known about the effect of ETI on CF AEC gene expression, we exposed primary human AEC to ETI for 48 h and interrogated the transcriptome by RNA-seq and qPCR. ETI increased CFTR Cl- secretion, and defensin gene expression (DEFB1), an observation consistent with reports of decreased bacterial burden in the lungs of people with CF (pwCF). ETI decreased MMP10 and MMP12 gene expression, suggesting that ETI may reduce proteolytic-induced lung destruction in CF. ETI also reduced the expression of the stress response gene heme oxygenase (HMOX1). qPCR analysis confirmed DEFB1, HMOX1, MMP10, and MMP12 gene expression results observed by RNA-seq. Gene pathway analysis revealed that ETI decreased inflammatory signaling, cellular proliferation, and MHC class II antigen presentation. Collectively, these findings suggest that the clinical observation that ETI reduces lung infections in pwCF is related in part to drug-induced increases in DEFB1 and that ETI may reduce lung damage by reducing MMP10 and MMP12 gene expression. Moreover, pathway analysis also identified several other genes responsible for the ETI-induced reduction in inflammation observed in pwCF.NEW & NOTEWORTHY Gene expression responses by CF AECs exposed to ETI suggest that in addition to improving CFTR channel function, ETI is likely to enhance resistance to bacterial infection by increasing levels of beta-defensin 1 (hBD-1). ETI may also reduce lung damage by suppressing MMP10 and MMP12 and reduce airway inflammation by repressing proinflammatory cytokine secretion by CF AECs.

One year of ETI reduces lung bacterial colonisation in adults with cystic fibrosis

The triple combination elexacaftor-tezacaftor-ivacaftor (ETI) has provided unprecedented clinical benefits for people with cystic fibrosis (pwCF) and drastically transformed the outcome of this disease. We aimed to describe the evolution of lung bacterial colonization in 198 French adult pwCF taking into account the use of concomitantly respiratory treatment. We collected sputum cultures produced during the entire follow-up period starting 3 years before and ending 1 year after ETI initiation. All sputum cultures were centralized and analyzed at our bacteriological laboratory. Clinical data included pulmonary function, respiratory treatments, physiotherapy, number of IV antibiotics treatment, as well as inpatient stays. We observed a significant decrease in colonization prevalence by any CF pathogen after one year of treatment with ETI (p < 0.001). This decrease was confirmed for Pseudomonas aeruginosa, MRSA and MSSA, Stenotrophomonas maltophilia, Achromobacter spp. and nontuberculous mycobacteria (NTM). The maximal density of bacteria documented in sputum cultures decreased from 2.107 CFU/ml to 1.106 CFU/ml after one year of ETI. We also found a decrease in prevalence of Pseudomonas aeruginosa chronic colonization and in the density of Pseudomonas aeruginosa after one year of ETI. These results confirm the decrease in prevalence and bacterial density of lung colonisation for most of the CF pathogens, including Achromobacter spp, Stenotrophomonas maltophilia concomitantly to the clinical improvement. Further studies are needed to better understand the underlying mechanisms of these microbiological changes.

Ivacaftor ameliorates mucus burden, bacterial load, and inflammation in acute but not chronic P. aeruginosa infection in hG551D rats

BACKGROUND

Newly approved highly effective modulation therapies (HEMT) have been life-changing for people with CF. Although these drugs have resulted in significant improvements in lung function and exacerbation rate, bacterial populations in the lung have not been eradicated. The mechanisms behind the continued colonization are not completely clear.

METHODS

We used a humanized rat to assess the effects of ivacaftor therapy on infection outcomes. Rats harbor an insert expressing humanized CFTR cDNA, including the G551D mutation. hG551D rats were treated with ivacaftor either during or before infection with P. aeruginosa. The response to infection was assessed by bacterial burden in the lung and mucus burden in the lung.

RESULTS

We found that hG551D rats treated with ivacaftor had reduced bacteria present in the lung in the acute phase of the infection but were not different than vehicle control in the chronic phase of the infection. Similarly, the percentage of neutrophils in the airways were reduced at the acute, but not chronic, timepoints. Overall weight data indicated that the hG551D rats had significantly better weight recovery during the course of infection when treated with ivacaftor. Potentiation of the G551D mutation with ivacaftor resultant in short-circuit current measurements equal to WT, even during the chronic phase of the infection. Despite the persistent infection, hG551D rats treated with ivacaftor had fewer airways with mucus plugs during the chronic infection.

CONCLUSIONS

The data indicate that the hG551D rats have better outcomes during infection when treated with ivacaftor compared to the vehicle group. Rats have increased weight gain, increased CFTR protein function, and decreased mucus accumulation, despite the persistence of infection and inflammation. These data suggest that ivacaftor improves tolerance of infection, rather than eradication, in this rat model.

Lung function improvement on triple modulators: high-resolution, nationwide data from the Danish Cystic Fibrosis Cohort

Background

People living with cystic fibrosis in Denmark had early, universal access to triple modulator treatment with elexacaftor/tezacaftor/ivacaftor. Close monitoring allowed us to assess the impact of treatment on lung function and progression of lung disease in an unselected nationwide cystic fibrosis population from 6 years of age.

Methods

Data were analysed using linear mixed-effect models to assess changes in levels and annual rates of change (slopes) in percent predicted (pp) forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and forced expiratory flow at 25-75% of FVC (ppFEF25-75%) between the 12 months pre-treatment and treatment periods. Subgroup analyses assessed the impact of elexacaftor/tezacaftor/ivacaftor among those with/without previous modulator treatment, normal/mild/moderate/severe lung disease at treatment initiation, children/adults and birth cohorts.

Results

We included 392 people living with cystic fibrosis with a median (interquartile range) 12 (nine to 15) spirometry measurements per person. The mean (95% CI) improvement in ppFEV1 was 13.0 (11.3-14.6) 12 months after initiation of elexacaftor/tezacaftor/ivacaftor treatment. The annual rate of change improved from -1.4 (-2.1 - -0.6) ppFEV1 in the pre-treatment year to 2.7 (1.8-3.5) ppFEV1 per year during treatment. Similarly, ppFVC increased by 8.0 (7.1-8.9) and FEF25--75% by 19.5 (17.0-21.9).

Conclusions

Using high-resolution data from a nationwide real-world setting, our study documents the impact of elexacaftor/tezacaftor/ivacaftor on lung function across subgroups based on age, disease severity and treatment history. These findings point towards a new period of consistent lung function improvement among people living with cystic fibrosis on elexacaftor/tezacaftor/ivacaftor.

Changing profile of bacterial infection and microbiome in cystic fibrosis: when to use antibiotics in the era of CFTR-modulator therapy

The advent of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy, especially the triple therapy combining the drugs elexacaftor, tezacaftor, ivacaftor (ETI), has significantly changed the course of the disease in people with cystic fibrosis (pwCF). ETI, which is approved for the majority (80-90%) of pwCF, partially restores CFTR channel function, resulting in improved mucociliary clearance and, consequently, improved lung function, respiratory symptoms and pulmonary exacerbations. The bacterial burden of classical CF pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus is reduced without reaching eradication in the majority of infected patients. Limited data is available on less common or emerging bacterial pathogens. ETI has a positive effect on the lung microbiome but does not fully restore it to a healthy state. Due to the significant reduction in sputum production under ETI, respiratory samples such as deep-throat swabs are commonly taken, despite their inadequate representation of lower respiratory tract pathogens. Currently, there are still unanswered questions related to this new therapy, such as the clinical impact of infection with cystic fibrosis (CF) pathogens, the value of molecular diagnostic tests, the durability of the effects on respiratory infection and the role of fungal and viral infections. This article reviews the changes in bacterial lung infections and the microbiome in CF to provide evidence for the use of antibiotics in the era of ETI.

Gene expression responses of CF airway epithelial cells exposed to elexacaftor/tezacaftor/ivacaftor (ETI) suggest benefits beyond improved CFTR channel function

The combination of elexacaftor/tezacaftor/ivacaftor (ETI, Trikafta) reverses the primary defect in Cystic Fibrosis (CF) by improving CFTR mediated Cl - and HCO 3 - secretion by airway epithelial cells (AEC), leading to improved lung function and less frequent exacerbations and hospitalizations. However, studies have shown that CFTR modulators like ivacaftor, a component of ETI, has numerous effects on CF cells beyond improved CFTR channel function. Because little is known about the effect of ETI on CF AEC gene expression we exposed primary human AEC to ETI for 48 hours and interrogated the transcriptome by RNA-seq and qPCR. ETI increased defensin gene expression ( DEFB1 ) an observation consistent with reports of decreased bacterial burden in the lungs of people with CF (pwCF). ETI also decreased MMP10 and MMP12 gene expression, suggesting that ETI may reduce proteolytic induced lung destruction in CF. ETI also reduced the expression of the stress response gene heme oxygenase ( HMOX1 ). qPCR analysis confirmed DEFB1, HMOX1, MMP10 and MMP12 gene expression results observed by RNA-seq. Gene pathway analysis revealed that ETI decreased inflammatory signaling, cellular proliferation and MHC Class II antigen presentation. Collectively, these findings suggest that the clinical observation that ETI reduces lung infections in pwCF is related in part to drug induced increases in DEFB1 , and that ETI may reduce lung damage by reducing MMP10 and MMP12 gene expression, which is predicted to reduce matrix metalloprotease activity. Moreover, pathway analysis also identified several genes responsible for the ETI induced reduction in inflammation observed in people with CF.

New and Noteworthy

Gene expression responses by CF AEC exposed to ETI suggest that in addition to improving CFTR channel function, ETI is likely to increase resistance to bacterial infection by increasing levels of beta defensin 1 (hBD-1). ETI may also reduce lung damage by suppressing MMP10, and reduce airway inflammation by repressing proinflammatory cytokine secretion by AEC cells.

Cystic Fibrosis Carrier States Are Associated With More Severe Cases of Bronchiectasis

Background

People with cystic fibrosis (CF) are at increased risk for bronchiectasis, and several reports suggest that CF carriers may also be at higher risk for developing bronchiectasis. The purpose of this study was to determine if CF carriers are at risk for more severe courses or complications of bronchiectasis.

Methods

Using MarketScan data (2001-2021), we built a cohort consisting of 105 CF carriers with bronchiectasis and 300 083 controls with bronchiectasis but without a CF carrier diagnosis. We evaluated if CF carriers were more likely to be hospitalized for bronchiectasis. In addition, we examined if CF carriers were more likely to be infected with Pseudomonas aeruginosa or nontuberculous mycobacteria (NTM) or to have filled more antibiotic prescriptions. We considered regression models for incident and rate outcomes that controlled for age, sex, smoking status, and comorbidities.

Results

The odds of hospitalization were almost 2.4 times higher (95% CI, 1.116-5.255) for CF carriers with bronchiectasis when compared with non-CF carriers with bronchiectasis. The estimated odds of being diagnosed with a Pseudomonas infection for CF carriers vs noncarriers was about 4.2 times higher (95% CI, 2.417-7.551) and 5.4 times higher (95% CI, 3.398-8.804) for being diagnosed with NTM. The rate of distinct antibiotic fill dates was estimated to be 2 times higher for carriers as compared with controls (95% CI, 1.735-2.333), and the rate ratio for the total number of days of antibiotics supplied was estimated as 2.8 (95% CI, 2.290-3.442).

Conclusions

CF carriers with bronchiectasis required more hospitalizations and more frequent administration of antibiotics as compared with noncarriers. Given that CF carriers were also more likely to be diagnosed with Pseudomonas and NTM infections, CF carriers with bronchiectasis may have a phenotype more resembling CF-related bronchiectasis than non-CF bronchiectasis.

Dual species sphingosine-1-phosphate lyase inhibitors to combine antifungal and anti-inflammatory activities in cystic fibrosis: a feasibility study

Cystic fibrosis (CF) is an autosomal recessive disorder characterized by respiratory failure due to a vicious cycle of defective Cystic Fibrosis Transmembrane conductance Regulator (CFTR) function, chronic inflammation and recurrent bacterial and fungal infections. Although the recent introduction of CFTR correctors/potentiators has revolutionized the clinical management of CF patients, resurgence of inflammation and persistence of pathogens still posit a major concern and should be targeted contextually. On the background of a network-based selectivity that allows to target the same enzyme in the host and microbes with different outcomes, we focused on sphingosine-1-phosphate (S1P) lyase (SPL) of the sphingolipid metabolism as a potential candidate to uniquely induce anti-inflammatory and antifungal activities in CF. As a feasibility study, herein we show that interfering with S1P metabolism improved the immune response in a murine model of CF with aspergillosis while preventing germination of Aspergillus fumigatus conidia. In addition, in an early drug discovery process, we purified human and A. fumigatus SPL, characterized their biochemical and structural properties, and performed an in silico screening to identify potential dual species SPL inhibitors. We identified two hits behaving as competitive inhibitors of pathogen and host SPL, thus paving the way for hit-to-lead and translational studies for the development of drug candidates capable of restraining fungal growth and increasing antifungal resistance.

Host Susceptibility to Nontuberculous Mycobacterial Pulmonary Disease

Nontuberculous mycobacteria (NTM) pulmonary disease is a chronic progressive pulmonary infectious disease caused by low virulence pathogens. The existence of host susceptibility to NTM infection has been recognized from a high incidence among Asians compared to other populations in the United States, a high incidence among slender, middle-aged women, and the presence of familial clusters. Recent whole exome sequencing and genome-wide association studies have identified immune, CFTR, cilia, connective tissue and ion homeostasis genes as host susceptibility genes. Large-scale international collaborative studies and functional analyses are expected to elucidate host susceptibility in the future.

Impact of Elexacaftor/Tezacaftor/Ivacaftor on Healthcare Resource Utilization and Associated Costs Among People With Cystic Fibrosis in the US: A Retrospective Claims Analysis

INTRODUCTION

Cystic fibrosis (CF) is a life-limiting genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) is a CFTR modulator (CFTRm) that targets the underlying cause of CF. Based on safety and efficacy demonstrated in clinical trials, ELX/TEZ/IVA is approved in the US for the treatment of CF in people aged ≥ 2 years who have ≥ 1 F508del-CFTR mutation or a CFTR mutation that is responsive to ELX/TEZ/IVA based on in vitro data. While ELX/TEZ/IVA demonstrated unprecedented improvements in lung function and dramatic reductions in pulmonary exacerbations (PEx) and associated hospitalizations in clinical trials, a limited number of studies have examined the impact of ELX/TEZ/IVA on healthcare resource utilization (HCRU) and associated costs in a real-world setting. The aim of this retrospective study was to evaluate changes in PEx, HCRU, and associated non-CFTRm healthcare costs following initiation of ELX/TEZ/IVA among people with CF aged ≥ 12 years in the US.

METHODS

We evaluated the rates of PEx, HCRU, and associated costs before and after initiation of ELX/TEZ/IVA in people with CF aged ≥ 12 years using data from the Merative MarketScan® Commercial Claims and Encounters Database and the Merative Multi-State Medicaid Database from April 21, 2019 to December 31, 2020. Because the study period included time following the onset of the COVID-19 pandemic, we limited our primary analysis to the period prior to the pandemic (October 21, 2019 to March 12, 2020). Outcomes following the onset of the pandemic (March 13 to December 31, 2020) were examined in an exploratory analysis.

RESULTS

In both commercially insured and Medicaid-insured people with CF, ELX/TEZ/IVA was associated with reductions in PEx, hospitalizations, and associated costs prior to the COVID-19 pandemic, and these reductions were maintained following the onset of the pandemic.

CONCLUSIONS

These findings suggest that ELX/TEZ/IVA reduces the burden and costs associated with PEx and hospitalizations in people with CF.

Complications and Practice Variation in the Use of Peripherally Inserted Central Venous Catheters in People With Cystic Fibrosis: The Prospective Study of Peripherally Inserted Venous Catheters in People With Cystic Fibrosis Study

BACKGROUND

Peripherally inserted central catheters (PICCs) are used commonly to administer antibiotics to people with cystic fibrosis (CF), but their use can be complicated by venous thrombosis and catheter occlusion.

RESEARCH QUESTION

Which participant-, catheter-, and catheter management-level attributes are associated with increased risk of complications of PICCs among people with CF?

STUDY DESIGN AND METHODS

This was a prospective observational study of adults and children with CF who received PICCs at 10 CF care centers in the United States. The primary end point was defined as occlusion of the catheter resulting in unplanned removal, symptomatic venous thrombosis in the extremity containing the catheter, or both. Three categories of composite secondary outcomes were identified: difficult line placement, local soft tissue or skin reactions, and catheter malfunction. Data specific to the participant, catheter placement, and catheter management were collected in a centralized database. Risk factors for primary and secondary outcomes were analyzed by multivariate logistic regression.

RESULTS

Between June 2018 and July 2021, 157 adults and 103 children older than 6 years with CF had 375 PICCs placed. Patients underwent 4,828 catheter-days of observation. Of the 375 PICCs, 334 (89%) were ≤ 4.5 F, 342 (91%) were single lumen, and 366 (98%) were placed using ultrasound guidance. The primary outcome occurred in 15 PICCs for an event rate of 3.11 per 1,000 catheter-days. No cases of catheter-related bloodstream infection occurred. Other secondary outcomes developed in 147 of 375 catheters (39%). Despite evidence of practice variation, no risk factors for the primary outcome and few risk factors for secondary outcomes were identified.

INTERPRETATION

This study affirmed the safety of contemporary approaches to inserting and using PICCs in people with CF. Given the low rate of complications in this study, observations may reflect a widespread shift to selecting smaller-diameter PICCs and using ultrasound to guide their placement.

Druggable redox pathways against Mycobacterium abscessus in cystic fibrosis patient-derived airway organoids

Mycobacterium abscessus (Mabs) drives life-shortening mortality in cystic fibrosis (CF) patients, primarily because of its resistance to chemotherapeutic agents. To date, our knowledge on the host and bacterial determinants driving Mabs pathology in CF patient lung remains rudimentary. Here, we used human airway organoids (AOs) microinjected with smooth (S) or rough (R-)Mabs to evaluate bacteria fitness, host responses to infection, and new treatment efficacy. We show that S Mabs formed biofilm, and R Mabs formed cord serpentines and displayed a higher virulence. While Mabs infection triggers enhanced oxidative stress, pharmacological activation of antioxidant pathways resulted in better control of Mabs growth and reduced virulence. Genetic and pharmacological inhibition of the CFTR is associated with better growth and higher virulence of S and R Mabs. Finally, pharmacological activation of antioxidant pathways inhibited Mabs growth, at least in part through the quinone oxidoreductase NQO1, and improved efficacy in combination with cefoxitin, a first line antibiotic. In conclusion, we have established AOs as a suitable human system to decipher mechanisms of CF-driven respiratory infection by Mabs and propose boosting of the NRF2-NQO1 axis as a potential host-directed strategy to improve Mabs infection control.

Optimal treatment of the underlying aetiology is the most effective antimicrobial stewardship for chronic respiratory disease: a lesson learned from cystic fibrosis

AMS in chronic lung disease can be challenging. Causal treatment of treatable traits may be the most successful AMS strategy for patients with any chronic pulmonary disease and should be brought into focus. https://bit.ly/3ptrmV8.

Post-approval studies with the CFTR modulators Elexacaftor-Tezacaftor-Ivacaftor

Triple combination therapy with the CFTR modulators elexacaftor (ELX), tezacaftor (TEZ) and ivacaftor (IVA) has been qualified as a game changer in cystic fibrosis (CF). We provide an overview of the body of literature on ELX/TEZ/IVA published between November 2019 and February 2023 after approval by the regulators. Recombinant ELX/TEZ/IVA-bound Phe508del CFTR exhibits a wild type conformation in vitro, but in patient's tissue a CFTR glyoisoform is synthesized that is distinct from the wild type and Phe508del isoforms. ELX/TEZ/IVA therapy improved the quality of life of people with CF in the real-life setting irrespective of their anthropometry and lung function at baseline. ELX/TEZ/IVA improved sinonasal and abdominal disease, lung function and morphology, airway microbiology and the basic defect of impaired epithelial chloride and bicarbonate transport. Pregnancy rates were increasing in women with CF. Side effects of mental status changes deserve particular attention in the future.

Efficacy and Safety of Elexacaftor-Tezacaftor-Ivacaftor in the Treatment of Cystic Fibrosis: A Systematic Review

Elexacaftor/Tezacaftor/Ivacaftor (ELX/TEZ/IVA) is a new CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) modulator treatment, used over the last few years, which has shown an improvement in different clinical outcomes in patients with cystic fibrosis (CF). The objective of this study was a systematic research of the literature on the efficacy and safety of this CFTR modulator on patients with CF. A search of Pubmed was conducted for randomized clinical trials and observational studies published from 2012 to September 2022. The included full manuscripts comprised nine clinical trials and 16 observational studies, whose participants were aged ≥12 years or were children 6–11 years old with at least one Phe508del mutation and/or advanced lung disease (ALD). These studies reported that ELX/TEZ/IVA has a significant positive effect on the lung function of patients with CF, by ameliorating parameters such as FEV1, LCI, pulmonary exacerbations or sweat chloride concentration, increasing BMI and improving quality of their life. Its role in cystic fibrosis-related diabetes (CFRD) is not yet clear. It was found that this new CFTR modulator has an overall favorable safety profile, with mild to moderate adverse events. Further studies are needed for a deeper understanding of the impact of CFTR modulators on other CF manifestations, or the possibility of treating with ELX/TEZ/IVA CF patients with rare CFTR mutations.

Elexacaftor-Tezacaftor-Ivacaftor: A Life-Changing Triple Combination of CFTR Modulator Drugs for Cystic Fibrosis

Cystic fibrosis (CF) is a potentially fatal monogenic disease that causes a progressive multisystemic pathology. Over the last decade, the introduction of CF transmembrane conductance regulator (CFTR) modulator drugs into clinical practice has profoundly modified the lives of many people with CF (PwCF) by targeting the fundamental cause of the disease. These drugs consist of the potentiator ivacaftor (VX-770) and the correctors lumacaftor (VX-809), tezacaftor (VX-661), and elexacaftor (VX-445). In particular, the triple combination of CFTR modulators composed of elexacaftor, tezacaftor, and ivacaftor (ETI) represents a life-changing therapy for the majority of PwCF worldwide. A growing number of clinical studies have demonstrated the safety and efficacy of ETI therapy in both short- and long-term (up to two years of follow-up to date) and its ability to significantly reduce pulmonary and gastrointestinal manifestations, sweat chloride concentration, exocrine pancreatic dysfunction, and infertility/subfertility, among other disease signs and symptoms. Nevertheless, ETI therapy-related adverse effects have also been reported, and close monitoring by a multidisciplinary healthcare team remains vital. This review aims to address and discuss the major therapeutic benefits and adverse effects reported by the clinical use of ETI therapy for PwCF.

Impact of elexacaftor/tezacaftor/ivacaftor on bacterial cultures from people with cystic fibrosis

BACKGROUND

Cystic fibrosis transmembrane conductance regulator (CFTR) modulators have shown beneficial effects on both forced expiratory volume in 1 s (FEV₁ ) and frequency of pulmonary exacerbations in people with cystic fibrosis (CF). These positive outcomes may be related to changes in bacterial colonization within the lungs. Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) is the first triple therapy CFTR modulator approved for use in people with CF 6 years and older. This study aimed to determine the impact of ELX/TEZ/IVA on the isolation of Pseudomonas aeruginosa (Pa), methicillin-resistant and methicillin-susceptible Staphylococcus aureus (MRSA and MSSA, respectively) in respiratory cultures.

METHODS

A retrospective chart review of the electronic medical record at the University of Iowa was completed for individuals 12 years and older taking ELX/TEZ/IVA for at least 12 months. The primary outcome was determined by assessing bacterial cultures pre- and postinitiation of ELX/TEZ/IVA. Baseline demographic and clinical characteristics were summarized using mean and standard deviation for continuous outcomes and count and percentage for categorical outcomes. Culture positivity for Pa, MSSA, and MRSA was compared among enrolled subjects between pre- and posttriple combination therapy periods using an exact McNemar's test.

RESULTS

One hundred and twenty-four subjects prescribed ELX/TEZ/IVA for at least 12 months met the requirements for inclusion within our analysis. Culture positivity for Pa, MSSA, and MRSA was approximately 54%, 33%, and 31%, respectively, for the pre-ELX/TEZ/IVA period. Prevalence decreased to approximately 30%, 32%, and 24% (-24.2% [p < 0.0001], -0.7% [p = 1.00], and -6.5% [p = 0.0963], respectively) post-ELX/TEZ/IVA. The source of bacterial culture was predominantly sputum (70.2%) in the pre-ELX/TEZ/IVA group, whereas a throat source (66.1%) was more common post-ELX/TEZ/IVA.

CONCLUSIONS

ELX/TEZ/IVA treatment has an appreciable impact on the detection of common bacterial pathogens in CF respiratory cultures. While previous studies have found a similar effect with single and double CFTR modulator therapies, this is the first single-center study to show the impact of triple therapy, ELX/TEZ/IVA, on bacterial isolation from airway secretions.

Role of the Physical Therapist in Cystic Fibrosis Care

In looking back on 2020 and 2021, this Perspective reflects on the monumental impacts of the rollout of cystic fibrosis (CF) transmembrane conductance regulator highly effective modulator therapies and the COVID-19 pandemic on the management of CF. Advancements in the clinical management of people with CF have been both enormous and rapid, and physical therapists specializing in the care of people with CF have been at the forefront of driving this evolution in care. This year sees the 30th anniversary of the UK Association of Chartered Physiotherapists in Cystic Fibrosis and, as is inevitable in reaching such milestones, thoughts have turned to origins, role, impacts, and the future. With the changing demographics of the population of people with CF after the introduction of highly effective modulator therapies, potentially with fewer secondary complications, the future role of the physical therapist who specializes in CF is in question. This Perspective reflects on and highlights the role of physical therapy within CF and provides insights into how physical therapists and respiratory therapists can evolve their roles to ensure relevance for the future.

New Aspects of Lung Transplantation: A Narrative Overview Covering Important Aspects of Perioperative Management

The management of lung transplant patients has continued to evolve in recent years. The year 2021 was marked by the publication of the International Consensus Recommendations for Anesthetic and Intensive Care Management of Lung Transplantation. There have been major changes in lung transplant programs over the last few years. This review will summarize the knowledge in anesthesia management of lung transplantation with the most recent data. It will highlight the following aspects which concern anesthesiologists more specifically: (1) impact of COVID-19, (2) future of transplantation for cystic fibrosis patients, (3) hemostasis management, (4) extracorporeal membrane oxygenation management, (5) early prediction of primary graft dysfunction, and (6) pain management.

Mucins and CFTR: Their Close Relationship

Mucociliary clearance is a critical defense mechanism for the lungs governed by regionally coordinated epithelial cellular activities, including mucin secretion, cilia beating, and transepithelial ion transport. Cystic fibrosis (CF), an autosomal genetic disorder caused by the dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) channel, is characterized by failed mucociliary clearance due to abnormal mucus biophysical properties. In recent years, with the development of highly effective modulator therapies, the quality of life of a significant number of people living with CF has greatly improved; however, further understanding the cellular biology relevant to CFTR and airway mucus biochemical interactions are necessary to develop novel therapies aimed at restoring CFTR gene expression in the lungs. In this article, we discuss recent advances of transcriptome analysis at single-cell levels that revealed a heretofore unanticipated close relationship between secretory MUC5AC and MUC5B mucins and CFTR in the lungs. In addition, we review recent findings on airway mucus biochemical and biophysical properties, focusing on how mucin secretion and CFTR-mediated ion transport are integrated to maintain airway mucus homeostasis in health and how CFTR dysfunction and restoration of function affect mucus properties.

Potential opportunities and challenges for infection prevention and control for cystic fibrosis in the modern era

PURPOSE OF REVIEW

We describe recent changes in care for people with cystic fibrosis (PwCF) that could impact infection prevention and control (IP&C) practices.

RECENT FINDINGS

Current IP&C guidelines primarily aim to prevent acquisition and transmission of pathogens in PwCF utilizing evidence-based recommendations for healthcare settings. Currently, highly effective modulator therapy (HEMT) is dramatically improving the clinical manifestations of cystic fibrosis and reducing pulmonary exacerbations and hospitalizations. Thus, it is feasible that long-term, sustained improvements in pulmonary manifestations of cystic fibrosis could favorably alter cystic fibrosis microbiology. The COVID-19 pandemic increased the use of virtual care, enabling PwCF to spend less time in healthcare settings and potentially reduce the risk of acquiring cystic fibrosis pathogens. The increasing use of whole genome sequencing (WGS) shows great promise in elucidating sources of cystic fibrosis pathogens, shared strains, and epidemic strains and ultimately could allow the cystic fibrosis community to monitor the safety of changed IP&C practices, if deemed appropriate. Finally, given the nonhealthcare environmental reservoirs for cystic fibrosis pathogens, practical guidance can inform PwCF and their families about potential risks and mitigation strategies.

SUMMARY

New developments in the treatment of PwCF, a shift toward virtual care delivery of care, and use of WGS could change future IP&C practices.

Muc5b Contributes to Mucus Abnormality in Rat Models of Cystic Fibrosis

Cystic fibrosis (CF) airway disease is characterized by excessive and accumulative mucus in the airways. Mucociliary clearance becomes defective as mucus secretions become hyperconcentrated and viscosity increases. The CFTR-knockout (KO) rat has been previously shown to progressively develop delayed mucociliary transport, secondary to increased viscoelasticity of airway secretions. The humanized-G551D CFTR rat model has demonstrated that abnormal mucociliary clearance and hyperviscosity is reversed by ivacaftor treatment. In this study, we sought to identify the components of mucus that changes as the rat ages to contribute to these abnormalities. We found that Muc5b concentrations, and to a lesser extent Muc5ac, in the airway were increased in the KO rat compared to WT, and that Muc5b concentration was directly related to the viscosity of the mucus. Additionally, we found that methacholine administration to the airway exacerbates these characteristics of disease in the KO, but not WT rat trachea. Lastly we determined that at 6 months of age, CF rats had mucus that was adherent to the airway epithelium, a process that is reversed by ivacaftor therapy in the hG551D rat. Overall, these data indicate that accumulation of Muc5b initiates the muco-obstructive process in the CF lung prior to infection.