J Fungi (Basel). 2023 Apr 22;9(5):502. doi: 10.3390/jof9050502.

ABSTRACT

Over the last years, the interkingdom microbial interactions concerning bacteria and fungi cohabiting and/or responsible for human pathologies have been investigated. In this context, the Gram-negative bacterium Pseudomonas aeruginosa and fungal species belonging to the Scedosporium/Lomentospora genera are widespread, multidrug-resistant, emergent, opportunistic pathogens that are usually co-isolated in patients with cystic fibrosis. The available literature reports that P. aeruginosa can inhibit the in vitro growth of Scedosporium/Lomentospora species; however, the complex mechanisms behind this phenomenon are mostly unknown. In the present work, we have explored the inhibitory effect of bioactive molecules secreted by P. aeruginosa (3 mucoid and 3 non-mucoid strains) on S. apiospermum (n = 6 strains), S. minutisporum (n = 3), S. aurantiacum (n = 6) and L. prolificans (n = 6) under cultivation in a cystic fibrosis mimic environment. It is relevant to highlight that all bacterial and fungal strains used in the present study were recovered from cystic fibrosis patients. The growth of Scedosporium/Lomentospora species was negatively affected by the direct interaction with either mucoid or non-mucoid strains of P. aeruginosa. Moreover, the fungal growth was inhibited by the conditioned supernatants obtained from bacteria-fungi co-cultivations and by the conditioned supernatants from the bacterial pure cultures. The interaction with fungal cells induced the production of pyoverdine and pyochelin, 2 well-known siderophores, in 4/6 clinical strains of P. aeruginosa. The inhibitory effects of these four bacterial strains and their secreted molecules on fungal cells were partially reduced with the addition of 5-flucytosine, a classical repressor of pyoverdine and pyochelin production. In sum, our results demonstrated that distinct clinical strains of P. aeruginosa can behave differently towards Scedosporium/Lomentospora species, even when isolated from the same cystic fibrosis patient. Additionally, the production of siderophores by P. aeruginosa was induced when co-cultivated with Scedosporium/Lomentospora species, indicating competition for iron and deprivation of this essential nutrient, leading to fungal growth inhibition.

PMID:37233213 | DOI:10.3390/jof9050502

Pediatr Pulmonol. 2023 May 26. doi: 10.1002/ppul.26502. Online ahead of print.

ABSTRACT

OBJECTIVES: Airway clearance therapy (ACT) is an important component of therapy for cystic fibrosis (CF) but is associated with significant treatment burden. Highly effective CFTR modulator therapy (HEMT) has improved pulmonary function for many people with CF (pwCF). We sought to understand changes in attitudes and practices about ACT in the post-HEMT era.

STUDY DESIGN: Surveys of CF community members and CF care team members.

METHODOLOGY: Separate surveys were created for the CF community and CF care providers to evaluate attitudes towards ACT and exercise in the post-HEMT era. We solicited answers from pwCF via the CF Foundation's Community Voice and from CF care providers via CF Foundation listservs. Surveys were available between July 20 and August 3, 2021.

RESULTS: Surveys were completed by 153 community members (parents of children and pwCF) and 192 CF care providers. Belief that exercise can substitute partially for ACT was endorsed similarly by community members (59%) and providers (68%). After starting HEMT, 36% of parents of children and 51% of adults did fewer ACT treatments including 13% who stopped ACT. Adults reported altering their ACT regimen more than parents of children, though the sample size was limited. Half of providers had changed their ACT recommendations for those on HEMT. Fifty-three percent of respondents had discussed changing ACT with their care team (36% of parents, 58% of pwCF).

CONCLUSIONS: Providers should be aware that ACT management changes may have been undertaken by pwCF who have pulmonary benefits of HEMT. Treatment burden should be considered in co-management decisions regarding ACT and exercise.

PMID:37232336 | DOI:10.1002/ppul.26502

Pediatr Pulmonol. 2023 May 26. doi: 10.1002/ppul.26494. Online ahead of print.

ABSTRACT

BACKGROUND: Adolescents with cystic fibrosis (CF) and their parents must navigate changing roles and responsibilities within the family including transfer of disease management responsibilities.

AIM/OBJECTIVE: The aim of this qualitative study was to explore how families share and transfer CF management responsibility from the perspectives of adolescents with CF and their parents.

METHODS: Guided by qualitative descriptive methodology, we purposively sampled adolescent/parent dyads. Participants completed two surveys measuring family responsibility (Family Responsibility Questionnaire [FRQ]) and transition readiness (Transition Readiness Assessment Questionnaire [TRAQ]) We conducted semistructured video or phone interviews, used a codebook to guide team coding and analyzed qualitative data using both content analysis and dyadic interview analysis.

RESULTS: Thirty participants (15 dyads) enrolled (7% Black; 33% Latina/o; 40% female; adolescent age 14.4 ± 2 years; 66% prescribed highly effective modulator therapy; 80% of parents were mothers). Parent FRQ and TRAQ scores were significantly higher than their adolescent indicating differing perceptions of responsibility and transition readiness. We inductively identified four themes: (1) CF management is a delicate balance (CF management is a routine which is easily disrupted), (2) Growing up and parenting under extraordinary circumstances (the burden of CF weighs on families as they navigate adolescence), (3) Differing Perceptions of risk and responsibility (adolescent and parent perceptions of treatment responsibility and the risks of nonadherence do not always align), and (4) Balancing independence and protection (families must weigh the benefits and risks of allowing adolescents increased independence).

CONCLUSIONS: Adolescents and parents demonstrated differing perceptions of CF management responsibility, which may be related to a lack of communication between family members about this topic. To help facilitate alignment of parent and adolescent expectations, discussion of family roles and responsibility for CF management should begin early during the transition process and be discussed regularly during clinic visits.

PMID:37232332 | DOI:10.1002/ppul.26494

BMJ Open Respir Res. 2023 May;10(1):e001447. doi: 10.1136/bmjresp-2022-001447.

ABSTRACT

BACKGROUND: Ivacaftor approval was extended to people with cystic fibrosis (CF) and an R117H variant in 2014 in the USA. This observational, real-world, postapproval study evaluated long-term outcomes among people with CF and an R117H variant on ivacaftor using data from the US Cystic Fibrosis Foundation Patient Registry.

METHODS: Key outcomes were evaluated in ivacaftor-treated people with CF and an R117H variant for up to 36 months before and after treatment initiation using within-group comparisons. Analyses were descriptive in nature, focused on evaluation of observed outcome patterns over time and were performed both overall and for age groups ≥2 to <6 years, ≥6 to <18 years and ≥18 years. Key outcomes included lung function, body mass index (BMI), pulmonary exacerbations (PEx) and hospitalisations.

RESULTS: The ivacaftor cohort included 369 people with CF and an R117H variant who initiated therapy between 1 January 2015 and 31 December 2016. During each of the 12-month intervals following treatment initiation, the mean observed percent predicted forced expiratory volume in 1 s (ppFEV1) and BMI values were higher and the mean annualised number of PEx and hospitalisation events were lower than pretreatment values. Mean change in ppFEV1 from pretreatment baseline was an increase of 1.5 (95% CI 0.8 to 2.3), 1.7 (95% CI 0.7 to 2.7) and 1.8 (95% CI 0.6 to 3.0) percentage points in the first, second and third years of treatment, respectively. Similar trends were observed in adult and paediatric subgroups.

CONCLUSIONS: The results support the clinical effectiveness of ivacaftor in people with CF and an R117H variant, including adult and paediatric subgroups.

PMID:37230763 | DOI:10.1136/bmjresp-2022-001447

Int J Radiat Oncol Biol Phys. 2023 May 23:S0360-3016(23)00514-X. doi: 10.1016/j.ijrobp.2023.05.029. Online ahead of print.

ABSTRACT

PURPOSE: Radiation therapy (RT) is indispensable for managing thoracic carcinomas. However, its application is limited by radiation-induced lung injury (RILI), one of the most common and fatal complications of thoracic RT. Nonetheless, the exact molecular mechanisms of RILI remain poorly understood.

METHODS AND MATERIALS: To elucidate the underlying mechanisms, various knockout (KO) mouse strains were subjected to 16 Gy whole-thoracic RT. RILI was assessed by qRT-PCR, ELISA, histology, western blot, immunohistochemistry, and CT examination. To perform further mechanistic studies on the signaling cascade during the RILI process, pulldown, CHIP, and rescue assays were conducted.

RESULTS: We found that the cGAS-STING pathway was significantly upregulated after irradiation exposure in both the mouse models and clinical lung tissues. Knocking down either cGAS or STING led to attenuated inflammation and fibrosis in mouse lung tissues. NLRP3 is hardwired to the upstream DNA-sensing cGAS-STING pathway to trigger of the inflammasome and amplification of the inflammatory response. STING deficiency suppressed the expressions of the NLRP3 inflammasome and pyroptosis-pertinent components containing IL-1β, IL-18, GSDMD-N and cleaved caspase-1. Mechanistically, interferon regulatory factor 3, the essential transcription factor downstream of cGAS-STING, promoted the pyroptosis by transcriptionally activating NLRP3. Moreover, we found that RT triggered the release of self-dsDNA in the bronchoalveolar space, which is essential for the activation of cGAS-STING and the downstream NLRP3-mediated pyroptosis. Of note, Pulmozyme, an old drug for the management of cystic fibrosis, was revealed to have the potential to mitigate RILI by degrading extracellular dsDNA and then inhibiting the cGAS-STING-NLRP3 signaling pathway.

CONCLUSIONS: These results delineated the crucial function of cGAS-STING as a key mediator of RILI, and described a mechanism of pyroptosis linking cGAS-STING activation with the amplification of initial RILI. These findings indicate that the dsDNA-cGAS-STING-NLRP3 axis might be potentially amenable to therapeutic targeting for RILI.

PMID:37230431 | DOI:10.1016/j.ijrobp.2023.05.029

J Cyst Fibros. 2023 May 23:S1569-1993(23)00142-X. doi: 10.1016/j.jcf.2023.05.012. Online ahead of print.

ABSTRACT

The ongoing development and integration of telehealth within CF care has been accelerated in response to the Covid-19 pandemic, with many centres publishing their experiences. Now, as the restrictions of the pandemic ease, the use of telehealth appears to be waning, with many centres returning to routine traditional face-to-face services. For most, telehealth is not integrated into clinical care models, and there is a lack of guidance on how to integrate such a service into clinical care. The aims of this systematic review were to first identify manuscripts which may inform best CF telehealth practices, and second, to analyse these finding to determine how the CF community may use telehealth to improve care for patients, families, and Multidisciplinary Teams into the future. To achieve this, the PRISMA review methodology was utilised, in combination with a modified novel scoring system that consolidates expert weighting from key CF stakeholders, allowing for the manuscripts to be placed in a hierarchy in accordance with their scientific robustness. From the 39 found manuscripts, the top ten are presented and further analysed. The top ten manuscripts are exemplars of where telehealth is used effectively within CF care at this time, and demonstrate specific use cases of its potential best practices. However, there is a lack of guidance for implementation and clinical decision making, which remains an area for improvement. Thus, it is suggested that further work explores and provides guidance for standardised implementation into CF clinical practice.

PMID:37230808 | DOI:10.1016/j.jcf.2023.05.012

J Cyst Fibros. 2023 May 23:S1569-1993(23)00140-6. doi: 10.1016/j.jcf.2023.05.010. Online ahead of print.

ABSTRACT

OBJECTIVE: To provide interim advice and considerations to the CF Community around CF nutrition in the current era.

METHODS: The Cystic Fibrosis (CF) Foundation organized a multidisciplinary committee to develop a Nutrition Position Paper based on the rapidly changing nutrition landscape in CF, due in part to widespread use of cystic fibrosis transmembrane regulator highly effective modulator therapy (HEMT). Four workgroups were formed: Weight Management, Eating Behavior/Food Insecurity, Salt Homeostasis and Pancreatic Enzyme use. Each workgroup conducted their own focused review of the literature.

RESULTS: The committee summarized current understanding of issues pertaining to the four workgroup topics and provided 6 key take-aways around CF Nutrition in the new era.

CONCLUSION: People with CF (pwCF) are living longer, particularly with the advent of HEMT. The traditional high fat, high calorie CF diet may have negative nutritional and cardiovascular consequences as pwCF age. Individuals with CF may have poor diet quality, food insecurity, distorted body image, and an higher incidence of eating disorders. An increase in overweight and obesity may lead to new considerations for nutritional management, given potential effects of overnutrition on pulmonary and cardiometabolic parameters.

PMID:37230807 | DOI:10.1016/j.jcf.2023.05.010

J Pediatr Gastroenterol Nutr. 2023 May 24. doi: 10.1097/MPG.0000000000003844. Online ahead of print.

ABSTRACT

BACKGROUND: The quality of health care clinician (HCC) communication varies, yet few studies evaluate ways to improve communication among adolescents with cystic fibrosis (CF). We sought to characterize the attitudes of adolescents and young adults (AYA) with CF about HCC communication and describe the components important for high-quality communication.

METHODS: AYA with CF aged 12-20 years from a single large pediatric CF care center participated in a brief survey and semi-structured individual and group virtual interviews that were recorded, transcribed, coded and analyzed with a combined deductive and inducive approach. Discrepancies were resolved by consensus.

RESULTS: Among the 39 survey respondents, most were white (77%), male (51%), and averaged 15.51 years (range 12 - 20 years). Many (40%) perceived their health status as "neutral" and over half (61%) were "very satisfied" with HCC communication. Overall, among the 17 interviews (averaged 53.6 minutes, range 31.5-74 min), participants reported a desire to be actively engaged in discussions about their health and included in the decision-making process with HCC to support adolescent autonomy and cultivate trust. Some factors detract (loss of control and fear of diagnosis), and others strengthen (transition to adult care and external motivators) adolescent autonomy. Some factors detract (perceived lack of interdisciplinary communication, statements of non-compliance, and being compared to others) and others strengthen (inherent trust and familiarity over time) the cultivation of trust.

CONCLUSIONS: The development of adolescent autonomy and the cultivation and maintenance of trust between the patient and HCC are two essential components of quality communication that should inform future communication-focused interventions.

PMID:37229765 | DOI:10.1097/MPG.0000000000003844

Curr Res Microb Sci. 2023 May 10;4:100191. doi: 10.1016/j.crmicr.2023.100191. eCollection 2023.

ABSTRACT

Dispersion is an essential step in the lifecycle of biofilms, since it enables the dissemination of microbial cells and, consequently, the potential colonization of new sites. Filamentous fungi belonging to the Scedosporium/Lomentospora genera are opportunistic human pathogens able to form multidrug-resistant biofilms on surfaces of different chemical compositions, environments and nutritional conditions. Despite the rising understanding of how biofilms are formed by Scedosporium/Lomentospora species, the cell dispersal step has not yet been explored. In the present study, the cell dispersion was investigated during biofilm formation by S. apiospermum, S. minutisporum, S. aurantiacum and L. prolificans cells. The results revealed that conidia were the major type of dispersed cells, which were detected throughout biofilm development (from 24 to 72 h). Dispersion was not influenced by increased glucose concentration (the main source for energetic metabolism) neither the presence of voriconazole (the most common antifungal used to treat scedosporiosis); however, the presence of mucin (a component of mucous, present in the lungs of cystic fibrosis patients, who are usually affected by these filamentous fungi) triggered cell dispersion. Contrarily, a poor nutritional environment (e.g., phosphate-buffered saline) inhibited this step. Overall, our study reveals new insights into the biofilm development of Scedosporium/Lomentospora species.

PMID:37229517 | PMC:PMC10203734 | DOI:10.1016/j.crmicr.2023.100191

Front Pharmacol. 2023 May 9;14:1176815. doi: 10.3389/fphar.2023.1176815. eCollection 2023.

ABSTRACT

Introduction: Recently, cystic fibrosis transmembrane regulator modulator therapy with elexacaftor/tezacaftor/ivacaftor has become available for children with cystic fibrosis (CF) carrying at least one F508del mutation. Objective: To assess the intermediate term effects of elexacaftor/tezacaftor/ivacaftor in children with cystic fibrosis in a real-world setting. Methods: We performed a retrospective analysis of records of children with cystic fibrosis, who started elexacaftor/tezacaftor/ivacaftor between 8/2020 and 10/2022. Pulmonary function tests, nutritional status, sweat chloride and laboratory data were assessed before, 3 and 6 months after the start of elexacaftor/tezacaftor/ivacaftor respectively. Results: Elexacaftor/tezacaftor/ivacaftor was started in 22 children 6-11 years and in 24 children 12-17 years. Twenty-seven (59%) patients were homozygous for F508del (F/F) and 23 (50%) patients were transitioned from ivacaftor/lumacaftor (IVA/LUM) or tezacaftor/ivacaftor (TEZ/IVA) to elexacaftor/tezacaftor/ivacaftor. Overall, mean sweat chloride concentration decreased by 59.3 mmol/L (95% confidence interval: -65.0 to -53.7 mmol/L, p < 0.0001) under elexacaftor/tezacaftor/ivacaftor. Sweat chloride concentration also decreased significantly after transition from IVA/LUM or TEZ/IVA to elexacaftor/tezacaftor/ivacaftor (-47.8 mmol/l; 95% confidence interval: -57.6 to -37.8 mmol/l, n = 14, p < 0.0001). Sweat chloride reduction was more marked in children with the F/F than in those with the F/MF genotype (69.4 vs 45.9 mmol/L, p < 0.0001). At 3 months follow-up, body-mass-index-z-score increased by 0.31 (95% CI, 0.2-0.42, p < 0.0001) with no further increase at 6 months. BMI-for-age-z-score was more markedly improved in the older group. Overall pulmonary function (percent predicted FEV1) at 3 months follow-up increased by 11.4% (95% CI: 8.0-14.9, p < 0.0001) with no further significant change after 6 months. No significant differences were noted between the age groups. Children with the F/MF genotype had a greater benefit regarding nutritional status and pulmonary function tests than those with the F/F genotype. Adverse events led to elexacaftor/tezacaftor/ivacaftor dose reduction in three cases and a temporary interruption of therapy in four cases. Conclusion: In a real-world setting, elexacaftor/tezacaftor/ivacaftor therapy had beneficial clinical effects and a good safety profile in eligible children with cystic fibrosis comparable to previously published data from controlled clinical trials. The positive impact on pulmonary function tests and nutritional status seen after 3 months of elexacaftor/tezacaftor/ivacaftor therapy was sustained at 6 months follow-up.

PMID:37229253 | PMC:PMC10203630 | DOI:10.3389/fphar.2023.1176815

Front Pediatr. 2023 May 9;11:1130792. doi: 10.3389/fped.2023.1130792. eCollection 2023.

ABSTRACT

BACKGROUND: Malnutrition is both a feature and major cause of morbidity in cystic fibrosis (CF). Therefore, nutritional management is an essential element of patient care. In 2016, an international guideline for nutritional management in patients with CF was published. In light of these recommendations, the aim of this study was to investigate the dietary intake of children with CF at the University Hospital of Bordeaux.

METHODS: We conducted a retrospective study at the Paediatric CF Centre of the University Hospital of Bordeaux. Patients aged 2-18 years with CF who completed a 3-day food diary at home between January 2015 and December 2020 were included.

RESULTS: A total of 130 patients, with a median age of 11.8 [interquartile range (IQR): 8.3; 13.4] years, were included. The median Z-score for BMI was -0.35 (IQR: -0.9; 0.2) and 20% of the patients had a Z-score for BMI < -1. Recommended total energy intakes were achieved in 53% of the patients, particularly those with nutritional support. Recommended protein intake was met in 28% of the cases, while fat and carbohydrate intakes were met in 54%. Vitamin and micronutrient levels were normal in 80% of the patients, with the exception of vitamin K, which was within the therapeutic range in only 42% of the cases.

CONCLUSION: Recommended nutritional targets are difficult to achieve in patients with CF, and providing nutritional support during follow-up remains a challenge.

PMID:37228437 | PMC:PMC10203471 | DOI:10.3389/fped.2023.1130792

ERJ Open Res. 2023 May 22;9(3):00628-2022. doi: 10.1183/23120541.00628-2022. eCollection 2023 May.

ABSTRACT

The European Respiratory Society International Congress took place both in person, in Barcelona, Spain, and online in 2022. The congress welcomed over 19 000 attendees on this hybrid platform, bringing together exciting updates in respiratory science and medicine from around the world. In this article, Early Career Members of the Respiratory Infections Assembly (Assembly 10) summarise a selection of sessions across a broad range of topics, including presentations on bronchiectasis, nontuberculous mycobacteria, tuberculosis, cystic fibrosis and coronavirus disease 2019.

PMID:37228292 | PMC:PMC10204818 | DOI:10.1183/23120541.00628-2022

ERJ Open Res. 2023 May 15;9(3):00569-2022. doi: 10.1183/23120541.00569-2022. eCollection 2023 May.

ABSTRACT

BACKGROUND: Recently, the Rome classification was proposed in which objective and readily measurable variables were integrated to mark exacerbations of COPD (ECOPD) severity. The aim of this study is to investigate the distribution of a real-world patient population with hospitalised ECOPD according to the current classification across the newly proposed severity classification. We assume that a significant proportion of hospitalised patients will have a mild or moderate event.

METHODS: The Rome classification was applied to a cohort of 364 COPD patients hospitalised at the Department of Respiratory Medicine of Maastricht University Medical Center (MUMC) with a severe ECOPD. Differences in in-hospital, 30- and 90-day mortality were compared between mild, moderate and severe ECOPD according to the new classification. Moreover, data were stratified by the different severity classes and compared regarding general disease characteristics and clinical parameters.

RESULTS: According to the Rome proposal, 52 (14.3%) patients had a mild ECOPD, 204 (56.0%) a moderate and 108 (29.7%) a severe ECOPD. In-hospital mortality in mild, moderate and severe events was 3.8%, 6.9% and 13.9%, respectively. Most clinical parameters indicated a significantly worse condition in patients classified in the severe group, compared to those in mild or moderate groups.

CONCLUSION: Most of the events, traditionally all classified as severe because of the hospitalisation, were classified as moderate, while almost 15% were mild. The results of this study provide insight into the heterogeneity of hospitalised ECOPD and show that the newly proposed Rome criteria can differentiate between events with different short-term mortality rates.

PMID:37228266 | PMC:PMC10204729 | DOI:10.1183/23120541.00569-2022

ERJ Open Res. 2023 May 22;9(3):00653-2022. doi: 10.1183/23120541.00653-2022. eCollection 2023 May.

ABSTRACT

This review has been prepared by the Early Career Members and Chairs of the European Respiratory Society (ERS) Assembly 7: Paediatrics. We here summarise the highlights of the advances in paediatric respiratory research presented at the ERS International Congress 2022. The eight scientific groups of this Assembly cover a wide range of research areas, including respiratory physiology and sleep, asthma and allergy, cystic fibrosis (CF), respiratory infection and immunology, neonatology and intensive care, respiratory epidemiology, bronchology, and lung and airway developmental biology. Specifically, we report on abstracts presented at the congress on the effect of high altitude on sleep, sleep disorders, the hypoxic challenge test, and measurements of ventilation inhomogeneity. We discuss prevention of preschool wheeze and asthma, and new asthma medications. In children with CF, we describe how to monitor the effect of CF transmembrane conductance regulator modulator therapy. We present respiratory manifestations and chronic lung disease associated with common variable immunodeficiency. Furthermore, we discuss how to monitor respiratory function in neonatal and paediatric intensive care units. In respiratory epidemiology, we present the latest news from population-based and clinical cohort studies. We also focus on innovative and interventional procedures for the paediatric airway, such as cryotherapy. Finally, we stress the importance of better understanding the molecular mechanisms underlying normal and abnormal lung development.

PMID:37228264 | PMC:PMC10204827 | DOI:10.1183/23120541.00653-2022

Cell Rep. 2023 May 23;42(6):112540. doi: 10.1016/j.celrep.2023.112540. Online ahead of print.

ABSTRACT

Pseudomonas aeruginosa and Staphylococcus aureus are among the most frequently isolated bacterial species from polymicrobial infections of patients with cystic fibrosis and chronic wounds. We apply mass spectrometry guided interaction studies to determine how chemical interaction shapes the fitness and community structure during co-infection of these two pathogens. We demonstrate that S. aureus is equipped with an elegant mechanism to inactivate pyochelin via the yet uncharacterized methyltransferase Spm (staphylococcal pyochelin methyltransferase). Methylation of pyochelin abolishes the siderophore activity of pyochelin and significantly lowers pyochelin-mediated intracellular reactive oxygen species (ROS) production in S. aureus. In a murine wound co-infection model, an S. aureus mutant unable to methylate pyochelin shows significantly lower fitness compared with its parental strain. Thus, Spm-mediated pyochelin methylation is a mechanism to increase S. aureus survival during in vivo competition with P. aeruginosa.

PMID:37227819 | DOI:10.1016/j.celrep.2023.112540

Haematologica. 2023 May 25. doi: 10.3324/haematol.2023.282949. Online ahead of print.

ABSTRACT

Shwachman-Diamond syndrome is a rare inherited bone marrow failure syndrome characterized by neutropenia, exocrine pancreatic insufficiency, and skeletal abnormalities. In 10-30%, transformation to a myeloid neoplasm occurs. Approximately 90% of patients have biallelic pathogenic variants in the SBDS gene located on human chromosome 7q11. In the past several years, pathogenic variants in three other genes have been identified to cause similar phenotypes. These are DNAJC21, EFL1, and SRP54. Clinical manifestations involve multiple organ systems and those classically associated with the Shwachman-Diamond syndrome (bone, blood, and pancreas). Neurocognitive, dermatologic, and retinal changes may also be found. There are specific gene-phenotype differences. To date, SBDS, DNAJC21, and SRP54 variants have been associated with myeloid neoplasia. Common to SBDS, EFL1, DNAJC21, and SRP54 is their involvement in ribosome biogenesis or early protein synthesis. These four genes constitute a common biochemical pathway conserved from yeast to humans that involve early stages of protein synthesis and demonstrate the importance of this synthetic pathway in myelopoiesis. We propose to use the terms Shwachman-Diamond-like syndrome or Shwachman-Diamond syndromes.

PMID:37226705 | DOI:10.3324/haematol.2023.282949

Nature. 2023 May 24. doi: 10.1038/s41586-023-06111-7. Online ahead of print.

ABSTRACT

The ability to switch between different lifestyles allows bacterial pathogens to thrive in diverse ecological niches1,2. However, a molecular understanding of their lifestyle changes within the human host is lacking. Here, by directly examining bacterial gene expression in human-derived samples, we discover a gene that orchestrates the transition between chronic and acute infection in the opportunistic pathogen Pseudomonas aeruginosa. The expression level of this gene, here named sicX, is the highest of the P. aeruginosa genes expressed in human chronic wound and cystic fibrosis infections, but it is expressed at extremely low levels during standard laboratory growth. We show that sicX encodes a small RNA that is strongly induced by low-oxygen conditions and post-transcriptionally regulates anaerobic ubiquinone biosynthesis. Deletion of sicX causes P. aeruginosa to switch from a chronic to an acute lifestyle in multiple mammalian models of infection. Notably, sicX is also a biomarker for this chronic-to-acute transition, as it is the most downregulated gene when a chronic infection is dispersed to cause acute septicaemia. This work solves a decades-old question regarding the molecular basis underlying the chronic-to-acute switch in P. aeruginosa and suggests oxygen as a primary environmental driver of acute lethality.

PMID:37225987 | DOI:10.1038/s41586-023-06111-7

Pediatr Pulmonol. 2023 May 24. doi: 10.1002/ppul.26485. Online ahead of print.

ABSTRACT

BACKGROUND: In people with cystic fibrosis (pwCF), the impact of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies, such as Elexacaftor-Tezacaftor-Ivacaftor (ETI), on structural changes in the lungs is unclear.

OBJECTIVE: To determine the impact of ETI on clinical parameters and on structural lung disease as measured by the changes in the chest computed tomography (CT) scans in pwCF.

METHODS: Percent predicted forced expiratory volume in one second (ppFEV1), body mass index (BMI), and microbiologic data were collected at initiation and 3-month intervals for 1 year. Chest CT scans before starting ETI therapy (baseline) and at 1-year on ETI therapy were compared by two pulmonologists independently.

RESULTS: The sample size was 67 pwCF, 30 (44.8%) males, median age of 25 (16, 33.5) years. Significant increases in ppFEV1 and BMI observed by 3 months of ETI therapy persisted throughout 1 year of ETI therapy (p < 0.001 at all-time points for both). After 1 year on ETI, pwCF had significant reductions in Pseudomonas aeruginosa (-42%) and MRSA (-42%) positivity. None of the pwCF had worsening of chest CT parameters during 1 year of ETI therapy. Comparing chest CT findings at baseline and at 1-year follow-up, bronchiectasis was present in 65 (97%) pwCF and at 1-year follow-up decreased in 7 (11%). Bronchial wall thickening 64 (97%), decreased in 53 (79%). Mucous plugging in 63 (96%), absent in 11 (17%), and decreased in 50 (77%). Hyperinflation/air trapping in 44 (67%), decreased in 11 (18%), absent in 27 (44%) CONCLUSIONS: ETI significantly improved clinical outcomes and lung disease as documented by improvement in chest CT scans.

PMID:37222417 | DOI:10.1002/ppul.26485

Pediatr Pulmonol. 2023 May 24. doi: 10.1002/ppul.26484. Online ahead of print.

ABSTRACT

BACKGROUND: Hispanic people with cystic fibrosis (CF) have decreased life expectancy and earlier acquisition of Pseudomonas aeruginosa compared to non-Hispanic white individuals with CF. Racial and ethnic differences in the airway microbiome of CF may contribute to known health disparity, but have not been studied. The objective was to describe differences in the upper airway microbial community in Hispanic and non-Hispanic white children with CF.

METHODS: This prospective, observational cohort study of 59 Hispanic and non-Hispanic white children with CF, ages 2-10 years old, was performed at Texas Children's Hospital (TCH) from February 2019 to January 2020. Oropharyngeal swabs were collected from the cohort during clinic visit. Swab samples underwent sequencing (16S V4 rRNA), diversity analysis, and taxonomic profiling. Key demographic and clinical data were collected from the electronic medical record and the CF Foundation Patient Registry (CFFPR). Statistical analysis compared sequencing, demographic, and clinical data.

RESULTS: We found no significant difference in Shannon diversity or relative abundance of bacterial phyla between Hispanic and non-Hispanic children with CF. However, a low abundant taxa- "uncultured bacterium" belonging to the order Saccharimonadales was significantly higher in Hispanic children (mean relative abundance = 0.13%) compared to the non-Hispanic children (0.03%). Hispanic children had increased incidence of P. aeruginosa (p = 0.045) compared to non-Hispanic children.

CONCLUSION: We did not find a significant difference in the airway microbial diversity between Hispanic and non-Hispanic white children with CF. However, we found a greater relative abundance of Saccharimonadales and higher incidence of P. aeruginosa in Hispanic children with CF.

PMID:37222404 | DOI:10.1002/ppul.26484

Pediatr Pulmonol. 2023 May 24. doi: 10.1002/ppul.26486. Online ahead of print.

ABSTRACT

INTRODUCTION: A triple combination of CFTR modulators ELE/TEZ/IVA (elexacaftor/tezacaftor/ivacaftor, Trikafta™) has been evaluated in clinical trials for people with cystic fibrosis (pwCF) and was approved to the European and US market. During registration and settling reimbursement in Europe, it could be requested on a compassionate use basis, for patients with advanced lung disease (ppFEV1 < 40).

AIM: The aim of this study is to evaluate 2 years of experience with the clinical and radiological response of ELE/TEZ/IVA in pwCF in a compassionate use setting.

METHODS: pwCF who started ELE/TEZ/IVA in a compassionate use setting were prospectively followed with assessment of spirometry, BMI, chest CT, CFQ-R and sweat chloride concentration (SCC) before start and after 3 months. Furthermore, spirometry, sputum cultures, and BMI were repeated after 1, 6, 12, 18, and 24 months.

RESULTS: Eighteen patients were eligible for this evaluation, nine with F508del/F508del genotype (eight of whom were using dual CFTR modulators) and nine with F508del/minimal function mutation. After 3 months, mean change in SCC was -44.9 (p ≤ 0.001), together with significant improvement in CT (change in Brody score: -28.27 p ≤ 0.001) and CFQ-R results (change in respiratory domain: +18.8, p = 0.002). After 24 months, ppFEV1 change was +8.89 (p = 0.002), BMI had improved by +1.53 kg/m2 (p ≤ 0.001) and exacerbation rate declined from 5.94 in 24 months before start to 1.17 (p ≤ 0.001) in the 24 months after.

CONCLUSION: pwCF with advanced lung disease experience relevant clinical benefit after 2 years of treatment with ELE/TEZ/IVA in a compassionate use setting. Structural lung damage, quality of life, exacerbation rate, and BMI improved significantly with treatment. Gain in ppFEV1 is lower compared to the phase III trials that included younger patients with moderately affected lung function.

PMID:37222401 | DOI:10.1002/ppul.26486