Cystic Fibrosis

CFTR dysfunction and targeted therapies: A vision from non-cystic fibrosis bronchiectasis and COPD

Fri, 2022-05-13 06:00

J Cyst Fibros. 2022 May 9:S1569-1993(22)00107-2. doi: 10.1016/j.jcf.2022.04.018. Online ahead of print.

NO ABSTRACT

PMID:35551858 | DOI:10.1016/j.jcf.2022.04.018

Categories: Literature Watch

Enhancing CRISPR/Cas gene editing through modulating cellular mechanical properties for cancer therapy

Fri, 2022-05-13 06:00

Nat Nanotechnol. 2022 May 12. doi: 10.1038/s41565-022-01122-3. Online ahead of print.

ABSTRACT

Genome editing holds great potential for cancer treatment due to the ability to precisely inactivate or repair cancer-related genes. However, delivery of CRISPR/Cas to solid tumours for efficient cancer therapy remains challenging. Here we targeted tumour tissue mechanics via a multiplexed dendrimer lipid nanoparticle (LNP) approach involving co-delivery of focal adhesion kinase (FAK) siRNA, Cas9 mRNA and sgRNA (siFAK + CRISPR-LNPs) to enable tumour delivery and enhance gene-editing efficacy. We show that gene editing was enhanced >10-fold in tumour spheroids due to increased cellular uptake and tumour penetration of nanoparticles mediated by FAK-knockdown. siFAK + CRISPR-PD-L1-LNPs reduced extracellular matrix stiffness and efficiently disrupted PD-L1 expression by CRISPR/Cas gene editing, which significantly inhibited tumour growth and metastasis in four mouse models of cancer. Overall, we provide evidence that modulating the stiffness of tumour tissue can enhance gene editing in tumours, which offers a new strategy for synergistic LNPs and other nanoparticle systems to treat cancer using gene editing.

PMID:35551240 | DOI:10.1038/s41565-022-01122-3

Categories: Literature Watch

Taxonomic position, antibiotic resistance and virulence factor production by Stenotrophomonas isolates from patients with cystic fibrosis and other chronic respiratory infections

Fri, 2022-05-13 06:00

BMC Microbiol. 2022 May 12;22(1):129. doi: 10.1186/s12866-022-02466-5.

ABSTRACT

BACKGROUND: The potential pathogenic role of Stenotrophomonas maltophilia in lung disease and in particular in cystic fibrosis is unclear. To develop further understanding of the biology of this taxa, the taxonomic position, antibiotic resistance and virulence factors of S. maltophilia isolates from patients with chronic lung disease were studied.

RESULTS: A total of 111 isolates recovered between 2003 and 2016 from respiratory samples from patients in five different countries were included. Based on a cut-off of 95%, analysis of average nucleotide identity by BLAST (ANIb) showed that the 111 isolates identified as S. maltophilia by Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS) belonged to S. maltophilia (n = 65), S. pavanii (n = 6) and 13 putative novel species (n = 40), which each included 1-5 isolates; these groupings coincided with the results of the 16S rDNA analysis, and the L1 and L2 ß-lactamase Neighbor-Joining phylogeny. Chromosomally encoded aminoglycoside resistance was identified in all S. maltophilia and S. pavani isolates, while acquired antibiotic resistance genes were present in only a few isolates. Nevertheless, phenotypic resistance levels against commonly used antibiotics, determined by standard broth microbroth dilution, were high. Although putative virulence genes were present in all isolates, the percentage of positive isolates varied. The Xps II secretion system responsible for the secretion of the StmPr1-3 proteases was mainly limited to isolates identified as S. maltophilia based on ANIb, but no correlation with phenotypic expression of protease activity was found. The RPF two-component quorum sensing system involved in virulence and antibiotic resistance expression has two main variants with one variant lacking 190 amino acids in the sensing region.

CONCLUSIONS: The putative novel Stenotrophomonas species recovered from patient samples and identified by MALDI-TOF/MS as S. maltophilia, differed from S. maltophilia in resistance and virulence genes, and therefore possibly in pathogenicity. Revision of the Stenotrophomonas taxonomy is needed in order to reliably identify strains within the genus and elucidate the role of the different species in disease.

PMID:35549675 | DOI:10.1186/s12866-022-02466-5

Categories: Literature Watch

Limitations of standard cost-effectiveness methods for health technology assessment of treatments for rare, chronic diseases: a case study of treatment for cystic fibrosis

Fri, 2022-05-13 06:00

J Med Econ. 2022 May 13:1-30. doi: 10.1080/13696998.2022.2077550. Online ahead of print.

ABSTRACT

OBJECTIVES: Cost-effectiveness analysis (CEA) is useful to assess the value of health care interventions based on clinical effectiveness and costs. However, standard CEA methods make important assumptions that may significantly increase the incremental cost-effectiveness ratio (ICER) for lifelong treatments for rare, chronic diseases. We used the cost-effectiveness of elexacaftor/tezacaftor/ivacaftor and ivacaftor (ELX/TEZ/IVA) for the treatment of cystic fibrosis as a case study to explore how alternative assumptions for (1) discounting, (2) utility measures, (3) disease management costs, and (4) static drug pricing impact cost-effectiveness outcomes.

MATERIALS AND METHODS: Cost-effectiveness of ELX/TEZ/IVA was evaluated using base-case inputs and assumptions reflecting standard CEA methods and was then compared with cost-effectiveness estimates obtained with alternate assumptions: (1) applying a lower discount rate to health benefits (1.5%) than costs (3%); (2) including a treatment-specific utility increment; (3) excluding disease management costs incurred during the period of extended survival attributable to ELX/TEZ/IVA treatment; and (4) decreasing the price of ELX/TEZ/IVA following loss of exclusivity.

RESULTS: Modifying assumptions for these four factors together reduced the ICER by 75% from the base case, with the largest reduction (45%) occurring when the price trajectory was modified to allow for generic entry. Differential discounting, use of a treatment-specific utility increment, and exclusion of additional disease management costs each individually reduced the ICER by 36%, 14%, and 10%, respectively, from the base case.

CONCLUSIONS: This study illustrates the impact that modifications to standard CEA methods may have on measures of cost-effectiveness for rare, chronic diseases.

PMID:35549639 | DOI:10.1080/13696998.2022.2077550

Categories: Literature Watch

Adaptive Immune Response to <em>Mycobacterium abscessus</em> Complex (MABSC) in Cystic Fibrosis and the Implications of Cross-Reactivity

Fri, 2022-05-13 06:00

Front Cell Infect Microbiol. 2022 Apr 20;12:858398. doi: 10.3389/fcimb.2022.858398. eCollection 2022.

ABSTRACT

BACKGROUND: We aimed to characterise the adaptive immune response to Mycobacterium abscessus complex (MABSC) and its cross-reactivity with Mycobacterium avium complex (MAC) and Mycobacterium bovis (Bacille Calmette-Guérin, BCG) in cystic fibrosis (CF) patients and non-CF controls in terms of lymphocyte proliferation and immunophenotyping, cytokine production and anti-MABSC IgG plasma levels.

METHODS: In this cross-sectional analysis, peripheral blood mononuclear cells (PBMC) from CF patients with MABSC (CF/MABSC, n=12), MAC infection history (CF/MAC, n=5), no NTM history (CF/NTM-, n=15), BCG-vaccinated (C/BCG+, n=9) and non-vaccinated controls (C/BCG-, n=8) were cultured for four days under stimulation with an in-house MABSC lysate and we used flow cytometry to assess lymphocyte proliferation (given by lymphoblast formation) and immunophenotypes. Cytokine production was assessed after overnight whole blood stimulation with the same lysate, and anti-MABSC IgG levels were measured in plasma from non-stimulated blood.

RESULTS: All CF/MABSC patients had increased CD3+ and CD19+ lymphoblast formation upon PBMC stimulation with MABSC lysate. There was a higher rate of CD3+ than CD19+ lymphoblasts, predominance of CD4+ over CD8+ lymphoblasts, IFN-γ, TNF-α and IL-2 production, low production of the Th17-associated IL-17, and discrete or no production of Th2/B cell-associated cytokines soluble CD40 ligand (CD40L), IL-4 and IL-5, indicating a Th1-dominated phenotype and infection restricted to the lungs. A similar pattern was seen in C/BCG+ controls, and CF/MAC patients, pointing to cross-reactivity. MABSC-IgG levels were higher in CF/MABSC patients than in both control groups, but not CF/NTM- patients, most of whom also had CD3+ and/or CD19+ lymphoblast formation upon PBMC stimulation, indicating previous exposure, subclinical or latent infection with MABSC or other NTM.

CONCLUSION: The anti-MABSC immune response is Th1-skewed and underlines the cross-reactivity in the anti-mycobacterial immune response. The results, together with published clinical observations, indicate that BCG vaccination may cross-react against NTM in CF patients, and this should be investigated. Due to cross-reactivity, it would also be interesting to investigate whether a combination of MABSC-induced cytokine production by blood cells and anti-MABSC IgG measurement can be useful for identifying latent or subclinical infection both with MABSC and other NTM in CF patients.

PMID:35548464 | PMC:PMC9084186 | DOI:10.3389/fcimb.2022.858398

Categories: Literature Watch

<em>In vitro</em> Activity of Antivirulence Drugs Targeting the <em>las</em> or <em>pqs</em> Quorum Sensing Against Cystic Fibrosis <em>Pseudomonas aeruginosa</em> Isolates

Fri, 2022-05-13 06:00

Front Microbiol. 2022 Apr 25;13:845231. doi: 10.3389/fmicb.2022.845231. eCollection 2022.

ABSTRACT

The chronic lung infection caused by Pseudomonas aeruginosa is a major cause of morbidity and mortality in cystic fibrosis (CF) patients. Antivirulence drugs targeting P. aeruginosa quorum sensing (QS) systems are intensively studied as antibiotics substitutes or adjuvants. Previous studies, carried out in non-CF P. aeruginosa reference strains, showed that the old drugs niclosamide and clofoctol could be successfully repurposed as antivirulence drugs targeting the las and pqs QS systems, respectively. However, frequent emergence of QS-defective mutants in the CF lung undermines the use of QS inhibitors in CF therapy. Here, QS signal production and susceptibility to niclosamide and clofoctol have been investigated in 100 P. aeruginosa CF isolates, with the aim of broadening current knowledge on the potential of anti-QS compounds in CF therapy. Results showed that 85, 78, and 69% of the CF isolates from our collection were proficient for the pqs, rhl, and las QS systems, respectively. The ability of both niclosamide and clofoctol to inhibit QS and virulence in vitro was highly variable and strain-dependent. Niclosamide showed an overall low range of activity and its negative effect on las signal production did not correlate with a decreased production of virulence factors. On the other hand, clofoctol displayed a broader QS inhibitory effect in CF isolates, with consequent reduction of the pqs-controlled virulence factor pyocyanin. Overall, this study highlights the importance of testing new antivirulence drugs against large panels of P. aeruginosa CF clinical isolates before proceeding to further pre-clinical studies and corroborates previous evidence that strains naturally resistant to QS inhibitors occur among CF isolates. However, it is also shown that resistance to pqs inhibitors is less frequent than resistance to las inhibitors, thus supporting the development of pqs inhibitors for antivirulence therapy in CF.

PMID:35547141 | PMC:PMC9083110 | DOI:10.3389/fmicb.2022.845231

Categories: Literature Watch

Corneal opacification, an atypical presentation of cystic fibrosis: a case report and review of the literature

Fri, 2022-05-13 06:00

J Med Case Rep. 2022 May 12;16(1):188. doi: 10.1186/s13256-022-03410-x.

ABSTRACT

BACKGROUND: Respiratory and gastrointestinal manifestations are the main causes of mortality and morbidity in cystic fibrosis. Although these symptoms are well recognized, ophthalmic involvement of cystic fibrosis secondary to vitamin A deficiency is uncommon and has been reported very rarely in the medical literature.

CASE PRESENTATION: Here, we report a 2.5-year-old Iranian boy who presented with bilateral corneal xerosis and corneal opacity secondary to vitamin A deficiency related to cystic fibrosis malabsorption.

CONCLUSION: Malabsorption of fat-soluble vitamins is a common presentation in cystic fibrosis, but corneal opacity secondary to vitamin A deficiency as the initial presentation of cystic fibrosis is a very rare manifestation of fat malabsorption. This highlights the importance of complete systemic examination besides ophthalmic examination in approaching a child with ophthalmic complaint.

PMID:35546413 | DOI:10.1186/s13256-022-03410-x

Categories: Literature Watch

Pseudomonas aeruginosa Alters Peptidoglycan Composition under Nutrient Conditions Resembling Cystic Fibrosis Lung Infections

Thu, 2022-05-12 06:00

mSystems. 2022 May 12:e0015622. doi: 10.1128/msystems.00156-22. Online ahead of print.

ABSTRACT

Epidemic strains of Pseudomonas aeruginosa are highly virulent opportunistic pathogens with increased transmissibility and enhanced antimicrobial resistance. Understanding the cellular mechanisms behind this heightened virulence and resistance is critical. Peptidoglycan (PG) is an integral component of P. aeruginosa cells that is essential to its survival and a target for antimicrobials. Here, we examined the global PG composition of two P. aeruginosa epidemic strains, LESB58 and LESlike1, and compared them to the common laboratory strains PAO1 and PA14. We also examined changes in PG composition when the strains were cultured under nutrient conditions that resembled cystic fibrosis lung infections. We identified 448 unique muropeptides and provide the first evidence for stem peptides modified with O-methylation, meso-diaminopimelic acid (mDAP) deamination, and novel substitutions of mDAP residues within P. aeruginosa PG. Our results also present the first evidence for both d,l- and l,d-endopeptidase activity on the PG sacculus of a Gram-negative organism. The PG composition of the epidemic strains varied significantly when grown under conditions resembling cystic fibrosis (CF) lung infections, showing increases in O-methylated stem peptides and decreases in l,d-endopeptidase activity as well as an increased abundance of de-N-acetylated sugars and l,d-transpeptidase activity, which are related to bacterial virulence and antibiotic resistance, respectively. We also identified strain-specific changes where LESlike1 increased the addition of unique amino acids to the terminus of the stem peptide and LESB58 increased amidase activity. Overall, this study demonstrates that P. aeruginosa PG composition is primarily influenced by nutrient conditions that mimic the CF lung; however, inherent strain-to-strain differences also exist. IMPORTANCE Using peptidoglycomics to examine the global composition of the peptidoglycan (PG) allows insights into the enzymatic activity that functions on this important biopolymer. Changes within the PG structure have implications for numerous physiological processes, including virulence and antimicrobial resistance. The identification of highly unique PG modifications illustrates the complexity of this biopolymer in Pseudomonas aeruginosa. Analyzing the PG composition of clinical P. aeruginosa epidemic strains provides insights into the increased virulence and antimicrobial resistance of these difficult-to-eradicate infections.

PMID:35545925 | DOI:10.1128/msystems.00156-22

Categories: Literature Watch

Atomic-scale interactions between quorum sensing autoinducer molecules and the mucoid P. aeruginosa exopolysaccharide matrix

Wed, 2022-05-11 06:00

Sci Rep. 2022 May 11;12(1):7724. doi: 10.1038/s41598-022-11499-9.

ABSTRACT

Mucoid Pseudomonas aeruginosa is a prevalent cystic fibrosis (CF) lung coloniser whose chronicity is associated with the formation of cation cross-linked exopolysaccharide (EPS) matrices, which form a biofilm that acts as a diffusion barrier, sequestering cationic and neutral antimicrobials, and making it extremely resistant to pharmacological challenge. Biofilm chronicity and virulence of the colony is regulated by quorum sensing autoinducers (QSAIs), small signalling metabolites that pass between bacteria, through the biofilm matrix, regulating genetic responses on a population-wide scale. The nature of how these molecules interact with the EPS is poorly understood, despite the fact that they must pass through EPS matrix to reach neighbouring bacteria. Interactions at the atomic-scale between two QSAI molecules, C4-HSL and PQS-both utilised by mucoid P. aeruginosa in the CF lung-and the EPS, have been studied for the first time using a combined molecular dynamics (MD) and density functional theory (DFT) approach. A large-scale, calcium cross-linked, multi-chain EPS molecular model was developed and MD used to sample modes of interaction between QSAI molecules and the EPS that occur at physiological equilibrium. The thermodynamic stability of the QSAI-EPS adducts were calculated using DFT. These simulations provide a thermodynamic rationale for the apparent free movement of C4-HSL, highlight key molecular functionality responsible for EPS binding and, based on its significantly reduced mobility, suggest PQS as a viable target for quorum quenching.

PMID:35545629 | DOI:10.1038/s41598-022-11499-9

Categories: Literature Watch

Telemedicine of patients with cystic fibrosis during the COVID-19 pandemic

Wed, 2022-05-11 06:00

Rev Paul Pediatr. 2022 May 6;40:e2021118. doi: 10.1590/1984-0462/2022/40/2021118IN. eCollection 2022.

ABSTRACT

OBJECTIVE: To describe then experience of implementing routine teleconsultations in respiratory physiotherapy at a reference center for Cystic Fibrosis (CF) in Rio de Janeiro / Brazil, during the COVID-19 pandemic.

METHODS: Cross-sectional, descriptive, study with children and adolescents with CF. The sample was divided between participants and those who did not participate in the teleconsultations. The teleconsultations were multidisciplinary and carried out by videoconference or telephone, depending on the patient's availability. The sequence of care provided by the team was organized together with the professionals, so that everyone could carry out individual and sequential teleconsultations. Physiotherapy appointments were divided into two segments: teleconsultation and telemonitoring. Demographic and clinical data were collected.

RESULTS: Among the 184 patients assisted in the center, 153 (83.2%) participated in the teleservices and, of these, 33 (21.6%) required telemonitoring; 31 (16.8%) patients did not participate in the teleconsultations for not answering the calls. There was no statistical difference between the group that participated or not in teleservices, nor among those who participated in teleconsultations and telemonitoring. The mean age of the studied population was 7.0±0.4 years. Regarding the CFTR gene mutation, 64.7% had at least one F508del allele and 30.9% of the sample had no pathogens in the sputum test.

CONCLUSIONS: Most participants with CF participated in teleconsultations, highlighting the importance of remote assistance activities during the COVID-19 pandemic period. This strategy was considered as positive, and it may become permanent in the care of patients with CF.

PMID:35544907 | DOI:10.1590/1984-0462/2022/40/2021118IN

Categories: Literature Watch

Acute inflammatory response via neutrophil activation protects against the development of chronic pain

Wed, 2022-05-11 06:00

Sci Transl Med. 2022 May 11;14(644):eabj9954. doi: 10.1126/scitranslmed.abj9954. Epub 2022 May 11.

ABSTRACT

The transition from acute to chronic pain is critically important but not well understood. Here, we investigated the pathophysiological mechanisms underlying the transition from acute to chronic low back pain (LBP) and performed transcriptome-wide analysis in peripheral immune cells of 98 participants with acute LBP, followed for 3 months. Transcriptomic changes were compared between patients whose LBP was resolved at 3 months with those whose LBP persisted. We found thousands of dynamic transcriptional changes over 3 months in LBP participants with resolved pain but none in those with persistent pain. Transient neutrophil-driven up-regulation of inflammatory responses was protective against the transition to chronic pain. In mouse pain assays, early treatment with a steroid or nonsteroidal anti-inflammatory drug (NSAID) also led to prolonged pain despite being analgesic in the short term; such a prolongation was not observed with other analgesics. Depletion of neutrophils delayed resolution of pain in mice, whereas peripheral injection of neutrophils themselves, or S100A8/A9 proteins normally released by neutrophils, prevented the development of long-lasting pain induced by an anti-inflammatory drug. Analysis of pain trajectories of human subjects reporting acute back pain in the UK Biobank identified elevated risk of pain persistence for subjects taking NSAIDs. Thus, despite analgesic efficacy at early time points, the management of acute inflammation may be counterproductive for long-term outcomes of LBP sufferers.

PMID:35544595 | DOI:10.1126/scitranslmed.abj9954

Categories: Literature Watch

Prevalence and subtyping of biofilms present in bronchoalveolar lavage from children with protracted bacterial bronchitis or non-cystic fibrosis bronchiectasis: a cross-sectional study

Wed, 2022-05-11 06:00

Lancet Microbe. 2022 Mar;3(3):e215-e223. doi: 10.1016/S2666-5247(21)00300-1. Epub 2022 Feb 1.

ABSTRACT

BACKGROUND: Lower airway biofilms are hypothesised to contribute to poor treatment outcomes among children with chronic lung disease; however, data are scarce. We aimed to determine the presence and prevalence of biofilm in bronchoalveolar lavage from children with protracted bacterial bronchitis (PBB) or bronchiectasis; whether biofilm was associated with signs of lower airway infection; and whether biofilms were consistent with an upper or lower airway origin.

METHODS: In this cross-sectional study, fluorescent microscopy techniques were used to detect biofilm in archived bronchoalveolar lavage specimens from a paediatric cohort (age <18 years) with PBB or bronchiectasis who were prospectively recruited to observational studies of chronic cough at Royal Children's Hospital (Brisbane, Australia) or Royal Darwin Hospital (Darwin, Australia). Children with cystic fibrosis were excluded. Lower airway infection was defined as bronchoalveolar lavage neutrophil percentage of 15% or more, or a culture of a bacterial pathogen at 104 colony-forming units per mL or more, or both. Biofilms were subtyped as either of lower airway origin (unrelated to squamous epithelial cells) or of upper airway origin (observed in close association with squamous epithelial cells). Bronchoalveolar lavages were considered contaminated with upper airway secretions if the squamous cell proportion was more than ten cells per 1000 nucleated cells (>1%). Primary outcomes were the prevalence of each biofilm subtype among children with PBB compared with children with bronchiectasis. Secondary outcomes were the prevalence of each biofilm subtype among children with signs of lower airway infection compared to children without.

FINDINGS: Biofilm testing was performed on 144 bronchoalveolar lavage specimens collected between Jan 1, 2011, and Dec 16, 2014, and preserved at -80°C before biofilm testing (69 children with PBB from Brisbane and 75 children with bronchiectasis from Darwin). The prevalence of lower airway biofilms (unrelated to squamous epithelial cells) was similar among the children with PBB (25 [36%] of 69) and children with bronchiectasis (31 [41%] of 75; odds ratio [OR] 1·24, 95% CI 0·63-2·43), but higher among children with signs of lower airway infection (46 [48%] of 95) than children without (eight [19%] of 43; OR 4·11, 95% CI 1·73-9·78), irrespective of the underlying diagnosis. By contrast, upper airway biofilms (associated with squamous epithelial cells) were more prevalent among children with bronchiectasis (32 [43%] of 75) than children with PBB (16 [23%] of 69; OR 2·47, 95% CI 1·20-5·08) and were unrelated to lower airway infection. Upper airway contamination was uncommon (eight [11%] of 71) and was not evident in 23 (79%) of 29 bronchoalveolar lavages that were positive for upper airway biofilms.

INTERPRETATION: Lower airway biofilms are prevalent, but not ubiquitous, in bronchoalveolar lavage from children with PBB or bronchiectasis, suggesting anti-biofilm therapies might be beneficial for some children. Detection of upper airway biofilms in bronchoalveolar lavage that did not have signs of contamination suggests that microaspiration might be important in some children. Specimen quality measures are recommended for future studies to account for the presence of upper airway biofilms.

FUNDING: Financial Markets for Children Project Grant, National Health and Medical Research Council of Australia, Rebecca L Cooper Medical Research Foundation, Queensland Children's Hospital Foundation, and BrightSpark Foundation.

PMID:35544075 | DOI:10.1016/S2666-5247(21)00300-1

Categories: Literature Watch

Optimization of a Liposomal DNase I Formulation with an Extended Circulating Half-Life

Wed, 2022-05-11 06:00

Mol Pharm. 2022 May 11. doi: 10.1021/acs.molpharmaceut.2c00086. Online ahead of print.

ABSTRACT

Drug delivery systems such as liposomes are widely used to stabilize and increase the plasma half-life of therapeutics. In this article, we have investigated two strategies to increase the half-life of deoxyribonuclease I, an FDA-approved enzyme used for the treatment of cystic fibrosis, and a potential candidate for the reduction of uncontrolled inflammation induced by neutrophil extracellular traps. We demonstrate that our optimized preparation procedure resulted in nanoparticles with improved plasma half-life and total exposure relative to native protein, while maintaining enzymatic activity.

PMID:35543327 | DOI:10.1021/acs.molpharmaceut.2c00086

Categories: Literature Watch

Urinary bicarbonate and metabolic alkalosis during exacerbations in cystic fibrosis

Wed, 2022-05-11 06:00

ERJ Open Res. 2022 May 9;8(2):00669-2021. doi: 10.1183/23120541.00669-2021. eCollection 2022 Apr.

ABSTRACT

The aetiology of increased serum bicarbonate and metabolic alkalosis in CF is complex and appears to be driven, at least in part, by renal tubular CFTR dysfunction https://bit.ly/3NFPkUu.

PMID:35539439 | PMC:PMC9081541 | DOI:10.1183/23120541.00669-2021

Categories: Literature Watch

Tissue-localized immune responses in people with cystic fibrosis and respiratory nontuberculous mycobacteria infection

Tue, 2022-05-10 06:00

JCI Insight. 2022 May 10:e157865. doi: 10.1172/jci.insight.157865. Online ahead of print.

ABSTRACT

Nontuberculous mycobacteria (NTM) are an increasingly common cause of respiratory infection in people with cystic fibrosis (PwCF). Relative to those with no history of NTM infection (CF-NTMNEG), PwCF and a history of NTM infection (CF-NTMPOS) are more likely to develop severe lung disease and experience complications over the course of treatment. In other mycobacterial infections (e.g. tuberculosis), an overexuberant immune response causes pathology and compromises organ function; however, since the immune profiles of CF-NTMPOS and CF-NTMNEG airways are largely unexplored, it is unknown which if any immune responses distinguish these cohorts or concentrate in damaged tissues. Here we evaluated lung lobe-specific immune profiles of three cohorts (CF-NTMPOS, CF-NTMNEG, and non-CF adults) and found that CF-NTMPOS airways are distinguished by a hyper-inflammatory cytokine profile. Importantly, the CF-NTMPOS airway immune profile was dominated by B cells, classical macrophages and the cytokines which support their accumulation. These and other immunological differences between cohorts, including the near absence of NK cells and complement pathway members, were enriched in the most damaged lung lobes. The implications of these findings for our understanding of lung disease in PwCF are discussed, as are how they may inform the development of host-directed therapies to improve NTM disease treatment.

PMID:35536650 | DOI:10.1172/jci.insight.157865

Categories: Literature Watch

Effects of Elexacaftor/Tezacaftor/Ivacaftor Therapy on Lung Clearance Index and Magnetic Resonance Imaging in Patients with Cystic Fibrosis and One or Two <em>F508del</em> Alleles

Tue, 2022-05-10 06:00

Am J Respir Crit Care Med. 2022 May 10. doi: 10.1164/rccm.202201-0219OC. Online ahead of print.

ABSTRACT

RATIONALE: We recently demonstrated that triple combination CFTR modulator therapy with elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) improves CFTR function in airway and intestinal epithelia to 40 to 50% of normal in patients with cystic fibrosis (CF) with one or two F508del alleles. In previous studies, this improvement of CFTR function was shown to improve clinical outcomes, however, effects on the lung clearance index (LCI) determined by multiple breath washout and abnormalities in lung morphology and perfusion detected by magnetic resonance imaging (MRI) have not been studied.

OBJECTIVES: To examine the effect of ELX/TEZ/IVA on LCI and lung MRI scores in patients with CF and one or two F508del alleles aged 12 years and older.

METHODS: This prospective, observational, multicenter, post-approval study assessed LCI and lung MRI scores before and 8-16 weeks after initiation of ELX/TEZ/IVA.

MEASUREMENTS AND MAIN RESULTS: A total of 91 patients with CF including 45 heterozygous for F508del and a minimal function mutation (MF) and 46 homozygous for F508del were enrolled in this study. Treatment with ELX/TEZ/IVA improved LCI in F508del/MF (-2.4;IQR, -3.7 - -1.1;P<0.001) and F508del homozygous (-1.4;IQR, -2.4 - -0.4;P<0.001) patients. Further, ELX/TEZ/IVA improved the MRI global score in F508del/MF (-6.0;IQR, -11.0 - -1.3;P<0.001) and F508del homozygous (-6.5;IQR, -11.0 - -1.3;P<0.001) patients.

CONCLUSIONS: Our data demonstrate that improvement of CFTR function by ELX/TEZ/IVA improves lung ventilation and abnormalities in lung morphology including airway mucus plugging and wall thickening in adolescent and adult patients with CF and one or two F508del alleles in a real-world, post-approval setting.

PMID:35536314 | DOI:10.1164/rccm.202201-0219OC

Categories: Literature Watch

Potential Cross-Transmission of Mycobacterium abscessus among Non-Cystic Fibrosis Patients at a Tertiary Hospital in Japan

Tue, 2022-05-10 06:00

Microbiol Spectr. 2022 May 10:e0009722. doi: 10.1128/spectrum.00097-22. Online ahead of print.

ABSTRACT

Mycobacterium abscessus (M. abscessus) is a highly antimicrobial-resistant pathogen that causes refractory pulmonary disease. Recently, the possibility of M. abscessus cross-transmission among cystic fibrosis (CF) patients has been reported. CF is rare in Asia, but M. abscessus pulmonary disease is common. Therefore, we investigated the possibility of M. abscessus cross-transmission in a Japanese hospital setting. Of 104 M. abscessus isolates, 25 isolates from 24 patients were classified into four clusters based on their variable number of tandem repeat profiles and were subjected to whole-genome sequencing (WGS). The epidemiological linkages among our patients were investigated by integrating the WGS data of previously reported nosocomial outbreak-related M. abscessus clinical isolates in the United Kingdom and the United States. Eight transmissible clusters (TCs) were identified. The United Kingdom and United States isolates were assigned to four clusters (TC1, TC2, TC5, and TC8) and one cluster (TC3), respectively. A total of 12 isolates from our hospital belonged to 4 clusters (TC4, TC5, TC6, and TC7). Epidemiological linkage analysis inferred direct or indirect transmission between patients in our hospital in TC4 and TC5 but not in TC6 and TC7. In TC5, the single nucleotide polymorphism distance between isolates from Japanese and United Kingdom patients was less than 21; however, there was no contact. This study revealed that genetically closely related isolates exist, even in non-CF patients. However, the transmission route remains unclear, and further research is warranted to clarify whether cross-transmission is involved. IMPORTANCE Although the possibility of Mycobacterium abscessus (M. abscessus) cross-transmission in cystic fibrosis (CF) patients has often been reported, it is not clear whether similar events have occurred in Asian non-CF patients. Whole-genome sequencing analysis of M. abscessus isolates from Fukujuji Hospital in Japan indicated that genetically closely related M. abscessus isolates exist. In addition, according to epidemiological linkage analysis, some clusters were suspected of direct or indirect transmission between patients within our hospital. However, the transmission route of M. abscessus remains unclear, because interestingly, one cluster showed a single nucleotide polymorphism distance of less than 21 from the United Kingdom isolates, but no epidemiological linkage was identified.

PMID:35536059 | DOI:10.1128/spectrum.00097-22

Categories: Literature Watch

Disease phenotype and outcomes of very early-onset inflammatory bowel disease

Mon, 2022-05-09 06:00

Eur J Intern Med. 2022 May 6:S0953-6205(22)00173-X. doi: 10.1016/j.ejim.2022.05.001. Online ahead of print.

NO ABSTRACT

PMID:35534375 | DOI:10.1016/j.ejim.2022.05.001

Categories: Literature Watch

Evaluation of freely available data profiling tools for health data research application: a functional evaluation review

Mon, 2022-05-09 06:00

BMJ Open. 2022 May 9;12(5):e054186. doi: 10.1136/bmjopen-2021-054186.

ABSTRACT

OBJECTIVES: To objectively evaluate freely available data profiling software tools using healthcare data.

DESIGN: Data profiling tools were evaluated for their capabilities using publicly available information and data sheets. From initial assessment, several underwent further detailed evaluation for application on healthcare data using a synthetic dataset of 1000 patients and associated data using a common health data model, and tools scored based on their functionality with this dataset.

SETTING: Improving the quality of healthcare data for research use is a priority. Profiling tools can assist by evaluating datasets across a range of quality dimensions. Several freely available software packages with profiling capabilities are available but healthcare organisations often have limited data engineering capability and expertise.

PARTICIPANTS: 28 profiling tools, 8 undergoing evaluation on synthetic dataset of 1000 patients.

RESULTS: Of 28 potential profiling tools initially identified, 8 showed high potential for applicability with healthcare datasets based on available documentation, of which two performed consistently well for these purposes across multiple tasks including determination of completeness, consistency, uniqueness, validity, accuracy and provision of distribution metrics.

CONCLUSIONS: Numerous freely available profiling tools are serviceable for potential use with health datasets, of which at least two demonstrated high performance across a range of technical data quality dimensions based on testing with synthetic health dataset and common data model. The appropriate tool choice depends on factors including underlying organisational infrastructure, level of data engineering and coding expertise, but there are freely available tools helping profile health datasets for research use and inform curation activity.

PMID:35534084 | DOI:10.1136/bmjopen-2021-054186

Categories: Literature Watch

Reducing exacerbations in children and adults with primary ciliary dyskinesia using erdosteine and/or azithromycin therapy (REPEAT trial): study protocol for a multicentre, double-blind, double-dummy, 2×2 partial factorial, randomised controlled trial

Mon, 2022-05-09 06:00

BMJ Open Respir Res. 2022 May;9(1):e001236. doi: 10.1136/bmjresp-2022-001236.

ABSTRACT

INTRODUCTION: Primary ciliary dyskinesia (PCD) is a rare, progressive, inherited ciliopathic disorder, which is incurable and frequently complicated by the development of bronchiectasis. There are few randomised controlled trials (RCTs) involving children and adults with PCD and thus evidence of efficacy for interventions are usually extrapolated from people with cystic fibrosis. Our planned RCT seeks to address some of these unmet needs by employing a currently prescribed (but unapproved for long-term use in PCD) macrolide antibiotic (azithromycin) and a novel mucolytic agent (erdosteine). The primary aim of our RCT is to determine whether regular oral azithromycin and erdosteine over a 12-month period reduces acute respiratory exacerbations among children and adults with PCD. Our primary hypothesis is that: people with PCD who regularly use oral azithromycin and/or erdosteine will have fewer exacerbations than those receiving the corresponding placebo medications. Our secondary aims are to determine the effect of the trial medications on PCD-specific quality-of-life (QoL) and other clinical outcomes (lung function, time-to-next exacerbation, hospitalisations) and nasopharyngeal bacterial carriage and antimicrobial resistance.

METHODS AND ANALYSIS: We are currently undertaking a multicentre, double-blind, double-dummy RCT to evaluate whether 12 months of azithromycin and/or erdosteine is beneficial for children and adults with PCD. We plan to recruit 104 children and adults with PCD to a parallel, 2×2 partial factorial superiority RCT at five sites across Australia. Our primary endpoint is the rate of exacerbations over 12 months. Our main secondary outcomes are QoL, lung function and nasopharyngeal carriage by respiratory bacterial pathogens and their associated azithromycin resistance.

ETHICS AND DISSEMINATION: Our RCT is conducted in accordance with Good Clinical Practice and the Australian legislation and National Health and Medical Research Council guidelines for ethical conduct of Research, including that for First Nations Australians.

TRIAL REGISTRATION NUMBER: ACTRN12619000564156.

PMID:35534039 | DOI:10.1136/bmjresp-2022-001236

Categories: Literature Watch

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