Cystic Fibrosis

A multicentric evaluation of pediatric lung transplantation in Italy

Thu, 2022-07-21 06:00

J Thorac Cardiovasc Surg. 2022 Jun 20:S0022-5223(22)00704-8. doi: 10.1016/j.jtcvs.2022.06.010. Online ahead of print.

ABSTRACT

BACKGROUND: Pediatric lung transplantation is performed in highly experienced centers due to the peculiar population characteristics. The literature is limited and not representative of individual countries' differences. The purpose of this study was to analyze the Italian experience.

METHODS: A multicentric retrospective analysis was performed on 110 pediatric patients (<18 years old) who underwent lung transplantation from 1992 to 2019 at 9 Italian centers. Heart-lung transplantations and lung retransplantations were excluded.

RESULTS: The population was composed of 44 male and 66 female patients, with a median age of 15 years. The most frequent indication was cystic fibrosis (83%). One quarter of patients were transplanted in an emergency setting. Median donors' Oto score and age were 1 and 15 years, respectively, with 43% of adult donors. In 17% of patients a graft reduction was performed. Postoperatively, the median duration of mechanical ventilation, intensive care unit, and in-hospital stay were 48 hours, 11 and 35 days, respectively. Thirty-day mortality was 6%, and 1-, 5-, and 10-year survival was 72%, 52%, and 33%, respectively. Risk factors for mortality were Oto score and recipients' body mass index.

CONCLUSIONS: The outcomes of pediatric lung transplantation in Italy are comparable with current literature. Particular attention should be paid to the Oto score and recipient body mass index. Conversely, adult donors and graft reductions can be safely used to expand the donor pool.

PMID:35863967 | DOI:10.1016/j.jtcvs.2022.06.010

Categories: Literature Watch

Primary palliative care for heart failure provided within ambulatory cardiology: A randomized pilot trial

Thu, 2022-07-21 06:00

Heart Lung. 2022 Jul 18;56:125-132. doi: 10.1016/j.hrtlng.2022.07.002. Online ahead of print.

ABSTRACT

BACKGROUND: Heart failure is characterized by physical and emotional symptoms and decreased quality of life (QoL). Palliative care can reduce burdens of serious illness but often is limited to inpatient or academic settings.

OBJECTIVES: To develop and test the Primary Education for Nurses in Palliative care-HF (PENPal-HF) intervention, training outpatient cardiology nurses to address symptom burden, patient priorities for care and QoL, and advance care planning as part of quarterly HF visits.

METHODS: We conducted a pilot randomized clinical trial for adults with NYHA Stage III or IV HF and ≥ 2 hospitalizations in the past 12 months, recruited from a community-based cardiology clinic. Participants were randomized 2:1, PENPal-HF plus usual care versus usual care alone. Primary outcomes were feasibility and acceptability.

RESULTS: We randomized 30 adults with Stage III HF - 20 to PENPal-HF and 10 to usual care. Most in the intervention group (71%) and in the control group (62%) completed the study through the final outcome assessment in week 56; 5 participants died. Of 20 participants in the intervention, 14 (70%) remained in the study through the end of intervention visits; 11 (55%) completed all visits. Most intervention participants (93.75%) agreed or strongly agreed that they were satisfied with their care, and 87.5% agreed or strongly agreed that all people with HF should receive the intervention. Most intervention group participants (93.75%) reported a perceived improvement in physical symptoms, mood, and/or QoL.

CONCLUSIONS: This pilot study suggests that nurse-led primary palliative care in outpatient cardiology settings is promising. Research is warranted to determine efficacy and effectiveness.

PMID:35863099 | DOI:10.1016/j.hrtlng.2022.07.002

Categories: Literature Watch

Genomic Analysis of Mycobacterium abscessus Complex Isolates from Patients with Pulmonary Infection in China

Thu, 2022-07-21 06:00

Microbiol Spectr. 2022 Jul 12:e0011822. doi: 10.1128/spectrum.00118-22. Online ahead of print.

ABSTRACT

Members of the Mycobacterium abscessus complex (MABC) are multidrug-resistant nontuberculous mycobacteria and increasingly cause opportunistic pulmonary infections. However, the genetic typing of MABC isolates remains largely unclear in China. Genomic analyses were conducted for 69 MABC clinical isolates obtained from patients with lower respiratory tract infections in Shanghai Pulmonary Hospital between 2014 and 2016. The draft genomes of the 69 clinical strains were assembled, with a total length of 4.5 to 5.6 Mb, a percent GC content (GC%) ranging from 63.9 to 68.1%, and 4,492 to 5,404 genes per genome. Susceptibility test shows that most isolates are resistant to many antimicrobials, including clarithromycin, but susceptible to tigecycline. Analyses revealed the presence of genes conferring resistance to antibiotics, including macrolides, aminoglycosides, rifampicin, and tetracyclines. Furthermore, 80 to 114 virulence genes were identified per genome, including those related to the invasion of macrophages, iron incorporation, and avoidance of immune clearance. Mobile genetic elements, including insertion sequences, transposons, and genomic islands, were discovered in the genomes. Phylogenetic analyses of all MABC isolates with another 41 complete MABC genomes identified three clades; 46 isolates were clustered in clade I, corresponding to M. abscessus subsp. abscessus, and 25 strains belonged to existing clonal complexes. Overall, this is the first comparative genomic analysis of MABC clinical isolates in China. These results show significant intraspecies variations in genetic determinants encoding antimicrobial resistance, virulence, and mobile elements and controversial subspecies classification using current marker gene combinations. This information will be useful in understanding the evolution, antimicrobial resistance, and pathogenesis of MABC strains and facilitating future vaccine development and drug design. IMPORTANCE Over the past decade, infections by Mycobacterium abscessus complex (MABC) isolates have been increasingly reported worldwide. MABC strains often show a high incidence in cystic fibrosis (CF) patients, whereas in Asia, these strains are frequently recovered from non-CF patients with significant genomic diversity. The present work involves analyses of the antimicrobial resistance, virulence, and phylogeny of 69 selected MABC isolates from non-CF pulmonary patients in Shanghai Pulmonary Hospital by whole-genome sequencing; it represents the first comprehensive investigation of MABC strains in China at the genomic level. These findings highlight the diversity of this group of nontuberculous mycobacteria and provide a mechanistic understanding of evolution and pathogenesis, which is valuable for the development of novel and effective antimicrobial therapies for deadly MABC infections in China.

PMID:35863029 | DOI:10.1128/spectrum.00118-22

Categories: Literature Watch

Specificity of Immunoglobulin Response to Nontuberculous Mycobacteria Infection in People with Cystic Fibrosis

Thu, 2022-07-21 06:00

Microbiol Spectr. 2022 Jul 6:e0187422. doi: 10.1128/spectrum.01874-22. Online ahead of print.

ABSTRACT

Nontuberculous mycobacteria (NTM) infections are increasingly prevalent in chronic lung diseases, including cystic fibrosis (CF). Mycobacterium abscessus is of particular concern due to relatively greater virulence and intrinsic antimicrobial resistance. Airway culture identification, the standard method for detecting pulmonary infection, is hindered by low sensitivity, long culture times, and reliance on sputum production or lavage. A culture-independent test for detecting NTM infection could complement, or replace, sputum culture, which is becoming more difficult to obtain with reduced sputum production by people with CF (pwCF) on highly effective modulator therapy. We describe an assay for the detection of plasma anti-M. abscessus antibodies of pwCF to antigens from M. abscessus lysates. Anti-M. abscessus IgG and IgA, but not IgM, discriminated with high specificity subjects infected with M. abscessus from those infected by M. avium complex, and from those with distant or no NTM infections. The IgG3 subclass predominated with minor contributions by other subclasses. Both aqueous and organic soluble antigens were recognized by plasma IgG. A validation cohort measuring IgG and IgG3 identified M. abscessus positive subjects, and elevated IgG was sustained over several years. These studies show the benefit of M. abscessus cell lysates to detect plasma IgG of subjects with CF and M. abscessus infections. Subclass analysis suggests that IgG3 is the predominant subtype in these subjects with chronic bacterial infections suggesting a defect in class maturation. Serodiagnosis could be useful to monitor M. abscessus group infections in chronic lung disease as an adjunct or alternative to culture. IMPORTANCE Lung infections with nontuberculous mycobacteria (NTM), and particularly Mycobacterium abscessus, a pathogen with high antibiotic resistance, are of great concern due to poor clinical outcomes and challenging detection in people with cystic fibrosis and other diseases. Standard detection methods are insensitive and increasingly difficult. We describe the measurement of NTM-specific antibodies from plasma to identify subjects infected with M. abscessus. The assay is sensitive and provides information on the immune response to NTM infections. This assay could be used to help identify subjects with NTM pulmonary infections and track disease progression, either alone or in conjunction with other tests.

PMID:35863022 | DOI:10.1128/spectrum.01874-22

Categories: Literature Watch

Transcription of the Alginate Operon in Pseudomonas aeruginosa Is Regulated by c-di-GMP

Thu, 2022-07-21 06:00

Microbiol Spectr. 2022 Jul 11:e0067522. doi: 10.1128/spectrum.00675-22. Online ahead of print.

ABSTRACT

Overproduction of the exopolysaccharide alginate contributes to the pathogenicity and antibiotic tolerance of Pseudomonas aeruginosa in chronic infections. The second messenger, c-di-GMP, is a positive regulator of the production of various biofilm matrix components and is known to regulate alginate synthesis at the posttranslational level in P. aeruginosa. We provide evidence that c-di-GMP also regulates transcription of the alginate operon in P. aeruginosa. Previous work has shown that transcription of the alginate operon is regulated by nine different proteins, AmrZ, AlgP, IHFα, IHFβ, CysB, Vfr, AlgR, AlgB, and AlgQ, and we investigated if some of these proteins function as a c-di-GMP effector. We found that deletion of algP, algQ, IHFα, and IHFβ had only a marginal effect on the transcription of the alginate operon. Deletion of vfr and cysB led to decreased transcription of the alginate operon, and the dependence of the c-di-GMP level was less pronounced, indicating that Vfr and CysB could be partially required for c-di-GMP-mediated regulation of alginate operon transcription. Our experiments indicated that the AmrZ, AlgR, and AlgB proteins are absolutely required for transcription of the alginate operon. However, differential radial capillary action of ligand assay (DRaCALA) and site-directed mutagenesis indicated that c-di-GMP does not bind to any of the AmrZ, AlgR, and AlgB proteins. IMPORTANCE The proliferation of alginate-overproducing P. aeruginosa variants in the lungs of cystic fibrosis patients often leads to chronic infection. The alginate functions as a biofilm matrix that protects the bacteria against host immune defenses and antibiotic treatment. Knowledge about the regulation of alginate synthesis is important in order to identify drug targets for the development of medicine against chronic P. aeruginosa infections. We provide evidence that c-di-GMP positively regulates transcription of the alginate operon in P. aeruginosa. Moreover, we revisited the role of the known alginate regulators, AmrZ, AlgP, IHFα, IHFβ, CysB, Vfr, AlgR, AlgB, and AlgQ, and found that their effect on transcription of the alginate operon is highly varied. Deletion of algP, algQ, IHFα, or IHFβ only had a marginal effect on transcription of the alginate operon, whereas deletion of vfr or cysB led to decreased transcription and deletion of amrZ, algR, or algB abrogated transcription.

PMID:35862969 | DOI:10.1128/spectrum.00675-22

Categories: Literature Watch

Surface Motility Favors Codependent Interaction between Pseudomonas aeruginosa and Burkholderia cenocepacia

Thu, 2022-07-21 06:00

mSphere. 2022 Jul 7:e0015322. doi: 10.1128/msphere.00153-22. Online ahead of print.

ABSTRACT

Interactions between different bacterial species shape bacterial communities and their environments. The opportunistic pathogens Pseudomonas aeruginosa and Burkholderia cenocepacia both can colonize the lungs of individuals affected by cystic fibrosis. Using the social surface behavior called swarming motility as a study model, we noticed intricate interactions between B. cenocepacia K56-2 and P. aeruginosa PA14. While strain K56-2 does not swarm under P. aeruginosa favorable swarming conditions, co-inoculation with a nonmotile PA14 flagellum-less ΔfliC mutant restored spreading for both strains. We show that P. aeruginosa provides the wetting agent rhamnolipids allowing K56-2 to perform swarming motility, while aflagellated PA14 appears to "hitchhike" along with K56-2 cells in the swarming colony. IMPORTANCE Pseudomonas aeruginosa and Burkholderia cenocepacia are important opportunistic pathogens often found together in the airways of persons with cystic fibrosis. Laboratory cocultures of both species often ends with one taking over the other. We used a surface motility assay to study the social interactions between populations of these bacterial species. Under our conditions, B. cenocepacia cannot swarm without supplementation of the wetting agent produced by P. aeruginosa. In a mixed colony of both species, an aflagellated mutant of P. aeruginosa provides the necessary wetting agent to B. cenocepacia, allowing both bacteria to swarm and colonize a surface. We highlight this peculiar interaction where both bacteria set aside their antagonistic tendencies to travel together.

PMID:35862793 | DOI:10.1128/msphere.00153-22

Categories: Literature Watch

Preclinical Aortic Atherosclerosis in Adolescents With Chronic Disease

Thu, 2022-07-21 06:00

J Am Heart Assoc. 2022 Jul 19;11(14):e024675. doi: 10.1161/JAHA.122.024675. Epub 2022 Jul 13.

ABSTRACT

Background Adolescents with chronic disease are often exposed to inflammatory, metabolic, and hemodynamic risk factors for early atherosclerosis. Since postmortem studies have shown that atherogenesis starts in the aorta, the CDACD (Cardiovascular Disease in Adolescents with Chronic Disease) study investigated preclinical aortic atherosclerosis in these adolescents. Methods and Results The cross-sectional CDACD study enrolled 114 adolescents 12 to 18 years old with chronic disorders including juvenile idiopathic arthritis, cystic fibrosis, obesity, corrected coarctation of the aorta, and healthy controls with a corrected atrial septal defect. Cardiovascular magnetic resonance was used to assess aortic pulse wave velocity and aortic wall thickness, as established aortic measures of preclinical atherosclerosis. Cardiovascular magnetic resonance showed a higher aortic pulse wave velocity, which reflects aortic stiffness, and higher aortic wall thickness in all adolescent chronic disease groups, compared with controls (P<0.05). Age (β=0.253), heart rate (β=0.236), systolic blood pressure (β=-0.264), and diastolic blood pressure (β=0.365) were identified as significant predictors for aortic pulse wave velocity, using multivariable linear regression analysis. Aortic wall thickness was predicted by body mass index (β=0.248) and fasting glucose (β=0.242), next to aortic lumen area (β=0.340). Carotid intima-media thickness was assessed using ultrasonography, and was only higher in adolescents with coarctation of the aorta, compared with controls (P<0.001). Conclusions Adolescents with chronic disease showed enhanced aortic stiffness and wall thickness compared with controls. The enhanced aortic pulse wave velocity and aortic wall thickness in adolescents with chronic disease could indicate accelerated atherogenesis. Our findings underscore the importance of the aorta for assessment of early atherosclerosis, and the need for tailored cardiovascular follow-up of children with chronic disease.

PMID:35861840 | DOI:10.1161/JAHA.122.024675

Categories: Literature Watch

Exploring the role of antibiotics and steroids in managing respiratory diseases

Thu, 2022-07-21 06:00

J Biochem Mol Toxicol. 2022 Jul 21:e23174. doi: 10.1002/jbt.23174. Online ahead of print.

ABSTRACT

Respiratory diseases (RDs), such as chronic obstructive pulmonary disease, cystic fibrosis, asthma, and pneumonia, are associated with significant morbidity and mortality. Treatment usually consists of antibiotics and steroids. Relevant published literature reviews, studies, and clinical trials were accessed from institutional and electronic databases. The keywords used were respiratory diseases, steroids, antibiotics, and combination of steroids and antibiotics. Selected articles and literature were carefully reviewed. Antibiotics are often prescribed as the standard therapy to manage RDs. Types of causative respiratory pathogens, spectrum of antibiotics activity, route of administration, and course of therapy determine the type of antibiotics that are prescribed. Despite being associated with good clinical outcome, treatment failure and recurrence rate are still high. In addition, antibiotic resistance has been widely reported due to bacterial mutations in response to the use of antibiotics, which render them ineffective. Nevertheless, there has been a growing demand for corticosteroids (CS) and antibiotics to treat a wide variety of diseases, including various airway diseases, due to their immunosuppressive and anti-inflammatory properties. The use of CS is well established and there are different formulations based on the diseases, such as topical administration, tablets, intravenous injections, and inhaled preparations. Both antibiotics and CS possess similar properties in terms of their anti-inflammatory effects, especially regulating cytokine release. Thus, the current review examines and discusses the different applications of antibiotics, CS, and their combination in managing various RDs. Drawbacks of these interventions are also discussed.

PMID:35861662 | DOI:10.1002/jbt.23174

Categories: Literature Watch

Evaluating Differences in the Disease Experiences of Minority Adults With Cystic Fibrosis

Thu, 2022-07-21 06:00

J Patient Exp. 2022 Jul 14;9:23743735221112629. doi: 10.1177/23743735221112629. eCollection 2022.

ABSTRACT

Extensive research has demonstrated disparities in health outcomes and survival between non-Hispanic Caucasian (NHC) and non-Caucasian or Hispanic (minority) persons with cystic fibrosis (CF) in the United States (US). However, very little research has been done to explore the disease experiences of racial and ethnic minority persons with CF. Adult subjects with CF were approached for study participation and to characterize their experiential disease perceptions. Survey data were analyzed using Chi-Square tests and Mann-Whitney U-test for basic categorical and continuous variables, and Kruskal-Wallis one-way ANOVA using ranks for Likert scales. Minority persons reported significantly lower scores (more negative experience) when comparing themselves to others with CF (15.18 ± 2.89 vs 18.40 ± 3.18, P < .01), particularly in the areas of representation in research, experience, and support. We were able to identify the unique experiences of minority persons with CF, including perceived lower disease understanding and poorer representation compared to most others with CF. Further large studies are needed to develop and assess interventions that may be useful for serving these diverse populations.

PMID:35860790 | PMC:PMC9289912 | DOI:10.1177/23743735221112629

Categories: Literature Watch

Toward an ontology of collaborative learning healthcare systems

Thu, 2022-07-21 06:00

Learn Health Syst. 2022 Feb 26;6(3):e10306. doi: 10.1002/lrh2.10306. eCollection 2022 Jul.

ABSTRACT

OBJECTIVE: To establish a basis for a domain ontology - a formal, explicit specification of a shared conceptualization - of collaborative learning healthcare systems (CLHSs) in order to facilitate measurement, explanation, and improvement.

METHODS: We adapted the "Methontology" approach to begin building an ontology of CLHSs. We specified the purpose of an ontology, acquired domain knowledge via literature review, conceptualized a common framework of CLHSs using a grounded approach, refined these concepts based on expert panel input, and illustrated concept application via four cases.

RESULTS: The set of concepts identified as important to include in an ontology includes goals, values, structure, actors, environment, and products. To establish this set of concepts, we gathered input from content experts in two ways. First, expert panel methods were used to elicit feedback on these concepts and to test the elicitation of terms for the vocabulary of the Values concept. Second, from these discussions we developed a mapping exercise to test the intuitiveness of the concepts, requesting that network leaders from four CLHSs complete a mapping exercise to associate characteristics of their networks with the high-level concepts, building the vocabulary for each concept in a grounded fashion. We also solicited feedback from these participants on the experience of completing the mapping exercise, finding that the exercise is acceptable and could aid in CLHS development and collaboration. Respondents identified opportunities to improve the operational definitions of each concept to ensure that corresponding vocabularies are distinct and non-overlapping.

DISCUSSION: Our results provide a foundation for developing a formal, explicit shared conceptualization of CLHSs. Once developed, such a tool can be useful for measurement, explanation, and improvement. Further work, including alignment to a top-level ontology, expanding the vocabulary, and defining relations between vocabulary is required to formally build out an ontology for these uses.

PMID:35860315 | PMC:PMC9284927 | DOI:10.1002/lrh2.10306

Categories: Literature Watch

Resistance evolution can disrupt antibiotic exposure protection through competitive exclusion of the protective species

Thu, 2022-07-21 06:00

ISME J. 2022 Jul 20. doi: 10.1038/s41396-022-01285-w. Online ahead of print.

ABSTRACT

Antibiotic degrading bacteria can reduce the efficacy of drug treatments by providing antibiotic exposure protection to pathogens. While this has been demonstrated at the ecological timescale, it is unclear how exposure protection might alter and be affected by pathogen antibiotic resistance evolution. Here, we utilised a two-species model cystic fibrosis (CF) community where we evolved the bacterial pathogen Pseudomonas aeruginosa in a range of imipenem concentrations in the absence or presence of Stenotrophomonas maltophilia, which can detoxify the environment by hydrolysing β-lactam antibiotics. We found that P. aeruginosa quickly evolved resistance to imipenem via parallel loss of function mutations in the oprD porin gene. While the level of resistance did not differ between mono- and co-culture treatments, the presence of S. maltophilia increased the rate of imipenem resistance evolution in the four μg/ml imipenem concentration. Unexpectedly, imipenem resistance evolution coincided with the extinction of S. maltophilia due to increased production of pyocyanin, which was cytotoxic to S. maltophilia. Together, our results show that pathogen resistance evolution can disrupt antibiotic exposure protection due to competitive exclusion of the protective species. Such eco-evolutionary feedbacks may help explain changes in the relative abundance of bacterial species within CF communities despite intrinsic resistance to anti-pseudomonal drugs.

PMID:35859161 | DOI:10.1038/s41396-022-01285-w

Categories: Literature Watch

Genetic spectrum of Chinese children with cystic fibrosis: comprehensive data analysis from the main referral centre in China

Wed, 2022-07-20 06:00

J Med Genet. 2022 Jul 20:jmedgenet-2022-108501. doi: 10.1136/jmg-2022-108501. Online ahead of print.

ABSTRACT

BACKGROUND AND OBJECTIVES: Cystic fibrosis (CF) is a heterogeneous disease with a diverse genetic spectrum among populations. Few patients with CF of Chinese origin have been reported worldwide. The objective of this study is to characterise the genotypic features of CF in Chinese children.

METHODS: We recruited and characterised the genetic manifestations of 103 Chinese children with CF in Beijing Children's Hospital from 2010 to 2022. Whole-exome sequencing were performed to define the genotypes. Meanwhile, other 99 genetically confirmed patients with Chinese origin described in 45 references were also summarised.

RESULTS: 158 different variants including 23 novel observations were identified after sequencing. The majority of CFTR variants (82.3%) in Chinese have been observed only once or twice. 43.7% of the variants were only identified in patients of Chinese origin. The c.2909G>A(p.Gly970Asp), c.1766+5G>T and c.1657C>T(p.Arg553X) were the most frequent variants among Chinese patients, with allele frequency of 12.1%, 5.4% and 3.6%, respectively. The first two variants both showed significant Chinese ethnic tendency, while the latter one most likely came from Europeans for historical reasons. They also demonstrated significant differences in geographical distribution. c.1521_1523delCTT(p.F508del) was rarely observed in patients of pure Chinese origin, with an allele frequency of 1.8%. Two de novo variants (c.960dupA[p.Ser321IlefsX43] and c.2491-2A>G) and two deep-intronic variants (c.3718-2477C>T and c.3874-4522A>G) were identified, which were also quite rare among Chinese.

CONCLUSIONS: The genetic spectrum of CF in Chinese is unique and quite different from that observed in Caucasians. The geographical distributions of the most frequent variants were reported for the first time.

PMID:35858753 | DOI:10.1136/jmg-2022-108501

Categories: Literature Watch

Elevated intracellular Na<sup>+</sup> and osmolarity stimulate catalytic activity of the ubiquitin ligase Nedd4-2

Wed, 2022-07-20 06:00

Proc Natl Acad Sci U S A. 2022 Jul 26;119(30):e2122495119. doi: 10.1073/pnas.2122495119. Epub 2022 Jul 18.

ABSTRACT

Regulation of catalytic activity of E3 ubiquitin ligases is critical for their cellular functions. We identified an unexpected mode of regulation of E3 catalytic activity by ions and osmolarity; enzymatic activity of the HECT family E3 Nedd4-2/Nedd4L is enhanced by increased intracellular Na+ ([Na+]i) and by hyperosmolarity. This stimulated activity is mediated by activation of p38-MAPK and is inhibited by WNKs. Moreover, protease (Furin)-mediated activation of the epithelial Na+ channel ENaC (a bona fide Nedd4-2 substrate), which leads to increased [Na+]i and osmolarity, results in enhanced Nedd4-2 catalytic activity. This enhancement is inhibited by a Furin inhibitor, by a protease-resistant ENaC mutant, or by treatment with the ENaC inhibitor amiloride. Moreover, WNK inhibition, which stimulates catalytic activity of Nedd4-2, leads to reduced levels of cell-surface ENaC and reduced channel activity. ENaC activity does not affect Nedd4-2:ENaC binding. Therefore, these results demonstrate activation of a ubiquitin ligase by Na+ and osmotic changes. Importantly, they reveal a negative feedback loop in which active ENaC leads to stimulation of catalytic activity of its own suppressor, Nedd4-2, to protect cells from excessive Na+ loading and hyperosmotic stress and to protect the animal from hypertension.

PMID:35858421 | DOI:10.1073/pnas.2122495119

Categories: Literature Watch

CFTR genotype analysis of Asians in international registries highlights disparities in the diagnosis and treatment of Asian patients with cystic fibrosis

Wed, 2022-07-20 06:00

Genet Med. 2022 Jul 20:S1098-3600(22)00818-8. doi: 10.1016/j.gim.2022.06.009. Online ahead of print.

ABSTRACT

PURPOSE: Cystic fibrosis (CF) is not well-characterized in Asians, potentially resulting in delayed diagnosis and poor prognosis. We characterized CF in Asian subgroups to address these disparities.

METHODS: De-identified ethnicity and CFTR variant data were obtained from the United States, United Kingdom, and Canadian CF registries. We measured the prevalence of CF, CFTR variant allele frequencies, effectiveness of screening panels, and eligibility for modulator therapies.

RESULTS: The prevalence of CF was 1 in 74,982 people (Canada) to 1 in 13,340 people (United Kingdom) for South Asians and 1 in 256,541 (Canada) to 1 in 52,563 (United Kingdom) for other Asians, suggesting 26,000 to 146,000 patients with CF in South Asia. p.(F508del) variant was markedly less frequent in Asians than in non-Hispanic Whites. Splicing and nonsense variants occurred at high allelic frequencies in Asians, resulting in 41% to 49% of South Asians and 21% to 39% of other Asians being ineligible for CFTR modulator therapies. Hologic/EU2v1 panels failed to identify 37% to 47% of South Asian and 23% to 46% of other Asian patients with CF.

CONCLUSIONS: Among Asians, CF appears to be more common in South Asians. A significant CF population may exist in South Asia. CFTR variants in South and other Asians markedly differ from non-Hispanic Whites causing inequities in newborn screening, diagnosis, and treatment. New strategies are necessary to mitigate these health care disparities.

PMID:35857025 | DOI:10.1016/j.gim.2022.06.009

Categories: Literature Watch

Content validation for the Chilean population of the quality of life assessment instrument in children, adolescents and adults with Cystic Fibrosis: CFQ-R CYSTIC FIBROSIS QUESTIONNAIRE-REVISED version in Spanish, Chile

Wed, 2022-07-20 06:00

Andes Pediatr. 2022 Jun;93(3):312-326. doi: 10.32641/andespediatr.v93i3.3871.

ABSTRACT

INTRODUCTION: Cystic Fibrosis (CF) is the most frequent chronic hereditary disease in the white race. Although the impact on the quality of life of this disease is significant, there are no validated instruments in the Chilean population to measure it.

OBJECTIVE: To carry out a cultural and linguistic adaptation and validate the content and reliability of the CFQ-R Cystic Fibrosis Questionnaire, Spanish version 2.0.

PATIENTS AND METHOD: The process was carried out in two stages. The first stage consists of an ins trumental design to adapt it culturally and linguistically, evaluate content validity by consulting ex perts, and test the comprehension of the questionnaire in patients and parents through qualitative interviews and a focus group. In the second stage with an observational and cross-sectional design in a sample of 122 people with CF or their caregivers, the behavior of the questionnaire was analyzed using descriptive statistics and Cronbach's alpha for reliability.

RESULTS: Stage 1: the instrument in its three versions is considered valid with Lynn's index > 0.8 and Validity Coefficient > 0.7. Stage 2: The adolescent/adult and parent/caregiver versions obtain Cronbach's a > 0.7 and an average > 3 in most dimensions.

CONCLUSION: The questionnaire is adapted and validated in the Chilean population and requires minor modifications. This version is reliable, valid, and allows the assessment of the quality of life in people with CF. It is suggested to increase the sample for the analysis of construct validity with a larger number of patients.

PMID:35857002 | DOI:10.32641/andespediatr.v93i3.3871

Categories: Literature Watch

Extreme electrolyte depletion associated with septic shock as a form of presentation of cystic fibrosis

Wed, 2022-07-20 06:00

Andes Pediatr. 2022 Feb;93(1):110-116. doi: 10.32641/andespediatr.v93i1.3766.

ABSTRACT

In the pediatric emergency department, dehydrated children are one of the most frequent causes for consultation, however, the coexistence of hyponatremia with hypochloremia and metabolic alkalosis is rare. The presence of metabolic alkalosis due to chloride depletion has been reported as a form of presentation of Cystic Fibrosis (CF).

OBJECTIVE: to describe a case of cystic fibrosis of unusual presen tation in a pediatric patient.

CLINICAL CASE: we report a 3-month-old previously healthy male infant who presented with internal environment abnormalities consisting of metabolic alkalosis, hypona tremia, hypokalemia, and extreme hypochloremia associated with septic shock due to mixed viral- bacterial pneumonia (Rhino/enterovirus, Streptococcus pneumoniae, and Staphylococcus aureus). Cys tic fibrosis (CF) was suspected, thus the diagnosis was corroborated by sweat test and genetic study which showed the pathogenic variants c.2834C>T (p.Ser945Leu) and c.3484C>T (p.Arg1162X), both heterozygous.

CONCLUSION: special attention should be paid to the existence of hypochloremia with metabolic alkalosis and hyponatremia associated or not with pulmonary disease, suspecting CF as the first option. This consideration becomes more relevant in those countries where the neonatal screening test is not widely available.

PMID:35856954 | DOI:10.32641/andespediatr.v93i1.3766

Categories: Literature Watch

A New Era for Cystic Fibrosis and CFTR Modulator Trials in Infants

Wed, 2022-07-20 06:00

Am J Respir Crit Care Med. 2022 Jul 20. doi: 10.1164/rccm.202207-1356ED. Online ahead of print.

NO ABSTRACT

PMID:35856818 | DOI:10.1164/rccm.202207-1356ED

Categories: Literature Watch

The <em>In Vitro</em> Replication Cycle of Achromobacter xylosoxidans and Identification of Virulence Genes Associated with Cytotoxicity in Macrophages

Wed, 2022-07-20 06:00

Microbiol Spectr. 2022 Jul 20:e0208322. doi: 10.1128/spectrum.02083-22. Online ahead of print.

ABSTRACT

Achromobacter xylosoxidans is an opportunistic pathogen implicated in a wide variety of human infections including the ability to colonize the lungs of cystic fibrosis (CF) patients. The role of A. xylosoxidans in human pathology remains controversial due to the lack of optimized in vitro and in vivo model systems to identify and test bacterial gene products that promote a pathological response. We have previously identified macrophages as a target host cell for A. xylosoxidans-induced cytotoxicity. By optimizing our macrophage infection model, we determined that A. xylosoxidans enters macrophages and can reside within a membrane bound vacuole for extended periods of time. Intracellular replication appears limited with cellular lysis preceding an enhanced, mainly extracellular replication cycle. Using our optimized in vitro model system along with transposon mutagenesis, we identified 163 genes that contribute to macrophage cytotoxicity. From this list, we characterized a giant RTX adhesin encoded downstream of a type one secretion system (T1SS) that mediates bacterial binding and entry into host macrophages, an important first step toward cellular toxicity and inflammation. The RTX adhesin is encoded by other human isolates and is recognized by antibodies present in serum isolated from CF patients colonized by A. xylosoxidans, indicating this virulence factor is produced and deployed in vivo. This study represents the first characterization of A. xylosoxidans replication during infection and identifies a variety of genes that may be linked to virulence and human pathology. IMPORTANCE Patients affected by CF develop chronic bacterial infections characterized by inflammatory exacerbations and tissue damage. Advancements in sequencing technologies have broadened the list of opportunistic pathogens colonizing the CF lung. A. xylosoxidans is increasingly recognized as an opportunistic pathogen in CF, yet our understanding of the bacterium as a contributor to human disease is limited. Genomic studies have identified potential virulence determinants in A. xylosoxidans isolates, but few have been mechanistically studied. Using our optimized in vitro cell model, we identified and characterized a bacterial adhesin that mediates binding and uptake by host macrophages leading to cytotoxicity. A subset of serum samples from CF patients contains antibodies that recognize the RTX adhesion, suggesting, for the first time, that this virulence determinant is produced in vivo. This work furthers our understanding of A. xylosoxidans virulence factors at a mechanistic level.

PMID:35856670 | DOI:10.1128/spectrum.02083-22

Categories: Literature Watch

Secondary Metabolites Produced during Aspergillus fumigatus and Pseudomonas aeruginosa Biofilm Formation

Wed, 2022-07-20 06:00

mBio. 2022 Jul 20:e0185022. doi: 10.1128/mbio.01850-22. Online ahead of print.

ABSTRACT

In cystic fibrosis (CF), mucus plaques are formed in the patient's lungs, creating a hypoxic condition and a propitious environment for colonization and persistence of many microorganisms. There is clinical evidence showing that Aspergillus fumigatus can cocolonize CF patients with Pseudomonas aeruginosa, which has been associated with lung function decline. P. aeruginosa produces several compounds with inhibitory and antibiofilm effects against A. fumigatus in vitro; however, little is known about the fungal compounds produced in counterattack. Here, we annotated fungal and bacterial secondary metabolites (SM) produced in mixed biofilms under normoxia and hypoxia conditions. We detected nine SM produced by P. aeruginosa. Phenazines and different analogs of pyoverdin were the main compounds produced by P. aeruginosa, and their secretion levels were increased by the fungal presence. The roles of the two operons responsible for phenazine production (phzA1 and phzA2) were also investigated, and mutants lacking one of those operons were able to produce partial sets of phenazines. We detected a total of 20 SM secreted by A. fumigatus either in monoculture or in coculture with P. aeruginosa. All these compounds were secreted during biofilm formation in either normoxia or hypoxia. However, only eight compounds (demethoxyfumitremorgin C, fumitremorgin, ferrichrome, ferricrocin, triacetylfusigen, gliotoxin, gliotoxin E, and pyripyropene A) were detected during biofilm formation by the coculture of A. fumigatus and P. aeruginosa under normoxia and hypoxia conditions. Overall, we showed how diverse SM secretion is during A. fumigatus and P. aeruginosa mixed culture and how this can affect biofilm formation in normoxia and hypoxia. IMPORTANCE The interaction between Pseudomonas aeruginosa and Aspergillus fumigatus has been well characterized in vitro. In this scenario, the bacterium exerts a strong inhibitory effect against the fungus. However, little is known about the metabolites produced by the fungus to counterattack the bacteria. Our work aimed to annotate secondary metabolites (SM) secreted during coculture between P. aeruginosa and A. fumigatus during biofilm formation in both normoxia and hypoxia. The bacterium produces several different types of phenazines and pyoverdins in response to presence of the fungus. In contrast, we were able to annotate 29 metabolites produced during A. fumigatus biofilm formation, but only 8 compounds were detected during biofilm formation by the coculture of A. fumigatus and P. aeruginosa upon either normoxia or hypoxia. In conclusion, we detected many SM secreted during A. fumigatus and P. aeruginosa biofilm formation. This analysis provides several opportunities to understand the interactions between these two species.

PMID:35856657 | DOI:10.1128/mbio.01850-22

Categories: Literature Watch

Clinical characteristics, multiorgan dysfunction and outcomes of patients with COVID-19: a prospective case series

Tue, 2022-07-19 06:00

CMAJ Open. 2022 Jul 19;10(3):E675-E684. doi: 10.9778/cmajo.20210151. Print 2022 Jul-Sep.

ABSTRACT

BACKGROUND: Characterizing the multiorgan manifestations and outcomes of patients hospitalized with COVID-19 will inform resource requirements to address the long-term burden of this disease. We conducted a descriptive analysis using prospectively collected data to describe the clinical characteristics and spectrum of organ dysfunction, and in-hospital and longer-term clinical outcomes of patients hospitalized with COVID-19 during the first wave of the pandemic at a Canadian centre.

METHODS: We conducted a prospective case series involving adult patients (aged ≥ 18 yr) with COVID-19 admitted to 1 of 2 hospitals in London, Ontario, from Mar. 17 to June 18, 2020, during the first wave of the pandemic. We recorded patients' baseline characteristics, physiologic parameters, measures of organ function and therapies administered during hospitalization among patients in the intensive care unit (ICU) and in non-ICU settings, and compared the characteristics of hospital survivors and nonsurvivors. Finally, we recorded follow-up thoracic computed tomography (CT) and echocardiographic findings after hospital discharge.

RESULTS: We enrolled 100 consecutive patients (47 women) hospitalized with COVID-19, including 32 patients who received ICU care and 68 who received treatment in non-ICU settings. Respiratory sequelae were common: 23.0% received high-flow oxygen by nasal cannula, 9.0% received noninvasive ventilation, 24.0% received invasive mechanical ventilation and 2.0% received venovenous extracorporeal membrane oxygenation. Overall, 9.0% of patients had cerebrovascular events (3.0% ischemic stroke, 6.0% intracranial hemorrhage), and 6.0% had pulmonary embolism. After discharge, 11 of 19 patients had persistent abnormalities on CT thorax, and 6 of 15 had persistent cardiac dysfunction on echocardiography.

INTERPRETATION: This study provides further evidence that COVID-19 is a multisystem disease involving neurologic, cardiac and thrombotic dysfunction, without evidence of hepatic dysfunction. Patients have persistent organ dysfunction after hospital discharge, underscoring the need for research on long-term outcomes of COVID-19 survivors.

PMID:35853662 | DOI:10.9778/cmajo.20210151

Categories: Literature Watch

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