Intradialytic parenteral nutrition improves nutritional status in a complex cystic fibrosis patient with redo double lung transplant and end-stage renal disease.

BMJ Case Rep. 2020 Mar 19;13(3):

Authors: Melville T, Vardy K, Milliner L, Angus R

Abstract
This case study reports on the use of intradialytic parenteral nutrition (IDPN) to address severe malnutrition in a 38-year-old woman, redo double lung transplant recipient with a complex medical history including cystic fibrosis and end-stage renal disease (ESRD) on haemodialysis. Gastroparesis and severe postprandial abdominal pain limited oral/enteral nutrition input. The addition of IDPN resulted in a dry weight increase of 13.6% over a 12-month period and an improvement in the patient's malnutrition status from severe (Patient-Generated Subjective Global Assessment (PG SGA) C24) to moderate (PG SGA B7). The patient stated she would recommend IDPN to others in a similar situation. Management of patients with coexisting cystic fibrosis and ESRD with or without haemodialysis requires patient engagement in treatment planning and a multidisciplinary team approach for clinical judgement in the absence of guidelines. As advances in medical care see more patients with these coexisting conditions, IDPN may provide an increasingly useful adjunct therapy.

PMID: 32198225 [PubMed - as supplied by publisher]

Modulator treatment for people with cystic fibrosis: moving in the right direction.

Eur Respir Rev. 2020 Mar 31;29(155):

Authors: Elborn JS

PMID: 32198220 [PubMed - as supplied by publisher]

Impact of CFTR modulator use on outcomes in people with severe cystic fibrosis lung disease.

Eur Respir Rev. 2020 Mar 31;29(155):

Authors: Shteinberg M, Taylor-Cousar JL

Abstract
Drug compounds that augment the production and activity of the cystic fibrosis (CF) transmembrane regulator (CFTR) have revolutionised CF care. Many adults and some children with CF suffer advanced and severe lung disease or await lung transplantation. While the hope is that these drug compounds will prevent lung damage when started early in life, there is an ongoing need to care for people with advanced lung disease. The focus of this review is the accumulating data from clinical trials and case series regarding the benefits of CFTR modulator therapy in people with advanced pulmonary disease. We address the impact of treatment with ivacaftor, lumacaftor/ivacaftor, tezacaftor/ivacaftor and elexacaftor/tezacaftor/ivacaftor on lung function, pulmonary exacerbations, nutrition and quality of life. Adverse events of the different CFTR modulators, as well as the potential for drug-drug interactions, are discussed.

PMID: 32198216 [PubMed - as supplied by publisher]

Comparative whole genome phylogeny of animal, environmental, and human strains confirms the genogroup organization and diversity of the Stenotrophomonas maltophilia complex.

Appl Environ Microbiol. 2020 Mar 20;:

Authors: Mercier-Darty M, Royer G, Lamy B, Charron C, Lemenand O, Gomart C, Fourreau F, Madec JY, Jumas-Bilak E, Decousser JW, RESAPATH Network, ColBVH Network

Abstract
The Stenotrophomonas maltophilia complex (Smc) comprises opportunistic environmental Gram negative bacilli responsible for a variety of infections in both humans and animals. Beyond its large genetic diversity, its genetic organization in genogroups was recently confirmed through the whole genome sequencing of human and environmental strains. Animal strains being poorly represented in these analyses, we sequenced the whole genomes of 93 animal strains to determine their genetic background and characteristics. Combining these data with 81 newly sequenced human strains and the genomes available from RefSeq, we performed a genomic analysis that included 375 non-duplicated genomes with various origins (animal: 104, human: 226, environment: 30, unknown: 15). Phylogenetic analysis and clustering based on genome-wide average nucleotide identity confirmed and specified the genetic organization of Smc in at least 20 genogroups. Two new genogroups were identified and two previously described groups were further divided into two subgroups, each. Comparing the strains isolated from different host types and their genogroup affiliation, we observed a clear disequilibrium in certain groups. Surprisingly, some antimicrobial resistance genes, integrons, and/or CALIN sequences targeting antimicrobial compounds extensively used in animals, were mainly identified in animal strains. We also identified genes commonly found in animal strains coding for efflux systems. The result of a large whole genome analysis performed by us supports the hypothesis of putative contribution of animals as a reservoir of Stenotrophomonas maltophilia complex strains and/or resistance genes for strains in humans.Importance:Given its naturally large antimicrobial resistance profile, Smc is a set of emerging pathogens of immunosuppressed and cystic fibrosis patients. As an environmental group of microorganisms, this adaptation to humans is an opportunity to understand the genetic and metabolic selective mechanisms involved in this process. The previously reported genomic organization was incomplete as data from animal strains were underrepresented. We added the missing piece of the puzzle with whole-genome sequencing of 93 strains of animal origin. Beyond describing the phylogenetic organization, we confirmed the genetic diversity of the Smc, which could not be estimated through routine phenotype or MALDI-TOF based laboratory tests. Animals strains seem to play a key role in the diversity of Smc and could act a reservoir for mobile resistance genes. Some genogroups seem to be clearly associated with particular hosts; the genetic support of this association and the role of the determinants/corresponding genes need to be explored.

PMID: 32198168 [PubMed - as supplied by publisher]

The origin of extracellular DNA in bacterial biofilm infections in vivo.

Pathog Dis. 2020 Mar 20;:

Authors: Alhede M, Alhede M, Qvortrup K, Kragh KN, Jensen PØ, Stewart PS, Bjarnsholt T

Abstract
Extracellular DNA (eDNA) plays an important role in both the aggregation of bacteria and in the interaction of the resulting biofilms with polymorphonuclear leukocytes (PMNs) during an inflammatory response. Here, transmission electron and confocal scanning laser microscopy were used to examine the interaction between biofilms of Pseudomonas aeruginosa and PMNs in a murine implant model and in lung tissue from chronically infected cystic fibrosis patients. PNA FISH, DNA staining, labeling of PMN DNA with a thymidine analogue, and immunohistochemistry were applied to localize bacteria, eDNA, PMN-derived eDNA, PMN-derived histone H3 (H3), neutrophil elastase (NE), and citrullinated H3 (citH3). Host-derived eDNA was observed surrounding bacterial biofilms but not within the biofilms. H3 localized to the lining of biofilms while NE was found throughout biofilms. CitH3, a marker for neutrophil extracellular traps (NETs) was detected only sporadically indicating that most host-derived eDNA in vivo was not a result of NETosis. Together these observations show that, in these in vivo biofilm infections with P. aeruginosa, the majority of eDNA is found external to the biofilm and derives from the host.

PMID: 32196074 [PubMed - as supplied by publisher]

Evaluation of secondhand smoke effects on CFTR function in vivo.

Respir Res. 2020 Mar 20;21(1):70

Authors: Rasmussen LW, Stanford D, Patel K, Raju SV

PMID: 32192506 [PubMed - in process]

Cryptides Identified in Human Apolipoprotein B as New Weapons to Fight Antibiotic Resistance in Cystic Fibrosis Disease.

Int J Mol Sci. 2020 Mar 17;21(6):

Authors: Gaglione R, Cesaro A, Dell'Olmo E, Di Girolamo R, Tartaglione L, Pizzo E, Arciello A

Abstract
Chronic respiratory infections are the main cause of morbidity and mortality in cystic fibrosis (CF) patients, and are characterized by the development of multidrug resistance (MDR) phenotype and biofilm formation, generally recalcitrant to treatment with conventional antibiotics. Hence, novel effective strategies are urgently needed. Antimicrobial peptides represent new promising therapeutic agents. Here, we analyze for the first time the efficacy of three versions of a cryptide identified in human apolipoprotein B (ApoB, residues 887-922) towards bacterial strains clinically isolated from CF patients. Antimicrobial and anti-biofilm properties of ApoB-derived cryptides have been analyzed by broth microdilution assays, crystal violet assays, confocal laser scanning microscopy and scanning electron microscopy. Cell proliferation assays have been performed to test cryptide effects on human host cells. ApoB-derived cryptides have been found to be endowed with significant antimicrobial and anti-biofilm properties towards Pseudomonas and Burkholderia strains clinically isolated from CF patients. Peptides have been also found to be able to act in combination with the antibiotic ciprofloxacin, and they are harmless when tested on human bronchial epithelial mesothelial cells. These findings open interesting perspectives to cryptide applicability in the treatment of chronic lung infections associated with CF disease.

PMID: 32192076 [PubMed - in process]

Persistent Stridor in a 10-year-old Patient with Cystic Fibrosis.

Am J Respir Crit Care Med. 2020 Mar 19;:

Authors: Kohlmaier B, Strenger V, Egger M, Modl M, Pfleger A, Gugatschka M, Brcic L, Gorkiewicz G, Eber E

PMID: 32191838 [PubMed - as supplied by publisher]

The value of chest magnetic resonance imaging compared to chest radiographs with and without additional lung ultrasound in children with complicated pneumonia.

PLoS One. 2020;15(3):e0230252

Authors: Konietzke P, Mueller J, Wuennemann F, Wagner WL, Schenk JP, Alrajab A, Kauczor HU, Stahl M, Mall MA, Wielpütz MO, Sommerburg O

Abstract
INTRODUCTION: In children with pneumonia, chest x-ray (CXR) is typically the first imaging modality used for diagnostic work-up. Repeated CXR or computed tomography (CT) are often necessary if complications such as abscesses or empyema arise, thus increasing radiation exposure. The aim of this retrospective study was to evaluate the potential of radiation-free chest magnetic resonance imaging (MRI) to detect complications at baseline and follow-up, compared to CXR with and without additional lung ultrasound (LUS).
METHODS: Paired MRI and CXR scans were retrospectively reviewed by two blinded readers for presence and severity of pulmonary abscess, consolidation, bronchial wall thickening, mucus plugging and pleural effusion/empyema using a chest MRI scoring system. The scores for MRI and CXR were compared at baseline and follow-up. Furthermore, the MRI scores at baseline with and without contrast media were evaluated.
RESULTS: 33 pediatric patients (6.3±4.6 years), who had 33 paired MRI and CXR scans at baseline and 12 at follow-up were included. MRI detected significantly more lung abscess formations with a prevalence of 72.7% compared to 27.3% by CXR at baseline (p = 0.001), whereas CXR+LUS was nearly as good as MRI. MRI also showed a higher sensitivity in detecting empyema (p = 0.003). At follow-up, MRI also showed a slightly better sensitivity regarding residual abscesses. The overall severity of disease was rated higher on MRI. Contrast material did not improve detection of abscesses or empyema by MRI.
CONCLUSION: CXR and LUS seem to be sufficient in most cases. In cases where LUS cannot be realized or the combination of CXR+LUS might be not sufficient, MRI, as a radiation free modality, should be preferred to CT. Furthermore, the admission of contrast media is not mandatory in this context.

PMID: 32191736 [PubMed - as supplied by publisher]

Antibiotic treatment for Stenotrophomonas maltophilia in people with cystic fibrosis.

Cochrane Database Syst Rev. 2020 Mar 18;3:CD009249

Authors: Amin R, Jahnke N, Waters V

Abstract
BACKGROUND: Stenotrophomonas maltophilia is one of the most common emerging multi-drug resistant organisms found in the lungs of people with cystic fibrosis and its prevalence is increasing. Chronic infection with Stenotrophomonas maltophilia has recently been shown to be an independent predictor of pulmonary exacerbation requiring hospitalization and antibiotics. However, the role of antibiotic treatment of Stenotrophomonas maltophilia infection in people with cystic fibrosis is still unclear. This is an update of a previously published review.
OBJECTIVES: The objective of our review is to assess the effectiveness of antibiotic treatment for Stenotrophomonas maltophilia in people with cystic fibrosis. The primary objective is to assess this in relation to lung function and pulmonary exacerbations in the setting of acute pulmonary exacerbations. The secondary objective is to assess this in relation to the eradication of Stenotrophomonas maltophilia.
SEARCH METHODS: We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched a registry of ongoing trials and the reference lists of relevant articles and reviews. Date of latest search: 03 March 2020.
SELECTION CRITERIA: Randomized controlled trials of Stenotrophomonas maltophilia mono-infection or Stenotrophomonas maltophilia co-infection with Pseudomonas aeruginosa in either the setting of an acute pulmonary exacerbation or a chronic infection treated with suppressive antibiotic therapy.
DATA COLLECTION AND ANALYSIS: Both authors independently assessed the trials identified by the search for potential inclusion in the review.
MAIN RESULTS: We identified only one trial of antibiotic treatment of pulmonary exacerbations that included people with cystic fibrosis with Stenotrophomonas maltophilia. However, this trial had to be excluded because data was not available per pathogen.
AUTHORS' CONCLUSIONS: This review did not identify any evidence regarding the effectiveness of antibiotic treatment for Stenotrophomonas maltophilia in people with cystic fibrosis. Until such evidence becomes available, clinicians need to use their clinical judgement as to whether or not to treat Stenotrophomonas maltophilia infection in people with cystic fibrosis. Randomized clinical trials are needed to address these unanswered clinical questions.

PMID: 32189337 [PubMed - in process]

Functional Role of Basolateral ClC-2 Channels in the Regulation of Duodenal Anion Secretion in Mice.

Dig Dis Sci. 2019 09;64(9):2527-2537

Authors: Du C, Liu J, Wan H, Dong H, Zhao X

Abstract
BACKGROUND: Although ClC-2 channels are important in colonic Cl- secretion, it is unclear about their roles in small intestinal anion secretion. Therefore, we sought to examine whether ClC-2 channels play important roles in anion secretion, particularly duodenal bicarbonate secretion (DBS).
METHODS: Duodenal mucosae from mice were stripped of seromuscular layers and mounted in Ussing chambers. Both duodenal short-circuit current (Isc) and HCO3- secretion in vitro were simultaneously recorded. DBS in vivo was measured by a CO2-sensitive electrode.
RESULTS: Lubiprostone, a selective ClC-2 activator, concentration-dependently increased both duodenal Isc and DBS only when applied basolaterally, but not when applied apically. Removal of extracellular Cl- abolished lubiprostone-induced duodenal Isc, but did not alter HCO3- secretion even in the presence of DIDS, a Cl-/HCO3- exchanger inhibitor. However, further addition of glibenclamide, a CFTR channel blocker, abolished lubiprostone-evoked HCO3- secretion. Moreover, lubiprostone-induced HCO3- secretion was impaired in CFTR-/- mice compared to wild-type littermates. Luminal perfusion of duodenal lumen with lubiprostone did not alter basal DBS in vivo, but lubiprostone (i.p.) was able to induce DBS, which was also significantly inhibited by Cd2+, a ClC-2 channel blocker. [Ca2+]cyt level, Ca2+-activated K+ channel- and cAMP-mediated duodenal Isc, and HCO3- secretion were unchanged by lubiprostone.
CONCLUSIONS: We have provided the first evidence for the novel functional role of basolateral ClC-2 channels in the regulation of duodenal anion secretion.

PMID: 30874987 [PubMed - indexed for MEDLINE]

Epigenetic Modification of CFTR in Head and Neck Cancer.

J Clin Med. 2020 Mar 09;9(3):

Authors: Shin Y, Kim M, Won J, Kim J, Oh SB, Lee JH, Park K

Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR), a cyclic AMP (cAMP)-regulated chloride channel, is critical for secretion and absorption across diverse epithelia. Mutations or absence of CFTR result in pathogeneses, including cancer. While CFTR has been proposed as a tumor suppressing gene in tumors of the intestine, lung, and breast cancers, its effects in head and neck cancer (HNC) have yet to be investigated. This study aimed to define expression patterns and epigenetic modifications of CFTR in HNC. CFTR was expressed in normal but not in HNC cells and tissues. Treatment with 5-aza-2'-deoxycytidine (5-Aza-CdR) was associated with rescued expression of CFTR, whose function was confirmed by patch clamp technique. Further experiments demonstrated that CFTR CpG islands were hypermethylated in cancer cells and tissues and hypomethylated in normal cells and tissue. Our results suggest that CFTR epigenetic modifications are critical in both down-regulation and up-regulation of CFTR expression in HNC and normal cells respectively. We then investigated the impact of CFTR on expressions and functions of cancer-related genes. CFTR silencing was closely associated with changes to other cancer-related genes, suppressing apoptosis while enhancing proliferation, cell motility, and invasion in HNC. Our findings demonstrate that hypermethylation of CFTR CpG islands and CFTR deficiency is closely related to HNC.

PMID: 32182826 [PubMed]

Psychological interventions for people with hemophilia.

Cochrane Database Syst Rev. 2020 Mar 18;3:CD010215

Authors: Palareti L, Melotti G, Cassis F, Nevitt SJ, Iorio A

Abstract
BACKGROUND: Managing hemophilia is challenging both in terms of medical treatment and its broad impact on many aspects of the individual's life, including self-perception. Several psychosocial issues are potentially relevant in the clinical management of hemophilia, including it being a chronic and incurable condition; e.g. people with hemophilia must adapt to optimally interact with peers and to practice sports - even choosing a sport represents an issue for perceived limitations, expectations and cultural influences on the individual and their family. People with hemophilia can react by denying their condition and its manifestations and not adhering to treatment. Due to the complexity of relationships surrounding genetic diseases, parents and relatives may have their own issues that contribute to making life easier or more difficult for the person with hemophilia. Anxiety, sadness and depression resulting in mental health disorders are reported in this population and may influence quality of life (QoL) depending on cultural background, religious beliefs, family support and other variables.
OBJECTIVES: Primarily to assess the effectiveness of psychological therapies for improving the ability of people with hemophilia to cope with their chronic condition.
SEARCH METHODS: We aimed to identify trials from the Cochrane Cystic Fibrosis and Genetic Disorders Group's Coagulopathies Trials Register, Embase and PsycINFO, CINAHL, MEDLINE and trial registries. We searched reference lists of included publications. Most recent search of the Group's register: 13 June 2019.
SELECTION CRITERIA: Randomized controlled trials (RCTs) and quasi-RCTs in people with hemophilia of any age or gender, type A or B, any severity, with or without inhibitors, with or without HIV or hepatitis C virus. All psychological interventions for promoting emotional, intellectual and spiritual wellness. Individual, group or family group therapy interventions were eligible.
DATA COLLECTION AND ANALYSIS: We independently assessed trials, extracted data and assessed the risk of bias and assessed the quality of the evidence using GRADE.
MAIN RESULTS: Seven trials were included (362 participants randomized, data from 264 participants available for analysis); six of parallel design and one a partial cross-over design. One multicenter trial was conducted in Canada; the remaining six were single centre undertaken in the UK, USA, Iran and in the Netherlands. All trials had a high risk of bias for participant blinding and use of patient-reported outcomes. Evidence was retrieved on four interventions: psycho-education (DVD plus information booklet versus information booklet alone; computerised learning versus no intervention); cognitive therapy (auto-hypnosis (self-hypnosis) versus control); and behavioural therapy (relaxation (progressive or self control) versus no treatment). We also aimed to assess psychodynamic therapy and systemic therapy, but no trials were identified. Heterogeneity of the outcome measures and measurements precluded meta-analyses. No trial reported the cost of the psychological intervention and family adjustment. DVD plus information booklet compared to information booklet alone One trial (108 participants) showed coping strategies may lower pre-contemplation scores and negative thoughts, mean difference (MD) -0.24 (95%CI -0.48 - 0.00, low-certainty evidence), however, other measures of coping strategies in the same trial suggest little or no difference between groups, e.g. contemplation, MD (-0.09, 95%CI -0.32 - 0.14, low-certainty evidence). The same trial measured QoL and showed little or no difference between treatment groups for the physical domain, MD 0.59 (95% CI -3.66 to 4.84, low-certainty evidence), but may improve scores in the mental health domain for those receiving the booklet plus DVD compared to booklet alone, MD (4.70, 95% CI 0.33 to 9.07, low-certainty evidence). Mood or personal well-being were not reported. Computerised learning compared to no intervention Two trials (57 participants) reported on interventions aimed at children and adolescents and their impact on promoting a sense of self-efficacy (primary outcome 'Mood and personal well-being'), but only one showed an increase, MD 7.46 (95%CI 3.21 to 11.71, 17 participants, very low-certainty evidence); the second did not report control group data. One trial (30 participants) showed the intervention did not improve self-efficacy in adults, but appropriate data could not be extracted. Two trials (47 participants) reported coping strategies; one only reported within-group differences from baseline, the second showed an increase from baseline in coping strategies in the Internet program group compared to the no intervention group (disease-specific knowledge, MD 2.45 (95% CI 0.89 to 4.01); self-management ability and transition readiness, MD 19.90 (95% CI 3.61 to 36.19; low-certainty evidence). One trial reported QoL but with insufficient information to calculate changes from baseline; no difference in post-treatment scores was seen between groups, MD -8.65, 95% CI -18.30 to 1.00, very low-certainty evidence). Auto-hypnosis (self-hypnosis) compared to control There were two older trials that reported on this intervention (50 participants) focusing mainly on the secondary outcome 'physical health'; only one trial reported the primary outcome 'mood and personal well-being' (only within-group differences in the treatment group). Coping strategies and QoL were not assessed in the trials. Relaxation (progressive or self control) compared to no treatment Only one trial (seven participants) from 1985, was included which focused on 'physical health' and did not report on any of our primary outcomes.
AUTHORS' CONCLUSIONS: Not all of the seven included trials analysed the effects of the interventions on our primary outcomes (mood and personal well-being, coping strategies and QoL). Three trials were conducted in the 1970s and 1980s using techniques of auto-hypnosis or relaxation and, in accordance with the needs and therapeutic possibilities of the time, they focused on secondary outcomes, e.g. frequency of bleeding (physical health) and adherence to the intervention. The four newer trials assessed psycho-educational interventions all mediated by the use of technologies (DVD or computer) and often created according to age needs of the target group. In these cases, attention was shifted to our pre-defined primary outcomes. This review has identified low- and very low-certainty evidence, prompting caution in its interpretation. The major problem we encountered was the heterogeneity of trial designs, of interventions and of outcome measures used across the trials. We strongly suggest that researchers consider developing a core outcome set to streamline future research; randomization was proven to be safe and acceptable, and blinding should be considered for those assessing patient-reported outcomes.

PMID: 32187661 [PubMed - as supplied by publisher]

When tissue is the issue: a histological review of chronic lung allograft dysfunction.

Am J Transplant. 2020 Mar 17;:

Authors: Verleden SE, von J, der Thüsen, Roux A, Brouwers ES, Braubach P, Kuehnel M, Laenger F, Jonigk D

Abstract
Although chronic lung allograft dysfunction (CLAD) remains the major life-limiting factor following lung transplantation, much of its pathophysiology remains unknown. The discovery that CLAD can manifest both clinically and morphologically in vastly different ways led to the definition of distinct subtypes of CLAD. In this review, recent advances in our understanding of the pathophysiological mechanisms of the different phenotypes of CLAD will be discussed with a particular focus on tissue-based and molecular studies. An overview of the current knowledge on the mechanisms of the airway-centered bronchiolitis obliterans syndrome (BOS), as well as the airway and alveolar injuries in the restrictive allograft syndrome (RAS) and also the vascular compartment in chronic antibody mediated rejection is provided. Specific attention is also given to morphological and molecular markers for early CLAD diagnosis or histological changes associated with subsequent CLAD development. Evidence for a possible overlap between different forms of CLAD is presented and discussed. In the end, "tissue remains the (main) issue", as we are still limited in our knowledge about the actual triggers and specific mechanisms of all late forms of post-transplant graft failure, a shortcoming which needs to be addressed in order to further improve the outcome of lung transplant recipients.

PMID: 32185874 [PubMed - as supplied by publisher]

Cystic Fibrosis: A Simple and Customized Strategy for Genetic Screening Able to Detect Over 90% of Identified Mutated Alleles in Brazilian Newborns.

Mol Diagn Ther. 2020 Mar 17;:

Authors: Rispoli T, Rodrigues GM, de Castro SM, Prado MJ, da Silva CMD, Grandi T, Fischer GB, Pinto LA, Maróstica PJC, Scortegagna LCR, Mocelin HT, Vargas JE, Rossetti MLR

Abstract
INTRODUCTION: The incorporation of molecular genetic testing into cystic fibrosis (CF) screening programs increases the specificity of the diagnostic strategy and has the potential to decrease the rate of false- positive results. In this sense, our objective was to develop a genotyping assay that could detect 25 pathogenic variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene with high sensitivity and that could be incorporated into the routine of newborn screening, complementing the current existing protocol used in our public health institution.
METHODS: A mini-sequencing assay was standardized using single-base extension in a previously genotyped control sample. This strategy was validated in a Brazilian cohort of CF patients by Sanger sequencing.
RESULTS: The inclusion of the 25 variants in the current newborn screening program increased the identification rates of two alleles from 33 to 52.43% in CF patients. This new approach was able to detect a total of 37 variants, which represents 93.01% of all mutated alleles described in the last CF Brazilian Register.
CONCLUSIONS: Mini-sequencing for the simultaneous detection of 25 CFTR gene variants improves the screening of Brazilian newborns and decreases the number of inconclusive cases. This method uses minimal hands-on time and is suited for rapid screening, which reduces sample processing costs.

PMID: 32185651 [PubMed - as supplied by publisher]

TMEM16A drives renal cyst growth by augmenting Ca2+ signaling in M1 cells.

J Mol Med (Berl). 2020 Mar 18;:

Authors: Cabrita I, Buchholz B, Schreiber R, Kunzelmann K

Abstract
Polycystic kidney disease (PKD) leads to continuous decline of renal function by growth of renal cysts. Enhanced proliferation and transepithelial chloride secretion through cystic fibrosis transmembrane conductance regulator (CFTR) and Ca2+-activated TMEM16A Cl- channels is thought to cause an increase in cyst volume. Recent work shows the pro-proliferative role of the Ca2+ activated Cl- channel TMEM16A (anoctamin 1), and demonstrates the essential contribution of TMEM16A to CFTR-dependent Cl- secretion. The present data demonstrate an increase in intracellular Ca2+ ([Ca2+]i) signals and Cl- secretion by TMEM16A, in renal collecting duct principle cells from dog (MDCK) and mouse (M1) as well as primary tubular epithelial cells from PKD1-/- knockout mice. M1 organoids proliferated, increased expression of TMEM16A, and secreted Cl- upon knockdown of endogenous polycystin 1 or 2 (PKD1,2), by retroviral transfection with shPKD1 and shPKD2, respectively. Knockdown of PKD1 or PKD2 increased basal intracellular Ca2+ levels and enhanced purinergic Ca2+ release from endoplasmic reticulum. In contrast, ryanodine receptors were found not to be expressed in mouse renal epithelial cells and caffeine had no effects on [Ca2+]i. Ca2+ signals, proliferation, and Cl- secretion were largely reduced by knockdown or blockade of TMEM16A. TMEM16A may be therefore important for enhanced Ca2+ release from IP3-sensitive Ca2+ stores in polycystic kidney disease. KEY MESSAGES: • ADPKD leads to continuous decline of renal function by growth of renal cysts. • Knockdown of PKD1 or PKD2 increases TMEM16A expression. • TMEM16A enhanced intracellular Ca2+ signals, Cl- secretion, and proliferation. • TMEM16A contributes to cyst growth in ADPKD.

PMID: 32185407 [PubMed - as supplied by publisher]

Contextual Flexibility in Pseudomonas aeruginosa Central Carbon Metabolism during Growth in Single Carbon Sources.

mBio. 2020 Mar 17;11(2):

Authors: Dolan SK, Kohlstedt M, Trigg S, Vallejo Ramirez P, Kaminski CF, Wittmann C, Welch M

Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen, particularly noted for causing infections in the lungs of people with cystic fibrosis (CF). Previous studies have shown that the gene expression profile of P. aeruginosa appears to converge toward a common metabolic program as the organism adapts to the CF airway environment. However, we still have only a limited understanding of how these transcriptional changes impact metabolic flux at the systems level. To address this, we analyzed the transcriptome, proteome, and fluxome of P. aeruginosa grown on glycerol or acetate. These carbon sources were chosen because they are the primary breakdown products of an airway surfactant, phosphatidylcholine, which is known to be a major carbon source for P. aeruginosa in CF airways. We show that the fluxes of carbon throughout central metabolism are radically different among carbon sources. For example, the newly recognized "EDEMP cycle" (which incorporates elements of the Entner-Doudoroff [ED] pathway, the Embden-Meyerhof-Parnas [EMP] pathway, and the pentose phosphate [PP] pathway) plays an important role in supplying NADPH during growth on glycerol. In contrast, the EDEMP cycle is attenuated during growth on acetate, and instead, NADPH is primarily supplied by the reaction catalyzed by isocitrate dehydrogenase(s). Perhaps more importantly, our proteomic and transcriptomic analyses revealed a global remodeling of gene expression during growth on the different carbon sources, with unanticipated impacts on aerobic denitrification, electron transport chain architecture, and the redox economy of the cell. Collectively, these data highlight the remarkable metabolic plasticity of P. aeruginosa; that plasticity allows the organism to seamlessly segue between different carbon sources, maximizing the energetic yield from each.IMPORTANCE Pseudomonas aeruginosa is an opportunistic human pathogen that is well known for causing infections in the airways of people with cystic fibrosis. Although it is clear that P. aeruginosa is metabolically well adapted to life in the CF lung, little is currently known about how the organism metabolizes the nutrients available in the airways. In this work, we used a combination of gene expression and isotope tracer ("fluxomic") analyses to find out exactly where the input carbon goes during growth on two CF-relevant carbon sources, acetate and glycerol (derived from the breakdown of lung surfactant). We found that carbon is routed ("fluxed") through very different pathways during growth on these substrates and that this is accompanied by an unexpected remodeling of the cell's electron transfer pathways. Having access to this "blueprint" is important because the metabolism of P. aeruginosa is increasingly being recognized as a target for the development of much-needed antimicrobial agents.

PMID: 32184246 [PubMed - in process]

Pharmacokinetic/pharmacodynamic adequacy of polymyxin B against extensively drug-resistant gram-negative bacteria in critically ill, general ward and cystic fibrosis patient populations.

Int J Antimicrob Agents. 2020 Mar 14;:105943

Authors: Xie J, Roberts JA, Lipman J, Cai Y, Wang H, Zhao N, Xu X, Yang S, Li Y, Zhang K

Abstract
BACKGROUND: Dose-limiting nephrotoxicity is a marked side effect of polymyxin B. Only limited clinical studies describe the pharmacodynamics of polymyxin B with little guidance existing for treatment optimization against multidrug-resistant gram-negative pathogens.
METHODS: Herein, we evaluated the differences in likelihood of achieving efficacious and toxic exposures of polymyxin B for critically ill, general ward, and cystic fibrosis patients. The following dosing regimens were tested: maintenance dose (1, 1.25, and 1.5 mg/kg/12 h) and loading doses (2 mg/kg followed by 1.25 mg/kg/12 h; and 2.5 mg/kg followed by 1.5 mg/kg/12 h).
RESULTS: Patient weight notably influence exposure and the required patient dose. To achieve an optimized exposure with minimal toxicity risk, an empirical polymyxin B dose of 2 mg/kg/12 h was required for critically ill patients weighing 50 kg, whereas doses of 1.25 and 1 mg/kg/12 h were required for those weighing 75 and 100 kg, respectively. Conversely, 2 mg/kg/12 h was required for general ward patients weighing 75 kg. For general ward and cystic fibrosis patients weighing 50 kg, the target exposure could not be achieved with any regimen. Further, the likelihood of toxicity was always high for bacteria with minimum inhibitory concentrations ≥ 2 mg/L.
CONCLUSION: Our findings support the use of a loading dose to increase the achievement of polymyxin B target exposures. To improve efficacy, doses should be optimized according to the patient population.

PMID: 32184115 [PubMed - as supplied by publisher]

An investigation on parenting stress of children with cystic fibrosis.

Ital J Pediatr. 2020 Mar 18;46(1):33

Authors: Continisio GI, Serra N, Guillari A, Civitella MT, Sepe A, Simeone S, Gargiulo G, Toscano S, Esposito MR, Raia V, Rea T

Abstract
BACKGROUND: The management of chronic diseases, particularly in children, requires an integrated physical and psychological approach to both sick children and their family. This is the case of Cystic Fibrosis (CF), a complex genetic chronic disease, where, a comprehensive evaluation of the emotional impact and an effective multidimensional approach are indicated.
AIM: This study investigates on parenting stress in children and adolescents with CF and its determinants related to parents, children and the disease severity.
METHODS: The study involved 34.04% adult males and 65.96% adult females (range 21-55 years) and 47 children with CF, 54.35% males and 45.65% females (range 1-17 years). The data were obtained through a Parenting Stress Index - Short Form (PSI-SF) questionnaire. According to the PSI-SF scoring system, three types of stress were detected: a typical stress pattern (normal), a high stress pattern (increased) and a defensive response, which may be considered as a high stress feature in children which requires monitoring and clinical evaluation.
RESULTS: This study shows a significant presence of stress in females (60.23%), of subject married (84.62%), unemployed (69.23%) and with education level such as "middle School" (61.54%). Concerning children of parents with high stress, it resulted most frequent children with one sibling (53.85%). Finally, by univariate analysis, it resulted a significant positive correlation between parenting stress and disease degree of children. Instead by multivariate analysis, we found that the variables: Number of siblings and Birth order were a significant positive and negative predictor of parenting stress respectively.
CONCLUSION: An increased stress level was detected in less than one third of parents of subjects with CF. These data may be related to the psychological support which is part of the routine management of CF care team. However, as children's features seem to act as a determinant of stress more than parental ones, the parental-child dysfunction should be the target for further integrated interventions.

PMID: 32183848 [PubMed - in process]

Plasma Levels of the Bioactive Sphingolipid Metabolite S1P in Adult Cystic Fibrosis Patients: Potential Target for Immunonutrition?

Nutrients. 2020 Mar 14;12(3):

Authors: Halilbasic E, Fuerst E, Heiden D, Japtok L, Diesner SC, Trauner M, Kulu A, Jaksch P, Hoetzenecker K, Kleuser B, Kazemi-Shirazi L, Untersmayr E

Abstract
Recent research has linked sphingolipid (SL) metabolism with cystic fibrosis transmembrane conductance regulator (CFTR) activity, affecting bioactive lipid mediator sphingosine-1-phosphate (S1P). We hypothesize that loss of CFTR function in cystic fibrosis (CF) patients influenced plasma S1P levels. Total and unbound plasma S1P levels were measured in 20 lung-transplanted adult CF patients and 20 healthy controls by mass spectrometry and enzyme-linked immunosorbent assay (ELISA). S1P levels were correlated with CFTR genotype, routine laboratory parameters, lung function and pathogen colonization, and clinical symptoms. Compared to controls, CF patients showed lower unbound plasma S1P, whereas total S1P levels did not differ. A positive correlation of total and unbound S1P levels was found in healthy controls, but not in CF patients. Higher unbound S1P levels were measured in ΔF508-homozygous compared to ΔF508-heterozygous CF patients (p = 0.038), accompanied by higher levels of HDL in ΔF508-heterozygous patients. Gastrointestinal symptoms were more common in ΔF508 heterozygotes compared to ΔF508 homozygotes. This is the first clinical study linking plasma S1P levels with CFTR function and clinical presentation in adult CF patients. Given the emerging role of immunonutrition in CF, our study might pave the way for using S1P as a novel biomarker and nutritional target in CF.

PMID: 32183316 [PubMed - in process]