Candida thrombophlebitis in children: a systematic review of the literature.

Ital J Pediatr. 2020 Oct 06;46(1):145

Authors: Colomba C, Campa L, Siracusa L, Giordano S, Vella MC, Corsello G, Giuffrè M, Cascio A

Abstract
OBJECTIVE: To describe a case of thrombophlebitis associated with Candida infection and to analyze other published reports to define clinical characteristics, prognostic data, diagnostic and therapeutic strategies.
STUDY DESIGN: A computerized search was performed without language restriction using PubMed and Scopus databases. An article was considered eligible for inclusion if it reported cases with Candida thrombophlebitis. Our case was also included in the analysis.
RESULTS: A total of 16 articles reporting 27 cases of Candida thrombophlebitis were included in our review. The median age of patients was 4 years. In 10 cases there was a thrombophlebitis of peripheral veins; in the remaining cases the deep venous circle was interested. Candida albicans was the most frequently involved fungal species. The most recurrent risk factors were central venous catheter (19/28), broad spectrum antibiotics (17/28), intensive care unit (8/28), surgery (3/28), mechanical assisted ventilation (5/28), total parenteral nutrition (8/28), cancer (2/28), premature birth (6/28), cystic fibrosis (2/28). Fever was the most frequent clinical feature. All children with peripheral and deep thrombophlebitis were given antifungal therapy: amphotericin B was the most used, alone or in combination with other antifungal drugs. Heparin was most frequently used as anticoagulant therapy. Illness was fatal in two cases.
CONCLUSION: Candida thrombophlebitis is a rare but likely underdiagnosed infectious complication in pediatric critically ill patients. It is closely connected to risk factors such as central venous catheter, hospitalization in intensive care unit, prematurity, assisted ventilation, chronic inflammatory diseases. Antifungal therapy and anticoagulant drugs should be optimized for each patient and surgical resection is considered in the persistence of illness.

PMID: 33023609 [PubMed - in process]

Does cystic fibrosis constitute an advantage in COVID-19 infection?

Ital J Pediatr. 2020 Oct 06;46(1):143

Authors: Bezzerri V, Lucca F, Volpi S, Cipolli M

Abstract
The Veneto region is one of the most affected Italian regions by COVID-19. Chronic lung diseases, such as chronic obstructive pulmonary disease (COPD), may constitute a risk factor in COVID-19. Moreover, respiratory viruses were generally associated with severe pulmonary impairment in cystic fibrosis (CF). We would have therefore expected numerous cases of severe COVID-19 among the CF population. Surprisingly, we found that CF patients were significantly protected against infection by SARS-CoV-2. We discussed this aspect formulating some reasonable theories.

PMID: 33023602 [PubMed - in process]

Antecedent Administration of Angiotensin Converting Enzyme Inhibitors or Angiotensin II Receptor Antagonists and Survival After Hospitalization for SARS-CoV-2 (COVID-19).

J Am Heart Assoc. 2020 Oct 07;:e017364

Authors: Palazzuoli A, Mancone M, De Ferrari GM, Forleo G, Secco GG, Ruocco GM, D'Ascenzo F, Monticone S, Paggi A, Vicenzi M, Palazzo AG, Landolina M, Taravelli E, Tavazzi G, Blasi F, Infusino F, Fedele F, De Rosa FG, Emmett M, Schussler JM, Tecson KM, McCullough PA

Abstract
Background SARS-CoV-2 (COVID-19) utilizes the angiotensin converting enzyme-2 (ACE-2) receptor to enter human cells. Angiotensin converting enzyme inhibitors (ACEI) and angiotensin II receptor antagonists (ARB) are associated with ACE-2 upregulation. We hypothesized that antecedent use of ACEI/ARB may be associated with mortality in COVID-19. Methods and Results We used the Coracle registry, which contains data of hospitalized COVID-19 patients in 4 regions of Italy, and restricted analyses to those ≥ 50 years of age. The primary outcome was in-hospital mortality. Among these 781 acutely ill patients, 133 (17.0%) used an ARB and 171 (21.9%) used an ACEI. While neither sex nor smoking status differed by user groups, patients on ACEI/ARB tended to be older and more likely to have hypertension, diabetes mellitus, and congestive heart failure. The overall mortality rate was 15.1% (118/781) and increased with age (PTrend < 0.0001). The crude odds ratios (ORs) for death for ACEI users and ARB users were 0.98, 95% confidence interval (CI): 0.60-1.60, p=0.9333, and 1.13, 95% CI: 0.67-1.91, p=0.6385, respectively. After adjusting for age, hypertension, diabetes mellitus, and congestive heart failure, antecedent ACEI administration was associated with reduced mortality (OR: 0.55, 95% CI: 0.31-0.98, p=0.0436); a similar, but weaker trend was observed for ARB administration (OR: 0.58, 95% CI: 0.32-1.07, p=0.0796). Conclusions In those aged ≥50 years hospitalized with COVID-19, antecedent use of ACEI was independently associated with reduced risk of inpatient death. Our findings suggest the protective role of renin-angiotensin-aldosterone system inhibition in patients with high cardiovascular risk affected by COVID-19.

PMID: 33023356 [PubMed - as supplied by publisher]

Ivacaftor in Infants Aged 4 to <12 Months With Cystic Fibrosis and a Gating Mutation: Results of a 2-Part Phase 3 Clinical Trial.

Am J Respir Crit Care Med. 2020 Oct 07;:

Authors: Davies JC, Wainwright CE, Sawicki GS, Higgins MN, Campbell D, Harris C, Panorchan P, Haseltine E, Tian S, Rosenfeld M, ARRIVAL Study Group

Abstract
Rationale: We previously reported that ivacaftor was safe and well tolerated in cohorts aged 12 to <24 months with cystic fibrosis and gating mutations in the ARRIVAL study; here we report results for cohorts aged 4 to <12 months. Objectives: Evaluate safety, pharmacokinetics, and pharmacodynamics of ivacaftor in infants aged 4 to <12 months with ≥1 gating mutation. Methods: ARRIVAL is a single-arm phase 3 study. Infants received ivacaftor 25 or 50 mg every 12 hours based on age and weight for 4 days in part A and 24 weeks in part B. Measurements and Main Results: Primary endpoints were safety (parts A and B) and pharmacokinetics (part A). Secondary/tertiary endpoints (part B) included pharmacokinetics and changes in sweat chloride levels, growth, and markers of pancreatic function. Twenty-five infants received ivacaftor, 12 in part A and 17 in part B (4 participated in both). Pharmacokinetics was consistent with that in older groups. Most adverse events were mild/moderate. In part B, cough was the most common adverse event (n=10 [58.8%]). Five infants (part A: n=1 [8.3%]; part B: n=4 [23.5%]) had serious adverse events, all considered not/unlikely related to ivacaftor. No deaths or treatment discontinuations occurred. One infant (5.9%) experienced an alanine transaminase elevation >3 to ≤5 × upper limit of normal at week 24. No other adverse trends in laboratory tests, vital signs, or electrocardiogram parameters were reported. Sweat chloride levels and measures of pancreatic obstruction improved. Conclusions: This study of ivacaftor in the first year of life supports treating the underlying cause of cystic fibrosis in children aged ≥4 months with ≥1 gating mutation. Clinical trial registration available at www.clinicaltrials.gov, ID:NCT02725567.

PMID: 33023304 [PubMed - as supplied by publisher]

[Therapy of cystic fibrosis - new drugs give hope].

Dtsch Med Wochenschr. 2020 Oct;145(20):1486-1489

Authors: Eschenhagen P, Schwarz C

Abstract
For decades there were only symptom-oriented therapies for the monogenetic disease cystic fibrosis. With the new modulator therapies there are new hopes to better influence the course of the disease, which has its manifestation in several organs such as the lungs, the liver or pancreas.In addition to ivacaftor, lumacaftor/ivacaftor and tezacaftor/ivacaftor, a triple combination with elexacaftor/tezacaftor/ivacaftor was developed. Studies in F508del homozygous and heterozygous patients with cystic fibrosis have resulted in significant clinical improvement and have therefore been approved by the FDA for the first time in the USA.The results are very promising as already after 4 weeks a significant improvement of FEV1 and a significant decrease of the sweat chloride content could be detected. In the USA all patients with at least one F508del mutation can be prescribed the drug. This corresponds to approximately 90 % of all patients with cystic fibrosis and has the potential to change the landscape of cystic fibrosis.

PMID: 33022731 [PubMed - as supplied by publisher]

The 34th Annual North American Cystic Fibrosis Conference, October 7-23, 2020.

Pediatr Pulmonol. 2020 Oct;55 Suppl 2:S38-S361

Authors:

PMID: 33022144 [PubMed - as supplied by publisher]

Micro-rheological properties of lung homogenates correlate with infection severity in a mouse model of Pseudomonas aeruginosa lung infection.

Sci Rep. 2020 Oct 05;10(1):16502

Authors: Murgia X, Kany AM, Herr C, Ho DK, De Rossi C, Bals R, Lehr CM, Hirsch AKH, Hartmann RW, Empting M, Röhrig T

Abstract
Lung infections caused by Pseudomonas aeruginosa pose a serious threat to patients suffering from, among others, cystic fibrosis, chronic obstructive pulmonary disease, or bronchiectasis, often leading to life-threatening complications. The establishment of a chronic infection is substantially related to communication between bacteria via quorum-sensing networks. In this study, we aimed to assess the role of quorum-sensing signaling molecules of the Pseudomonas quinolone signal (PQS) and to investigate the viscoelastic properties of lung tissue homogenates of PA-infected mice in a prolonged acute murine infection model. Therefore, a murine infection model was successfully established via intra-tracheal infection with alginate-supplemented Pseudomonas aeruginosa NH57388A. Rheological properties of lung homogenates were analyzed with multiple particle tracking (MPT) and quorum-sensing molecules were quantified with LC-MS/MS. Statistical analysis of bacterial load and quorum-sensing molecules showed a strong correlation between these biomarkers in infected lungs. This was accompanied by noticeable changes in the consistency of lung homogenates with increasing infection severity. Furthermore, viscoelastic properties of the lung homogenates strongly correlated with bacterial load and quorum sensing molecules. Considering the strong correlation between the viscoelasticity of lung homogenates and the aforementioned biomarkers, the viscoelastic properties of infected lungs might serve as reliable new biomarker for the evaluation of the severity of P. aeruginosa infections in murine models.

PMID: 33020513 [PubMed - in process]

Intestinal current measurement and nasal potential difference to make a diagnosis of cases with inconclusive CFTR genetics and sweat test.

BMJ Open Respir Res. 2020 Oct;7(1):

Authors: Minso R, Schulz A, Dopfer C, Alfeis N, Barneveld AV, Makartian-Gyulumyan L, Hansen G, Junge S, Müller C, Ringshausen FCC, Sauer-Heilborn A, Stanke F, Stolpe C, Tamm S, Welte T, Dittrich AM, Tümmler B

Abstract
BACKGROUND: Nasal potential difference (NPD) and intestinal current measurements (ICM) are cystic fibrosis transmembrane conductance regulator (CFTR) biomarkers recommended to make a diagnosis in individuals with inconclusive sweat test and CFTR genetics and a clinical suspicion for cystic fibrosis (CF) or CFTR-related disorder (CFTR-RD).
METHODS: NPD and ICM were measured according to standard operating procedures of the European Cystic Fibrosis Society Diagnostic Network Working Group.
RESULTS: We assessed 219 individuals by NPD or ICM who had been referred to our laboratory due to clinical symptoms suggestive of CF, but inconclusive sweat test and CFTR genetics (median age: 16.3 years, range 0.4 to 76 years). CF or CFTR-related disorder was diagnosed in 22 of 29 patients (76%) with a CFTR genotype of unknown or variable clinical significance and in 51 of 190 carriers (27%) of one (35/42) or no (16/148) identified CFTR mutation. If two CFTR sequence variants had been identified, the outcome of NPD and ICM was consistent with the classification of the CFTR2 database. Moreover, a suspected false-positive diagnosis of CF was confirmed in seven and withdrawn in eight patients. Of 26 individuals assessed by both NPD and ICM, eleven individuals exhibited discordant tracings of ICM and NPD, with one measurement being in the CF range and the other in the normal range.
CONCLUSION: The majority of patients whom we diagnosed with CF or CFTR-RD by extended electrophysiology are carriers of the wild-type CFTR coding sequence on at least one of their CF alleles. The disease-causing genetic lesions should reside in the non-coding region of CFTR or elsewhere in the genome, affecting the regulation of CFTR expression in a tissue-depending fashion which may explain the large within-group variability of CFTR activity in the respiratory and intestinal epithelium seen in this group.

PMID: 33020115 [PubMed - in process]

Investigating outcome measures for assessing airway clearance techniques in adults with cystic fibrosis: protocol of a single-centre randomised controlled crossover trial.

BMJ Open Respir Res. 2020 Oct;7(1):

Authors: Stanford G, Davies JC, Usmani O, Banya W, Charman S, Jones M, Simmonds NJ, Bilton D

Abstract
INTRODUCTION: Airway clearance techniques (ACTs) are a gold standard of cystic fibrosis management; however, the majority of research evidence for their efficacy is of low standard; often attributed to the lack of sensitivity from outcome measures (OMs) used historically. This randomised controlled trial (RCT) investigates these standard OMs (sputum weight, forced expiratory volume in 1 s) and new OMs (electrical impedance tomography (EIT), multiple breath washout (MBW) and impulse oscillometry (IOS)) to determine the most useful measures of ACT.
METHODS AND ANALYSIS: This is a single-centre RCT with crossover design. Participants perform MBW, IOS and spirometry, and then are randomised to either rest or supervised ACT lasting 30-60 min. MBW, IOS and spirometry are repeated immediately afterwards. EIT and sputum are collected during rest/ACT. On a separate day, the OMs are performed with the other intervention. Primary endpoint is difference in change in OMs before and after ACT/rest. Sample size was calculated with 80% power and significance of 5% for each OM (target n=64).
ETHICS AND DISSEMINATION: Ethics approval was gained from the London-Chelsea Research Ethics Committee (reference 16/LO/0995, project ID 154635). Dissemination will involve scientific conference presentation and publication in a peer-reviewed journal.
TRIAL REGISTRATION NUMBERS: ISRCTN11220163 and NCT02721498.

PMID: 33020113 [PubMed - in process]

Congenital Cytomegalovirus Infection: Update on Diagnosis and Treatment.

Microorganisms. 2020 Oct 01;8(10):

Authors: Chiopris G, Veronese P, Cusenza F, Procaccianti M, Perrone S, Daccò V, Colombo C, Esposito S

Abstract
Congenital cytomegalovirus (cCMV) infection is the most common congenital viral infection and is the leading non-genetic cause of sensorineural hearing loss (SNLH) and an important cause of neurodevelopmental disabilities. The risk of intrauterine transmission is highest when primary infection occurs during pregnancy, with a higher rate of vertical transmission in mothers with older gestational age at infection, while the risk of adverse fetal effects significantly increases if fetal infection occurs during the first half of pregnancy. Despite its prevalence and morbidity among the neonatal population, there is not yet a standardized diagnostic test and therapeutic approach for cCMV infection. This narrative review aims to explore the latest developments in the diagnosis and treatment of cCMV infection. Literature analysis shows that preventive interventions other than behavioral measures during pregnancy are still lacking, although many clinical trials are currently ongoing to formulate a vaccination for women before pregnancy. Currently, we recommend using a PCR assay in blood, urine, and saliva in neonates with suspected cCMV infection. At present, there is no evidence of the benefit of antiviral therapy in asymptomatic infants. In the case of symptomatic cCMV, we actually recommend treatment with oral valganciclovir for a duration of 12 months. The effectiveness and tolerability of this therapy option have proven effective for hearing and neurodevelopmental long-term outcomes. Valganciclovir is reserved for congenitally-infected neonates with the symptomatic disease at birth, such as microcephaly, intracranial calcifications, abnormal cerebrospinal fluid index, chorioretinitis, or sensorineural hearing loss. Treatment with antiviral drugs is not routinely recommended for neonates with the mildly symptomatic disease at birth, for neonates under 32 weeks of gestational age, or for infants more than 30 days old because of insufficient evidence from studies. However, since these populations represent the vast majority of neonates and infants with cCMV infection and they are at risk of developing late-onset sequelae, a biomarker able to predict long-term sequelae should also be found to justify starting treatment and reducing the burden of CMV-related complications.

PMID: 33019752 [PubMed]

Surfactant-secreted phospholipase A2 interplay and respiratory outcome in preterm neonates.

Am J Physiol Lung Cell Mol Physiol. 2020 07 01;319(1):L95-L104

Authors: De Luca D, Shankar-Aguilera S, Autilio C, Raschetti R, Vedovelli L, Fitting C, Payré C, Jeammet L, Perez-Gil J, Cogo PE, Carnielli VP, Lambeau G, Touqui L

Abstract
Secreted phospholipase A2 hydrolyzes surfactant phospholipids and is crucial for the inflammatory cascade; preterm neonates are treated with exogenous surfactant, but the interaction between surfactant and phospholipase is unknown. We hypothesize that this interplay is complex and the enzyme plays a relevant role in neonates needing surfactant replacement. We aimed to: 1) identify phospholipases A2 isoforms expressed in preterm lung; 2) study the enzyme role on surfactant retreatment and function and the effect of exogenous surfactant on the enzyme system; and 3) verify whether phospholipase A2 is linked to respiratory outcomes. In bronchoalveolar lavages of preterm neonates, we measured enzyme activity (alone or with inhibitors), enzyme subtypes, surfactant protein-A, and inflammatory mediators. Surfactant function and phospholipid profile were also tested. Urea ratio was used to obtain epithelial lining fluid concentrations. Follow-up data were prospectively collected. Subtype-IIA is the main phospholipase isoform in preterm lung, although subtype-IB may be significantly expressed. Neonates needing surfactant retreatment have higher enzyme activity (P = 0.021) and inflammatory mediators (P always ≤ 0.001) and lower amounts of phospholipids (P always < 0.05). Enzyme activity was inversely correlated to surfactant adsorption (ρ = -0.6; P = 0.008; adjusted P = 0.009), total phospholipids (ρ = -0.475; P = 0.05), and phosphatidylcholine (ρ = -0.622; P = 0.017). Exogenous surfactant significantly reduced global phospholipase activity (P < 0.001) and subtype-IIA (P = 0.005) and increased dioleoylphosphatidylglycerol (P < 0.001) and surfactant adsorption (P < 0.001). Enzyme activity correlated with duration of ventilation (ρ = 0.679, P = 0.005; adjusted P = 0.04) and respiratory morbidity score at 12 mo postnatal age (τ-b = 0.349, P = 0.037; adjusted P = 0.043) but was not associated with mortality, bronchopulmonary dysplasia, or other long-term respiratory outcomes.

PMID: 32401671 [PubMed - indexed for MEDLINE]

Live imaging and quantitative analysis of Aspergillus fumigatus growth and morphology during inter-microbial interaction with Pseudomonas aeruginosa.

Virulence. 2020 Dec;11(1):1329-1336

Authors: Wurster S, Sass G, Albert ND, Nazik H, Déziel E, Stevens DA, Kontoyiannis DP

Abstract
Pseudomonas aeruginosa (PA) and Aspergillus fumigatus (AF) chronically colonize the airways of patients with cystic fibrosis or chronic immunosuppression and mutually affect each other's pathogenesis. Here, we evaluated IncuCyte time-lapse imaging and NeuroTrackTM (NT) analysis (Wurster et al., 2019, mBio) as a toolbox to study mycelial expansion and morphogenesis of AF during interaction with PA. Co-incubation of AF with supernatant filtrates of wild-type (WT) PA strains strongly inhibited hyphal growth and branching. Consonant with prior metabolic studies, pyoverdine-deficient PA mutants had significantly attenuated inhibitory capacity. Accordingly, purified PA products pyoverdine and pyocyanin suppressed mycelial expansion of AF in a concentration-dependent way. Using fluorescence-guided tracking of GFP-AF293 mycelia during co-culture with live WT PA cells, we found significant inoculum-dependent mycelial growth inhibition and robust precision of the NT algorithm. Collectively, our experiments position IncuCyte NT as an efficient platform for longitudinal analysis of fungal growth and morphogenesis during bacterial co-infection.

PMID: 33017225 [PubMed - as supplied by publisher]

Are patients with lung cystic fibrosis at increased risk for severe and fatal COVID-19? Interleukin-6 as a predictor of COVID-19 outcome.

Pol Arch Intern Med. 2020 Oct 05;:

Authors: Marcinkiewicz J, Mazurek H, Majka G, Chain B

PMID: 33016684 [PubMed - as supplied by publisher]

Identification of Compounds That Promote Readthrough of Premature Termination Codons in the CFTR.

SLAS Discov. 2020 Oct 05;:2472555220962001

Authors: Smith E, Dukovski D, Shumate J, Scampavia L, Miller JP, Spicer TP

Abstract
Cystic fibrosis (CF) is caused by a mutation of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene, which disrupts an ion channel involved in hydration maintenance via anion homeostasis. Nearly 5% of CF patients possess one or more copies of the G542X allele, which results in a stop codon at residue 542, preventing full-length CFTR protein synthesis. Identifying small-molecule modulators of mutant CFTR biosynthesis that affect the readthrough of this and other premature termination codons to synthesize a fully functional CFTR protein represents a novel target area of drug discovery. We describe the implementation and integration for large-scale screening of a homogeneous, 1536-well functional G542X-CFTR readthrough assay. The assay uses HEK 293 cells engineered to overexpress the G542X-CFTR mutant, whose functional activity is monitored with a membrane potential dye. Cells are co-incubated with a CFTR amplifier and CFTR corrector to maximize mRNA levels and trafficking of CFTR to the cell surface. Compounds that allow translational readthrough and synthesis of functional CFTR chloride channels are reflected by changes in membrane potential in response to cAMP stimulation with forskolin and CFTR channel potentiation with genistein. Assay statistics yielded Z' values of 0.69 ± 0.06. As further evidence of its suitability for high-throughput screening, we completed automated screening of approximately 666,000 compounds, identifying 7761 initial hits. Following secondary and tertiary assays, we identified 188 confirmed hit compounds with low and submicromolar potencies. Thus, this approach takes advantage of a phenotypic screen with high-throughput scalability to identify new small-molecule G542X-CFTR readthrough modulators.

PMID: 33016182 [PubMed - as supplied by publisher]

Functional Profiling of CFTR-Directed Therapeutics Using Pediatric Patient-Derived Nasal Epithelial Cell Models.

Front Pediatr. 2020;8:536

Authors: Park JK, Shrivastava A, Zhang C, Pollok BA, Finkbeiner WE, Gibb ER, Ly NP, Illek B

Abstract
Functional profiling of CFTR-directed therapeutics offers the potential to provide significant benefits to young people with cystic fibrosis (CF). However, the development of 2D airway epithelial cell models for individual response tests in CF children remains a central task. The objective of this study was to determine the utility of EpiXTM technology for expansion of nasal epithelial cells for use in electrophysiological CFTR function measurements. An initial harvest of as few as 20,000 cells was sufficient to expand up to 50 million cells that were used to generate air-liquid interface (ALI) cultures for ion transport studies with the Ussing assay. CFTR function was assessed by measuring responses to forskolin and the CFTR potentiator VX-770 (ivacaftor) in ALI cultures generated from passage 3 and 4 cells. Short-circuit current (Isc) measurements of blocked CFTR currents (ΔICFTRinh) discriminated CFTR function between healthy control (wild type, WT) and patients with intermediate (F508del/R117H-7T: 56% WT) and severe (F508del/F508del: 12% WT) CF disease. For the mixed genotypes, CFTR activity for F508del/c.850dupA was 12% WT, R334W/406-1G>A was 24% WT, and CFTRdele2,3(21 kb)/CFTRdele2,3(21 kb) was 9% WT. The CFTR correctors VX-809 (lumacaftor) and VX-661 (tezacaftor) significantly increased CFTR currents for F508del/R117H to 73 and 67% WT, respectively. Cultures with the large deletion mutation CFTRdele2,3(21 kb) unexpectedly responded to VX-661 treatment (20% WT). Amiloride-sensitive sodium currents were robust and ranged between 20-80 μA/cm2 depending on the subject. In addition to characterizing the electrophysiological profile of mutant CFTR activity in cultures for five genotypes, our study exemplifies the promising paradigm of bed-to-bench side cooperation and personalized medicine.

PMID: 33014932 [PubMed]

High Occurrence of Bacterial Competition Among Clinically Documented Opportunistic Pathogens Including Achromobacter xylosoxidans in Cystic Fibrosis.

Front Microbiol. 2020;11:558160

Authors: Menetrey Q, Dupont C, Chiron R, Jumas-Bilak E, Marchandin H

Abstract
Cystic Fibrosis (CF) airways favor abnormal microbial development. Infections are considered as polymicrobial and competition can be observed between microorganisms. The current literature on bacterial competition in CF mostly consists of studies with limited numbers of strains, mainly focused on the major pathogens Pseudomonas aeruginosa (Pa) and Staphylococcus aureus (Sa) and does not give a comprehensive overview of the overall importance of bacterial interactions or the behavior of less often encountered emerging bacteria such as Achromobacter. In this context, we screened a panel of 39 strains from six CF patients, of either clinical or domestic environmental origin, distinguished according to genotype and belonging to four opportunistic pathogens, Pa (n = 15), Sa (n = 3), Stenotrophomonas maltophilia (Sm, n = 10) and Achromobacter xylosoxidans (Ax, n = 11). We investigated their capacity to compete in terms of growth, motility, and pigment production on agar media through 203 crossing experiments. Eleven strains selected via the initial screening results were further studied for competitive growth in liquid medium and biofilm formation. Competition was noted for 33% (67/203) of the pairs of strains with 85 modifications observed between monocultures and co-cultures, impacting growth (23.6%), motility (13.8%), and/or pigment production (6.1%). Under all conditions of the study (clinical, environmental strains; intra-, inter-patients; intra-, inter-species levels), competition was significantly more frequent among pairs of strains with at least one clinical strain. While Pa mainly outcompeted other species, in one patient with chronic colonization by Ax and sporadic colonization by Pa, we showed that some Ax inhibited the growth and pigmentation of Pa whereas biofilm formation was drastically reduced. Enlarging the panel of strains tested in competition assays gave new perspectives on the complex interactions taking place among the CF airway community. Indeed, the frequent occurrence of varied, strain-dependent interactions is revealed here. We report the first results of competition assays for Ax with the ability of certain strains to outcompete Pa. Our results are linked to the patient's colonization history and question the importance of bacterial competitiveness in the colonization pattern of CF airways.

PMID: 33013789 [PubMed]

The Probable, Possible, and Novel Functions of ERp29.

Front Physiol. 2020;11:574339

Authors: Brecker M, Khakhina S, Schubert TJ, Thompson Z, Rubenstein RC

Abstract
The luminal endoplasmic reticulum (ER) protein of 29 kDa (ERp29) is a ubiquitously expressed cellular agent with multiple critical roles. ERp29 regulates the biosynthesis and trafficking of several transmembrane and secretory proteins, including the cystic fibrosis transmembrane conductance regulator (CFTR), the epithelial sodium channel (ENaC), thyroglobulin, connexin 43 hemichannels, and proinsulin. ERp29 is hypothesized to promote ER to cis-Golgi cargo protein transport via COP II machinery through its interactions with the KDEL receptor; this interaction may facilitate the loading of ERp29 clients into COP II vesicles. ERp29 also plays a role in ER stress (ERS) and the unfolded protein response (UPR) and is implicated in oncogenesis. Here, we review the vast array of ERp29's clients, its role as an ER to Golgi escort protein, and further suggest ERp29 as a potential target for therapies related to diseases of protein misfolding and mistrafficking.

PMID: 33013490 [PubMed]

Designing Clinical Trials for Anti-Inflammatory Therapies in Cystic Fibrosis.

Front Pharmacol. 2020;11:576293

Authors: Perrem L, Ratjen F

Abstract
The inflammatory response in the CF airway begins early in the disease process and becomes persistent through life in most patients. Inflammation, which is predominantly neutrophilic, worsens airway obstruction and plays a critical role in the development of structural lung damage. While cystic fibrosis transmembrane regulator modulators will likely have a dramatic impact on the trajectory of CF lung disease over the coming years, addressing other important aspects of lung disease such as inflammation will nevertheless remain a priority. Considering the central role of neutrophils and their products in the inflammatory response, potential therapies should ultimately affect neutrophils and their products. The ideal anti-inflammatory therapy would exert a dual effect on the pro-inflammatory and pro-resolution arms of the inflammatory cascade, both of which contribute to dysregulated inflammation in CF. This review outlines the key factors to be considered in the design of clinical trials evaluating anti-inflammatory therapies in CF. Important lessons have been learned from previous clinical trials in this area and choosing the right efficacy endpoints is key to the success of any anti-inflammatory drug development program. Identifying and validating non-invasive biomarkers, novel imaging techniques and sensitive lung function tests capable of monitoring disease activity and therapeutic response are important areas of research and will be useful for the design of future anti-inflammatory drug trials.

PMID: 33013419 [PubMed]

Multi-Omics Approaches: The Key to Improving Respiratory Health in People With Cystic Fibrosis?

Front Pharmacol. 2020;11:569821

Authors: Lee AJ, Einarsson GG, Gilpin DF, Tunney MM

Abstract
The advent of high-throughput multi-omics technologies has underpinned the expansion in lung microbiome research, increasing our understanding of the nature, complexity and significance of the polymicrobial communities harbored by people with CF (PWCF). Having established that structurally complex microbial communities exist within the airways, the focus of recent research has now widened to investigating the function and dynamics of the resident microbiota during disease as well as in health. With further refinement, multi-omics approaches present the opportunity to untangle the complex interplay between microbe-microbe and microbe-host interactions in the lung and the relationship with respiratory disease progression, offering invaluable opportunities to discover new therapeutic approaches for our management of airway infection in CF.

PMID: 33013411 [PubMed]

CFTR Modulator Therapy Enhances Peripheral Blood Monocyte Contributions to Immune Responses in People With Cystic Fibrosis.

Front Pharmacol. 2020;11:1219

Authors: Hisert KB, Birkland TP, Schoenfelt KQ, Long ME, Grogan B, Carter S, Liles WC, McKone EF, Becker L, Manicone AM, Gharib SA

Abstract
Background: CFTR modulators decrease some etiologies of CF airway inflammation; however, data indicate that non-resolving airway infection and inflammation persist in individuals with CF and chronic bacterial infections. Thus, identification of therapies that diminish airway inflammation without allowing unrestrained bacterial growth remains a critical research goal. Novel strategies for combatting deleterious airway inflammation in the CFTR modulator era require better understanding of cellular contributions to chronic CF airway disease, and how inflammatory cells change after initiation of CFTR modulator therapy. Peripheral blood monocytes, which traffic to the CF airway, can develop both pro-inflammatory and inflammation-resolving phenotypes, represent intriguing cellular targets for focused therapies. This therapeutic approach, however, requires a more detailed knowledge of CF monocyte cellular programming and phenotypes.
Material and Methods: In order to characterize the inflammatory phenotype of CF monocytes, and how these cells change after initiation of CFTR modulator therapy, we studied adults (n=10) with CF, chronic airway infections, and the CFTR-R117H mutations before and 7 days after initiation of ivacaftor. Transcriptomes of freshly isolated blood monocytes were interrogated by RNA-sequencing (RNA-seq) followed by pathway-based analyses. Plasma concentrations of cytokines and chemokines were evaluated by multiplex ELISA.
Results: RNAseq identified approximately 50 monocyte genes for which basal expression was significantly changed in all 10 subjects after 7 days of ivacaftor. Of these, the majority were increased in expression post ivacaftor, including many genes traditionally associated with enhanced inflammation and immune responses. Pathway analyses confirmed that transcriptional programs were overwhelmingly up-regulated in monocytes after 7 days of ivacaftor, including biological modules associated with immunity, cell cycle, oxidative phosphorylation, and the unfolded protein response. Ivacaftor increased plasma concentrations of CXCL2, a neutrophil chemokine secreted by monocytes and macrophages, and CCL2, a monocyte chemokine.
Conclusions: Our results demonstrate that ivacaftor causes acute changes in blood monocyte transcriptional profiles and plasma chemokines, and suggest that increased monocyte inflammatory signals and changes in myeloid cell trafficking may contribute to changes in airway inflammation in people taking CFTR modulators. To our knowledge, this is the first report investigating the transcriptomic response of circulating blood monocytes in CF subjects treated with a CFTR modulator.

PMID: 33013356 [PubMed]