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GM1 as Adjuvant of Innovative Therapies for Cystic Fibrosis Disease. Int J Mol Sci 2020; 21:ijms21124486. [PMID: 32599772 PMCID: PMC7350007 DOI: 10.3390/ijms21124486] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/20/2020] [Accepted: 06/21/2020] [Indexed: 01/26/2023] Open
Abstract
Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein is expressed at the apical plasma membrane (PM) of different epithelial cells. The most common mutation responsible for the onset of cystic fibrosis (CF), F508del, inhibits the biosynthesis and transport of the protein at PM, and also presents gating and stability defects of the membrane anion channel upon its rescue by the use of correctors and potentiators. This prompted a multiple drug strategy for F508delCFTR aimed simultaneously at its rescue, functional potentiation and PM stabilization. Since ganglioside GM1 is involved in the functional stabilization of transmembrane proteins, we investigated its role as an adjuvant to increase the effectiveness of CFTR modulators. According to our results, we found that GM1 resides in the same PM microenvironment as CFTR. In CF cells, the expression of the mutated channel is accompanied by a decrease in the PM GM1 content. Interestingly, by the exogenous administration of GM1, it becomes a component of the PM, reducing the destabilizing effect of the potentiator VX-770 on rescued CFTR protein expression/function and improving its stabilization. This evidence could represent a starting point for developing innovative therapeutic strategies based on the co-administration of GM1, correctors and potentiators, with the aim of improving F508del CFTR function.
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Recent progress in translational cystic fibrosis research using precision medicine strategies. J Cyst Fibros 2017; 17:S52-S60. [PMID: 28986017 DOI: 10.1016/j.jcf.2017.09.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 09/21/2017] [Accepted: 09/21/2017] [Indexed: 01/17/2023]
Abstract
Significant progress has been achieved in developing precision therapies for cystic fibrosis; however, highly effective treatments that target the ion channel, CFTR, are not yet available for many patients. As numerous CFTR therapeutics are currently in the clinical pipeline, reliable screening tools capable of predicting drug efficacy to support individualized treatment plans and translational research are essential. The utilization of bronchial, nasal, and rectal tissues from individual cystic fibrosis patients for drug testing using in vitro assays such as electrophysiological measurements of CFTR activity and evaluation of fluid movement in spheroid cultures, has advanced the prediction of patient-specific responses. However, for precise prediction of drug effects, in vitro models of CFTR rescue should incorporate the inflamed cystic fibrosis airway environment and mimic the complex tissue structures of airway epithelia. Furthermore, novel assays that monitor other aspects of successful CFTR rescue such as restoration of mucus characteristics, which is important for predicting mucociliary clearance, will allow for better prognoses of successful therapies in vivo. Additional cystic fibrosis treatment strategies are being intensively explored, such as development of drugs that target other ion channels, and novel technologies including pluripotent stem cells, gene therapy, and gene editing. The multiple therapeutic approaches available to treat the basic defect in cystic fibrosis combined with relevant precision medicine models provide a framework for identifying optimal and sustained treatments that will benefit all cystic fibrosis patients.
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Plummer A, Wildman M, Gleeson T. Duration of intravenous antibiotic therapy in people with cystic fibrosis. Cochrane Database Syst Rev 2016; 9:CD006682. [PMID: 27582394 PMCID: PMC6457596 DOI: 10.1002/14651858.cd006682.pub5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Respiratory disease is the major cause of mortality and morbidity in cystic fibrosis. Life expectancy of people with cystic fibrosis has increased dramatically in the last 40 years. One of the major reasons for this increase is the mounting use of antibiotics to treat chest exacerbations caused by bacterial infections. The optimal duration of intravenous antibiotic therapy is not clearly defined. Individuals usually receive intravenous antibiotics for 14 days, but treatment may range from 10 to 21 days. A shorter duration of antibiotic treatment risks inadequate clearance of infection which could lead to further lung damage. Prolonged courses of intravenous antibiotics are expensive and inconvenient and the incidence of allergic reactions to antibiotics also increases with prolonged courses. The use of aminoglycosides requires frequent monitoring to avoid some of their side effects. However, some organisms which infect people with cystic fibrosis are known to be multi-resistant to antibiotics, and may require a longer course of treatment. This is an update of previously published reviews. OBJECTIVES To assess the optimal duration of intravenous antibiotic therapy for treating chest exacerbations in people with cystic fibrosis. SEARCH METHODS We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals, abstract books and conference proceedings.Most recent search of the Group's Cystic Fibrosis Trials Register: 05 May 2016. SELECTION CRITERIA Randomised and quasi-randomised controlled trials comparing different durations of intravenous antibiotic courses for acute respiratory exacerbations in people with CF, either with the same drugs at the same dosage, the same drugs at a different dosage or frequency or different antibiotics altogether, including studies with additional therapeutic agents. DATA COLLECTION AND ANALYSIS No eligible trials were identified. MAIN RESULTS No eligible trials were identified. AUTHORS' CONCLUSIONS There are no clear guidelines on the optimum duration of intravenous antibiotic treatment. Duration of treatment is currently based on unit policies and response to treatment. Shorter duration of treatment should improve quality of life and compliance; result in a reduced incidence of drug reactions; and be less costly. However, this may not be sufficient to clear a chest infection and may result in an early recurrence of an exacerbation. This systematic review identifies the need for a multicentre, randomised controlled trial comparing different durations of intravenous antibiotic treatment as it has important clinical and financial implications.
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Affiliation(s)
- Amanda Plummer
- Northern General HospitalPharmacy DepartmentHerries RoadSheffieldUKS5 7AU
| | - Martin Wildman
- Northern General HospitalAdult Cystic Fibrosis UnitHerries RoadSheffieldUKS5 7AU
| | - Tim Gleeson
- Northern General HospitalPharmacy DepartmentHerries RoadSheffieldUKS5 7AU
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Cholon DM, Esther CR, Gentzsch M. Efficacy of lumacaftor-ivacaftor for the treatment of cystic fibrosis patients homozygous for the F508del-CFTR mutation. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2016; 1:235-243. [PMID: 27482545 DOI: 10.1080/23808993.2016.1175299] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cystic fibrosis (CF) results from mutations in the CF transmembrane conductance regulator (CFTR) gene, which codes for the CFTR channel protein. The most common mutation in CF is F508del, which produces a misfolded protein with diminished channel activity. The development of small-molecule CFTR-modulator compounds offers an exciting and novel approach for pharmacological treatment of CF. The corrector lumacaftor helps rescue F508del-CFTR to the cell surface, and potentiator ivacaftor increases F508del-CFTR channel activity. The combination of lumacaftor-ivacaftor (Vertex Pharmaceuticals Incorporated) represents the first FDA-approved therapy for CF patients with two copies of the F508del mutation. Although this combination therapy is the first treatment to directly target the F508del-CFTR mutation, patients taking this drug displayed only modest improvements in lung function. This article summarizes recent data from clinical trials and research discoveries relating to the lumacaftor-ivacaftor treatment, and considers options for identifying future therapies that will be most efficacious for all CF patients.
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Affiliation(s)
- Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Charles R Esther
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Division of Pediatric Pulmonology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Martina Gentzsch
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Cholon DM, Quinney NL, Fulcher ML, Esther CR, Das J, Dokholyan NV, Randell SH, Boucher RC, Gentzsch M. Potentiator ivacaftor abrogates pharmacological correction of ΔF508 CFTR in cystic fibrosis. Sci Transl Med 2015; 6:246ra96. [PMID: 25101886 DOI: 10.1126/scitranslmed.3008680] [Citation(s) in RCA: 256] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR). Newly developed "correctors" such as lumacaftor (VX-809) that improve CFTR maturation and trafficking and "potentiators" such as ivacaftor (VX-770) that enhance channel activity may provide important advances in CF therapy. Although VX-770 has demonstrated substantial clinical efficacy in the small subset of patients with a mutation (G551D) that affects only channel activity, a single compound is not sufficient to treat patients with the more common CFTR mutation, ΔF508. Thus, patients with ΔF508 will likely require treatment with both correctors and potentiators to achieve clinical benefit. However, whereas the effectiveness of acute treatment with this drug combination has been demonstrated in vitro, the impact of chronic therapy has not been established. In studies of human primary airway epithelial cells, we found that both acute and chronic treatment with VX-770 improved CFTR function in cells with the G551D mutation, consistent with clinical studies. In contrast, chronic VX-770 administration caused a dose-dependent reversal of VX-809-mediated CFTR correction in ΔF508 homozygous cultures. This result reflected the destabilization of corrected ΔF508 CFTR by VX-770, markedly increasing its turnover rate. Chronic VX-770 treatment also reduced mature wild-type CFTR levels and function. These findings demonstrate that chronic treatment with CFTR potentiators and correctors may have unexpected effects that cannot be predicted from short-term studies. Combining these drugs to maximize rescue of ΔF508 CFTR may require changes in dosing and/or development of new potentiator compounds that do not interfere with CFTR stability.
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Affiliation(s)
- Deborah M Cholon
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nancy L Quinney
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - M Leslie Fulcher
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Charles R Esther
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Division of Pediatric Pulmonology, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jhuma Das
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nikolay V Dokholyan
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Scott H Randell
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Richard C Boucher
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Martina Gentzsch
- Marsico Lung Institute/Cystic Fibrosis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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Staudinger BJ, Muller JF, Halldórsson S, Boles B, Angermeyer A, Nguyen D, Rosen H, Baldursson O, Gottfreðsson M, Guðmundsson GH, Singh PK. Conditions associated with the cystic fibrosis defect promote chronic Pseudomonas aeruginosa infection. Am J Respir Crit Care Med 2014; 189:812-24. [PMID: 24467627 DOI: 10.1164/rccm.201312-2142oc] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
RATIONALE Progress has been made in understanding how the cystic fibrosis (CF) basic defect produces lung infection susceptibility. However, it remains unclear why CF exclusively leads to chronic infections that are noninvasive and highly resistant to eradication. Although biofilm formation has been suggested as a mechanism, recent work raises questions about the role of biofilms in CF. OBJECTIVES To learn how airway conditions attributed to CF transmembrane regulator dysfunction could lead to chronic infection, and to determine if biofilm-inhibiting genetic adaptations that are common in CF isolates affect the capacity of Pseudomonas aeruginosa to develop chronic infection phenotypes. METHODS We studied P. aeruginosa isolates grown in agar and mucus gels containing sputum from patients with CF and measured their susceptibility to killing by antibiotics and host defenses. We also measured the invasive virulence of P. aeruginosa grown in sputum gels using airway epithelial cells and a murine infection model. MEASUREMENTS AND MAIN RESULTS We found that conditions likely to result from increased mucus density, hyperinflammation, and defective bacterial killing could all cause P. aeruginosa to grow in bacterial aggregates. Aggregated growth markedly increased the resistance of bacteria to killing by host defenses and antibiotics, and reduced their invasiveness. In addition, we found that biofilm-inhibiting mutations do not impede aggregate formation in gel growth environments. CONCLUSIONS Our findings suggest that conditions associated with several CF pathogenesis hypotheses could cause the noninvasive and resistant infection phenotype, independently of the bacterial functions needed for biofilm formation.
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Abstract
BACKGROUND Respiratory disease is the major cause of mortality and morbidity in cystic fibrosis (CF). Life expectancy of people with CF has increased dramatically in the last 40 years. One of the major reasons for this increase is the mounting use of antibiotics to treat chest exacerbations caused by bacterial infections. The optimal duration of intravenous antibiotic therapy is not clearly defined. Individuals usually receive intravenous antibiotics for 14 days, but treatment may range from 10 to 21 days. A shorter duration of antibiotic treatment risks inadequate clearance of infection which could lead to further lung damage. Prolonged courses of intravenous antibiotics are expensive and inconvenient and the incidence of allergic reactions to antibiotics also increases with prolonged courses. The use of aminoglycosides requires frequent monitoring to avoid some of their side effects. However, some organisms which infect people with CF are known to be multi-resistant to antibiotics, and may require a longer course of treatment. OBJECTIVES To assess the optimal duration of intravenous antibiotic therapy for treating chest exacerbations in people with cystic fibrosis. SEARCH METHODS We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals, abstract books and conference proceedings.Most recent search of the Group's Cystic Fibrosis Trials Register: 15 November 2012. SELECTION CRITERIA Randomised and quasi-randomised controlled trials comparing different durations of intravenous antibiotic courses for acute respiratory exacerbations in people with CF, either with the same drugs at the same dosage, the same drugs at a different dosage or frequency or different antibiotics altogether, including studies with additional therapeutic agents. DATA COLLECTION AND ANALYSIS No eligible trials were identified. MAIN RESULTS No eligible trials were identified. AUTHORS' CONCLUSIONS There are no clear guidelines on the optimum duration of intravenous antibiotic treatment. Duration of treatment is currently based on unit policies and response to treatment. Shorter duration of treatment should improve quality of life and compliance; result in a reduced incidence of drug reactions; and be less costly. However, this may not be sufficient to clear a chest infection and may result in an early recurrence of an exacerbation. This systematic review identifies the need for a multicentre, randomised controlled trial comparing different durations of intravenous antibiotic treatment as it has important clinical and financial implications.
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Affiliation(s)
- Amanda Plummer
- Pharmacy Department, Northern General Hospital, Sheffield, UK.
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Sibley CD, Grinwis ME, Field TR, Eshaghurshan CS, Faria MM, Dowd SE, Parkins MD, Rabin HR, Surette MG. Culture enriched molecular profiling of the cystic fibrosis airway microbiome. PLoS One 2011; 6:e22702. [PMID: 21829484 PMCID: PMC3145661 DOI: 10.1371/journal.pone.0022702] [Citation(s) in RCA: 160] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Accepted: 07/04/2011] [Indexed: 12/30/2022] Open
Abstract
The microbiome of the respiratory tract, including the nasopharyngeal and oropharyngeal microbiota, is a dynamic community of microorganisms that is highly diverse. The cystic fibrosis (CF) airway microbiome refers to the polymicrobial communities present in the lower airways of CF patients. It is comprised of chronic opportunistic pathogens (such as Pseudomonas aeruginosa) and a variety of organisms derived mostly from the normal microbiota of the upper respiratory tract. The complexity of these communities has been inferred primarily from culture independent molecular profiling. As with most microbial communities it is generally assumed that most of the organisms present are not readily cultured. Our culture collection generated using more extensive cultivation approaches, reveals a more complex microbial community than that obtained by conventional CF culture methods. To directly evaluate the cultivability of the airway microbiome, we examined six samples in depth using culture-enriched molecular profiling which combines culture-based methods with the molecular profiling methods of terminal restriction fragment length polymorphisms and 16S rRNA gene sequencing. We demonstrate that combining culture-dependent and culture-independent approaches enhances the sensitivity of either approach alone. Our techniques were able to cultivate 43 of the 48 families detected by deep sequencing; the five families recovered solely by culture-independent approaches were all present at very low abundance (<0.002% total reads). 46% of the molecular signatures detected by culture from the six patients were only identified in an anaerobic environment, suggesting that a large proportion of the cultured airway community is composed of obligate anaerobes. Most significantly, using 20 growth conditions per specimen, half of which included anaerobic cultivation and extended incubation times we demonstrate that the majority of bacteria present can be cultured.
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Affiliation(s)
- Christopher D. Sibley
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Margot E. Grinwis
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Tyler R. Field
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | | | - Monica M. Faria
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Scot E. Dowd
- Medical Biofilm Research Institute, Lubbock, Texas, United States of America
- Research and Testing Laboratory of the South Plains, Lubbock, Texas, United States of America
| | - Michael D. Parkins
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada
- Adult Cystic Fibrosis Clinic, University of Calgary, Calgary, Alberta, Canada
| | - Harvey R. Rabin
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada
- Adult Cystic Fibrosis Clinic, University of Calgary, Calgary, Alberta, Canada
| | - Michael G. Surette
- Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Farncombe Family Digestive Health Research Institute, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
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Abstract
BACKGROUND Respiratory disease is the major cause of mortality and morbidity in cystic fibrosis (CF). Life expectancy of people with CF has increased dramatically in the last 40 years. One of the major reasons for this increase is the mounting use of antibiotics to treat chest exacerbations caused by bacterial infections. The optimal duration of intravenous antibiotic therapy is not clearly defined. Individuals usually receive intravenous antibiotics for 14 days, but treatment may range from 10 to 21 days. A shorter duration of antibiotic treatment risks inadequate clearance of infection which could lead to further lung damage. Prolonged courses of intravenous antibiotics are expensive and inconvenient and the incidence of allergic reactions to antibiotics also increases with prolonged courses. The use of aminoglycosides requires frequent monitoring to avoid some of their side effects. However, some organisms which infect people with CF are known to be multi-resistant to antibiotics, and may require a longer course of treatment. OBJECTIVES To assess the optimal duration of intravenous antibiotic therapy for treating chest exacerbations in people with cystic fibrosis. SEARCH STRATEGY We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals, abstract books and conference proceedings.Most recent search of the Group's Cystic Fibrosis Trials Register: 3 December 2010. SELECTION CRITERIA Randomised and quasi-randomised controlled trials comparing different durations of intravenous antibiotic courses for acute respiratory exacerbations in people with CF, either with the same drugs at the same dosage, the same drugs at a different dosage or frequency or different antibiotics altogether, including studies with additional therapeutic agents. DATA COLLECTION AND ANALYSIS No eligible trials were identified. MAIN RESULTS No eligible trials were identified. AUTHORS' CONCLUSIONS There are no clear guidelines on the optimum duration of intravenous antibiotic treatment. Duration of treatment is currently based on unit policies and response to treatment. Shorter duration of treatment should improve quality of life and compliance; result in a reduced incidence of drug reactions; and be less costly. However, this may not be sufficient to clear a chest infection and may result in an early recurrence of an exacerbation. This systematic review identifies the need for a multicentre, randomised controlled trial comparing different durations of intravenous antibiotic treatment as it has important clinical and financial implications.
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Affiliation(s)
- Amanda Plummer
- Pharmacy Department, Northern General Hospital, Herries Road, Sheffield, UK, S5 7AU
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10
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Rogers GB, Carroll MP, Bruce KD. Studying bacterial infections through culture-independent approaches. J Med Microbiol 2009; 58:1401-1418. [DOI: 10.1099/jmm.0.013334-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The ability to characterize accurately the cause of infection is fundamental to effective treatment. The impact of any antimicrobial agents used to treat infection will, however, always be constrained by both the appropriateness of their use and our ability to determine their effectiveness. Traditional culture-based diagnostic microbiology is, in many cases, unable to provide this information. Molecular microbiological approaches that assess the content of clinical samples in a culture-independent manner promise to change dramatically the types of data that are obtained routinely from clinical samples. We argue that, in addition to the technical advance that these methodologies offer, a conceptual advance in the way that we reflect on the information generated is also required. Through the development of both of these advances, our understanding of infection, as well as the ways in which infections can be treated, may be improved. In the analysis of the microbiological content of certain clinical samples, such as blood, cerebrospinal fluid, brain and bone biopsy, culture-independent approaches have been well documented. Herein, we discuss how extensions to such studies can shape our understanding of infection at the many sites of the human body where a mixed flora, or in more ecological terms, a community of microbes, is present. To do this, we consider the underlying principles that underpin diagnostic systems, describe the ways in which these systems can be applied to community characterization, and discuss the significance of the data generated. We propose that at all locations within the human body where infection is routinely initiated within the context of a community of microbes, the same principles will apply. To consider this further, we take insights from areas such as the gut, oral cavity and skin. The main focus here is understanding respiratory tract infection, and specifically the infections of the cystic fibrosis lung. The impact that the use of culture-independent, molecular analyses will have on the way we approach the treatment of infections is also considered.
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Affiliation(s)
- Geraint B. Rogers
- Molecular Microbiology Research Laboratory, Pharmaceutical Science Division, Franklin-Wilkins Building, King's College London, 150 Stamford Street, London SE1 9NH, UK
| | - Mary P. Carroll
- Cystic Fibrosis Unit, Southampton University Hospitals NHS Trust, Tremona Road, Southampton SO16 6YD, UK
| | - Kenneth D. Bruce
- Molecular Microbiology Research Laboratory, Pharmaceutical Science Division, Franklin-Wilkins Building, King's College London, 150 Stamford Street, London SE1 9NH, UK
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Fernandes B, Plummer A, Wildman M. Duration of intravenous antibiotic therapy in people with cystic fibrosis. Cochrane Database Syst Rev 2008:CD006682. [PMID: 18425963 DOI: 10.1002/14651858.cd006682.pub2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Respiratory disease is the major cause of mortality and morbidity in cystic fibrosis (CF). Life expectancy of people with CF has increased dramatically in the last 40 years. One of the major reasons for this increase is the mounting use of antibiotics to treat chest exacerbations caused by bacterial infections. The optimal duration of intravenous antibiotic therapy is not clearly defined. Individuals usually receive intravenous antibiotics for 14 days, but treatment may range from 10 to 21 days. A shorter duration of antibiotic treatment risks inadequate clearance of infection which could lead to further lung damage. Prolonged courses of intravenous antibiotics are expensive and inconvenient and the incidence of allergic reactions to antibiotics also increases with prolonged courses. The use of aminoglycosides requires frequent monitoring to avoid some of their side effects. However, some organisms which infect people with CF are known to be multi-resistant to antibiotics, and may require a longer course of treatment. OBJECTIVES To assess the optimal duration of intravenous antibiotic therapy for treating chest exacerbations in people with cystic fibrosis. SEARCH STRATEGY We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals, abstract books and conference proceedings. Most recent search of the Group's Cystic Fibrosis Trials Register: February 2008. SELECTION CRITERIA Randomised and quasi-randomised controlled trials comparing different durations of intravenous antibiotic courses for acute respiratory exacerbations in people with CF, either with the same drugs at the same dosage, the same drugs at a different dosage or frequency or different antibiotics altogether, including studies with additional therapeutic agents. DATA COLLECTION AND ANALYSIS No eligible trials were identified. MAIN RESULTS No eligible trials were identified. AUTHORS' CONCLUSIONS There are no clear guidelines on the optimum duration of intravenous antibiotic treatment. Duration of treatment is currently based on unit policies and response to treatment. Shorter duration of treatment should improve quality of life and compliance; result in a reduced incidence of drug reactions; and be less costly. However, this may not be sufficient to clear a chest infection and may result in an early recurrence of an exacerbation. This systematic review identifies the need for a multicentre, randomised controlled trial comparing different durations of intravenous antibiotic treatment as it has important clinical and financial implications.
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12
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Döring G, Hoiby N. Early intervention and prevention of lung disease in cystic fibrosis: a European consensus. J Cyst Fibros 2004; 3:67-91. [PMID: 15463891 DOI: 10.1016/j.jcf.2004.03.008] [Citation(s) in RCA: 193] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Accepted: 03/24/2004] [Indexed: 10/26/2022]
Abstract
In patients with cystic fibrosis (CF), early intervention and prevention of lung disease is of paramount importance. Principles to achieve this aim include early diagnosis of CF, regular monitoring of the clinical status, various hygienic measures to prevent infection and cross-infection, early use of antibiotic courses in patients with recurrent or continuous bacterial colonisation and appropriate use of chest physiotherapy.
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Affiliation(s)
- Gerd Döring
- Institute of General and Environmental Hygiene, Eberhard, Karls-University of Tübingen, Wilhelmstrasse 31, D-72074 Tübingen, Germany.
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Foell D, Seeliger S, Vogl T, Koch HG, Maschek H, Harms E, Sorg C, Roth J. Expression of S100A12 (EN-RAGE) in cystic fibrosis. Thorax 2003; 58:613-7. [PMID: 12832680 PMCID: PMC1746749 DOI: 10.1136/thorax.58.7.613] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Chronic airway inflammation and recurrent infections are a core phenomenon in cystic fibrosis (CF). Diagnosing acute infectious exacerbations is difficult in the presence of chronic inflammatory processes. S100A12 exhibits proinflammatory functions via interaction with the multiligand receptor for advanced glycation end products. Blocking this interaction inhibits inflammatory processes in mice. METHODS The expression of S100A12 in lung specimens of patients with end stage lung disease of CF was investigated, and S100A12 levels in the serum of patients with acute infectious exacerbations of CF were measured. RESULTS Immunohistochemical studies of CF lung biopsy specimens revealed a significant expression of S100A12 by infiltrating neutrophils. High S100A12 levels were found in the sputum of patients with CF, and serum levels of S100A12 during acute infectious exacerbations were significantly increased compared with healthy controls (median 225 ng/ml v 46 ng/ml). After treatment with intravenous antibiotics the mean S100A12 level decreased significantly. There was also a significant difference between S100A12 levels in patients with acute infectious exacerbations and 18 outpatients without exacerbations (median 225 ng/ml v 105 ng/ml). CONCLUSIONS S100A12 is extensively expressed at local sites of inflammation in CF. It is a serum marker for acute infectious exacerbations. High local expression of S100A12 suggests that this protein has a proinflammatory role during airway inflammation and may serve as a novel target for anti-inflammatory treatments.
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Affiliation(s)
- D Foell
- Department of Paediatrics, University of Muenster, Germany.
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Galan HL, Bennett ML, Tyson RW, Owens G, Regnault TRH, Accurso F, Hobbins JC, Schaack J. Inefficient transduction of sheep in utero after intra-amniotic injection of retroviral producer cells. Am J Obstet Gynecol 2002; 187:469-74. [PMID: 12193945 DOI: 10.1067/mob.2002.123601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Our purpose was to test the hypothesis that the intra-amniotic injection of a retroviral vector producer cell line into pregnant sheep will result in retrovirus-mediated transduction and stable gene transfer to the ovine fetus. STUDY DESIGN Thirteen pregnant ewes at various gestational ages underwent amniocentesis and injection of cells producing the retrovirus vector LIRESgeo, which is derived from Maloney murine leukemia virus and encodes Escherichia coli LacZ (beta-galactosidase) as a marker gene. Pregnant ewes and fetuses were killed, and amniotic fluid, placenta, and fetal tissues were collected and assayed for transgene expression 7 to 77 days after intraamniotic injection. In addition, serum was collected and analyzed for evidence of specific immune responses against the producer cells, and amniotic fluid was collected and analyzed for deleterious effects on producer cell viability, vector production, and vector transduction. RESULTS Only 1 of 10 fetuses exposed to the retroviral producer cells demonstrated beta-galactosidase activity that correlated with positive immunohistochemistry for LacZ in lung, trachea, pancreas, and small intestine. However, the presence of the LacZ gene could not be confirmed by polymerase chain reaction. Thus, we could not confirm transduction after any of the injections. The retroviral producer cells survived well in amniotic fluid and continued to produce high levels of retroviral vector after intra-amniotic injection, although amniotic fluid inhibited the transducing activity of the vector in a manner dependent on gestational age. CONCLUSIONS Intra-amniotic retroviral gene transfer with the use of these amphotropic producer cells does not result in reproducible gene transfer in the ovine fetus although amniotic fluid sustains producer cell viability and vector production. Possible reasons for the inefficient transduction are discussed.
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Affiliation(s)
- Henry L Galan
- Department of Obstetrics and Gynecology, University of Colorado Health Sciences Center, Denver, 80262, USA
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Bennett M, Galan H, Owens G, Dewey R, Banks R, Hobbins J, Accurso F, Schaack J. In utero gene delivery by intraamniotic injection of a retroviral vector producer cell line in a nonhuman primate model. Hum Gene Ther 2001; 12:1857-65. [PMID: 11589828 DOI: 10.1089/104303401753153910] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In utero gene therapy (IUGT) offers the promise of treating a wide variety of genetic diseases before the development of disease manifestations. The most convenient and potentially easiest method of targeting the fetus is through injection into the amniotic cavity. For long-term correction of genetic defects, retroviral vectors have great potential as a tool for gene therapy strategies. However, retroviral vectors are limited by growth to low titers. In an attempt to increase the amount of vector particles delivered and assess the potential of intraamniotic administration, we injected a retroviral vector producer cell line encoding the lacZ gene into the amniotic fluid of a nonhuman primate model. After birth the infants were analyzed for vector-mediated transduction. Two of four fetuses were successfully transduced, with transgene expression detected in the esophagus, trachea, and stomach. In some sections of tissue, nearly 100% of the cells lining the lumen of these tissues were positive for transduction. Although successful, the limited number of tissues in which transduction was observed led to an in vitro analysis of the effects of amniotic fluid (AF). The presence of amniotic fluid inhibited transduction by 99%. AF affected both the transducing activity of the vector and the health of the packaging cells. The negative effects of AF were gestational age dependent; greater inhibition was observed from AF collected at later stages of pregnancy. The fact that transduction was successful despite these negative effects indicates that this approach is a promising strategy for gene therapy.
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Affiliation(s)
- M Bennett
- Department of Microbiology, School of Medicine, University of Colorado Health Sciences Center, Denver, CO 80262, USA
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16
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Hubeau C, Lorenzato M, Couetil JP, Hubert D, Dusser D, Puchelle E, Gaillard D. Quantitative analysis of inflammatory cells infiltrating the cystic fibrosis airway mucosa. Clin Exp Immunol 2001; 124:69-76. [PMID: 11359444 PMCID: PMC1906034 DOI: 10.1046/j.1365-2249.2001.01456.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Airway inflammation represents a hallmark of the cystic fibrosis (CF) disease. However, the mucosal distribution of immune cells along the CF airways has not been clearly defined, particularly in intermediate bronchi and distal bronchioles. We analysed lung tissues collected at the time of transplantation from homozygous DeltaF508+/+CF patients versus non-CF donors. Using immunohistochemistry, the distribution of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin, polymorphonuclear neutrophils (PMN), mast cells, CD3+ T cells, including the CD4+ and CD8+ subsets, CD20+ B cells, CD38+ plasma cells and CD68+ macrophages, was analysed at lobar, segmental and distal levels of the bronchial tree. Using image cytometry, the number of cells per mm2 was assessed in the depth of the bronchial wall. In CF airways, alterations mainly consisted in lesions of the surface epithelium. Numerous immune cells were heterogeneously distributed all along the bronchial tree and mainly located in the mucosa, beneath the surface epithelium. Compared to non-CF donors, the lymphoid aggregates formed by B cells were significantly larger all along the CF airways (P = 0.001). The number of T lymphocytes was higher at the CF distal level (P = 0.035), where we observed an intense tissue damage. PMN preferentially accumulated (P = 0.033) in the CF surface epithelium, which overexpressed ICAM-1 but not VCAM-1 and E-selectin. These results highlight the nature of the inflammatory infiltrate in the CF airway mucosa and emphasize a prominent implication of PMN, B and T lymphocytes in the CF disease.
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Affiliation(s)
- C Hubeau
- Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Fédératif de Recherche (IFR) 53, Université de Reims Champagne-Ardenne, Reims, France
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17
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Wang X, Zhang Y, Amberson A, Engelhardt JF. New models of the tracheal airway define the glandular contribution to airway surface fluid and electrolyte composition. Am J Respir Cell Mol Biol 2001; 24:195-202. [PMID: 11159054 DOI: 10.1165/ajrcmb.24.2.3918] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Antibacterial defenses in the airway are dependent on multifactorial influences that determine the composition of both fluid and/or electrolytes at the surface of the airway and the secretory products that aid in bacterial killing and clearance. In cystic fibrosis (CF), these mechanisms of airway protection may be defective, leading to increased colonization with Pseudomonas aeruginosa. Submucosal glands, a predominant site of cystic fibrosis transmembrane conductance regulator (CFTR) protein expression in the airway, have been hypothesized to play an important role in protection of the airway. Furthermore, recent studies have suggested that the salt concentration at the airway surface may be a key factor in regulating the activity of antibacterial substances in the airway. To explore these issues, we have used a new model of the ferret tracheal airway to evaluate the contribution of submucosal glands in regulating airway surface fluid and electrolyte composition. Using tracheal xenograft models with and without submucosal glands, we have characterized several aspects of airway physiology that may be important in defining antibacterial properties. These endpoints included the contribution of submucosal glands in defining bioelectric properties of the surface airway epithelium, airway surface fluid (ASF) chloride composition, ASF volumes, and secretion of the antibacterial factor lysozyme. Findings from these studies demonstrate a significantly elevated secreted fluid volume (Vs) and chloride concentration ([Cl](s)) in ASF from airways with submucosal glands (Vs = 47 +/- 4 microl; [Cl](s) = 128 +/- 5 mM), as compared with xenograft airways without glands (Vs = 36 +/- 2 microl; [Cl](s) = 103 +/- 6 mM). Furthermore, a temperature labile factor secreted by submucosal glands appears to alter the baseline activation of 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid and/or diphenylamine-2-carboxylic acid-sensitive chloride channels in the surface airway epithelium. Lastly, the lysozyme content of tracheal airways with submucosal glands was 8.5-fold higher than were airways without glands. These studies demonstrate that submucosal glands affect both the ionic composition and bioelectric properties of the airway and suggest that models evaluating antibacterial properties of the airway in CF should take into account the contribution of glands in airway physiology.
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Affiliation(s)
- X Wang
- Department of Anatomy and Cell Biology, University of Iowa, College of Medicine, 51 Newton Road, Rm. 111-BSB, Iowa City, IA 52242, USA
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Bals R, Weiner DJ, Wilson JM. The innate immune system in cystic fibrosis lung disease. J Clin Invest 1999; 103:303-7. [PMID: 9927489 PMCID: PMC407907 DOI: 10.1172/jci6277] [Citation(s) in RCA: 161] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- R Bals
- Institute for Human Gene Therapy, Departments of Medicine and Molecular and Cellular Engineering, The Wistar Institute, Philadelphia, Pennsylvania 19104-4268, USA
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