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Barillaro M, Gonska T. Assessing accuracy of testing and diagnosis in cystic fibrosis. Expert Rev Respir Med 2023:1-13. [PMID: 37190981 DOI: 10.1080/17476348.2023.2213438] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Affiliation(s)
- Malina Barillaro
- Department of Physiology, University of Toronto, Toronto ON, Canada
- Translational Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
| | - Tanja Gonska
- Translational Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, Canada
- Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition, University of Toronto, Toronto ON, Canada
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2
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Barry PJ, Simmonds NJ. Diagnosing Cystic Fibrosis in Adults. Semin Respir Crit Care Med 2023; 44:242-251. [PMID: 36623819 DOI: 10.1055/s-0042-1759881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Diagnosing cystic fibrosis (CF) in adulthood is not a rare occurrence for CF centers despite the popular belief that the diagnosis is achieved almost universally in childhood by means of newborn screening or early clinical presentation. The purpose of this review article is to highlight specific considerations of adult diagnosis of CF. Obtaining a diagnosis of CF at any age is exceptionally important to ensure optimal treatment, monitoring, and support. In the new era of more personalized treatment with the advent of transformative therapies targeting the underlying protein defect, accurate diagnosis is of increasing importance. This review highlights the diagnostic algorithm leading to a new diagnosis of CF in adults. The diagnosis is usually confirmed in the presence of a compatible clinical presentation, evidence of cystic fibrosis transmembrane conductance regulator (CFTR) protein dysfunction, and/or identification of variants in the CFTR gene believed to alter protein function. Achieving the diagnosis, however, is not always straightforward as CFTR protein function exists on a continuum with different organs displaying varying sensitivity to diminution in function. We highlight the current knowledge regarding the epidemiology of CF diagnosed in adults and outline the various clinical presentations, including pulmonary and extrapulmonary, which are more common in this population. We expand on the stepwise testing procedures that lead to diagnosis, paying particular attention to additional levels of testing which may be required to achieve an accurate diagnosis. There continues to be an important need for both pulmonary and other specialists to be aware of the potential for later presentation of CF, as the improvements in treatment over decades have had large positive impacts on prognosis for people with this condition.
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Affiliation(s)
- Peter J Barry
- Manchester Adult Cystic Fibrosis Centre, Manchester University National Health Service Foundation Trust, Wythenshawe Hospital, Manchester, United Kingdom
| | - Nicholas J Simmonds
- Adult Cystic Fibrosis Centre, Royal Brompton Hospital, London, United Kingdom.,National Heart and Lung Institute, Imperial College London, London, United Kingdom
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3
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Berg P, Sorensen MV, Rousing AQ, Vebert Olesen H, Jensen-Fangel S, Jeppesen M, Leipziger J. Challenged Urine Bicarbonate Excretion as a Measure of Cystic Fibrosis Transmembrane Conductance Regulator Function in Cystic Fibrosis. Ann Intern Med 2022; 175:1543-1551. [PMID: 36315944 DOI: 10.7326/m22-1741] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND In cystic fibrosis (CF), renal base excretion is impaired. Accordingly, challenged urine bicarbonate excretion may be an in vivo biomarker of cystic fibrosis transmembrane conductance regulator (CFTR) function. OBJECTIVE To evaluate the association between challenged bicarbonate excretion and clinical characteristics at baseline, quantify the CFTR modulator drug elexacaftor/tezacaftor/ivacaftor-induced changes of challenged bicarbonate excretion after 6 months of treatment, and characterize the intraindividual variation in healthy adults. DESIGN Prospective observational study. SETTING Cystic fibrosis clinic, Aarhus University Hospital, Denmark. PATIENTS Fifty adult patients with CF starting CFTR modulator therapy with elexacaftor/tezacaftor/ivacaftor between May 2020 and June 2021. MEASUREMENTS Quantification of urine bicarbonate excretion after an acute oral sodium bicarbonate challenge before and 6 months after elexacaftor/tezacaftor/ivacaftor treatment. RESULTS At baseline, challenged urine bicarbonate excretion was associated with several CF disease characteristics. Bicarbonate excretion was higher in patients with residual function mutations. A higher bicarbonate excretion was associated with better lung function, pancreatic sufficiency, and lower relative risk for chronic pseudomonas infections. Elexacaftor/tezacaftor/ivacaftor treatment increased bicarbonate excretion by 3.9 mmol/3 h (95% CI, 1.6 to 6.1 mmol/3 h), reaching about 70% of that seen in healthy control participants. In healthy control participants, individual bicarbonate excretion at each visit correlated with the individual mean bicarbonate excretion. The median coefficient of variation was 31%. LIMITATION Single-center study without a placebo-controlled group. CONCLUSION Although further studies are needed to address the performance and sensitivity of this approach, this early-stage evaluation shows that challenged urine bicarbonate excretion may offer a new, simple, and safe quantification of CFTR function and the extent of its pharmacologic improvement. Elexacaftor/tezacaftor/ivacaftor partially restores renal CFTR function in patients with CF, likely resulting in decreased risk for electrolyte disorders and metabolic alkalosis. PRIMARY FUNDING SOURCE Innovation Fund Denmark.
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Affiliation(s)
- Peder Berg
- Department of Biomedicine, Aarhus University, Aarhus, Denmark (P.B., M.V.S., A.Q.R., J.L.)
| | - Mads V Sorensen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark (P.B., M.V.S., A.Q.R., J.L.)
| | - Amalie Quist Rousing
- Department of Biomedicine, Aarhus University, Aarhus, Denmark (P.B., M.V.S., A.Q.R., J.L.)
| | - Hanne Vebert Olesen
- Department of Pediatrics and Adolescent Medicine, Aarhus University Hospital, Aarhus, Denmark (H.V.O.)
| | - Søren Jensen-Fangel
- Department of Infectious Diseases, Aarhus University Hospital, Aarhus, Denmark (S.J., M.J.)
| | - Majbritt Jeppesen
- Department of Infectious Diseases, Aarhus University Hospital, Aarhus, Denmark (S.J., M.J.)
| | - Jens Leipziger
- Department of Biomedicine, Aarhus University, Aarhus, Denmark (P.B., M.V.S., A.Q.R., J.L.)
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4
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Sermet-Gaudelus I, Girodon E, Vermeulen F, Solomon G, Melotti P, Graeber S, Bronsveld I, Rowe S, Wilschanski M, Tümmler B, Cutting G, Gonska T. ECFS standards of care on CFTR-related disorders: Diagnostic criteria of CFTR dysfunction. J Cyst Fibros 2022; 21:922-936. [DOI: 10.1016/j.jcf.2022.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 09/06/2022] [Accepted: 09/14/2022] [Indexed: 11/06/2022]
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5
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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. 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; 7:7/1/e000736. [PMID: 33020115 PMCID: PMC7537139 DOI: 10.1136/bmjresp-2020-000736] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/31/2020] [Accepted: 09/05/2020] [Indexed: 12/16/2022] Open
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.
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Affiliation(s)
- Rebecca Minso
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Angela Schulz
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Christian Dopfer
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research DZL, Hannover, Germany
| | - Nadine Alfeis
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Andrea van Barneveld
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Hannover, Germany
| | - Lena Makartian-Gyulumyan
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Hannover, Germany
| | - Gesine Hansen
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research DZL, Hannover, Germany
| | - Sibylle Junge
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Carsten Müller
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Felix C C Ringshausen
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research DZL, Hannover, Germany.,Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
| | | | - Frauke Stanke
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research DZL, Hannover, Germany.,Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Hannover, Germany
| | - Cornelia Stolpe
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Stephanie Tamm
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Hannover, Germany
| | - Tobias Welte
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research DZL, Hannover, Germany.,Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
| | - Anna-Maria Dittrich
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research DZL, Hannover, Germany
| | - Burkhard Tümmler
- Clinic for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany .,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), German Center for Lung Research DZL, Hannover, Germany.,Klinische Forschergruppe, OE 6710, Medizinische Hochschule Hannover, Hannover, Germany
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6
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Kyrilli S, Henry T, Wilschanski M, Fajac I, Davies JC, Jais JP, Sermet-Gaudelus I. Insights into the variability of nasal potential difference, a biomarker of CFTR activity. J Cyst Fibros 2019; 19:620-626. [PMID: 31699569 DOI: 10.1016/j.jcf.2019.09.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/07/2019] [Accepted: 09/23/2019] [Indexed: 12/18/2022]
Abstract
BACKGROUND Nasal potential difference (NPD) is used to evaluate CFTR function in vivo. We aimed to evaluate the intrasubject and intersubject variability of NPD measurements. METHODS We reviewed NPD tracings of 116 patients with CF enrolled in the placebo arm of a multicenter study. Patients carried at least one nonsense mutation and underwent repeated NPD tests every 16 weeks. NPD parameters included basal potential difference (basal PD), inhibition of sodium absorption by amiloride (Δ Amiloride), chloride (Cl-) transport in response to a Cl--free solution (Δ Low Cl-), isoproterenol (Δ Isoproterenol), the sum of Δ Low Cl- and Δ Isoproterenol (Δ Low Cl--Isoproterenol) and ATP (Δ ATP). RESULTS Basal PD and Δ Amiloride displayed the highest variabilities, mainly stemming from intercenter and intrasubject effect. Δ Low Cl-, Δ Isoproterenol and Δ Low Cl--Isoproterenol demonstrated a large intrasubject variability but a smaller intersubject variability. The intrasubject measurement variability for Δ Low Cl--Isoproterenol, was within ± 7.2 mV with 95% probability. It was greater in patients reporting ongoing pulmonary exacerbations. CONCLUSIONS The large intercenter variability of basal PD and Δ Amiloride highlights the operator-dependent aspect of these measurements. A difference greater than 7.2 mV in Δ Low Cl--Isoproterenol in a given patient on CFTR modulator can be attributed, with 95% probability, to a treatment effect rather than to the variability inherent in the measurement.
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Affiliation(s)
- Spyridoula Kyrilli
- Centre Maladies Rares Mucoviscidose, Hôpital Universitaire Necker-Enfants Malades, Assistance-Publique Hôpitaux de Paris, Paris, France
| | - Theophraste Henry
- Bio-statistics Department, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | | | - Isabelle Fajac
- AP-HP, Hopital Cochin, Physiology Department, Paris, France; UPRES EA 2511, Paris, France; Université Paris Sorbonne, Paris, France
| | - Jane C Davies
- CF and Chronic Lung Infection, National Heart and Lung Institute, Imperial College London, UK; Department of Paediatric Respiratory Medicine, Royal Brompton and Harefield NHS Foundation Trust, London, United Kingdom
| | - Jean-Philippe Jais
- Bio-statistics Department, Hôpital Universitaire Necker-Enfants Malades, Paris, France; Université Paris Sorbonne, Paris, France
| | - Isabelle Sermet-Gaudelus
- Centre Maladies Rares Mucoviscidose, Hôpital Universitaire Necker-Enfants Malades, Assistance-Publique Hôpitaux de Paris, Paris, France; Université Paris Sorbonne, Paris, France; Institut Necker-Enfants Malades. INSERM U1151, Paris, France.
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7
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Abstract
Cystic fibrosis is a genetic disease affecting more than 70,000 people worldwide. Caused by a mutation in the CFTR gene, cystic fibrosis can result in difficulty breathing, widespread bacterial infections, edema, malnutrition, pancreatitis, and death. Current drug-based treatments struggle to reach the site of action due to the thick mucus, and only manage symptoms such as blocked airways, lung infections, and limited ability to digest food. Nanotechnology opens up possibilities for improved treatment strategies by focusing on drug penetration through the mucus lining, eliminating resulting bacterial infections, and targeting the underlying genetic cause of the disease. In this review, we present recent nanoparticle developments for cystic fibrosis, challenges in nanomedicine therapeutics, and future research directions in gene editing and nonviral vectors for gene delivery.
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Affiliation(s)
- Victor Ong
- 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Vincent Mei
- 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Lin Cao
- 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Kiana Lee
- 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Eun Ji Chung
- 1 Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
- 2 Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, USA
- 3 Division of Nephrology and Hypertension, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- 4 Division of Vascular Surgery and Endovascular Repair, Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- 5 Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA
- 6 Department of Stem Cell Biology and Regenerative Medicine, University of Southern California, Los Angeles, CA, USA
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8
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Gramegna A, Aliberti S, Seia M, Porcaro L, Bianchi V, Castellani C, Melotti P, Sorio C, Consalvo E, Franceschi E, Amati F, Contarini M, Gaffuri M, Roncoroni L, Vigone B, Bellofiore A, Del Monaco C, Oriano M, Terranova L, Patria MF, Marchisio P, Assael BM, Blasi F. When and how ruling out cystic fibrosis in adult patients with bronchiectasis. Multidiscip Respir Med 2018; 13:29. [PMID: 30151190 PMCID: PMC6101074 DOI: 10.1186/s40248-018-0142-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background Bronchiectasis is the final result of different processes and most of the guidelines advocate for a careful evaluation of those etiologies which might be treated or might change patients’ management, including cystic fibrosis (CF). Main body CFTR mutations have been reported with higher frequency in bronchiectasis population. Although ruling out CF is considered as a main step for etiological screening in bronchiectasis, CF testing lacks of a standardized approach both from a research and clinical point of view. In this review a list of most widely used tests in CF is provided. Conclusions Exclusion of CF is imperative for patients with bronchiectasis and CFTR testing should be implemented in usual screening for investigating bronchiectasis etiology. Physicians taking care of bronchiectasis patients should be aware of CFTR testing and its limitations in the adult population. Further studies on CFTR expression in human lung and translational research might elucidate the possible role of CFTR in the pathogenesis of bronchiectasis.
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Affiliation(s)
- Andrea Gramegna
- Department of Pathophysiology and Transplantation, University of Milan, Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Stefano Aliberti
- Department of Pathophysiology and Transplantation, University of Milan, Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Manuela Seia
- 2Medical Genetics Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Luigi Porcaro
- 2Medical Genetics Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Vera Bianchi
- 3UOSD Genetica Medica, Medical Genetics Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Carlo Castellani
- 4Centro Fibrosi Cistica, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Paola Melotti
- 4Centro Fibrosi Cistica, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Claudio Sorio
- 5Dipartimento di Patologia e Diagnostica, Università di Verona, Verona, Italy
| | - Enza Consalvo
- 2Medical Genetics Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Elisa Franceschi
- Department of Pathophysiology and Transplantation, University of Milan, Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Francesco Amati
- Department of Pathophysiology and Transplantation, University of Milan, Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Martina Contarini
- Department of Pathophysiology and Transplantation, University of Milan, Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Michele Gaffuri
- 6Department of Otolaryngology and Head and Neck Surgery, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, 20122 Milan, Italy
| | - Luca Roncoroni
- 6Department of Otolaryngology and Head and Neck Surgery, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Clinical Sciences and Community Health, University of Milan, 20122 Milan, Italy
| | - Barbara Vigone
- 7Scleroderma Unit, Referral Center for Systemic Autoimmune Diseases, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico di Milano, 20122 Milan, Italy
| | - Angela Bellofiore
- Department of Pathophysiology and Transplantation, University of Milan, Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Cesare Del Monaco
- Department of Pathophysiology and Transplantation, University of Milan, Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Martina Oriano
- Department of Pathophysiology and Transplantation, University of Milan, Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy.,9Molecular Medicine Department, University of Pavia, Viale Taramelli 3/b, 27100 Pavia, Italy
| | - Leonardo Terranova
- Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Maria Francesca Patria
- Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Paola Marchisio
- Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Baroukh M Assael
- Department of Pathophysiology and Transplantation, University of Milan, Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Francesco Blasi
- Department of Pathophysiology and Transplantation, University of Milan, Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Adult Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
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9
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Werlin S, Scotet V, Uguen K, Audrezet MP, Cohen M, Yaakov Y, Safadi R, Ilan Y, Konikoff F, Galun E, Mizrahi M, Slae M, Sayag S, Cohen-Cymberknoh M, Wilschanski M, Ferec C. Primary sclerosing cholangitis is associated with abnormalities in CFTR. J Cyst Fibros 2018; 17:666-671. [PMID: 29807875 DOI: 10.1016/j.jcf.2018.04.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 04/13/2018] [Accepted: 04/22/2018] [Indexed: 01/08/2023]
Abstract
BACKGROUND The etiology of primary sclerosing cholangitis (PSC) is unknown. PSC and Cystic Fibrosis related liver disease have common features: chronic inflammation, biliary damage and similar cholangiographic findings. It is unknown whether or not PSC is related to cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction. We hypothesize that a sub-group of PSC patients may be a "single-organ" presentation of CF. METHODS Patients with PSC underwent nasal potential difference (NPD) measurement, sweat chloride measurement and complete CFTR sequencing by new generation sequencing. RESULTS 6/32 patients aged 46 ± 13 yrs. had CFTR causing mutations on one allele and 19 had CFTR polymorphisms; 6/23 tested had abnormal and 21 had intermediate sweat tests; 4/32 patients had abnormal NPD. One patient had chronic pancreatitis and was infertile. CONCLUSIONS 19% of PSC patients had features of CFTR related disorder, 19% carry CFTR mutations and 50% had CFTR polymorphisms. In some patients, PSC may be a single organ presentation of CF or a CFTR-related disorder.
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Affiliation(s)
- Steven Werlin
- Pediatric Gastroenterology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Virginie Scotet
- Laboratory of Molecular Genetics and Histocompatibility, University Hospital of Brest, Institut National de la Santé et de la Recherche Médicale, U1078 Brest, France
| | - Kevin Uguen
- Laboratory of Molecular Genetics and Histocompatibility, University Hospital of Brest, Institut National de la Santé et de la Recherche Médicale, U1078 Brest, France
| | - Marie-Pierre Audrezet
- Laboratory of Molecular Genetics and Histocompatibility, University Hospital of Brest, Institut National de la Santé et de la Recherche Médicale, U1078 Brest, France
| | - Michael Cohen
- Pediatric Gastroenterology Unit and Cystic Fibrosis Center, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Yasmin Yaakov
- Pediatric Gastroenterology Unit and Cystic Fibrosis Center, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Rifaat Safadi
- Liver Unit, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Yaron Ilan
- Liver Unit, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Fred Konikoff
- Gastroenterology and Hepatology Department, Meir Medical Center, Kfar Saba, Israel
| | - Eitan Galun
- Goldyne Savad Institute of Gene Therapy, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Meir Mizrahi
- Liver Unit, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Mordechai Slae
- Pediatric Gastroenterology Unit and Cystic Fibrosis Center, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Shirley Sayag
- Pediatric Gastroenterology Unit and Cystic Fibrosis Center, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Malena Cohen-Cymberknoh
- Pediatric Pulmonology Unit and Cystic Fibrosis Center, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Michael Wilschanski
- Pediatric Gastroenterology Unit and Cystic Fibrosis Center, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
| | - Claude Ferec
- Laboratory of Molecular Genetics and Histocompatibility, University Hospital of Brest, Institut National de la Santé et de la Recherche Médicale, U1078 Brest, France
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Guimbellot J, Sharma J, Rowe SM. Toward inclusive therapy with CFTR modulators: Progress and challenges. Pediatr Pulmonol 2017; 52:S4-S14. [PMID: 28881097 PMCID: PMC6208153 DOI: 10.1002/ppul.23773] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 06/29/2017] [Indexed: 12/29/2022]
Abstract
Cystic fibrosis is caused by gene mutations that result in an abnormal Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein on the surface of cells. CFTR modulators are a novel class of drugs that directly target the molecular defect. CFTR modulators include potentiators that result in improved activity of the channel; correctors that help the protein traffic to the cell surface properly; and readthrough agents that restore full-length CFTR by suppression of premature termination codons, among other novel classes more recently established. While some of these drugs, CFTR potentiators in particular, have provided remarkable improvements for CF patients, others have yet to achieve profoundly improved outcomes, and many CF patients are not yet impacted by CFTR modulators due to lack of knowledge regarding susceptibility of their mutations to treatment. One limitation to expanding these types of therapies to the maximum number of patients with CF is the lack of rigorously validated clinical biomarkers that can determine efficacy on an individual basis, as well as few pre-clinical tools that can predict whether an individual with a rare combination of mutant alleles will respond to a particular CFTR modulator regimen. In this review, we discuss the various groups of CFTR modulators and their status in clinical development, as well as address the current literature on biomarkers, pre-clinical cell-based tools, and the role of pharmacometrics in creating therapeutic strategies to improve the lives of all patients with cystic fibrosis, regardless of their specific mutation.
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Affiliation(s)
- Jennifer Guimbellot
- Departments of Pediatrics, The University of Alabama at Birmingham, Birmingham, Alabama
- Gregory Fleming James Cystic Fibrosis Research Center, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Jyoti Sharma
- Gregory Fleming James Cystic Fibrosis Research Center, The University of Alabama at Birmingham, Birmingham, Alabama
- Cell Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Steven M. Rowe
- Departments of Pediatrics, The University of Alabama at Birmingham, Birmingham, Alabama
- Gregory Fleming James Cystic Fibrosis Research Center, The University of Alabama at Birmingham, Birmingham, Alabama
- Cell Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, Alabama
- Departments of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama
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11
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Zak SM, Clancy JP, Brewington JJ. CFTR functional assays in drug development. Expert Opin Orphan Drugs 2017. [DOI: 10.1080/21678707.2017.1393413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Sara M. Zak
- Department of Pediatrics, Division of Pulmonary Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, USA
| | - John P. Clancy
- Department of Pediatrics, Division of Pulmonary Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, USA
| | - John J. Brewington
- Department of Pediatrics, Division of Pulmonary Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, USA
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De Boeck K, Vermeulen F, Dupont L. The diagnosis of cystic fibrosis. Presse Med 2017; 46:e97-e108. [PMID: 28576637 DOI: 10.1016/j.lpm.2017.04.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 04/18/2017] [Accepted: 04/27/2017] [Indexed: 01/09/2023] Open
Abstract
Establishing the diagnosis of cystic fibrosis (CF) is straight forward in the majority of patients: they present with a clear clinical picture (most frequently chronic respiratory symptoms plus malabsorption), the sweat chloride value is>60mmol/L and two known disease causing CFTR mutations are identified. In less than 5% of subjects, mainly those with a milder or limited phenotype, the diagnostic process is more complex, because initial diagnostic test results are inconclusive: sweat chloride concentration in the intermediate range, less than 2 CF causing mutations identified or both. These patients should be referred to expert centers where bioassays of CFTR function like nasal potential difference measurement or intestinal current measurement can be done. Still, in some patients, despite symptoms compatible with CF and some indication of CFTR dysfunction (e.g. only intermediate sweat chloride value), diagnostic criteria are not met (e.g. only 1 CFTR mutation identified). For these subjects, the term CFTR related disorder (CFTR-RD) is used. Patients with disseminated bronchiectasis, congenital bilateral absence of the vas deferens and acute or recurrent pancreatitis may fall in this category. CF has a very wide disease spectrum and increasingly the diagnosis is being made during adult life, mainly in subjects with milder phenotypes. In many countries, nationwide CF newborn screening (NBS) has been introduced. In screen positive babies, the diagnosis of CF must be confirmed by a sweat test demonstrating a sweat chloride concentration above 60mmol/L. To achieve the benefit of NBS, every baby in whom the diagnosis of CF is confirmed must receive immediate follow-up and treatment in a CF reference center. CF NBS is not full proof: some diagnoses will be missed and in some babies the diagnosis cannot be confirmed nor ruled out with certainty. Screening algorithms that include gene sequencing will detect a high number of such babies that are screen positive with an inconclusive diagnosis (CFSPID). Even in 2016, the most reliable and widely available diagnostic test for CF is the measurement of chloride concentration in sweat. The method of choice is sweat induction by pilocarpine iontophoresis, followed by sweat collection on a gauze or filter paper or in a Macroduct coil. Since mutation specific therapies have become available, it is important to identify the mutations responsible for CF in each individual patient.
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Affiliation(s)
- Kris De Boeck
- University of Leuven, Department of Pulmonology, 3000 Leuven, Belgium.
| | | | - Lieven Dupont
- University of Leuven, Department of Pulmonology, Leuven, Belgium
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Abstract
Cystic Fibrosis (CF) is a rare, multisystem disease leading to significant morbidity and mortality. CF is caused by defects in the cystic fibrosis transmembrane conductance regulator protein (CFTR), a chloride and bicarbonate transporter. Early diagnosis and access to therapies provides benefits in nutrition, pulmonary health, and cognitive ability. Several screening and diagnostic tests are available to support a diagnosis. We discuss the characteristics of screening and diagnostic tests for CF and guideline-based algorithms using these tools to establish a diagnosis. We discuss classification and management of common "diagnostic dilemmas," including the CFTR-related metabolic syndrome and other CFTR-associated diseases.
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Affiliation(s)
- John Brewington
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, MLC 2021, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - J P Clancy
- Division of Pulmonary Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, MLC 2021, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
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Sad IR, Higa LYS, Leal T, Martins RDS, de Almeida AC, Ramos EG, de Cabello GMK, Peixoto MVM. Repeatability and Diagnostic Value of Nasal Potential Difference in a Genetically Admixed Population. J Clin Med Res 2015; 8:15-24. [PMID: 26668678 PMCID: PMC4676341 DOI: 10.14740/jocmr2312w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/18/2015] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The genetic diversity of the Brazilian population results from three ethnic groups admixture: Europeans, Africans and Amerindians, thus increasing the difficulty of performing cystic fibrosis (CF) diagnosis. The nasal potential difference (NPD) evaluates the cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) activity. Despite being a useful CF diagnostic test and a biomarker of CFTR-modulator drugs, it is also highly operator dependent. Therefore, it may be difficult to get accurate results and to interpret them. Wilschanski and Sermet scores were proposed to address these issues. This study aimed to evaluate repeatability and diagnostic value of NPD parameters and Wilschanski and Sermet scores in a CF center in Rio de Janeiro. METHODS NPD was performed in 78 subjects. Maximal PD, amiloride response, total chloride response, and Wilschanski and Sermet scores were explored as means (confidence interval, CI). One-way ANOVA was used to compare mean differences and Scheffe test was used to pair-wise comparisons. Repeatability was evaluated by scatter and Bland-Altman plots. The Ethics Committee of the CF Center has approved the study protocol. Parents and adult participants signed an informed consent form. RESULTS Forty-eight healthy-volunteers, 19 non-CF and 11 CF patients were enrolled in this study. Significant differences were found when comparing CF patients' NPD parameters to the other two groups (P = 0.000). Moreover, no significant differences were found when parameters from non-CF patients were compared with those from healthy volunteers (P > 0.05). The means of NPD parameters and diagnostic scores of each group were in concordance with disease/non-disease conditions. The repeatability data - Wilschanski and Sermet and NPD - allow NPD to be performed in this Brazilian CF Center. CONCLUSIONS The present study gathered consistent data for Bland-Altman plots. The results of Wilschanski and Sermet diagnostic scores suggest that they were concordant with CF/non-CF conditions. More NPD tests should be performed in the Rio de Janeiro CF dynamic cohort to contribute to international NPD validation studies and to provide NPD as a biomarker in Brazil.
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Affiliation(s)
- Izabela Rocha Sad
- Pediatric Pulmonology, Pediatric Department, Fernandes Figueira National Institute of Woman, Child and Adolescent Health, Oswaldo Cruz Foundation/FIOCRUZ, Rio de Janeiro, Brazil
| | - Laurinda Yoko Shinzato Higa
- Pediatric Pulmonology, Pediatric Department, Fernandes Figueira National Institute of Woman, Child and Adolescent Health, Oswaldo Cruz Foundation/FIOCRUZ, Rio de Janeiro, Brazil
| | - Teresinha Leal
- Louvain Center for Toxicology and Applied Pharmacology (LTAP), Institut de Recherche Experimentale et Clinique (IREC) Universite Catholique de Louvain, Brussels, Belgium
| | - Raisa da Silva Martins
- Pediatric Pulmonology, Pediatric Department, Fernandes Figueira National Institute of Woman, Child and Adolescent Health, Oswaldo Cruz Foundation/FIOCRUZ, Rio de Janeiro, Brazil
| | - Ana Claudia de Almeida
- Laboratory of Quantitative Methods, Fernandes Figueira National Institute of Woman, Child and Adolescent Health, Oswaldo Cruz Foundation/FIOCRUZ, Rio de Janeiro, Brazil
| | - Eloane Goncalves Ramos
- Clinical Research Unit, Fernandes Figueira National Institute of Woman, Child and Adolescent Health, Oswaldo Cruz Foundation/FIOCRUZ, Rio de Janeiro, Brazil
| | - Giselda Maria Kalil de Cabello
- Laboratory of Human Genetics, Oswaldo Cruz Institute, Oswaldo Cruz Foundation/FIOCRUZ, Pavilhao Leonidas Deane, sala 611, Rio de Janeiro, Brazil
| | - Maria Virginia Marques Peixoto
- Laboratory of Quantitative Methods, Fernandes Figueira National Institute of Woman, Child and Adolescent Health, Oswaldo Cruz Foundation/FIOCRUZ, Rio de Janeiro, Brazil
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Vermeulen F, Proesmans M, Boon M, De Boeck K. Improved repeatability of nasal potential difference with a larger surface catheter. J Cyst Fibros 2014; 14:317-23. [PMID: 25439742 DOI: 10.1016/j.jcf.2014.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 08/13/2014] [Accepted: 08/18/2014] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To increase the power of nasal potential difference (NPD) as a biomarker of CFTR function, improvement of its repeatability is needed. We evaluated the improvement in repeatability resulting from measuring NPD (1) over a larger surface area and (2) at a fixed location. METHODS To assess repeatability, NPD was measured on two occasions with a new method using a larger surface catheter at fixed locations on the nasal floor (LSC-floor(5cm) and LSC-floor(3cm)) or at the most negative basal potential (LSC-floor(max)); with a sidehole catheter on the nasal floor at 5 cm) from the nasal margin (SHC-floor(5cm)) or at the most negative potential (SHC-floor(max)); and with an endhole catheter below the inferior surface of the lower turbinate at the most negative potential (EHC-turb(max)). RESULTS The within-subject standard deviation (S(w)) for repeated measurements of the total chloride response in the controls was smallest with the LSC-floor at a fixed location (LSC-floor(5cm) 3.1 mV; 95% CI 2.3-4.6 mV) and highest with the SHC-floor (SHC-floor(max) 14.6 mV; 95% CI 10.9-22.2 mV) or the EHC-turbinate (EHC-turb(max) 12.5 mV; 95% CI 10.7-23.0 mV) at the most negative basal potential. Measuring with the LSC-floor at the maximal potential increased the Sw (LSC-floor(max) 8.8 mV, 95% CI 6.0-16.1 mV, p=0.009 vs LSC-floor(5cm)), while measuring with the SHC-floor at a fixed location slightly decreased the Sw (SHC-floor(5cm) 9.8 mV, 95% CI 8.9-20.6 mV, p=0.06 vs SHC-floor(max)). In patients with cystic fibrosis, the S(w) was comparable, between 2.2 mV and 4.3 mV. Sample size calculations for trials using NPD to assess changes in ion transport showed that the number of subjects to be included could be approximately halved measuring with the larger surface catheter at a fixed location vs SHC or EHC at fixed locations. CONCLUSION Measuring the NPD at a fixed location and over a larger surface resulted in increased repeatability and thereby also power as a biomarker of CFTR modulation.
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Affiliation(s)
- François Vermeulen
- CF Center, Department of Pediatrics, University Hospital of Leuven, Leuven, Belgium.
| | - Marijke Proesmans
- CF Center, Department of Pediatrics, University Hospital of Leuven, Leuven, Belgium
| | - Mieke Boon
- CF Center, Department of Pediatrics, University Hospital of Leuven, Leuven, Belgium
| | - Kris De Boeck
- CF Center, Department of Pediatrics, University Hospital of Leuven, Leuven, Belgium
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16
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Keenan K, Avolio J, Rueckes-Nilges C, Tullis E, Gonska T, Naehrlich L. Nasal potential difference: Best or average result for CFTR function as diagnostic criteria for cystic fibrosis? J Cyst Fibros 2014; 14:310-6. [PMID: 25300456 DOI: 10.1016/j.jcf.2014.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 09/11/2014] [Accepted: 09/12/2014] [Indexed: 12/23/2022]
Abstract
BACKGROUND The current practice of averaging the nasal potential difference (NPD) results of right and left nostril measurements reduce inter-individual variability but may underestimate individual CFTR function. METHODS Best NPD response to Cl(-)-free and isoproterenol perfusion (=largest ΔPD(0Cl/Iso)) from the right and left nostril was compared to the average result in 13 cystic fibrosis (CF), 78 query-CF patients and 22 healthy controls from 2 cohorts. RESULTS Despite moderate to good correlation (p<0.001) between right and left measured ΔPD(0Cl/Iso), we observed large differences in some individuals. A comparison of average versus best ΔPD(0Cl/Iso) showed only moderate agreement (Giessen κ=0.538; Toronto κ=0.607). Averaging ΔPD(0Cl/Iso) showed a lower composite chloride response compared to best ΔPD(0Cl/Iso) and altered diagnostic NPD interpretation in 30 of 113 (27%) subjects. CONCLUSIONS The current practice of averaging the NPD results of right and left nostril measurements leads to an underestimation of the individual CFTR function and should be reconsidered.
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Affiliation(s)
- Katherine Keenan
- Division of Paediatric Gastroenterology, Hepatology and Nutrition, University of Toronto and Physiology and Experimental Medicine, Research Institute, the Hospital for Sick Children, Toronto, Ontario, Canada.
| | - Julie Avolio
- Division of Paediatric Gastroenterology, Hepatology and Nutrition, University of Toronto and Physiology and Experimental Medicine, Research Institute, the Hospital for Sick Children, Toronto, Ontario, Canada.
| | | | - Elizabeth Tullis
- Department of Medicine, University of Toronto and Division of Respirology and Keenan Research Centre of Li Ka Shing Knowledge Institute St. Michael's Hospital, Toronto, Ontario, Canada.
| | - Tanja Gonska
- Division of Paediatric Gastroenterology, Hepatology and Nutrition, University of Toronto and Physiology and Experimental Medicine, Research Institute, the Hospital for Sick Children, Toronto, Ontario, Canada.
| | - Lutz Naehrlich
- Department of Pediatrics, Justus-Liebig-University Giessen, Giessen, Germany.
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Xi J, Si XA, Gaide R. Electrophoretic particle guidance significantly enhances olfactory drug delivery: a feasibility study. PLoS One 2014; 9:e86593. [PMID: 24497957 PMCID: PMC3908962 DOI: 10.1371/journal.pone.0086593] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 12/17/2013] [Indexed: 11/18/2022] Open
Abstract
Background Intranasal olfactory drug delivery provides a non-invasive method that bypasses the Blood-Brain-Barrier and directly delivers medication to the brain and spinal cord. However, a device designed specifically for olfactory delivery has not yet been found. Methods In this study, a new delivery method was proposed that utilized electrophoretic forces to guide drug particles to the olfactory region. The feasibility of this method was numerically evaluated in both idealized 2-D and anatomically accurate 3-D nose models. The influence of nasal airflow, electrode strength, and drug release position were also studied on the olfactory delivery efficiency. Findings Results showed that by applying electrophoretic forces, the dosage to the olfactory region was significantly enhanced. In both 2-D and 3-D cases, electrophoretic-guided delivery achieved olfactory dosages nearly two orders of magnitude higher than that without electrophoretic forces. Furthermore, releasing drugs into the upper half of the nostril (i.e., partial release) led to olfactory dosages two times higher than releasing drugs over the entire area of the nostril. By combining the advantages of pointed drug release and appropriate electrophoretic guidance, olfactory dosages of more than 90% were observed as compared to the extremely low olfactory dosage (<1%) with conventional inhaler devices. Conclusion Results of this study have important implications in developing personalized olfactory delivery protocols for the treatment of neurological disorders. Moreover, a high sensitivity of olfactory dosage was observed in relation to different pointed release positions, indicating the importance of precise particle guidance for effective olfactory delivery.
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Affiliation(s)
- Jinxiang Xi
- Department of Mechanical and Biomedical Engineering, Central Michigan University, Mount Pleasant, Michigan, United States of America
- * E-mail:
| | - Xiuhua A. Si
- Department of Engineering, Calvin College, Grand Rapids, Michigan, United States of America
| | - Rachel Gaide
- Department of Engineering, Calvin College, Grand Rapids, Michigan, United States of America
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Rowe SM, Liu B, Hill A, Hathorne H, Cohen M, Beamer JR, Accurso FJ, Dong Q, Ordoñez CL, Stone AJ, Olson ER, Clancy JP. Optimizing nasal potential difference analysis for CFTR modulator development: assessment of ivacaftor in CF subjects with the G551D-CFTR mutation. PLoS One 2013; 8:e66955. [PMID: 23922647 PMCID: PMC3724869 DOI: 10.1371/journal.pone.0066955] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 05/13/2013] [Indexed: 11/18/2022] Open
Abstract
Nasal potential difference (NPD) is used as a biomarker of the cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) activity. We evaluated methods to detect changes in chloride and sodium transport by NPD based on a secondary analysis of a Phase II CFTR-modulator study. Thirty-nine subjects with CF who also had the G551D-CFTR mutation were randomized to receive ivacaftor (Kalydeco™; also known as VX-770) in four doses or placebo twice daily for at least 14 days. All data were analyzed by a single investigator who was blinded to treatment assignment. We compared three analysis methods to determine the best approach to quantify changes in chloride and sodium transport: (1) the average of both nostrils; (2) the most-polarized nostril at each visit; and (3) the most-polarized nostril at screening carried forward. Parameters of ion transport included the PD change with zero chloride plus isoproterenol (CFTR activity), the basal PD, Ringer's PD, and change in PD with amiloride (measurements of ENaC activity), and the delta NPD (measuring CFTR and ENaC activity). The average and most-polarized nostril at each visit were most sensitive to changes in chloride and sodium transport, whereas the most-polarized nostril at screening carried forward was less discriminatory. Based on our findings, NPD studies should assess both nostrils rather than a single nostril. We also found that changes in CFTR activity were more readily detected than changes in ENaC activity, and that rigorous standardization was associated with relatively good within-subject reproducibility in placebo-treated subjects (±2.8 mV). Therefore, we have confirmed an assay of reasonable reproducibility for detecting chloride-transport improvements in response to CFTR modulation.
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Affiliation(s)
- Steven M. Rowe
- University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Bo Liu
- University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Aubrey Hill
- University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Heather Hathorne
- University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Morty Cohen
- Seattle Children's Hospital, Seattle, Washington, United States of America
| | - John R. Beamer
- Seattle Children's Hospital, Seattle, Washington, United States of America
| | - Frank J. Accurso
- University of Colorado Denver, Aurora, Colorado, United States of America
| | - Qunming Dong
- Vertex Pharmaceuticals Incorporated, Cambridge, Massachusetts, United States of America
| | - Claudia L. Ordoñez
- Vertex Pharmaceuticals Incorporated, Cambridge, Massachusetts, United States of America
| | - Anne J. Stone
- Vertex Pharmaceuticals Incorporated, Cambridge, Massachusetts, United States of America
| | - Eric R. Olson
- Vertex Pharmaceuticals Incorporated, Cambridge, Massachusetts, United States of America
| | - John P. Clancy
- Cincinnati Children's Hospital Medical Center and the University of Cincinnati, Cincinnati, Ohio, United States of America
- * E-mail:
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Leonard A, Leal T, Lebecque P. [Mucoviscidosis: CFTR mutation-specific therapy: a ray of sunshine in a cloudy sky]. Arch Pediatr 2012. [PMID: 23199563 DOI: 10.1016/j.arcped.2012.10.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
There is a need to find a cure for pulmonary disease in cystic fibrosis (CF), though full benefit of this approach will be restricted to those patients with well-preserved lungs. The most promising route is currently that of a pharmacological mutation-specific approach aiming at correcting the mechanism by which mutations lead to impairment of chloride conductance across respiratory epithelial cells. In the past 14years, 7 candidate drugs (CPX, 4PBA, gentamicin, PTC124, VX-770 or Ivacaftor, VX-809 or Lumacaftor, and Miglustat) have been investigated in CF patients. A postulate of 14 out of the 15 published studies has been that an effective agent had to improve total chloride secretion as assessed in vivo by nasal potential difference measurements. The present review casts a critical look at these studies. Apparent inconsistencies are discussed as well as possible limitations of nasal potential difference measurements as outcome parameters in these trials. Primarily targeting a mutation carried by less than 2% of French CF patients, the 2 Ivacaftor studies could well be a milestone on the long road toward a cure for CF. However, further data on safety and long-term efficacy are obviously needed and the current price of this medication in the US would make it unaffordable for European patients.
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Affiliation(s)
- A Leonard
- Unité de pneumologie pédiatrique et mucoviscidose, cliniques Saint-Luc, université de Louvain, Bruxelles, Belgique.
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Leonard A, Lebecque P, Dingemanse J, Leal T. Miglustat effects on the basal nasal potential differences in cystic fibrosis. J Cyst Fibros 2012; 12:89. [PMID: 22727721 DOI: 10.1016/j.jcf.2012.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 06/05/2012] [Indexed: 10/28/2022]
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Leonard A, Lebecque P, Dingemanse J, Leal T. A randomized placebo-controlled trial of miglustat in cystic fibrosis based on nasal potential difference. J Cyst Fibros 2012; 11:231-6. [PMID: 22281182 DOI: 10.1016/j.jcf.2011.12.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 12/16/2011] [Accepted: 12/17/2011] [Indexed: 10/14/2022]
Abstract
BACKGROUND Preclinical data suggest that miglustat could restore the function of the cystic fibrosis transmembrane conductance regulator gene in cystic fibrosis cells. METHODS Single-center, randomized, double-blind, placebo-controlled, crossover Phase II study in 11 patients (mean±SD age, 26.3±7.7 years) homozygous for the F508del mutation received oral miglustat 200 mgt.i.d. or placebo for two 8-day cycles separated by a 14-day washout period. The primary endpoint was the change in total chloride secretion (TCS) assessed by nasal potential difference. RESULTS No statistically significant changes in TCS, sweat chloride values or FEV(1) were detected. Pharmacokinetic and safety were similar to those observed in patients with other diseases exposed to miglustat. CONCLUSIONS There was no evidence of a treatment effect on any nasal potential difference variable. Further studies with miglustat need to adequately address criteria for assessment of nasal potential difference.
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Affiliation(s)
- Anissa Leonard
- Pediatric Pulmonology & Cystic Fibrosis Unit, Cliniques St Luc, Université catholique de Louvain, 10 Avenue Hippocrate, 1200 Brussels, Belgium.
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Leonard A, Lubamba B, Dhooghe B, Noel S, Wallemacq P, Lebecque P, Leal T. Comparative Variability of Nasal Potential Difference Measurements in Human and Mice. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ojrd.2012.22007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Defective CFTR expression and function are detectable in blood monocytes: development of a new blood test for cystic fibrosis. PLoS One 2011; 6:e22212. [PMID: 21811577 PMCID: PMC3141019 DOI: 10.1371/journal.pone.0022212] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2010] [Accepted: 06/21/2011] [Indexed: 12/22/2022] Open
Abstract
Background Evaluation of cystic fibrosis transmembrane conductance regulator (CFTR) functional activity to assess new therapies and define diagnosis of cystic fibrosis (CF) is cumbersome. It is known that leukocytes express detectable levels of CFTR but the molecule has not been characterized in these cells. In this study we aim at setting up and validating a blood test to evaluate CFTR expression and function in leukocytes. Description Western blot, PCR, immunofluorescence and cell membrane depolarization analysis by single-cell fluorescence imaging, using the potential-sensitive DiSBAC2(3) probe were utilized. Expression of PKA phosphorylated, cell membrane-localized CFTR was detected in non-CF monocytes, being undetectable or present in truncated form in monocytes derived from CF patients presenting with nonsense mutations. CFTR agonist administration induced membrane depolarization in monocytes isolated from non-CF donors (31 subjects) and, to a lesser extent, obligate CFTR heterozygous carriers (HTZ: 15 subjects), but it failed in monocytes from CF patients (44 subjects). We propose an index, which values in CF patients are significantly (p<0.001) lower than in the other two groups. Nasal Potential Difference, measured in selected subjects had concordant results with monocytes assay (Kappa statistic 0.93, 95%CI: 0.80–1.00). Results and Significance CFTR is detectable and is functional in human monocytes. We also showed that CFTR-associated activity can be evaluated in 5 ml of peripheral blood and devise an index potentially applicable for diagnostic purposes and both basic and translational research: from drug development to evaluation of functional outcomes in clinical trials.
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De Boeck K, Derichs N, Fajac I, de Jonge H, Bronsveld I, Sermet I, Vermeulen F, Sheppard D, Cuppens H, Hug M, Melotti P, Middleton P, Wilschanski M. New clinical diagnostic procedures for cystic fibrosis in Europe. J Cyst Fibros 2011; 10 Suppl 2:S53-66. [DOI: 10.1016/s1569-1993(11)60009-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Vermeulen F, Proesmans M, Feyaerts N, De Boeck K. Nasal potential measurements on the nasal floor and under the inferior turbinate: does it matter? Pediatr Pulmonol 2011; 46:145-52. [PMID: 20865746 DOI: 10.1002/ppul.21333] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 06/28/2010] [Accepted: 07/02/2010] [Indexed: 11/10/2022]
Abstract
AIM Measurement of nasal potential difference (NPD) is increasingly used as diagnostic test for cystic fibrosis (CF) and for in vivo evaluation of treatments aimed at correcting the defective function of the cystic fibrosis transmembrane regulator (CFTR) protein. Several methods are used to measure NPD. This study explores the influence of the site of measurement and compares NPD results obtained on the nasal floor and under the inferior turbinate. METHODS NPD was measured in 34 CF, 26 heterozygote, and 61 control subjects. In every subject, measurements were taken simultaneously under the inferior turbinate in one nostril, and on the nasal floor in the other nostril. Criteria for interpretable tracings were predefined. Repeat measurements were done in 57 persons. RESULTS More interpretable tracings were obtained under the turbinate (120/124) than on the nasal floor (109/124), P = 0.015. Within each subject group, mean values obtained were similar for maximal basal potential, response to amiloride, and total chloride response. Both techniques discriminate well between CF and controls. Repeatability was similar with both methods: mean differences between two measurements approximated zero for most values. Also after correction for different number of interpretable tracings, simulation of sample size calculation for use in CFTR corrective trials was slightly in favor of measurements obtained on the nasal floor. CONCLUSION NPD measurements under the inferior turbinate and on the nasal floor have similar discriminative power for diagnostic use. Measurements under the turbinate result in a slightly higher proportion of interpretable tracings but sample size calculation slightly favors the nasal floor method.
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Affiliation(s)
- François Vermeulen
- Cystic Fibrosis Reference Centre, University Hospital Gasthuisberg, Catholic University of Leuven, Leuven, Belgium.
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26
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Rowe SM, Clancy JP, Wilschanski M. Nasal potential difference measurements to assess CFTR ion channel activity. Methods Mol Biol 2011; 741:69-86. [PMID: 21594779 DOI: 10.1007/978-1-61779-117-8_6] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Nasal potential difference measurement is used to measure the voltage across the nasal epithelium, which results from transepithelial ion transport and reflects in part CFTR function. The electrophysiologic abnormality in cystic fibrosis was first described 30 years ago and correlates with features of the CF phenotype. NPD measurement is an important in vivo research and diagnostic tool, and is used to assess the efficacy of new treatments such as gene therapy and ion transport modulators. This chapter will elaborate on the electrophysiological principles behind the test, the equipment required, the methods, and the analysis of the data.
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Affiliation(s)
- Steven M Rowe
- Department of Medicine, University of Alabama, Birmingham, AL 35294-0006, USA.
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Abstract
The report of the first CF patients to receive CFTR gene therapy appeared in 1993; since then, there have been over 20 clinical trials of both viral and non-viral gene transfer agents. These have largely been single dose to either nose or lower airway and have been designed around molecular or bioelectrical outcome measures. Both transgene mRNA and partial correction of chloride secretion have been reported, although sodium hyperabsorption has not been improved. The UK CF Gene Therapy Consortium is focussed on a clinical programme to establish whether these proof-of-principle measures translate into clinical benefit. Here, we discuss the considerations in designing such a programme, focusing in particular on our choice of the optimal, currently available delivery method and established and novel outcome measures. We highlight the logistic and regulatory complexities of such a clinical programme and finally, we look to the future and consider possible alternative strategies.
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Affiliation(s)
- Jane C Davies
- Department of Gene Therapy, Imperial College London, SW3 6LR, London, UK.
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28
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Middleton PG, House HH. Measurement of airway ion transport assists the diagnosis of cystic fibrosis. Pediatr Pulmonol 2010; 45:789-95. [PMID: 20597077 DOI: 10.1002/ppul.21253] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The nasal potential difference (PD) demonstrates the increased Na absorption and decreased Cl secretion typically found in cystic fibrosis (CF). It provides useful information for diagnostic purposes and measures the effect of new treatments on the ion transport defects found in CF. This study summarizes the nasal PD results in the respiratory tract of different groups of subjects, examines the responses in squamous epithelia and evaluates new ways to consider nasal PD results.Nasal PD was tested using the standard protocol of baseline, amiloride, low chloride, and isoproterenol solutions in 40 healthy non-CF volunteers, 46 CF subjects, and 78 subjects referred for investigation of possible CF. Nasal PD was also measured in the squamous epithelium at the anterior nares in six non-CF subjects.Baseline PD was elevated in the CF (47.5 (1.7) mV) compared with non-CF subjects: (14.0 (0.8) mV, P < 0.00001). Combined [Cl + Isop] responses were smaller in the CF (-0.1 (0.4) mV) compared with the non-CF subjects (26.2 (1.2) mV, P < 0.00001). In the diagnostic cohort 58 were given a non-CF diagnosis, 16 had CF confirmed, but 4 remained indeterminate. Separate consideration of Na and Cl transport was easily portrayed through X-Y plots. Finally, the nasal PD responses of squamous epithelium showed high baseline values, but little response to amiloride and low chloride solutions.The nasal PD provides useful information in the diagnostic algorithm of CF, and in the delineation of the two ion transport defects characteristically found in the respiratory epithelium. Avoidance of the squamous epithelium remains an important consideration for those performing and interpreting nasal PD responses.
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Affiliation(s)
- Peter G Middleton
- Cystic Fibrosis Unit, Ludwig Engel Centre for Respiratory Research, Westmead Millennium Institute, University of Sydney at Westmead, Westmead, NSW, Australia.
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29
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Solomon GM, Konstan MW, Wilschanski M, Billings J, Sermet-Gaudelus I, Accurso F, Vermeulen F, Levin E, Hathorne H, Reeves G, Sabbatini G, Hill A, Mayer-Hamblett N, Ashlock M, Clancy JP, Rowe SM. An international randomized multicenter comparison of nasal potential difference techniques. Chest 2010; 138:919-28. [PMID: 20472865 DOI: 10.1378/chest.10-0179] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND The transepithelial nasal potential difference (NPD) is used to assess cystic fibrosis transmembrane conductance regulator (CFTR) activity. Unreliability, excessive artifacts, and lack of standardization of current testing systems can compromise its use as a diagnostic test and outcome measure for clinical trials. METHODS To determine whether a nonperfusing (agar gel) nasal catheter for NPD measurement is more reliable and less susceptible to artifacts than a continuously perfusing nasal catheter, we performed a multicenter, randomized, crossover trial comparing a standardized NPD protocol using an agar nasal catheter with the same protocol using a continuously perfusing catheter. The data capture technique was identical in both protocols. A total of 26 normal adult subjects underwent NPD testing at six different centers. RESULTS Artifact frequency was reduced by 75% (P < .001), and duration was less pronounced using the agar catheter. The measurement of sodium conductance was similar between the two catheter methods, but the agar catheter demonstrated significantly greater CFTR-dependent hyperpolarization, because Δ zero Cl- + isoproterenol measurements were significantly more hyperpolarized with the agar catheter (224.2 ± 12.9 mV with agar vs 18.2 ± 9.1 mV with perfusion, P < .05). CONCLUSIONS The agar nasal catheter approach demonstrates superior reliability compared with the perfusion nasal catheter method for measurement of NPD. This nonperfusion catheter method should be considered for adoption as a standardized protocol to monitor CFTR activity in clinical trials.
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Affiliation(s)
- George M Solomon
- University of Alabama at Birmingham, Birmingham, AL 35294-0006, USA
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30
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Abstract
This review focuses on the pathobiology of the gastrointestinal and hepatic manifestations of cystic fibrosis (CF) disease in relation to their genetic basis in mutations of the CF transmembrane conductance regulator (CFTR) gene. It reviews the nature of the CFTR protein, a categorization of the types of gene mutations underlying CF's various manifestations, and the ways in which absent or reduced CFTR produces various functional abnormalities in the different organs affected by CF. Subsequently, the particular organ-related clinical manifestations of CF directly associated with loss of CFTR function are addressed. Thereafter, the review discusses some of the complexities of the genotype-phenotype relationships related to milder mutations or complex genetic disorders in which CFTR abnormalities interact with other genetic and environmental factors, and the potential diagnostic roles of sweat testing or other electrophysiologic testing. This discussion examines secondary gastrointestinal manifestations of CF and the particular cases of diseases that may be related to abnormalities of CFTR.
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Affiliation(s)
- Michael Wilschanski
- Pediatric Gastroenterology Unit, Division of Pediatrics, Hadassah University Hospitals, Hebrew University, POB 24035, Jerusalem, Israel.
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31
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Kerem E, Hirawat S, Armoni S, Yaakov Y, Shoseyov D, Cohen M, Nissim-Rafinia M, Blau H, Rivlin J, Aviram M, Elfring GL, Northcutt VJ, Miller LL, Kerem B, Wilschanski M. Effectiveness of PTC124 treatment of cystic fibrosis caused by nonsense mutations: a prospective phase II trial. Lancet 2008; 372:719-27. [PMID: 18722008 DOI: 10.1016/s0140-6736(08)61168-x] [Citation(s) in RCA: 316] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND In about 10% of patients worldwide and more than 50% of patients in Israel, cystic fibrosis results from nonsense mutations (premature stop codons) in the messenger RNA (mRNA) for the cystic fibrosis transmembrane conductance regulator (CFTR). PTC124 is an orally bioavailable small molecule that is designed to induce ribosomes to selectively read through premature stop codons during mRNA translation, to produce functional CFTR. METHODS This phase II prospective trial recruited adults with cystic fibrosis who had at least one nonsense mutation in the CFTR gene. Patients were assessed in two 28-day cycles. During the first cycle, patients received PTC124 at 16 mg/kg per day in three doses every day for 14 days, followed by 14 days without treatment; in the second cycle, patients received 40 mg/kg of PTC124 in three doses every day for 14 days, followed by 14 days without treatment. The primary outcome had three components: change in CFTR-mediated total chloride transport; proportion of patients who responded to treatment; and normalisation of chloride transport, as assessed by transepithelial nasal potential difference (PD) at baseline, at the end of each 14-day treatment course, and after 14 days without treatment. The trial was registered with who.int/ictrp, and with clinicaltrials.gov, number NCT00237380. FINDINGS Transepithelial nasal PD was evaluated in 23 patients in the first cycle and in 21 patients in the second cycle. Mean total chloride transport increased in the first treatment phase, with a change of -7.1 (SD 7.0) mV (p<0.0001), and in the second, with a change of -3.7 (SD 7.3) mV (p=0.032). We recorded a response in total chloride transport (defined as a change in nasal PD of -5 mV or more) in 16 of the 23 patients in the first cycle's treatment phase (p<0.0001) and in eight of the 21 patients in the second cycle (p<0.0001). Total chloride transport entered the normal range for 13 of 23 patients in the first cycle's treatment phase (p=0.0003) and for nine of 21 in the second cycle (p=0.02). Two patients given PTC124 had constipation without intestinal obstruction, and four had mild dysuria. No drug-related serious adverse events were recorded. INTERPRETATION In patients with cystic fibrosis who have a premature stop codon in the CFTR gene, oral administration of PTC124 to suppress nonsense mutations reduces the epithelial electrophysiological abnormalities caused by CFTR dysfunction.
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Affiliation(s)
- Eitan Kerem
- Hadassah Hebrew University Hospital, Jerusalem, Israel
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Jaron R, Yaakov Y, Rivlin J, Blau H, Bentur L, Yahav Y, Kerem E, Bibi H, Picard E, Wilschanski M. Nasal potential difference in non-classic cystic fibrosis-long term follow up. Pediatr Pulmonol 2008; 43:545-9. [PMID: 18433042 DOI: 10.1002/ppul.20807] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Nasal potential difference (NPD) measurement is an electrophysiological test that assesses cystic fibrosis transmembrane conductance regulator (CFTR) activity and is a recognized diagnostic tool in CF. The aim of this study is to assess in the long term the role of NPD in patients whose diagnosis is questionable. METHODS We performed follow up study on 70 patients with questionable CF (QCF) who were divided previously into two groups according to their NPD results: patients who likely have CF (QCF-CF) (n = 24), and those who likely do not have CF (QCF-non-CF) (n = 46). RESULTS Sixty out of 70 patients were available for study. Sixteen patients in the QCF-CF group were being followed up at CF Centers as opposed to 1 in the QCF-non-CF group (P < 0.01). Seven patients from the QCF-CF group developed sinusitis during the follow up years compared to none from the QCF-non-CF group. During the years of the follow up, 17 QCF-non-CF patients were diagnosed with other medical conditions that could explain their previous symptoms. On repeated NPD measurement in the QCF-CF group, the results were similar to the original test. CONCLUSIONS This study supports the diagnostic role of NPD measurement. Larger cohort studies are required for confirmation.
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Affiliation(s)
- Ranit Jaron
- Cystic Fibrosis Center, Hadassah University Hospital, Jerusalem, Israel
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Leal T, Fajac I, Wallace HL, Lebecque P, Lebacq J, Hubert D, Dall'Ava J, Dusser D, Ganesan AP, Knoop C, Cumps J, Wallemacq P, Southern KW. Airway ion transport impacts on disease presentation and severity in cystic fibrosis. Clin Biochem 2008; 41:764-72. [PMID: 18424267 DOI: 10.1016/j.clinbiochem.2008.03.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 03/15/2008] [Accepted: 03/23/2008] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Abnormal airway ion transport is a feature of cystic fibrosis. The aim of this study was to investigate whether distinct components of ion transport are associated with the clinical expression and severity of the disease. DESIGN AND METHODS Univariate and multivariate analyses were used to study interaction effects between nasal potential difference parameters and clinical status, recorded at stable conditions, in 75 F508del homozygous young adults. RESULTS All patients demonstrated increased sodium and reduced chloride conductances. Less sodium transport abnormalities were related to better respiratory function and nutrition. Presentation with digestive symptoms at diagnosis was associated with lower chloride conductance. With an accuracy of 85% good nutritional status was linked to more preserved lung function, increasing age and more preserved chloride conductance. CONCLUSIONS Ion transport abnormalities have distinct clinical outcomes. Sodium conductance relates to respiratory function and nutrition; chloride conductance to nutrition and presentation with digestive symptoms at diagnosis.
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Affiliation(s)
- Teresinha Leal
- Clinical Chemistry, Université Catholique de Louvain, Brussels, Belgium
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