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McGarry ME, Gibb ER, Oates GR, Schechter MS. Left behind: The potential impact of CFTR modulators on racial and ethnic disparities in cystic fibrosis. Paediatr Respir Rev 2022; 42:35-42. [PMID: 35277357 PMCID: PMC9356388 DOI: 10.1016/j.prrv.2021.12.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 12/16/2021] [Indexed: 12/16/2022]
Abstract
The advent of CFTR modulators, a genomic specific medication, revolutionized the treatment of CF for many patients. However, given that these therapeutics were only developed for specific CFTR mutations, not all people with CF have access to such disease-modifying drugs. Racial and ethnic minority groups are less likely to have CFTR mutations that are approved for CFTR modulators. This exclusion has the potential to widen existing health disparities.
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Affiliation(s)
- Meghan E. McGarry
- Division of Pulmonary Medicine, Department of Pediatrics, University of California San Francisco, San Francisco, CA
| | - Elizabeth R. Gibb
- Division of Pulmonary Medicine, Department of Pediatrics, University of California San Francisco, San Francisco, CA
| | - Gabriela R. Oates
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL
| | - Michael S. Schechter
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Virginia Commonwealth University and Children’s Hospital of Richmond at VCU, Richmond, VA
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2
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Bratcher PE, Yadav S, Shaughnessy CA, Thornell IM, Zeitlin PL. Effect of apical chloride concentration on the measurement of responses to CFTR modulation in airway epithelia cultured from nasal brushings. Physiol Rep 2021; 8:e14603. [PMID: 33038073 PMCID: PMC7547589 DOI: 10.14814/phy2.14603] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/02/2020] [Accepted: 09/18/2020] [Indexed: 12/16/2022] Open
Abstract
INTRODUCTION One method for assessing the in vitro response to CFTR-modulating compounds is by analysis of epithelial monolayers in an Ussing chamber, where the apical and basolateral surfaces are isolated and the potential difference, short-circuit current, and transepithelial resistance can be monitored. The effect of a chloride ion gradient across airway epithelia on transepithelial chloride transport and the magnitude of CFTR modulator efficacy were examined. METHODS CFTR-mediated changes in the potential difference and transepithelial currents of primary human nasal epithelial cell cultures were quantified in Ussing chambers with either symmetrical solutions or reduced chloride solutions in the apical chamber. CFTR activity in homozygous F508del CFTR epithelia was rescued by treatment with VX-661, C4/C18, 4-phenylbutyrate (4-PBA) for 24 hr at 37°C or by incubation at 29°C for 48 hr. RESULTS Imposing a chloride gradient increased CFTR-mediated and CaCC-mediated ion transport. Treatment of F508del CFTR homozygous cells with CFTR modulating compounds increased CFTR activity, which was significantly more evident in the presence of a chloride gradient. This observation was recapitulated with temperature-mediated F508del CFTR correction. CONCLUSIONS Imposing a chloride gradient during Ussing chamber measurements resulted in increased CFTR-mediated ion transport in expanded non-CF and F508del CFTR homozygous epithelia. In F508del CFTR homozygous epithelia, the magnitude of response to CFTR modulating compounds or low temperature was greater when assayed with a chloride gradient compared to symmetrical chloride, resulting in an apparent increase in measured efficacy. Future work may direct which methodologies utilized to quantify CFTR modulator response in vitro are most appropriate for the estimation of in vivo efficacy.
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Affiliation(s)
- Preston E Bratcher
- Department of Pediatrics, National Jewish Health, Denver, CO, USA.,Department of Pediatrics, Anschutz Medical Center, University of Colorado Denver, Aurora, CO, USA
| | - Sangya Yadav
- Department of Pediatrics, National Jewish Health, Denver, CO, USA
| | | | - Ian M Thornell
- Dept. of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Pamela L Zeitlin
- Department of Pediatrics, National Jewish Health, Denver, CO, USA.,Department of Pediatrics, Anschutz Medical Center, University of Colorado Denver, Aurora, CO, USA
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McGarry ME, McColley SA. Cystic fibrosis patients of minority race and ethnicity less likely eligible for CFTR modulators based on CFTR genotype. Pediatr Pulmonol 2021; 56:1496-1503. [PMID: 33470563 PMCID: PMC8137541 DOI: 10.1002/ppul.25285] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/21/2020] [Accepted: 12/31/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Cystic fibrosis transmembrane conductance regulator (CFTR) modulators are disease-modifying medications for cystic fibrosis (CF) and are shown to be efficacious for only specific CFTR mutations. CFTR mutation frequency varies by ancestry, which is different from but related to demographic racial and ethnic group. Eligibility for CFTR modulator therapy has not been previously reported by race and ethnicity. METHODS We conducted a cross-sectional study of patients in the 2018 CF Foundation Patient Registry. We analyzed the percentage of patients in each US Census defined racial and ethnic group eligible for CFTR modulators based on CFTR mutations approved by the US FDA and then based on both mutations and FDA approval by age. We compared lung function based on CFTR modulator eligibility and prescription. FINDINGS Based on CFTR mutations alone, 92.4% of non-Hispanic White patients, 69.7% of Black/African American patients, 75.6% of Hispanic patients, and 80.5% of other race patients eligible for CFTR modulators. For each CFTR modulator, Black/African American patients were least likely to have eligible mutations, and non-Hispanic White patients were most likely. There was no difference in the disparity between racial and/or ethnic groups with the addition of current FDA approval by age. The lowest pulmonary function in the cohort was seen in non-Hispanic White, Black/African American, and Hispanic patients not eligible for CFTR modulators. INTERPRETATION Patients with CF from minority groups are less likely to be eligible for CFTR modulators. Because people with CF who are racial and ethnic minorities have increased disease severity and earlier mortality, this will further contribute to health disparities.
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Affiliation(s)
- Meghan E McGarry
- Department of Pediatrics, University of California, San Francisco, California, USA
| | - Susanna A McColley
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
- Department of Pediatrics, Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
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Salvatore D, Carnovale V, Iacotucci P, Braggion C, Castellani C, Cimino G, Colangelo C, Francalanci M, Leonetti G, Lucidi V, Manca A, Vitullo P, Ferrara N. Effectivenesss of ivacaftor in severe cystic fibrosis patients and non-G551D gating mutations. Pediatr Pulmonol 2019; 54:1398-1403. [PMID: 31237430 DOI: 10.1002/ppul.24424] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 06/07/2019] [Indexed: 12/30/2022]
Abstract
BACKGROUND Ivacaftor is a significant innovation in the treatment of cystic fibrosis (CF) with gating mutations. A substantial percentage of patients with CF have severe lung involvement, but these patients are usually excluded from phase III clinical trials. Thus, the effectiveness of ivacaftor in this population has not been fully determined. METHODS Data were collected from Italian CF centers with patients enrolled in an ivacaftor compassionate use programme (percent predicted [pp] forced expiratory volume in 1 second [FEV1 ] < 40%, or on lung transplant waiting list, or with a fast worsening trend of lung function). Data were collected for 1 year before and 1 year after ivacaftor commencement. RESULTS Thirteen patients received ivacaftor for a median of 320 days. Mean (SD) ppFEV1 increased from 35.1% (14.3%) before treatment to 46.6% (18.8%) after 12 months of treatment (absolute increase 11.5%, relative increase 32.8%). Mean distance of the 6-minute walking test improved significantly, from 535.1 m before to 611.6 m after 12 months of treatment (P = .002). The number of pulmonary exacerbations decreased significantly, from 57 during the year before ivacaftor to 28 in the year following ivacaftor (P = .0048). Five of the 13 patients (38.5%) had no exacerbations during the 12 months after starting ivacaftor. Median weight increased significantly, from 52.7 kg to 55.6 kg (P = .0031). Mean (SD) sweat chloride concentration decreased significantly, from 99.5 (22.8) mmol/L to 39.3 (15.8) mmol/L (P < .0001). No safety concerns were registered. CONCLUSIONS Ivacaftor was safe and effective in patients with CF with severe lung disease and non-G551D gating mutations.
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Affiliation(s)
| | - Vincenzo Carnovale
- Adult Cystic Fibrosis Center, Department of Translational Medical Sciences, Federico II University of Naples, Naples, Italy
| | - Paola Iacotucci
- Adult Cystic Fibrosis Center, Department of Translational Medical Sciences, Federico II University of Naples, Naples, Italy
| | | | - Carlo Castellani
- Cystic Fibrosis Centre, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | | | | | | | | | - Vincenzina Lucidi
- Cystic Fibrosis Center, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Antonio Manca
- Cystic Fibrosis Center, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Pamela Vitullo
- Cystic Fibrosis Unit, Hospital G. Tatarella, Foggia, Italy
| | - Nicola Ferrara
- Cystic Fibrosis Center, Hospital San Carlo, Potenza, Italy
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Sweat rate analysis of ivacaftor potentiation of CFTR in non-CF adults. Sci Rep 2018; 8:16233. [PMID: 30389955 PMCID: PMC6214959 DOI: 10.1038/s41598-018-34308-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 10/15/2018] [Indexed: 12/14/2022] Open
Abstract
To determine if ivacaftor (Kalydeco) influences non-CF human CFTR function in vivo, we measured CFTR-dependent (C-sweat) and CFTR-independent (M-sweat) rates from multiple identified sweat glands in 8 non-CF adults. The two types of sweating were stimulated sequentially with intradermal injections of appropriate reagents; each gland served as its own control via alternating off-on drug tests on both arms, given at weekly intervals with 3 off and 3 on tests per subject. We compared drug effects on C-sweating stimulated by either high or low concentrations of β-adrenergic cocktail, and on methacholine-stimulated M-sweating. For each subject we measured ~700 sweat volumes from ~75 glands per arm (maximum 12 readings per gland), and sweat volumes were log-transformed for statistical analysis. T-tests derived from linear mixed models (LMMs) were more conservative than the familiar paired sample t-tests, and show that ivacaftor significantly increased C-sweating stimulated by both levels of agonist, with a larger effect in the low cocktail condition; ivacaftor did not increase M-sweat. Concurrent sweat chloride tests detected no effect of ivacaftor. We conclude that ivacaftor in vivo increases the open channel probability (PO) of WT CFTR, provided it is not already maximally stimulated.
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Ivacaftor restores CFTR-dependent sweat gland fluid secretion in cystic fibrosis subjects with S945L alleles. J Cyst Fibros 2018; 17:179-185. [DOI: 10.1016/j.jcf.2017.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Revised: 11/19/2017] [Accepted: 12/11/2017] [Indexed: 12/27/2022]
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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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Char JE, Dunn C, Davies Z, Milla C, Moss RB, Wine JJ. The magnitude of ivacaftor effects on fluid secretion via R117H-CFTR channels: Human in vivo measurements. PLoS One 2017; 12:e0175486. [PMID: 28419121 PMCID: PMC5395152 DOI: 10.1371/journal.pone.0175486] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 03/27/2017] [Indexed: 12/20/2022] Open
Abstract
We optically measured effects of orally available ivacaftor (Kalydeco®) on sweat rates of identified glands in 3 R117H subjects, each having a unique set of additional mutations, and compared them with 5 healthy control subjects tested contemporaneously. We injected β-adrenergic agonists intradermally to stimulate CFTR-dependent 'C-sweat' and methacholine to stimulate 'M-sweat', which persists in CF subjects. We focused on an R117H-7T/F508del subject who produced quantifiable C-sweat off ivacaftor and was available for 1 blinded, 3 off ivacaftor, and 3 on ivacaftor tests, allowing us to estimate in vivo fold-increase in sweat rates produced by ivacaftor's effect on the open probability (PO) of R117H-CFTR. Measured sweat rates must be corrected for sweat losses. With estimated sweat losses of 0.023 to 0.08 nl·gland-1·min-1, ivacaftor increased the average C-sweat rates 3-7 fold, and estimated function as % of WT were 4.1-12% off ivacaftor and 21.9-32% on ivacaftor (larger values reflect increased loss estimates). Based on single tests, an R117H-7T/ R117H-7T subject showed 6-9% WT function off ivacaftor and 28-43% on ivacaftor. Repeat testing of an R117H-5T/F508del subject detected only trace responding to ivacaftor. We conclude that in vivo, R117H PO is strongly increased by ivacaftor, but channel number, mainly determined by variable deletion of exon 10, has a marked influence on outcomes.
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Affiliation(s)
- Jessica E. Char
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
| | - Colleen Dunn
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Zoe Davies
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Carlos Milla
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Richard B. Moss
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Jeffrey J. Wine
- Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California, United States of America
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America
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9
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McGarry ME, Illek B, Ly NP, Zlock L, Olshansky S, Moreno C, Finkbeiner WE, Nielson DW. In vivo and in vitro ivacaftor response in cystic fibrosis patients with residual CFTR function: N-of-1 studies. Pediatr Pulmonol 2017; 52:472-479. [PMID: 28068001 PMCID: PMC5461115 DOI: 10.1002/ppul.23659] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 12/01/2016] [Accepted: 12/02/2016] [Indexed: 01/17/2023]
Abstract
RATIONALE Ivacaftor, a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator, decreases sweat chloride concentration, and improves pulmonary function in 6% of cystic fibrosis (CF) patients with specific CFTR mutations. Ivacaftor increases chloride transport in many other CFTR mutations in non-human cells, if CFTR is in the epithelium. Some CF patients have CFTR in the epithelium with residual CFTR function. The effect of ivacaftor in these patients is unknown. METHODS This was a series of randomized, crossover N-of-1 trials of ivacaftor and placebo in CF patients ≥8 years old with potential residual CFTR function (intermediate sweat chloride concentration, pancreatic sufficient, or mild bronchiectasis on chest CT). Human nasal epithelium (HNE) was obtained via nasal brushing and cultured. Sweat chloride concentration change was the in vivo outcome. Chloride current change in HNE cultures with ivacaftor was the in vitro outcome. RESULTS Three subjects had decreased sweat chloride concentration (-14.8 to -40.8 mmol/L, P < 0.01). Two subjects had unchanged sweat chloride concentration. Two subjects had increased sweat chloride concentration (+23.8 and +27.3 mmol/L, P < 0.001); both were heterozygous for A455E and pancreatic sufficient. Only subjects with decreased sweat chloride concentration had increased chloride current in HNE cultures. CONCLUSIONS Some CF patients with residual CFTR function have decreased sweat chloride concentration with ivacaftor. Increased chloride current in HNE cultures among subjects with decreased sweat chloride concentrations may predict clinical response to ivacaftor. Ivacaftor can increase sweat chloride concentration in certain mutations with unclear clinical effect. Pediatr Pulmonol. 2017;52:472-479. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Meghan E McGarry
- Pediatric Pulmonology, Department of Pediatrics, University of California, San Francisco, California
| | - Beate Illek
- Children's Hospital Oakland Research Institute, Oakland, California
| | - Ngoc P Ly
- Pediatric Pulmonology, Department of Pediatrics, University of California, San Francisco, California
| | - Lorna Zlock
- Department of Pathology, University of California, San Francisco, California
| | - Sabrina Olshansky
- Children's Hospital Oakland Research Institute, Oakland, California.,College of Pharmacy, Touro University, Vallejo, California
| | - Courtney Moreno
- Pediatric Pulmonology, Department of Pediatrics, University of California, San Francisco, California
| | - Walter E Finkbeiner
- Department of Pathology, University of California, San Francisco, California
| | - Dennis W Nielson
- Pediatric Pulmonology, Department of Pediatrics, University of California, San Francisco, California
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Ronan NJ, Fleming C, O'Callaghan G, Maher MM, Murphy DM, Plant BJ. The Role of Ivacaftor in Severe Cystic Fibrosis in a Patient With the R117H Mutation. Chest 2015; 148:e72-e75. [PMID: 26324139 DOI: 10.1378/chest.14-3215] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Cystic fibrosis (CF) conductance transmembrane regulator functions as a chloride (Cl-) channel in multiple organs, including the lungs. More than 1,800 disease-associated mutations have been identified, which can be divided into six classes. In patients with CF due to class III gating mutations, ivacaftor produces significant improvement in lung function, weight, reduction in sweat chloride level, and pulmonary exacerbations by enhancing the probability of chloride channel opening (gating). Although the benefit of ivacaftor in CF due to gating mutations is established, its potential role in patients with CF due to class IV conductance mutations is emerging. We report 6 months' prospective stability of lung function, improved BMI, reduced pulmonary exacerbations, and reduction in sweat chloride level in a patient with severe CF and the class IV R117H mutation. High-resolution CT scan also improved, thus highlighting the potential usefulness of ivacaftor in patients with severe CF due to class IV mutations.
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Affiliation(s)
- Nicola J Ronan
- Cork Adult Cystic Fibrosis Centre; Health Research Board Clinical Research Facility, University College Cork, Cork, Ireland
| | | | - Grace O'Callaghan
- Cork Adult Cystic Fibrosis Centre; Health Research Board Clinical Research Facility, University College Cork, Cork, Ireland
| | - Michael M Maher
- Department of Radiology, University College Cork, Cork University Hospital, Wilton
| | - Desmond M Murphy
- Cork Adult Cystic Fibrosis Centre; Health Research Board Clinical Research Facility, University College Cork, Cork, Ireland
| | - Barry J Plant
- Cork Adult Cystic Fibrosis Centre; Health Research Board Clinical Research Facility, University College Cork, Cork, Ireland.
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Yousef S, Solomon GM, Brody A, Rowe SM, Colin AA. Improved clinical and radiographic outcomes after treatment with ivacaftor in a young adult with cystic fibrosis with the P67L CFTR mutation. Chest 2015; 147:e79-e82. [PMID: 25732475 DOI: 10.1378/chest.14-1198] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The underlying cause of cystic fibrosis (CF) is the loss of epithelial chloride and bicarbonate transport due to mutations in the CF transmembrane conductance regulator (CFTR) gene encoding the CFTR protein. Ivacaftor is a gene-specific CFTR potentiator that augments in vivo chloride transport in CFTR mutations affecting channel gating. Originally approved for the G511D CFTR mutation, ivacaftor is now approved for eight additional alleles exhibiting gating defects and has also been tested in R117H, a CFTR mutation with residual function that exhibits abnormal gating. P67L is a class 4 conductance (nongating) mutation exhibiting residual CFTR function. We report marked clinical improvement, normalization of spirometry, and dramatic reduction in radiographic structural airway changes after > 1 year of treatment with ivacaftor in a young adult with the compound heterozygous genotype P67L/F508del CFTR. The case suggests that ivacaftor may have a potential benefit for patients with CF with nongating mutations.
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Affiliation(s)
- Shatha Yousef
- Division of Pediatric Pulmonology, Miller School of Medicine, University of Miami, Miami, FL
| | - George M Solomon
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Alan Brody
- Departments of Radiology and Pediatrics, Cincinnati Children's Hospital and the University of Cincinnati College of Medicine, Cincinnati, OH
| | - Steven M Rowe
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL.
| | - Andrew A Colin
- Division of Pediatric Pulmonology, Miller School of Medicine, University of Miami, Miami, FL
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Harrison M, Ronan N, Khan K, O'Callaghan G, Murphy D, Plant B. Ivacaftor therapy in siblings with cystic fibrosis-the potential implications of Itraconazole in dosage and efficacy. Pulm Pharmacol Ther 2015; 31:49-50. [DOI: 10.1016/j.pupt.2015.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/13/2015] [Accepted: 01/16/2015] [Indexed: 10/24/2022]
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