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Meng L, Treem W, Heap GA, Chen J. A stacking ensemble machine learning model to predict alpha-1 antitrypsin deficiency-associated liver disease clinical outcomes based on UK Biobank data. Sci Rep 2022; 12:17001. [PMID: 36220873 PMCID: PMC9554039 DOI: 10.1038/s41598-022-21389-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 09/27/2022] [Indexed: 12/29/2022] Open
Abstract
Alpha-1 antitrypsin deficiency associated liver disease (AATD-LD) is a rare genetic disorder and not well-recognized. Predicting the clinical outcomes of AATD-LD and defining patients more likely to progress to advanced liver disease are crucial for better understanding AATD-LD progression and promoting timely medical intervention. We aimed to develop a tailored machine learning (ML) model to predict the disease progression of AATD-LD. This analysis was conducted through a stacking ensemble learning model by combining five different ML algorithms with 58 predictor variables using nested five-fold cross-validation with repetitions based on the UK Biobank data. Performance of the model was assessed through prediction accuracy, area under the receiver operating characteristic (AUROC), and area under the precision-recall curve (AUPRC). The importance of predictor contributions was evaluated through a feature importance permutation method. The proposed stacking ensemble ML model showed clinically meaningful accuracy and appeared superior to any single ML algorithms in the ensemble, e.g., the AUROC for AATD-LD was 68.1%, 75.9%, 91.2%, and 67.7% for all-cause mortality, liver-related death, liver transplant, and all-cause mortality or liver transplant, respectively. This work supports the use of ML to address the unanswered clinical questions with clinically meaningful accuracy using real-world data.
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Affiliation(s)
- Linxi Meng
- Florida State University, Tallahassee, USA
| | - Will Treem
- Takeda Development Center Americas, Inc., Cambridge, MA, USA
| | - Graham A Heap
- Takeda Development Center Americas, Inc., Cambridge, MA, USA
| | - Jingjing Chen
- Takeda Development Center Americas, Inc., Cambridge, MA, USA.
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2
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Rahaghi FF. Alpha-1 antitrypsin deficiency research and emerging treatment strategies: what's down the road? Ther Adv Chronic Dis 2021; 12_suppl:20406223211014025. [PMID: 34408832 PMCID: PMC8367209 DOI: 10.1177/20406223211014025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/08/2021] [Indexed: 01/29/2023] Open
Abstract
Intravenous infusion of alpha-1 antitrypsin (AAT) was approved by the United States Food and Drug Administration (FDA) to treat emphysema associated with AAT deficiency (AATD) in 1987 and there are now several FDA-approved therapy products on the market, all of which are derived from pooled human plasma. Intravenous AAT therapy has proven clinical efficacy in slowing the decline of lung function associated with AATD progression; however, it is only recommended for individuals with the most severe forms of AATD as there is a lack of evidence that this treatment is effective in treating wild-type heterozygotes (e.g., PI*MS and PI*MZ genotypes), for which the prevalence may be much higher than previously thought. There are large numbers of individuals that are currently left untreated despite displaying symptoms of AATD. Furthermore, not all countries offer AAT augmentation therapy due to its expense and inconvenience for patients. More cost-effective treatments are now being sought that show efficacy for less severe forms of AATD and many new therapeutic technologies are being investigated, such as gene repair and other interference strategies, as well as the use of chemical chaperones. New sources of AAT are also being investigated to ensure there are enough supplies to meet future demand, and new methods of assessing response to treatment are being evaluated. There is currently extensive research into AATD and its treatment, and this chapter aims to highlight important emerging treatment strategies that aim to improve the lives of patients with AATD.
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Affiliation(s)
- Franck F Rahaghi
- Advanced Lung Disease Clinic, Cleveland Clinic Florida, 2950 Cleveland Clinic Boulevard, Weston, FL 33331, USA
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3
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Quinn M, Ellis P, Pye A, Turner AM. Obstacles to Early Diagnosis and Treatment of Alpha-1 Antitrypsin Deficiency: Current Perspectives. Ther Clin Risk Manag 2020; 16:1243-1255. [PMID: 33364772 PMCID: PMC7751439 DOI: 10.2147/tcrm.s234377] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 11/30/2020] [Indexed: 11/23/2022] Open
Abstract
This review summarizes the current research and outlooks regarding the obstacles to diagnosing and treating early alpha-1-antitrypsin deficiency (AATD). It draws on prior systematic reviews and expert surveys to discover precisely what difficulties exist in early diagnosis and treatment of AATD and elucidate potential solutions to ease these difficulties. The perceived rarity of AATD may translate to a condition poorly understood by primary care physicians, and even many respiratory physicians, which results in opportunities for diagnosis being missed, especially in mild or asymptomatic patients. There are diagnostic techniques involving biomarkers and home testing methods which could improve the rate of early diagnosis. With respect to treatment, AATD involves treating two separate pathologies, lung disease and liver disease. The only specific AATD treatment, augmentation therapy, has proven ability in treating lung disease but not liver disease. Alpha-1-antitrypsin (AAT) synthesized in the liver can form damaging polymers that also result in reduced circulating AAT levels and, whilst liver transplantation is used to effectively treat AATD, it is inappropriate in early disease. Novel therapeutic areas such as gene editing and increasing autophagy are therefore being researched as future treatments. Ultimately, diagnosis and treatment are intrinsically linked in AATD, with earlier diagnosis leading to better treatment options and thus better patient outcomes.
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Affiliation(s)
- Mark Quinn
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Paul Ellis
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Anita Pye
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - Alice M Turner
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK.,University Hospitals Birmingham, Birmingham, UK
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Sun D, Liu H, Ouyang Y, Liu X, Xu Y. Serum Levels of Gamma-Glutamyltransferase During Stable and Acute Exacerbations of Chronic Obstructive Pulmonary Disease. Med Sci Monit 2020; 26:e927771. [PMID: 33087693 PMCID: PMC7590526 DOI: 10.12659/msm.927771] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background One of the most important factors in the pathogenesis of COPD (chronic obstructive pulmonary disease) is oxidative stress. GGT (gamma-glutamyltransferase) has been regarded as a novel marker of oxidative stress over the last few years. This study aimed to compare the serum levels of GGT during stable and acute exacerbations of COPD at a single center. Material/Methods The research included 117 patients with AECOPD (acute exacerbation of chronic obstructive pulmonary disease), 107 patients with stable COPD, and 112 control subjects. Serum GGT, spirometry function, and other clinical parameters (anthropometric and biochemical measurements) were evaluated and compared among the subjects. Results Serum GGT was elevated in patients with stable COPD in comparison to the control subjects. Its level was inversely related to lung function. It was also significantly higher in AECOPD patients compared to stable COPD patients. We also found that a GGT level of 21.2 IU/L displays a reliable diagnostic prediction of COPD and that a GGT level of 26.5 IU/L can be applied to predict the exacerbation of COPD. Conclusions Our research demonstrates that serum GGT level is inversely associated with pulmonary function and may serve as a biomarker during the progression of COPD. The monitoring of GGT values can be applied to evaluating COPD and its exacerbation risk.
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Affiliation(s)
- Desheng Sun
- Department of Respiratory and Critical Care Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China (mainland).,Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China (mainland)
| | - Hongyan Liu
- Department of Acupuncture and Moxibustion, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China (mainland)
| | - Yao Ouyang
- Department of Respiratory and Critical Care Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China (mainland)
| | - Xiansheng Liu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China (mainland)
| | - Yongjian Xu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China (mainland)
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5
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Chukowry PS, Edgar RG, Turner AM. Alpha 1 antitrypsin deficiency: a rare multisystem disease, predominantly affecting the lung. Expert Opin Orphan Drugs 2019. [DOI: 10.1080/21678707.2019.1651640] [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: 10/26/2022]
Affiliation(s)
- Priya S Chukowry
- University Hospitals Birmingham NHS Foundation Trust, Heartlands Hospital, Birmingham, UK
| | - Ross Gareth Edgar
- University Hospitals Birmingham NHS Foundation Trust, Heartlands Hospital, Birmingham, UK
- Therapy Services, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Alice M Turner
- University Hospitals Birmingham NHS Foundation Trust, Heartlands Hospital, Birmingham, UK
- Therapy Services, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
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Torres-Durán M, Lopez-Campos JL, Barrecheguren M, Miravitlles M, Martinez-Delgado B, Castillo S, Escribano A, Baloira A, Navarro-Garcia MM, Pellicer D, Bañuls L, Magallón M, Casas F, Dasí F. Alpha-1 antitrypsin deficiency: outstanding questions and future directions. Orphanet J Rare Dis 2018; 13:114. [PMID: 29996870 PMCID: PMC6042212 DOI: 10.1186/s13023-018-0856-9] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/26/2018] [Indexed: 12/14/2022] Open
Abstract
Background Alpha-1 antitrypsin deficiency (AATD) is a rare hereditary condition that leads to decreased circulating alpha-1 antitrypsin (AAT) levels, significantly increasing the risk of serious lung and/or liver disease in children and adults, in which some aspects remain unresolved. Methods In this review, we summarise and update current knowledge on alpha-1 antitrypsin deficiency in order to identify and discuss areas of controversy and formulate questions that need further research. Results 1) AATD is a highly underdiagnosed condition. Over 120,000 European individuals are estimated to have severe AATD and more than 90% of them are underdiagnosed. Conclusions 2) Several clinical and etiological aspects of the disease are yet to be resolved. New strategies for early detection and biomarkers for patient outcome prediction are needed to reduce morbidity and mortality in these patients; 3) Augmentation therapy is the only specific approved therapy that has shown clinical efficacy in delaying the progression of emphysema. Regrettably, some countries reject registration and reimbursement for this treatment because of the lack of larger randomised, placebo-controlled trials. 4) Alternative strategies are currently being investigated, including the use of gene therapy or induced pluripotent stem cells, and non-augmentation strategies to prevent AAT polymerisation inside hepatocytes.
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Affiliation(s)
- María Torres-Durán
- Pulmonary Department, Hospital Álvaro Cunqueiro EOXI, Vigo, Spain.,NeumoVigo I+i Research Group, IIS Galicia Sur, Vigo, Spain
| | - José Luis Lopez-Campos
- Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio, Universidad de Sevilla, Sevilla, Spain.,CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Miriam Barrecheguren
- CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain.,Pneumology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Marc Miravitlles
- CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain.,Pneumology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Beatriz Martinez-Delgado
- Molecular Genetics Unit, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Silvia Castillo
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - Amparo Escribano
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Paediatrics, Obstetrics and Gynaecology, University of Valencia, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - Adolfo Baloira
- Pneumology Department, Complejo Hospitalario Universitario de Pontevedra, Pontevedra, Spain
| | - María Mercedes Navarro-Garcia
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - Daniel Pellicer
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - Lucía Bañuls
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - María Magallón
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - Francisco Casas
- Pneumology Department, Hospital Universitario San Cecilio, Granada, Spain
| | - Francisco Dasí
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain. .,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain.
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7
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Townsend SA, Edgar RG, Ellis PR, Kantas D, Newsome PN, Turner AM. Systematic review: the natural history of alpha-1 antitrypsin deficiency, and associated liver disease. Aliment Pharmacol Ther 2018; 47:877-885. [PMID: 29446109 DOI: 10.1111/apt.14537] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/21/2017] [Accepted: 01/03/2018] [Indexed: 12/15/2022]
Abstract
BACKGROUND Alpha-1 antitrypsin deficiency (AATD) is estimated to affect three million people worldwide. It causes liver disease in a proportion of carriers of the PiS and PiZ allele due to the formation and retention of polymers within the endoplasmic reticulum of hepatocytes. The reason for this selective penetrance is not known. Although clinical trials are underway, liver transplantation is the only effective treatment for liver disease due to AATD. AIMS To report the prevalence and natural history of liver disease among individuals with AATD, and assess the outcomes of liver transplantation through systematic review. METHODS A comprehensive search was conducted across multiple databases. Two independent authors selected the articles and assessed bias using the Newcastle-Ottawa Scale. Data were pooled for analysis, where comparable outcomes were reported. RESULTS Thirty-five studies were identified related to disease progression and 12 for the treatment of AATD. Seven per cent of children were reported to develop liver cirrhosis, with 16.5% of individuals presenting in childhood requiring liver transplantation. Of those surviving to adulthood, 10.5% had liver cirrhosis and 14.7% required transplantation. Liver transplantation was the only effective treatment reported and outcomes compare favourably to other indications, with 5-year survival reported as over 90% in children and over 80% in adults. DISCUSSION The clinical course of liver disease in individuals with AATD remains poorly understood, but affects about 10% of those with AATD. More research is required to identify those patients at risk of developing liver disease at an early stage, and to provide alternative treatments to liver transplantation.
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Affiliation(s)
- S A Townsend
- National Institute for Health Research Liver Biomedical Research Unit, University Hospitals Birmingham, NHS Foundation Trust, University of Birmingham, Birmingham, UK.,Centre for Liver Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK.,Liver Unit, BirminghamInstitute of Inflammation and Ageing, University Hospitals Birmingham NHS Foundation Trust, University of Birmingham, Birmingham, UK
| | - R G Edgar
- Centre for Liver Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK.,Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - P R Ellis
- Heart of England NHS Foundation Trust, Birmingham, UK
| | - D Kantas
- Centre for Liver Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - P N Newsome
- National Institute for Health Research Liver Biomedical Research Unit, University Hospitals Birmingham, NHS Foundation Trust, University of Birmingham, Birmingham, UK.,Centre for Liver Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK.,Liver Unit, BirminghamInstitute of Inflammation and Ageing, University Hospitals Birmingham NHS Foundation Trust, University of Birmingham, Birmingham, UK
| | - A M Turner
- Institute of Applied Health Research, University of Birmingham, Birmingham, UK.,Heart of England NHS Foundation Trust, Birmingham, UK
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8
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Ferrarotti I, Corsico AG, Stolk J, Ottaviani S, Fumagalli M, Janciauskiene S, Iadarola P. Advances in Identifying Urine/Serum Biomarkers in Alpha-1 Antitrypsin Deficiency for More Personalized Future Treatment Strategies. COPD 2016; 14:56-65. [PMID: 27827549 DOI: 10.1080/15412555.2016.1241760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Alpha1-antitrypsin deficiency (AATD) is a genetic disorder characterized by reduced serum levels of alpha1-antitrypsin (AAT) and increased risk for developing both early-onset lung emphysema and chronic liver disease. Laboratory diagnosis of AATD is not just a matter of degree, although the AAT serum level is the most important determinant for risk of lung damage. While being a single-gene disease, the clinical phenotype of AATD is heterogeneous. The current standard of care for patients affected by AATD-associated pulmonary emphysema is replacement therapy with weekly i.v. infusions of pooled human purified plasma AAT. Although no treatment for liver disease caused by deposition of abnormal AAT in hepatocytes is available, innovative treatments for this condition are on the horizon. This article aims to provide a critical review of the methodological steps that have marked progress in the detection of indicators described in the literature as being "clinically significant" biomarkers of the disease. The development and routine use of specific biomarkers would help both in identifying which patients and when they are eligible for treatment as well as providing additional parameters for monitoring the disease.
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Affiliation(s)
- Ilaria Ferrarotti
- a IRCCS Policlinico S. Matteo Foundation, Section of Pneumology , Pavia , Italy
| | - Angelo Guido Corsico
- b Department of Internal Medicine and Therapeutics , Pneumology Unit, Fondazione IRCCS Policlinico San Matteo, University of Pavia , Pavia , Italy
| | - Jan Stolk
- c Leiden University Medical Center, Pulmonology , Albinusdreef 2, Leiden , Netherlands
| | - Stefania Ottaviani
- a IRCCS Policlinico S. Matteo Foundation, Section of Pneumology , Pavia , Italy
| | - Marco Fumagalli
- d Department of Biology and Biotechnologies "L.Spallanzani" , University of Pavia , Pavia , Italy
| | - Sabina Janciauskiene
- e Department of Respiratory Medicine , Hannover Medical School, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH) , Hannover , Germany
| | - Paolo Iadarola
- d Department of Biology and Biotechnologies "L.Spallanzani" , University of Pavia , Pavia , Italy
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Stockley RA. Antitrypsin Deficiency Assessment and Programme for Treatment (ADAPT): The United Kingdom Registry. COPD 2016; 12 Suppl 1:63-8. [PMID: 25938295 DOI: 10.3109/15412555.2015.1021911] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The study of rare diseases is compromised by its rarity. The establishment of national and international registries can overcome many of the problems and be used for many monogenetic conditions with relatively consistent outcomes and thus lead to a consistency of clinical management by centres of excellence. However, in Alpha-1 antitrypsin deficiency (AATD), the outcome is highly variable in terms of the organ(s) most affected and the diversity of disease penetration and progression. This creates the added difficulty of understanding the disease sufficiently to monitor and advise the patients to the standard required and importantly design and deliver clinical trials that address the many facets of the disease. The development of research registries and centres of excellence provides the necessary expertise and data to further the understanding and management of diseases like AATD though with significant cost implications. The ADAPT programme was established in 1996 with extensive core funding to enable patients to be seen from all regions of the United Kingdom as an addition to the National Health Service without appointment time constraints and with the purpose of collecting extensive state of the art demographics. The model has proven to be highly productive providing new insights especially into the lung disease, generating and delivering on clinical trials and importantly establishing active patient groups and participation.
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Affiliation(s)
- Robert A Stockley
- ADAPT Project, Queen Elizabeth Hospital Birmingham , Birmingham , United Kingdom
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10
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α-1-Antitrypsin deficiency: clinical variability, assessment, and treatment. Trends Mol Med 2013; 20:105-15. [PMID: 24380646 DOI: 10.1016/j.molmed.2013.11.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/25/2013] [Accepted: 11/26/2013] [Indexed: 12/21/2022]
Abstract
The recognition of α-1-antitrypsin deficiency, its function, and its role in predisposition to the development of severe emphysema was a watershed in our understanding of the pathophysiology of the condition. This led to the concept and development of intravenous replacement therapy used worldwide to protect against lung damage induced by neutrophil elastase. Nevertheless, much remained unknown about the deficiency and its impact, although in recent years the genetic and clinical variations in manifestation have provided new insights into assessing impact, efficacy of therapy, and development of new therapeutic strategies, including gene therapy, and outcome measures, such as biomarkers and computed tomography. The current article reviews this progress over the preceding 50 years.
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11
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Everhart JE, Wright EC. Association of γ-glutamyl transferase (GGT) activity with treatment and clinical outcomes in chronic hepatitis C (HCV). Hepatology 2013; 57:1725-33. [PMID: 23258530 PMCID: PMC3624035 DOI: 10.1002/hep.26203] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 12/01/2012] [Indexed: 12/15/2022]
Abstract
UNLABELLED Increased γ-glutamyl transferase (GGT) activity is associated with liver injury and with mortality in the general population. Less is known about its association with chronic hepatitis C (HCV) outcomes. We examined GGT as a predictor of both virological response to treatment and long-term clinical outcomes in the Hepatitis C Anti-viral Treatment Against Cirrhosis Trial (HALT-C). HALT-C enrolled patients with advanced liver disease (Ishak fibrosis score ≥3) in two phases: a lead-in to establish lack of sustained viral response with full dose pegylated interferon (IFN) and ribavirin followed by a 3.5-year randomized trial with low-dose IFN. Low-dose IFN did not prevent liver disease progression, and patients were then followed for up to an additional 5 years off therapy. Analyses were performed for 1,319 patients who had GGT measured prior to initiation of treatment. Increases in risk with each increase in quintile of GGT (10-57, 58-89, 90-139, 140-230, 231-2,000 IU/L) were determined by logistic regression for treatment response or Cox regression for clinical outcomes. Baseline GGT was associated with male sex, nonwhite ethnicity, diabetes and insulin resistance, interleukin (IL)28B rs12979860 CT and TT genotypes, and numerous markers of liver disease injury and severity. In the lead-in phase, increasing GGT was strongly associated with diminished week 20 response, end of treatment response, and sustained virological response in both univariate and multivariate analyses controlling for factors known to be associated with treatment response (P < 0.0001). GGT was also associated with all clinical outcomes in univariate and multivariate analysis (P < 0.05) except for hepatocellular carcinoma (P = 0.46 in multivariate analysis). CONCLUSION GGT is an independent predictor of both virological response and clinical outcomes among patients with advanced liver disease due to HCV.
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