Author
Ratko Djukanovic
Other affiliations: University Hospital Southampton NHS Foundation Trust, Loughborough University, University of Wisconsin-Madison ...read more
Bio: Ratko Djukanovic is an academic researcher from University of Southampton. The author has contributed to research in topics: Asthma & Sputum. The author has an hindex of 82, co-authored 325 publications receiving 26594 citations. Previous affiliations of Ratko Djukanovic include University Hospital Southampton NHS Foundation Trust & Loughborough University.
Topics: Asthma, Sputum, Medicine, Allergy, Eosinophil
Papers published on a yearly basis
Papers
More filters
National Institutes of Health1, University of Pittsburgh2, McMaster University3, University of Washington4, University of Cape Town5, Wake Forest University6, University of Leicester7, Karolinska Institutet8, University of Southampton9, Boston Children's Hospital10, John Hunter Hospital11, McGill University12, University of Wisconsin-Madison13, University of Virginia14
TL;DR: Recommendations and guidelines on the evaluation and treatment of severe asthma in children and adults and coordinated research efforts for improved phenotyping will provide safe and effective biomarker-driven approaches to severe asthma therapy are provided.
Abstract: Severe or therapy-resistant asthma is increasingly recognised as a major unmet need. A Task Force, supported by the European Respiratory Society and American Thoracic Society, reviewed the definition and provided recommendations and guidelines on the evaluation and treatment of severe asthma in children and adults. A literature review was performed, followed by discussion by an expert committee according to the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach for development of specific clinical recommendations. When the diagnosis of asthma is confirmed and comorbidities addressed, severe asthma is defined as asthma that requires treatment with high dose inhaled corticosteroids plus a second controller and/or systemic corticosteroids to prevent it from becoming “uncontrolled” or that remains “uncontrolled” despite this therapy. Severe asthma is a heterogeneous condition consisting of phenotypes such as eosinophilic asthma. Specific recommendations on the use of sputum eosinophil count and exhaled nitric oxide to guide therapy, as well as treatment with anti-IgE antibody, methotrexate, macrolide antibiotics, antifungal agents and bronchial thermoplasty are provided. Coordinated research efforts for improved phenotyping will provide safe and effective biomarker-driven approaches to severe asthma therapy.
2,795 citations
TL;DR: A single dose of monoclonal antibody to IL-5 decreased blood eosinophils for up to 16 weeks and sputum eosInophils at 4 weeks, which has considerable therapeutic potential for asthma and allergy, however, the findings question the role of eos inophils in mediating the late asthmatic response and causing airway hyper-responsiveness.
1,824 citations
TL;DR: It is not possible to relate precisely the findings obtained by bronchoscopy to the clinical presentation and progression of asthma, but direct evidence obtained from allergen challenge leading to increased bronchial hyperresponsiveness during LAR, and direct evidence of inflammatory cells and their mediators in the airway mucosa and lumen after allergenic challenge argue for an active role of cells in bringing about inflammatory changes.
Abstract: Over the past decade, it has become increasingly recognized that airways inflammation is one of the major components of asthma. Until recently, measurements of bronchial responsiveness and mediators of allergic reactions were the only methods of studying pathogenetic mechanisms in asthma. With improved diagnostic procedures such as fiberoptic bronchoscopy, it has become possible to investigate these mechanisms and the resulting inflammatory changes in situ. BAL has highlighted the presence of mast cells and eosinophils and has given proof of their mediator participation in airways inflammation and hyperresponsiveness. Endobronchial biopsies have so far yielded results that are similar to those obtained from postmortem studies, although it appears that there are varying degrees of inflammation in living asthmatics. Even in mild disease, the histopathologic features of bronchial asthma are consistent with chronic inflammation. Indirect evidence obtained from allergen challenge leading to increased bronchial hyperresponsiveness during LAR, and direct evidence of inflammatory cells and their mediators in the airway mucosa and lumen after allergen challenge argue for an active role of cells in bringing about inflammatory changes. At present, however, it is not possible to relate precisely the findings obtained by bronchoscopy to the clinical presentation and progression of asthma. Cell activation with production of potent mediators of inflammation may be more relevant to inflammation than the simple presence of these cells in the airways. Almost all the inflammatory cells present in the bronchial wall and lumen have been implicated in the pathogenesis of mucosal inflammation in asthma, but with our current state of knowledge, none can be singled out as the most important contributor. The mast cell was the first to be investigated in depth, and despite the accumulation of large amounts of data concerning its ultrastructure and function, it remains uncertain to what extent this cell is involved in inflammatory responses. Thus, while its main role appears to be that of initiator of allergen-induced responses, the eosinophil has attracted more attention as a proinflammatory cell rather than as an antiinflammatory cell with a capacity to be selectively recruited from the circulation in response to IgE-dependent signals. The eosinophil secretes potent mediators that cause damage to the bronchial epithelium and lead to bronchoconstriction. The role of other cells is at present not as well defined.(ABSTRACT TRUNCATED AT 400 WORDS)
1,276 citations
TL;DR: Human mast cells are identified as a source of IL-4,IL-5, IL-6, and TNF-alpha and add to the view that, along with T cells, mast cells may play an important role in initiating and maintaining the inflammatory response in asthma.
Abstract: Asthma is characterized by the presence of an inflammatory cell infiltrate in the bronchial mucosa consisting of activated mast cells, eosinophils, and T cells. Several cytokines are considered to play a pivotal role in this response, particularly interleukin (IL)-4, IL-5, IL-6, and tumor necrosis factor-alpha (TNF-alpha). In this study, we have used immunohistochemistry applied to thin glycol methacrylate sections of bronchial mucosal biopsies to define the cellular provenance of these cytokines in normal and asthmatic airways. Both the asthmatic and normal mucosa contained numerous cells staining positively for all four cytokines, with the majority identified as mast cells by their tryptase content. Eosinophils also accounted for some IL-5 immunostaining in the asthmatic biopsies. By using two monoclonal antibodies directed to different epitopes of IL-4, we provide tentative evidence for enhanced IL-4 secretion in asthma. Similarly, a sevenfold increase in the number of mast cells staining for TNF-alpha in the asthmatic biopsies suggests that this cytokine is also up-regulated in this disease. These findings clearly identify human mast cells as a source of IL-4, IL-5, IL-6, and TNF-alpha and add to the view that, along with T cells, mast cells may play an important role in initiating and maintaining the inflammatory response in asthma.
847 citations
TL;DR: It is suggested that severe asthma might be a different form of asthma rather than an increase in asthma symptoms, and longitudinal studies and interventions are needed to define the mechanisms in severe asthma.
Abstract: Since severe asthma is a poorly understood, major health problem, 12 clinical specialist centres in nine European countries formed a European Network For Understanding Mechanisms Of Severe Asthma (ENFUMOSA). In a cross-sectional observational study, a total of 163 subjects with severe asthma were compared with 158 subjects whose asthma was controlled by low doses of inhaled corticosteroids (median dose of beclomethasone equivalents 666 mug). Despite being treated with higher doses of inhaled corticosteroids; (median dose 1773 mug) and for a third of the severe asthmatics also being treated with regular, oral-steroid therapy (median daily dose 19 mg), the subjects with severe asthma met the inclusion criteria. The criteria required subjects to have undergone at least one asthma exacerbation in the past year requiring oral steroid treatment. Females dominated the severe asthma group (female/male ratio 4.4:1 versus 1.6:1 in the controlled asthmatics), and compared with controlled asthmatics, they had a predominantly neutrophilic inflammation (sputum neutrophils, 36 versus 28%) and evidence of ongoing mediator release but less atopy. From these findings and other physiological and clinical data reported in this paper, it is suggested that severe asthma might be a different form of asthma rather than an increase in asthma symptoms. The findings prompt for longitudinal studies and interventions to define the mechanisms in severe asthma.
726 citations
Cited by
More filters
10,451 citations
Massachusetts Institute of Technology1, Broad Institute2, University of California, Los Angeles3, University of British Columbia4, Baylor College of Medicine5, Howard Hughes Medical Institute6, University of Washington7, Ludwig Institute for Cancer Research8, University of California, San Francisco9, University of Connecticut10, University of Zagreb11, University of Texas at Austin12, Washington University in St. Louis13, University of Queensland14, Harvard University15, Cold Spring Harbor Laboratory16, University of Southern California17, University of California, Santa Cruz18, Simon Fraser University19, Morgridge Institute for Research20, University of Texas at Dallas21, National Institutes of Health22
TL;DR: It is shown that disease- and trait-associated genetic variants are enriched in tissue-specific epigenomic marks, revealing biologically relevant cell types for diverse human traits, and providing a resource for interpreting the molecular basis of human disease.
Abstract: The reference human genome sequence set the stage for studies of genetic variation and its association with human disease, but epigenomic studies lack a similar reference. To address this need, the NIH Roadmap Epigenomics Consortium generated the largest collection so far of human epigenomes for primary cells and tissues. Here we describe the integrative analysis of 111 reference human epigenomes generated as part of the programme, profiled for histone modification patterns, DNA accessibility, DNA methylation and RNA expression. We establish global maps of regulatory elements, define regulatory modules of coordinated activity, and their likely activators and repressors. We show that disease- and trait-associated genetic variants are enriched in tissue-specific epigenomic marks, revealing biologically relevant cell types for diverse human traits, and providing a resource for interpreting the molecular basis of human disease. Our results demonstrate the central role of epigenomic information for understanding gene regulation, cellular differentiation and human disease.
5,037 citations
01 Jul 1997
4,630 citations
01 Feb 2015
TL;DR: In this article, the authors describe the integrative analysis of 111 reference human epigenomes generated as part of the NIH Roadmap Epigenomics Consortium, profiled for histone modification patterns, DNA accessibility, DNA methylation and RNA expression.
Abstract: The reference human genome sequence set the stage for studies of genetic variation and its association with human disease, but epigenomic studies lack a similar reference. To address this need, the NIH Roadmap Epigenomics Consortium generated the largest collection so far of human epigenomes for primary cells and tissues. Here we describe the integrative analysis of 111 reference human epigenomes generated as part of the programme, profiled for histone modification patterns, DNA accessibility, DNA methylation and RNA expression. We establish global maps of regulatory elements, define regulatory modules of coordinated activity, and their likely activators and repressors. We show that disease- and trait-associated genetic variants are enriched in tissue-specific epigenomic marks, revealing biologically relevant cell types for diverse human traits, and providing a resource for interpreting the molecular basis of human disease. Our results demonstrate the central role of epigenomic information for understanding gene regulation, cellular differentiation and human disease.
4,409 citations
Federal University of Bahia1, McMaster University2, University of Amsterdam3, National Institutes of Health4, Charité5, Catholic University of Cordoba6, University of Genoa7, Radboud University Nijmegen8, Transilvania University of Brașov9, Ghent University10, University of Tennessee Health Science Center11, University of Naples Federico II12, Laval University13, Universidade Federal de Minas Gerais14, University of Oslo15, University of Manchester16, Aarhus University17, Imperial College London18, Erasmus University Rotterdam19, George Washington University20, Seoul National University21, Medical University of Łódź22, Hai phong University Of Medicine and Pharmacy23, Université de Montréal24, Guangzhou Medical University25, University of South Florida26, University of California, San Diego27, University of California28, University of Chicago29, Monash University30, Teikyo University31, National and Kapodistrian University of Athens32, Nippon Medical School33, Sofia Medical University34, Leiden University35, Leiden University Medical Center36, University College London37, University of Manitoba38, University of Helsinki39, Finnish Institute of Occupational Health40, National University of Singapore41, Karolinska Institutet42, University of Minnesota43, Celal Bayar University44, University of Cape Town45, Pierre-and-Marie-Curie University46, Tunis University47, University of Ghana48, University of Wisconsin-Madison49, University of British Columbia50, Georgia Regents University51, Vilnius University52, University of Washington53, University of Dundee54, University of Poitiers55, University of Mississippi56, Federal University of São Paulo57, German Red Cross58, Jagiellonian University Medical College59, Chiba University60, American Pharmacists Association61, University of Aberdeen62, University of Nevada, Reno63, University of North Carolina at Chapel Hill64
TL;DR: The ARIA guidelines for the management of allergic rhinitis and asthma are similar in both the 1999 ARIA workshop report and the 2008 Update as discussed by the authors, but the GRADE approach is not yet available.
Abstract: Allergic rhinitis is a symptomatic disorder of the nose induced after allergen exposure by an IgE-mediated inflammation of the membranes lining the nose. It is a global health problem that causes major illness and disability worldwide. Over 600 million patients from all countries, all ethnic groups and of all ages suffer from allergic rhinitis. It affects social life, sleep, school and work and its economic impact is substantial. Risk factors for allergic rhinitis are well identified. Indoor and outdoor allergens as well as occupational agents cause rhinitis and other allergic diseases. The role of indoor and outdoor pollution is probably very important, but has yet to be fully understood both for the occurrence of the disease and its manifestations.
In 1999, during the Allergic Rhinitis and its Impact on Asthma (ARIA) WHO workshop, the expert panel proposed a new classification for allergic rhinitis which was subdivided into 'intermittent' or 'persistent' disease.
This classification is now validated. The diagnosis of allergic rhinitis is often quite easy, but in some cases it may cause problems and many patients are still under-diagnosed, often because they do not perceive the symptoms of rhinitis as a disease impairing their social life, school and work.
The management of allergic rhinitis is well established and the ARIA expert panel based its recommendations on evidence using an extensive review of the literature available up to December 1999. The statements of evidence for the development of these guidelines followed WHO rules and were based on those of Shekelle et al. A large number of papers have been published since 2000 and are extensively reviewed in the 2008 Update using the same evidence-based system. Recommendations for the management of allergic rhinitis are similar in both the ARIA workshop report and the 2008 Update. In the future, the GRADE approach will be used, but is not yet available.
Another important aspect of the ARIA guidelines was to consider co-morbidities. Both allergic rhinitis and asthma are systemic inflammatory conditions and often co-exist in the same patients. In the 2008 Update, these links have been confirmed.
The ARIA document is not intended to be a standard-of-care document for individual countries. It is provided as a basis for physicians, health care professionals and organizations involved in the treatment of allergic rhinitis and asthma in various countries to facilitate the development of relevant local standard-of-care documents for patients.
3,769 citations