Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where J. Barker is active.

Publication


Featured researches published by J. Barker.


Journal of The European Academy of Dermatology and Venereology | 2011

Assessment and management of methotrexate hepatotoxicity in psoriasis patients: report from a consensus conference to evaluate current practice and identify key questions toward optimizing methotrexate use in the clinic

J. Barker; E.J. Horn; M. Lebwohl; Richard B. Warren; Alexander Nast; W. Rosenberg; Catherine Smith

Experts in psoriasis, hepatology, pharmacokinetics and pharmacogenetics convened to discuss the safety and monitoring of methotrexate with respect to hepatotoxicity when used in the treatment of psoriasis. Methotrexate is an efficacious and cost‐effective treatment for psoriasis, but is associated with significant safety issues, particularly relating to hepatotoxicity. Current British, Dutch, German, EU and US guidelines for baseline evaluations, monitoring and prevention of hepatotoxicity in patients with psoriasis receiving methotrexate were evaluated. Liver safety monitoring is currently reliant upon multiple methods, including biopsy, serological tests for biomarkers such as type III procollagen amino terminal propeptide (PIIINP), and liver function tests based on liver enzymes. Monitoring of patients receiving long‐term therapy is expected to be improved by the utilization of serum biomarkers currently in development such as the Enhanced Liver Fibrosis (ELF) panel and other non‐invasive tests of hepatic architecture, such as fibroelastography, microbubbles and magnetic resonance imaging. Appropriate studies to determine optimal dosing to maximize efficacy and minimize toxicity, potentially utilizing pharmacogenetic principles, are clearly needed. Key questions for future research are identified including needs for optimal screening and monitoring, identification of appropriate biomarkers, assessment of relationships between dosing and safety, utility of liver biopsy, optimal dosing regimens (including route of administration), methods to measure methotrexate levels in blood, and use of methotrexate as a standardized active comparator in trials of experimental drugs used to treat psoriasis.


Journal of The European Academy of Dermatology and Venereology | 2011

Assessment and management of methotrexate hepatotoxicity in psoriasis patients

J. Barker; E.J. Horn; M. Lebwohl; Richard B. Warren; Alexander Nast; W. Rosenberg; Catherine Smith

Experts in psoriasis, hepatology, pharmacokinetics and pharmacogenetics convened to discuss the safety and monitoring of methotrexate with respect to hepatotoxicity when used in the treatment of psoriasis. Methotrexate is an efficacious and cost‐effective treatment for psoriasis, but is associated with significant safety issues, particularly relating to hepatotoxicity. Current British, Dutch, German, EU and US guidelines for baseline evaluations, monitoring and prevention of hepatotoxicity in patients with psoriasis receiving methotrexate were evaluated. Liver safety monitoring is currently reliant upon multiple methods, including biopsy, serological tests for biomarkers such as type III procollagen amino terminal propeptide (PIIINP), and liver function tests based on liver enzymes. Monitoring of patients receiving long‐term therapy is expected to be improved by the utilization of serum biomarkers currently in development such as the Enhanced Liver Fibrosis (ELF) panel and other non‐invasive tests of hepatic architecture, such as fibroelastography, microbubbles and magnetic resonance imaging. Appropriate studies to determine optimal dosing to maximize efficacy and minimize toxicity, potentially utilizing pharmacogenetic principles, are clearly needed. Key questions for future research are identified including needs for optimal screening and monitoring, identification of appropriate biomarkers, assessment of relationships between dosing and safety, utility of liver biopsy, optimal dosing regimens (including route of administration), methods to measure methotrexate levels in blood, and use of methotrexate as a standardized active comparator in trials of experimental drugs used to treat psoriasis.


Journal of The European Academy of Dermatology and Venereology | 2017

The role of IL-23 and the IL-23/TH17 immune axis in the pathogenesis and treatment of psoriasis

Giampiero Girolomoni; Robert Strohal; L. Puig; Hervé Bachelez; J. Barker; Wolf-Henning Boehncke; Jörg C. Prinz

Psoriasis is a chronic, immune‐mediated disease affecting more than 100 million people worldwide and up to 2.2% of the UK population. The aetiology of psoriasis is thought to originate from an interplay of genetic, environmental, infectious and lifestyle factors. The manner in which genetic and environmental factors interact to contribute to the molecular disease mechanisms has remained elusive. However, the interleukin 23 (IL‐23)/T‐helper 17 (TH17) immune axis has been identified as a major immune pathway in psoriasis disease pathogenesis. Central to this pathway is the cytokine IL‐23, a heterodimer composed of a p40 subunit also found in IL‐12 and a p19 subunit exclusive to IL‐23. IL‐23 is important for maintaining TH17 responses, and levels of IL‐23 are elevated in psoriatic skin compared with non‐lesional skin. A number of agents that specifically inhibit IL‐23p19 are currently in development for the treatment of moderate‐to‐severe plaque psoriasis, with recent clinical trials demonstrating efficacy with a good safety and tolerability profile. These data support the role of this cytokine in the pathogenesis of psoriasis. A better understanding of the IL‐23/TH17 immune axis is vital and will promote the development of additional targets for psoriasis and other inflammatory diseases that share similar genetic aetiology and pathogenetic pathways.


Journal of The European Academy of Dermatology and Venereology | 2017

European consensus statement on phenotypes of pustular psoriasis

Alexander A. Navarini; Ad Burden; Francesca Capon; Ulrich Mrowietz; Lluís Puig; S. Koks; Külli Kingo; Catherine Smith; J. Barker; P.C.M. van de Kerkhof; Richard B. Warren

Pustular psoriasis (PP) is a group of inflammatory skin conditions characterized by infiltration of neutrophil granulocytes in the epidermis to such an extent that clinically visible sterile pustules develop. Because of clinical co‐incidence, PP is currently grouped with psoriasis vulgaris (PV). However, PP and PV are phenotypically different, respond differently to treatments and seem to be distinct on the genetic level. In contrast to PV, the phenotypes of PP are not well defined. Descriptions of each form of PP are discordant among standard dermatology textbooks [Saurat Dermatologie 2016, Rooks Dermatology 2016, Fitzpatricks 2012 and Braun‐Falco 2012], encumbering the collection of phenotypically well‐matched groups of patients as well as clinical trials. The European Rare and Severe Psoriasis Expert Network (ERASPEN) was founded to define consensus criteria for diagnosis, deeply phenotype large groups of PP patients, analyse the genetics and pathophysiology and prepare for prospective clinical trials. This work reviews historical aspects of these conditions, new genetic findings and presents our initial considerations on the phenotypes of PP and a consensus classification of clinical phenotypes that will be used as a baseline for further, prospective studies of PP. Generalized pustular psoriasis (GPP) is defined as primary, sterile, macroscopically visible pustules on non‐acral skin (excluding cases where pustulation is restricted to psoriatic plaques). GPP can occur with or without systemic inflammation, with or without PV and can either be a relapsing (>1 episode) or persistent (>3 months) condition. Acrodermatitis continua of Hallopeau (ACH) is characterized by primary, persistent (>3 months), sterile, macroscopically visible pustules affecting the nail apparatus. Palmoplantar pustulosis (PPP) has primary, persistent (>3 months), sterile, macroscopically visible pustules on palms and/or soles and can occur with or without PV.


Journal of The European Academy of Dermatology and Venereology | 2018

Clinical use of dimethyl fumarate in moderate-to-severe plaque-type psoriasis: a European expert consensus

Ulrich Mrowietz; J. Barker; Wolf-Henning Boehncke; Lars Iversen; Brian Kirby; Luigi Naldi; K. Reich; Adrian Tanew; P.C.M. van de Kerkhof; Richard B. Warren

Fumaric acid esters (FAEs) are a group of small molecules that were first investigated for the treatment of psoriasis in 1959. The first fumarate‐based drug – Fumaderm® – was approved in Germany in 1994 for severe psoriasis and then in 2008, the label was expanded to include moderate psoriasis. Fumaderm is a combination of different FAEs: dimethyl fumarate (DMF), which is regarded as the main active component, plus calcium, magnesium and zinc salts of monoethyl fumarate (MEF). FAEs are the most frequently used first‐line systemic psoriasis treatment in Germany, with an overall treatment experience comprising more than 220 000 patient‐years. FAEs have demonstrated good, sustained clinical efficacy with an acceptable safety profile for the long‐term treatment of patients with moderate‐to‐severe psoriasis. Indeed, the European S3‐Guideline on the systemic treatment of Psoriasis vulgaris recommends FAEs for induction and long‐term treatment. Until recently, FAEs were only licensed (for the psoriasis indication) in Germany, but were imported to many other European countries, such as The Netherlands, UK, Ireland, Austria and Italy, for the treatment of psoriasis. In 2017, the European Medicines Agency (EMA) approved Skilarence®, a new oral formulation of DMF, for the treatment of adult patients with moderate‐to‐severe chronic plaque psoriasis in need of systemic therapy. Skilarence only contains DMF and is the first FAE for the treatment of psoriasis that has been approved by the EMA. This approval has given rise to a new oral treatment option for patients with moderate‐to‐severe plaque psoriasis across Europe. Here, we report the results of an expert meeting which was convened to deliver clinician‐agreed consensus and real‐world guidance on the clinical use of DMF in moderate‐to‐severe chronic plaque psoriasis. Guidance on appropriate patient selection, DMF dosage considerations, monitoring and side‐effect management is offered based upon available evidence and collective real‐world clinical experience.


Journal of The European Academy of Dermatology and Venereology | 2017

A European subset analysis from the population-based Multinational Assessment of Psoriasis and Psoriatic Arthritis shows country-specific features: results from psoriasis patients in Spain

L. Puig; P.C.M. van de Kerkhof; K. Reich; Hervé Bachelez; J. Barker; Giampiero Girolomoni; C. Paul

The Multinational Assessment of Psoriasis and Psoriatic Arthritis (MAPP) survey data were not analysed to account for cultural and healthcare system differences across European countries (EC).


Journal of The European Academy of Dermatology and Venereology | 2017

Quality of life and patient benefit following transition from methotrexate to ustekinumab in psoriasis

Matthias Augustin; C. Blome; C. Paul; L. Puig; Thomas A. Luger; Jo Lambert; Sergio Chimenti; Giampiero Girolomoni; K. Kragballe; D. Naessens; P. Bergmans; P. Smirnov; J. Barker; K. Reich

TRANSIT (NCT01059773) compared immediate and gradual transition from methotrexate to ustekinumab in psoriasis patients via multiple measures, including patient‐reported outcomes.


Journal of The European Academy of Dermatology and Venereology | 2018

Clinical outcomes in patients on secukinumab (Cosentyx®) within a specialist psoriasis clinic: a single centre, retrospective cohort study

A.V. Sears; C. Szlumper; K.W. Liu; Catherine Smith; J. Barker; Andrew Pink

Secukinumab, a fully human anti-IL-17A monoclonal antibody, is a highly effective therapy for chronic plaque psoriasis. Up to 81.6% of patients achieved ∆PASI75 responses after 12 weeks in trials1-3 . However, up to 30% of patients on systemic therapy for psoriasis would be ineligible to participate in such trials4,5 . The aim of this retrospective observational study was to assess the real-world clinical effectiveness of secukinumab in patients attending our specialist psoriasis clinic. This article is protected by copyright. All rights reserved.


Pediatric Rheumatology | 2015

A unifying molecular mechanism underlying the association of CARD14 alleles with autoinflammatory and T-cell mediated skin disorders

Dorottya M. Berki; Siew-Eng Choon; Ad Burden; C.E.M. Griffiths; Catherine Smith; J. Barker; Francesca Capon

The CARD14 (Caspase Recruitment Family Member 14) locus encodes a scaffold protein that mediates NF-kB signalling in keratinocytes and is therefore crucial to the maintenance of skin immune homeostasis. In keeping with this notion, gain-of-function CARD14 mutations have been observed in patients with plaque psoriasis and pityriasis rubra pilaris, two skin disorders mediated by abnormal T cell activation. More recently, a CARD14 missense variant has been tentatively associated with generalised pustular psoriasis (GPP), an auto-inflammatory condition characterised by acute episodes of skin pustulation and systemic upset.


Pediatric Rheumatology | 2013

OR6-006 – IL36RN alleles in skin auto-inflammation

Francesca Capon; Niovi Setta-Kaffetzi; Dorottya M. Berki; Satveer K. Mahil; Alexander A. Navarini; Varsha M. Patel; C Siew-Eng; Ad Burden; C.E.M. Griffiths; M.M.B. Seyger; Richard C. Trembath; Catherine Smith; J. Barker

Our group identified recessive mutations of the IL36RN gene in patients affected by Generalised Pustular Psoriasis (GPP), a severe skin disorder characterised by acute episodes of pustulation, fever and systemic upset.

Collaboration


Dive into the J. Barker's collaboration.

Top Co-Authors

Avatar

Catherine Smith

Guy's and St Thomas' NHS Foundation Trust

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

L. Puig

Autonomous University of Barcelona

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Richard B. Warren

Manchester Academic Health Science Centre

View shared research outputs
Top Co-Authors

Avatar

C. Paul

Paul Sabatier University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Jo Lambert

Ghent University Hospital

View shared research outputs
Top Co-Authors

Avatar

Kristian Reich

University of Göttingen

View shared research outputs
Researchain Logo
Decentralizing Knowledge