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Dive into the research topics where P. A. Bacon is active.

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Featured researches published by P. A. Bacon.


Arthritis & Rheumatism | 2013

2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides

Jc Jennette; Ronald J. Falk; P. A. Bacon; Neil Basu; Maria C. Cid; Ferrario F; Luis Felipe Flores-Suárez; W. L. Gross; Loïc Guillevin; Hagen Ec; Gary S. Hoffman; David Jayne; Cornelis Kallenberg; Peter Lamprecht; Carol A. Langford; Raashid Luqmani; Alfred Mahr; Eric L. Matteson; Peter A. Merkel; Seza Ozen; Charles D. Pusey; Niels Rasmussen; Rees Aj; Dgi Scott; Ulrich Specks; John H. Stone; Kei Takahashi; Richard A. Watts

2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides J. Jennette;R. Falk;P. Bacon;N. Basu;M. Cid;F. Ferrario;L. Flores-Suarez;W. Gross;L. Guillevin;E. Hagen;G. Hoffman;D. Jayne;C. Kallenberg;P. Lamprecht;C. Langford;R. Luqmani;A. Mahr;E. Matteson;P. Merkel;S. Ozen;C. Pusey;N. Rasmussen;A. Rees;D. Scott;U. Specks;J. Stone;K. Takahashi;R. Watts; Arthritis & Rheumatism


Annals of the Rheumatic Diseases | 2007

EULAR recommendations for conducting clinical studies and/or clinical trials in systemic vasculitis: focus on anti-neutrophil cytoplasm antibody-associated vasculitis

Bernhard Hellmich; Oliver Flossmann; Wolfgang L. Gross; P. A. Bacon; Jw Cohen-Tervaert; Loïc Guillevin; David Jayne; Alfred Mahr; Peter A. Merkel; Heiner Raspe; David G. I. Scott; James Witter; Hasan Yazici; Raashid Luqmani

Objectives: To develop the European League Against Rheumatism (EULAR) recommendations for conducting clinical studies and/or clinical trials in systemic vasculitis. Methods: An expert consensus group was formed consisting of rheumatologists, nephrologists and specialists in internal medicine representing five European countries and the USA, a clinical epidemiologist and representatives from regulatory agencies. Using an evidence-based and expert opinion-based approach in accordance with the standardised EULAR operating procedures, the group identified nine topics for a systematic literature search through a modified Delphi technique. On the basis of research questions posed by the group, recommendations were derived for conducting clinical studies and/or clinical trials in systemic vasculitis. Results: Based on the results of the literature research, the expert committee concluded that sufficient evidence to formulate guidelines on conducting clinical trials was available only for anti-neutrophil cytoplasm antibody-associated vasculitides (AAV). It was therefore decided to focus the recommendations on these diseases. Recommendations for conducting clinical trials in AAV were elaborated and are presented in this summary document. It was decided to consider vasculitis-specific issues rather than general issues of trial methodology. The recommendations deal with the following areas related to clinical studies of vasculitis: definitions of disease, activity states, outcome measures, eligibility criteria, trial design including relevant end points, and biomarkers. A number of aspects of trial methodology were deemed important for future research. Conclusions: On the basis of expert opinion, recommendations for conducting clinical trials in AAV were formulated. Furthermore, the expert committee identified a strong need for well-designed research in non-AAV systemic vasculitides.


Journal of The American Society of Nephrology | 2004

Prospective study of TNFα blockade with infliximab in anti-neutrophil cytoplasmic antibody-associated systemic Vasculitis

Anthony Booth; Lorraine Harper; Tariq Hammad; P. A. Bacon; Megan Griffith; Jeremy Levy; Caroline O. S. Savage; Charles D. Pusey; David Jayne

UNLABELLED Tumor necrosis factor alpha (TNFalpha) plays an important role in the pathogenesis of anti-neutrophil cytoplasmic antibody-associated systemic vasculitis. TNFalpha blockade is a potential therapy for these disorders. METHODS An open-label, multi-center, prospective clinical trial in two subgroups was performed. Study I examined acute disease, either first presentation or relapse (Birmingham Vasculitis Activity Score [BVAS] > or = 10; n = 16); study II examined persistent disease (BVAS > or = 4; n = 16). Patients received infliximab (5 mg/kg) at 0, 2, 6, and 10 wk. Concomitant therapy in study I included prednisolone and cyclophosphamide. Study II patients continued their existing treatment regimens, with prednisolone tapered according to clinical status. RESULTS Mean age was 52.4 yr, 53% of the patients were female, and follow-up was 16.8 mo. Twenty-eight patients (88%) achieved remission (14 per study group). BVAS decreased from 12.3 (confidence interval [CI] = 10.5 to 14.0) at entry to 0.3 (CI = 0.2 to 0.9) at wk 14 (P < 0.001). C-reactive protein (mg/L) decreased from 29.4 (CI = 16.8 to 42.0) at entry to 7.0 (CI = 3.3 to 10.9) by wk 14 (P = 0.001). Mean prednisolone dose (mg/d) in study II decreased from 23.8 (CI = 15.0 to 32.5) at entry to 8.8 (CI = 5.9 to 11.7) at wk 14 (P = 0.002). There were two deaths and seven serious infections. Relapse occurred in five patients (three in study II) after a mean of 27 wk. CONCLUSION TNFalpha blockade with infliximab was effective at inducing remission in 88% of patients with antibody-associated systemic vasculitis and permitted reduction in steroid doses. Severe infections were seen in 21% of patients, and despite continued infliximab, 20% of initial responders experienced disease flares. Infliximab is a promising new therapy for vasculitis both as a component of initial therapy and in the management of refractory disease. These results need confirmation in larger randomized trials.


Journal of Clinical Investigation | 1997

Inhibition of T cell apoptosis in the rheumatoid synovium.

Mike Salmon; Dagmar Scheel-Toellner; A. Huissoon; Darrell Pilling; N Shamsadeen; H Hyde; A D D'Angeac; P. A. Bacon; Paul Emery; Arne N. Akbar

Synovial T cells in rheumatoid arthritis are highly differentiated and express a phenotype suggesting susceptibility to apoptosis (CD45RB dull, CD45RO bright, Bcl-2 low, Bax high, Fas high). However, no evidence of T cell apoptosis was found in synovial fluid from any of 28 patients studied. In contrast, synovial fluid from 10 patients with crystal arthritis showed substantial levels of T cell apoptosis. The failre of apoptosis was not an intrinsic property of rheumatoid synovial T cells, as they showed rapid spontaneous apoptosis on removal from the joint. Synovial T cells from rheumatoid arthritis and gout patients could be rescued from spontaneous apoptosis in vitro either by IL-2R gamma chain signaling cytokines (which upregulate Bcl-2 and Bcl-XL) or by interaction with synovial fibroblasts (which upregulates Bcl-xL but not Bcl-2). The phenotype of rheumatoid synovial T cells ex vivo (Bcl-2 low, Bcl-xL high) suggested a fibroblast-mediated mechanism in vivo. This was confirmed by in vitro culture of synovial T cells with fibroblasts which maintained the Bcl-xL high Bcl-2 low phenotype. Synovial T cells from gout patients were Bcl-2 low Bcl-xL low and showed clear evidence of apoptosis in vivo. Inhibition experiments suggested that an integrin-ligand interaction incorporating the Arg-Gly-Asp motif is involved in fibroblast-mediated synovial T cell survival. We propose that environmental blockade of cell death resulting from interaction with stromal cells is a major factor in the persistent T cell infiltration of chronically inflamed rheumatoid synovium.


Annals of the Rheumatic Diseases | 2001

Phase I/II trial of autologous stem cell transplantation in systemic sclerosis : procedure related mortality and impact on skin disease

Michael Binks; Jakob Passweg; D.E. Furst; Peter A. McSweeney; Keith M. Sullivan; C. Besenthal; J Finke; Peter Hh; J M van Laar; F. C. Breedveld; Willem E. Fibbe; Dominique Farge; Eliane Gluckman; F Locatelli; Alberto Martini; F.H.J. van den Hoogen; L. B. A. Van De Putte; A V N Schattenberg; Rudolf Arnold; P. A. Bacon; Paul Emery; I Espigado; B. Hertenstein; Falk Hiepe; Ashwin Kashyap; Ina Kötter; Alberto M. Marmont; A Martinez; M J Pascual; Alois Gratwohl

BACKGROUND Systemic sclerosis (SSc, scleroderma) in either its diffuse or limited skin forms has a high mortality when vital organs are affected. No treatment has been shown to influence the outcome or significantly affect the skin score, though many forms of immunosuppression have been tried. Recent developments in haemopoietic stem cell transplantation (HSCT) have allowed the application of profound immunosuppression followed by HSCT, or rescue, to autoimmune diseases such as SSc. METHODS Results for 41 patients included in continuing multicentre open phase I/II studies using HSCT in the treatment of poor prognosis SSc are reported. Thirty seven patients had a predominantly diffuse skin form of the disease and four the limited form, with some clinical overlap. Median age was 41 years with a 5:1 female to male ratio. The skin score was >50% of maximum in 20/33 (61%) patients, with some lung disease attributable to SSc in 28/37 (76%), the forced vital capacity being <70% of the predicted value in 18/36 (50%). Pulmonary hypertension was described in 7/37 (19%) patients and renal disease in 5/37 (14%). The Scl-70 antibody was positive in 18/32 (56%) and the anticentromere antibody in 10% of evaluable patients. Peripheral blood stem cell mobilisation was performed with cyclophosphamide or granulocyte colony stimulating factor, alone or in combination. Thirty eight patients had ex vivo CD34 stem cell selection, with additional T cell depletion in seven. Seven conditioning regimens were used, but six of these used haemoimmunoablative doses of cyclophosphamide +/- anti-thymocyte globulin +/- total body irradiation. The median duration of follow up was 12 months (3–55). RESULTS An improvement in skin score of >25% after transplantation occurred in 20/29 (69%) evaluable patients, and deterioration in 2/29 (7%). Lung function did not change significantly after transplantation. One of five renal cases deteriorated but with no new occurrences of renal disease after HSCT, and the pulmonary hypertension did not progress in the evaluable cases. Disease progression was seen in 7/37 (19%) patients after HSCT with a median period of 67 (range 49–255) days. Eleven (27%) patients had died at census and seven (17%) deaths were considered to be related to the procedure (direct organ toxicity in four, haemorrhage in two, and infection/neutropenic fever in one). The cumulative probability of survival at one year was 73% (95% CI 58 to 88) by Kaplan-Meier analysis. CONCLUSION Despite a higher procedure related mortality rate from HSCT in SSc compared with patients with breast cancer and non-Hodgkins lymphoma, the marked impact on skin score, a surrogate marker of mortality, the trend towards stabilisation of lung involvement, and lack of other treatment alternatives justify further carefully designed studies. If future trials incorporate inclusion and exclusion criteria based on this preliminary experience, the predicted procedure related mortality should be around 10%.


Annals of the Rheumatic Diseases | 2008

Outcomes from studies of antineutrophil cytoplasm antibody associated vasculitis: a systematic review by the European League Against Rheumatism Systemic Vasculitis Task Force

Chetan Mukhtyar; Oliver Flossmann; Bernhard Hellmich; P. A. Bacon; Maria C. Cid; Jw Cohen-Tervaert; W. L. Gross; Loïc Guillevin; D Jayne; Alfred Mahr; Peter A. Merkel; Heiner Raspe; Dgi Scott; James Witter; Halil Yazici; Raashid Luqmani

Objectives: We undertook a systematic literature review as a background to the European League Against Rheumatism (EULAR) recommendations for conducting clinical trials in anti-neutrophil cytoplasm antibody associated vasculitis (AAV), and to assess the quality of evidence for outcome measures in AAV. Methods: Using a systematic Medline search, we categorised the identified studies according to diagnoses. Factors affecting remission, relapse, renal function and overall survival were identified. Results: A total of 44 papers were reviewed from 502 identified by our search criteria. There was considerable inconsistency in definitions of end points. Remission rates varied from 30% to 93% in Wegener granulomatosis (WG), 75% to 89% in microscopic polyangiitis (MPA) and 81% to 91% in Churg–Strauss syndrome (CSS). The 5-year survival for WG, MPA and CSS was 74–91%, 45–76% and 60–97%. Relapse (variably defined) was common in the first 2 years but the frequency varied: 18% to 60% in WG, 8% in MPA, and 35% in CSS. The rate of renal survival in WG varied from 23% at 15 months to 23% at 120 months. Methods used to assess morbidity varied between studies. Ignoring the variations in definitions of the stage of disease, factors influencing remission, relapse, renal and overall survival included immunosuppressive therapy used, type of organ involvement, presence of ANCA, older age and male gender. Conclusions: Factors influencing remission, relapse, renal and overall survival include the type of immunosuppressive therapy used, pattern of organ involvement, presence of ANCA, older age and male gender. Methodological variations between studies highlight the need for a consensus on terminology and definitions for future conduct of clinical studies in AAV.


The American Journal of Medicine | 1984

Intravenous cyclophosphamide plus methylprednisolone in treatment of systemic rheumatoid vasculitis

David G. I. Scott; P. A. Bacon

Systemic vasculitis in rheumatoid arthritis shows similarities to polyarteritis nodosa and may require equally aggressive therapy. Forty-five patients with systemic rheumatoid vasculitis were studied during treatment with either cyclophosphamide plus methylprednisolone given by intermittent bolus intravenous injection (21 patients) or a variety of other more conventional drug regimens (24 patients). In this open study, the intravenous treatment group had more severe initial disease, a higher incidence of neuropathy, and more frequent evidence of necrotizing arteritis on biopsy than the other treatment group. Despite this, intravenous cyclophosphamide plus methylprednisolone resulted in more frequent healing of vasculitic lesions including leg ulcers and neuropathy, a lower incidence of relapse, fewer serious complications, and a lower mortality than did other treatments. Toxic effects were similar in both study groups. Intravenous cyclophosphamide plus methylprednisolone is a useful early treatment for systemic rheumatoid vasculitis.


Journal of Clinical Investigation | 1985

Self-perpetuating mechanisms of immunoglobulin G aggregation in rheumatoid inflammation.

J Lunec; David R. Blake; S J McCleary; S Brailsford; P. A. Bacon

When human IgG is exposed to free radical generating systems such as ultraviolet irradiation, peroxidizing lipids, or activated human neutrophils, characteristic auto-fluorescent monomeric and polymeric IgG is formed (excitation [Ex], 360 nm, emission [Em], 454 nm). 1 h ultraviolet irradiation of IgG results in the following reductions in constituent amino acids; cysteine (37.0%), tryptophan (17.0%), tyrosine (10.5%), and lysine (3.6%). The fluorescent IgG complexes, when produced in vitro, can stimulate the release of superoxide from normal human neutrophils. In the presence of excess unaltered IgG, further fluorescent damage to IgG occurs. Measurement and isolation of fluorescent monomeric and polymeric IgG by high performance liquid chromatography, from in vitro systems and from fresh rheumatoid sera and synovial fluid, indicates that identical complexes are present in vivo; all these fluorescent complexes share the property of enhancing free radical production from neutrophils. The results described in this study support the hypothesis that fluorescent monomeric and aggregated IgG may be formed in vivo by oxygen-centered free radicals derived from neutrophils, and that in rheumatoid inflammation this reaction may be self-perpetuating within the inflamed joint.


Annals of the Rheumatic Diseases | 1984

Progression of radiological changes in rheumatoid arthritis.

D. L. Scott; K A Grindulis; G R Struthers; B L Coulton; A J Popert; P. A. Bacon

A prospective study over one year of patients who had active rheumatoid arthritis discovered 64 who had received treatment for an adequate time with second-line drugs. In these patients there was evidence of continuing joint destruction as shown by radiological progression. During the year there were highly significant correlations between improvements in clinical and laboratory measurements, but neither group of tests was related to the degree of radiological change. However, in the second 6 months of treatment there was evidence that radiological progression was reduced. In a second prospective study of 88 patients with rheumatoid arthritis given prolonged, intensive therapy with second-line drugs and followed up for 10 years two-thirds showed radiological progression. However, the number of joints damaged per year fell significantly during the study period. There was a divergence between deterioration in radiological features and improvements in the ESR and functional capacity, though patients with a persistently low ESR had less radiological progression. These studies provide evidence that treatment may be associated with a reduced rate of radiological progression but suggest that changes in radiological progression and clinical and laboratory measurements may result from different mechanisms.


Circulation | 2000

Suppression of Inflammation in Primary Systemic Vasculitis Restores Vascular Endothelial Function: Lessons for Atherosclerotic Disease?

Karim Raza; Jeetendra Thambyrajah; John N. Townend; A. R. Exley; C. Hortas; Andrew Filer; D. M. Carruthers; P. A. Bacon

BackgroundChronic inflammatory rheumatic disorders are associated with excess cardiovascular mortality. This may result from arteriosclerosis following inflammatory damage to the vessel wall by vasculitis. Our hypothesis that vasculitis results in arteriosclerosis by causing vascular endothelial dysfunction was tested in patients with primary systemic necrotizing vasculitis (SNV). Methods and ResultsEndothelial function was assessed in cross-sectional and longitudinal studies of patients with primary SNV by measuring flow-mediated, endothelium-dependent brachial artery vasodilatation. These patients exhibited marked endothelial dysfunction compared with controls. Remission induction in patients with active primary SNV restored endothelial function. ConclusionsEndothelial function is significantly impaired in adults with primary SNV, supporting the hypothesis that premature arteriosclerosis in chronic inflammatory rheumatic disorders results from endothelial dysfunction secondary to vasculitis. Normalization of endothelial function after the treatment of primary SNV suggests that early suppression of disease activity in chronic inflammatory rheumatic disorders may reduce long-term vascular damage. The role of inflammation in atheroma formation is increasingly appreciated; this work raises questions regarding the potential for anti-inflammatory therapy in atherosclerosis itself.

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George D. Kitas

Dudley Group NHS Foundation Trust

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M. Farr

University of Birmingham

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Mike Salmon

University of Birmingham

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Karim Raza

University of Birmingham

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A. R. Exley

University of Birmingham

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