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P J Roberts-Thomson

Publications and source records attributed to P J Roberts-Thomson.

At least 19 recordsLinked to original sources
PubMed2007

Characterisation of a dendritic cell subset in synovial tissue which strongly expresses Jak/STAT transcription factors from patients with rheumatoid arthritis.

OBJECTIVES: To characterise the phenotype of the putative dendritic cells strongly expressing Jak3 and STAT4, which have been previously identified in the synovial tissue of patients with active rheumatoid arthritis (RA). METHODS: Synovial biopsy specimens were obtained at arthroscopy from 30 patients with active RA (42 synovial biopsies). Immunohistological analysis was performed using monoclonal antibodies to detect dendritic cell subsets, including activation markers and cytokines relevant to dendritic cell function. Co-localisation of cell surface markers and cytokines was assessed primarily using sequential sections, with results confirmed by dual immunohistochemistry and immunofluorescence with confocal microscopy. RESULTS: The dendritic cells identified in RA synovial tissue that strongly express Jak3 also strongly express STAT4 and STAT 6 and are correlated with the presence of serum rheumatoid factor. These cells are not confined to a single dendritic cell subset, with cells having phenotypes consistent with both myeloid- and plasmacytoid-type dendritic cells. The activation status of these dendritic cells suggests that they are maturing or mature dendritic cells. These dendritic cells produce IL12 as well as interferon alpha and gamma. CONCLUSIONS: The close correlation of these dendritic cells with the presence of serum rheumatoid factor, a prognostic factor for worse disease outcome, and the strong expression by these cells of components of the Jak/STAT transcription factor pathway suggest a potential therapeutic target for the treatment of RA.

Adult↗
PubMed2006

Changes in synovial tissue Jak-STAT expression in rheumatoid arthritis in response to successful DMARD treatment.

BACKGROUND: Modulation of Jak-STAT signalling may provide an effective therapeutic strategy in inflammatory arthritis (IA). OBJECTIVE: To examine the effect of successful disease-modifying antirheumatic drug (DMARD) treatment on the expression of Jak-STAT in a cohort of patients with active rheumatoid arthritis. METHODS: Synovial tissue biopsy specimens from 16 patients with active rheumatoid arthritis, taken before and after initiation of DMARD treatment, were examined for the presence of janus kinase (Jak)3, signal transducer and activator of transcription (STAT)1, STAT4 and STAT6 expression using immunohistochemistry. RESULTS: Successful treatment with DMARDs results in reduction in STAT1 expression in the lining, and STAT1 and STAT6 in the sublining of rheumatoid arthritis synovial tissue. Although the overall expression of STAT4 and Jak3 was not significantly altered by DMARD treatment, there was a significant reduction in the expression of the STAT4 and Jak3 bright cells, thought to be an activated dendritic cell subpopulation. CONCLUSION: Results show that Jak3, STAT1, STAT4 expression and STAT6 sublining expression decrease in response to successful treatment of rheumatoid arthritis with standard DMARDs. Therefore, altering the expression of these pathways may represent an alternative treatment option, either through promoting up-regulation of inhibitory pathways, or suppressing inflammatory paths.

Antirheumatic Agents↗
PubMed2006

Scleroderma in South Australia: further epidemiological observations supporting a stochastic explanation.

The aim of this study was to determine the incidence, prevalence, survival and selective demographic characteristics of scleroderma occurring in South Australia over the 10-year period 1993-2002. Analysis of the database of the South Australian Scleroderma Register: a population-based register established in 1993. Patients with scleroderma resident in South Australia (n = 353 at 2002) were ascertained from multiple sources and clinical and demographic data were obtained from mailed questionnaire and from review of computerized hospital databases, case notes or referring letters. Time-space cluster analysis was carried out according to the Knox method. Control data were obtained from the Australian Bureau of Statistics census. The mean prevalence was 21.4 per 10(5) (95% confidence interval 20.2-22.6) and the mean cumulative incidence of 1.5 per 10(5) (95% confidence interval 1.32-1.73) with no significant change in incidence over the study period (P = 0.13). Cumulative survival improved over the study period, with patients with diffuse disease having significantly reduced survival (as compared with limited disease, P < 0.001). The proportion with diffuse disease ( approximately 22%) remained steady. There was a small but significant predisposition in patients with a continental European birthplace (P < 0.001). A family history of scleroderma was noted in 1.6% with lambda1 (familial risk) of 14.3 (95% confidence interval 5.9-34.5). However, a family history of systemic autoimmunity (especially rheumatoid arthritis) was more common (6%). No socioeconomic stratification, temporal clustering nor spatio-temporal clustering was observed either at time of initial symptom or at 10 years before disease onset. Scleroderma occurs relatively infrequently in South Australia with no significant change in incidence observed over the 10-year study period. However, cumulative survival has improved. Identified risk factors include family history of scleroderma (risk approximately 14-fold), female sex (risk approximately 5-fold) and European birthplace (risk approximately 2.5-fold); however, the majority of the disease variance appears unexplained. A stochastic explanation based on genetic instability is favoured to explain this paradox.

Female↗
PubMed2006

Scleroderma: it has been a long hard journey.

Progress in the understanding of the aetiopathogenesis of scleroderma (systemic sclerosis) has been painfully slow and this has greatly impeded the application of specific disease modifying treatments. This article provides a brief historical overview of scleroderma (including the important Australian contribution of Dr Alfred Barnett and colleagues--see accompanying article in this issue on pages 513-18), highlights some recent pathogenic developments and summarises some exciting new therapies. Cautious optimism can now be offered to scleroderma sufferers.

Animals↗
PubMed2005

The use of the hand anatomic index to assess deformity and impaired function in systemic sclerosis.

To determine the "hand anatomic index" (HAI--a quantitative measure of hand deformity) in systemic sclerosis (scleroderma) and to compare it with the other measures of hand deformity and functional impairment. The HAI (measure of open hand span minus closed hand span/lateral height of hand) was determined in 30 patients with scleroderma and compared with hand deformity (as assessed by two independent rheumatologists) and with the Health Assessment Questionnaire (mHAQ), hand strength and prehensile gripability data. The HAI was confirmed as a reliable measure which clearly distinguished patients with increasing hand deformity and separated patients with diffuse scleroderma (n=12) from limited scleroderma (n=18), P=0.005. The HAI correlated significantly with measures of global functional impairment (as measured by the mHAQ) r=-0.46, P=0.01, hand strength r=0.51, P=0.0001 and prehensile gripability, r=-0.37, P=0.05 but neither with disease duration r=-0.16, P=NS nor age at disease onset r=0.20, P=NS. It was estimated that the HAI accounts for ~25% of the total global disability (as measured by HAQ). Measurement of the HAI in scleroderma provides a reliable and objective measure reflecting variable degrees of hand deformity and functional impairment and might provide a valid clinical outcome measure in patients with this disabling disorder.

Adult↗
PubMed2005

Expression of Jak3, STAT1, STAT4, and STAT6 in inflammatory arthritis: unique Jak3 and STAT4 expression in dendritic cells in seropositive rheumatoid arthritis.

BACKGROUND: Modulation of Jak-STAT signalling may provide an effective therapeutic strategy in inflammatory arthritis. OBJECTIVE: To document Jak-STAT expression in a cohort of patients with active rheumatoid arthritis (RA), spondyloarthritis (SpA), and osteoarthritis (OA) and compare these subsets with normal synovial tissue. METHODS: Synovial tissue biopsy specimens from patients with RA, OA, and SpA and histologically normal tissue (n = 10 in each arthritis group) were examined for the presence of Jak3, STAT1, STAT4, and STAT6 expression using immunohistochemistry. Phenotyping was performed using immunohistochemistry and immunofluorescence. Clinical and serological characteristics of patients with RA expressing Jak3-STAT4 were assessed. RESULTS: STAT1, STAT4, and Jak3 protein expression was generally increased in inflammatory arthritis. In contrast, STAT6 expression was relatively heterogeneous. A subpopulation of CD1a positive dendritic cells unique to seropositive patients with RA was detected. These cells showed intense protein expression for Jak3, STAT4, and STAT6. CONCLUSION: CD1a positive dendritic cells intensely express Jak3, STAT4, and STAT6 in seropositive RA tissue and may be an alternative marker for dendritic cells in their early stages of activation as well as providing a tool for identifying RA at the level of the synovium. Jak3 inhibition may be a potential therapeutic target to prevent dendritic cell maturation in RA. STAT1 expression is increased in inflammatory arthritis, suggesting that its pro-apoptotic and anti-inflammatory effects cannot effectively counteract inflammation. STAT6 expression is heterogeneous in synovium, suggesting a possible homoeostatic role in addition to any anti-inflammatory effects.

Adult↗
PubMed2005

Isolated pulmonary hypertension in scleroderma.

BACKGROUND: Isolated pulmonary hypertension (PHT) is now the most frequent cause of disease-related death in limited cutaneous scleroderma, the commonest disease variant of this disabling connective tissue disorder. Endothelin-1 receptor antagonists provide symptomatic benefit but to date have not been shown to prolong survival. AIM: To determine the frequency, disease characteristics and survival of symptomatic patients with isolated PHT in our cohort of scleroderma patients. METHODS: Systematic review of the clinical course of all patients registered on the South Australian Scleroderma Register, a population-based register of 374 living and 234 deceased patients with scleroderma. RESULTS: Thirty-four patients were identified with isolated PHT, the majority with limited scleroderma. From our deceased register, we estimate that >11% of patients with this limited variant will develop this complication. Isolated PHT occurs as a late-stage complication approximately 20 years after the first symptoms of scleroderma. Patients with isolated PHT were characterized by the presence of multiple telangiectasia, reduced nailfold capillary density, digital ulceration, gross reduction of diffusing capacity for carbon monoxide and echocardiographic evidence of elevated pulmonary artery pressure. Survival was significantly shortened as compared with those patients without this complication (P=0.002), with a mean survival of 2.5 years from symptomatic onset of PHT. CONCLUSION: Isolated PHT occurs as a late-stage complication in > or =11% of patients with limited cutaneous scleroderma and leads to rapid death from right heart failure. The early use of endothelin-1 receptor antagonists may change the natural history of this fatal complication.

Aged↗
PubMed2005

Scleroderma in Australian aborigines.

Scleroderma (systemic sclerosis) has not been reported before in Australian Aborigines. We describe in detail a community middle-aged Aboriginal woman whose diffuse scleroderma terminated fatally with a renal crisis. Moreover, we have identified a further five Aboriginal patients on the South Australian Scleroderma Register (two with diffuse, two with limited and one with overlap scleroderma), a number consistent with that expected from the 2001 census data for our state. However, an analysis of all antinuclear antibody (ANA) requests from the Top End of Australia over a 6-year period revealed only two Aborigines with low titre anticentromere antibody (despite frequent occurrence of ANA with other specificities). Neither of these Aborigines had features of scleroderma. In conclusion, scleroderma does occur in indigenous Australians but further studies are needed to confirm the apparent infrequency of centromere-associated limited scleroderma (which is the commonest form of scleroderma in our Caucasian population).

Antibodies, Antinuclear↗
PubMed2005

Immune dysfunction in Australian Aborigines.

An examination of the prevalence and phenotype of immune disorders in different ethnic groups may provide important clues to the etiopathogenesis of these disorders. Whilst still conjectural the restricted and somewhat unique polymorphisms of the MHC (and other genetic loci involving host defences) of the Australian Aborigines may provide an explanation for their apparent heightened susceptibility to newly encountered infections and their resistance to many (auto) immune and allergic disorders. In comparison with non-Aboriginal Australians, Australian Aborigines have heightened frequencies of rheumatic fever, systemic lupus erythematosus, various infections and post-streptococcal glomerulonephritis. In contrast various autoimmune disorders (e.g. rheumatoid arthritis, multiple sclerosis, CREST, biliary cirrhosis, coeliac disease, pernicious anaemia, vitiligo), B27 related arthropathies, psoriasis, lymphoproliferative disorders and atopic disorders appear infrequent or absent. Similarly various autoantibodies occur with increased or diminished frequency. With continuing racial admixture, social deprivation and deleterious lifestyles of these people it is likely that further changes in both the frequencies and phenotype of these immune disorders will occur. It is only with a full understanding of the pathogenic mechanisms involved in these immune disorders that meaningful and clinical relevant interventions will be possible.

Australia↗
PubMed2003

Osteoprotegerin expression in synovial tissue from patients with rheumatoid arthritis, spondyloarthropathies and osteoarthritis and normal controls.

OBJECTIVES: To demonstrate the expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappaB ligand (RANKL) in synovial tissue from rheumatoid arthritis (RA) patients, establish the cell lineage expressing OPG and compare the expression of OPG in RA, spondyloarthropathies, osteoarthritis and normal synovial tissue. METHODS: Synovial biopsy specimens were obtained at arthroscopy from 16 RA and 12 spondyloarthropathy patients with active synovitis of a knee joint, six RA patients with no evidence of active synovitis, 10 patients with osteoarthritis and 18 normal subjects. Immunohistological analysis was performed using monoclonal antibodies (mAb) to detect OPG and RANKL expression. In addition, dual immunohistochemical evaluation was performed with lineage-specific monoclonal antibodies (macrophages, fibroblasts and endothelial cells) and OPG to determine the cell lineages expressing OPG. The sections were evaluated by computer-assisted image analysis and semiquantitative analysis. RESULTS: Two patterns of OPG expression were seen, one exclusively in endothelial cells and one expressed predominantly in macrophages in the synovial lining layer. Both patterns of OPG staining could be blocked with excess recombinant OPG. Endothelial and synovial lining expression of OPG was seen in all synovial tissues except those from patients with active RA. In contrast, RANKL expression was seen predominantly in synovial tissue from patients with active disease, mainly in sublining regions, particularly within areas of lymphocyte infiltration. CONCLUSIONS: OPG expression on macrophage type synovial lining cells as well as endothelial cells is deficient in RA patients with active synovitis, in contrast to that seen in spondyloarthropathy patients with active synovitis. This deficiency in OPG expression in the inflamed joint of RA patients may be important in the development of radiologically defined joint erosions.

Acute Disease↗
PubMed2001

Effects of intraarticular glucocorticoids on macrophage infiltration and mediators of joint damage in osteoarthritis synovial membranes: findings in a double-blind, placebo-controlled study.

OBJECTIVE: To investigate the effects of intraarticular glucocorticoid treatment on macrophage infiltration, the expression of the chemokines monocyte chemoattractant protein 1 (MCP-1) and macrophage inflammatory protein 1alpha (MIP-1alpha), and the expression of matrix metalloproteinases 1 and 3 (MMPs 1 and 3) and their inhibitors, the tissue inhibitors of metalloproteinases 1 and 2 (TIMPs 1 and 2), in osteoarthritis (OA) synovial membranes. METHODS: Forty patients underwent arthroscopic biopsy before and 1 month after intraarticular injection of glucocorticoids. Twenty-one patients received 120 mg of methylprednisolone acetate (Depo-Medrol; Upjohn, Kalamazoo, MI), and 20 patients received placebo (1 patient received placebo in 1 knee and methylprednisolone acetate in the other). Immunoperoxidase staining for the expression of CD68, MCP-1, MIP-1alpha, MMP-1, MMP-3, TIMP-1, and TIMP-2 was performed, and the immunostaining was quantified by color video image analysis. RESULTS: CD68, MCP-1, MIP-1alpha, MMP-1, MMP-3, TIMP-1, and TIMP-2 immunostaining was observed in all synovial membranes. Intraarticular glucocorticoid treatment was associated with a small (30%) but statistically significant (P = 0.048) reduction in CD68+ macrophage staining in the synovial lining layer, but there was no change in the CD68 expression in the synovial sublining layer. No significant differences were observed for MCP-1, MIP-1alpha, MMP-1, MMP-3, TIMP-1, and TIMP-2 immunostaining in the synovial lining or sublining layers. CONCLUSION: Intraarticular glucocorticoids may reduce CD68+ macrophage infiltration into the synovial lining layer, but not the expression of MCP-1, MIP-1alpha, MMP-1, MMP-3, TIMP-1, and TIMP-2 in the synovial membrane, in patients with OA.

Aged↗
PubMed2001

Treatment-induced remission in rheumatoid arthritis patients is characterized by a reduction in macrophage content of synovial biopsies.

OBJECTIVES: To document the change in synovial membrane macrophage and T-lymphocyte content in rheumatoid arthritis (RA) patients who achieve remission induced by disease-modifying anti-rheumatic drugs (DMARDs). METHODS: Arthroscopic synovial biopsies were taken from four to seven sites around a knee joint in 13 patients with RA before and at regular intervals after commencing treatment with a DMARD. The cellular content of synovial membrane biopsies taken at regular intervals for a period of up to 3 yr after commencing treatment was quantitated by routine histopathology and immunohistochemical labelling with anti-macrophage (CD68) and anti-T lymphocyte (UCHL-1) antibodies. Synovial biopsies were quantitated with a validated semiquantitative scoring system and video image analysis. RESULTS: Nine patients obtained clinical remission, as defined by American College of Rheumatology (ACR) criteria. The changes that occurred in the synovial biopsies included a reduction in lining layer thickness, reduced vascularity and cellular infiltrate. The most significant reduction in cellular infiltrate was in the lining layer macrophages, with less dramatic change in the subintimal macrophage infiltrate. Although there was a reduction in CD45 Ro-positive T lymphocytes in the synovial membranes of patients who attained ACR-defined disease remission, it was less significant than the reduction in macrophage content of the synovial membranes and tended to plateau at a reduced level of T-cell infiltration. CONCLUSIONS: Remission in RA patients is characterized by a predominant reduction in macrophage content of the synovial membrane, suggesting that current DMARDs may target this cell and its inflammatory mediators.

Aged↗
PubMed2001

Successful treatment of rheumatoid arthritis is associated with a reduction in synovial membrane cytokines and cell adhesion molecule expression.

OBJECTIVE: To investigate the change in synovial membrane cytokine content and cell adhesion molecule expression in sequential biopsies from the same knee joint of patients with rheumatoid arthritis, before and following anti-rheumatic drug treatment and to assess the relationship of these changes with clinical responses to the drug treatment. METHODS: A selected group of patients with rheumatoid arthritis, some of whom had achieved a disease remission based on American College of Rheumatology (ACR) criteria, were included in this study. Sequential synovial biopsies obtained before and throughout the treatment period were studied by immunohistochemical labelling techniques for the cellular content, production of a range of pro- and anti-inflammatory cytokines and the expression of cell adhesion molecules. The staining was quantitated using computer-assisted digital image analysis. RESULTS: There was a decrease in tumour necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) production in the synovial membrane lining and sublining of all patients who responded to treatment. The changes in IL-1 receptor antagonist production were variable. Paradoxically, there was a trend to decreased synovial membrane production of the anti-inflammatory cytokines, IL-10 and transforming growth factor-beta (TGFbeta), while IL-4 was not detectable in any of the synovial membrane biopsies. A significant reduction in the density and total amount of E-selectin expression in the synovial membrane was seen. Similarly, intercellular adhesion molecule-1 (ICAM-1) expression in the lining and sublining was decreased in those patients who had a significant clinical response to drug treatment or attained disease remission. There were no consistent or significant changes seen in the expression of other cell adhesion molecules in the synovial membranes of these patients. CONCLUSIONS: Successful drug treatment of rheumatoid arthritis patients is characterized at the synovial membrane level by a decrease in TNFalpha, IL-10 and TGFbeta production. Some (E-selectin and ICAM-1) but not all (P-selectin, VCAM-1, PECAM-1) cell adhesion molecules are modulated in patients who respond clinically to drug treatment. E-selectin and ICAM-1 may be important targets for the development of future drug treatments for rheumatoid arthritis.

Aged↗
PubMed2001

Effects of pulse methylprednisolone on macrophage chemotactic protein-1 and macrophage inflammatory protein-1alpha in rheumatoid synovium.

OBJECTIVE: To determine the effect of pulse methyprednisolone (PMP; 1000 mg) on the expression of monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha in rheumatoid synovial membrane. METHODS: Seven patients with rheumatoid arthritis (RA) were studied. Arthroscopically-directed synovial biopsies were taken before and 24 hours after treatment with intravenous PMP. Synovial membranes were stained by immunohistochemical techniques with monoclonal antibodies against MCP-1, MIP-1alpha and CD68 (a macrophage marker). Quantitation of staining was performed by computer-assisted color video image analysis. RESULTS: PMP therapy was associated with a rapid (within 24 hours) and substantial decrease in the expression of MCP-1 and MIP-1alpha expression by a mean of 55% (p = 0.05) and 45% (p = 0.03), respectively, with no effect on CD68 expression in the synovial lining layer. There was no significant change in MCP-1, MIP-1alpha or CD68 expression in the synovial sublining. CONCLUSION: PMP therapy rapidly reduces MCP-1 and MIP-1alpha levels in the synovial lining layer without a fall in macrophage numbers. It thus appears that the initial effect of PMP is that of reducing macrophage activation.

Aged↗
PubMed2001

The TGF beta receptor endoglin in systemic sclerosis.

Immunohistochemical, flow cytometric and ELISA studies were performed to examine the expression of endoglin (CD105, a TGF beta receptor) on dermal endothelial cells, peripheral blood monocytes and free and bound serum levels in patients with systemic sclerosis as compared with appropriate controls. Endoglin was found to be significantly upregulated on dermal blood vessels in patients with scleroderma (and in patients with inflammatory skin disorders) as compared to healthy skin (p < 0.05). In contrast, there was no significant difference in endoglin expression on circulating blood monocytes between scleroderma patients and patients with a rheumatic disoder or healthy control subjects; however, endoglin expression was upregulated on monocytes in inflammatory joint fluid from patients with rheumatoid arthritis. Endoglin expression on monocytes was also influenced by isolation techniques and during whole blood culture. No differences were found in circulating free or bound endoglin levels between scleroderma patients and healthy controls. In conclusion, endoglin expression on dermal endothelial cells was significantly enhanced in scleroderma but levels on circulating monocytes and in the serum were within normal limits. The functional significance of this upregulation is uncertain but may reflect endothelial activation in scleroderma.

Aged↗