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ID PMID Title PublicationDate abstract
16464986 Lack of association between the protein tyrosine phosphatase non-receptor 22 (PTPN22)*620W 2006 Sep The minor allele of the R620W missense single-nucleotide polymorphism (SNP; rs2476601) in the PTPN22 (protein tyrosine phosphatase non-receptor 22) gene has been reported to be associated with multiple autoimmune diseases, including type 1 diabetes, systemic lupus erythematosus, rheumatoid arthritis, juvenile idiopathic arthritis, autoimmune thyroiditis and vitiligo. Systemic sclerosis (SSc) is a connective tissue disease with some autoimmune abnormalities. The aim of our study was to test for association of the PTPN22*620W allele with SSc in a French Caucasian cohort with a case-control study of 121 patients with SSc and 103 controls. All patients and controls were genotyped for the PTPN22*R620W SNP. No association was found between the PTPN22*620W allele and SSc (7% v 9.2%, p = 0.39). The frequency of genotypes carrying at least one 620W allele was similar in both groups (13% v 17%, p = 0.38). The PTPN22*620W allele was also not associated with autoantibody patterns. Thus, the PTPN22*R620W polymorphism cannot be regarded as a genetic susceptibility factor for SSc in the French Caucasian population.
18198195 Lack of efficacy of etanercept in Sjögren syndrome correlates with failed suppression of 2008 Oct OBJECTIVE: To provide insight into the clinical failure of the tumour necrosis factor alpha (TNFalpha) inhibitor, etanercept, in primary Sjögren syndrome (pSS), an extensive analysis of the systemic immune profile of patients with pSS was carried out and the effect of etanercept treatment on these immune parameters monitored. METHODS: Peripheral blood mononuclear cells of patients with pSS and healthy controls were compared by flow cytometry to determine differences in distribution of specific cell populations (T cells, B cells, monocytes), and to determine their expression of activation markers (CD25, HLA-DR), TNF receptors and chemokine receptors (CXCR1, 2) before and after treatment. Systemic cytokine levels were measured by multiplex ELISA assay in plasma and in lipopolysaccharide-stimulated whole blood from healthy controls and from patients with pSS before and after etanercept treatment. Baseline cytokine levels were correlated with clinical markers of disease. RESULTS: Before treatment, salivary gland inflammatory focus scores did not correlate with circulating TNF levels. Furthermore, consistent with the lack of evidence of significant clinical benefit, enhanced markers of immune activation, frequency of cell subpopulations and aberrant cytokine profiles were not restored to normal levels by etanercept treatment. Remarkably, the levels of circulating TNFalpha were significantly increased after treatment. CONCLUSION: Etanercept is an ineffective therapeutic agent in pSS consistent with the absence of suppression of TNFalpha and other indicators of immune activation in this patient population. These data suggest that TNFalpha may not be a pivotal cytokine in the pathogenesis of pSS, impelling continued molecular characterisation of disease parameters to define appropriate intervention targets.
16918261 Epratuzumab (humanised anti-CD22 antibody) in autoimmune diseases. 2006 Sep B cells play an important role in the pathogenesis of many autoimmune diseases. Different approaches targeting the B cell compartment are under investigation. Selective modulation of B cells has been recently achieved using a humanised monoclonal antibody against the B cell surface marker CD22. This antibody (epratuzumab) was originally developed for the treatment of non-Hodgkin's lymphoma and was found to be effective, with a very good safety profile. Recent studies have demonstrated the efficacy and safety of epratuzumab in several autoimmune diseases, including systemic lupus erythematosus and primary Sjögren's syndrome.
16496080 Primary biliary cirrhosis (PBC)-CREST overlap syndrome with coexistence of Sjögren's synd 2007 Apr Calcinosis, Raynaud's phenomenon, oesophageal dysmotility, sclerodactyly, telangiectasia (CREST) syndrome, a limited form of systemic sclerosis, is sometimes complicated by primary biliary cirrhosis (PBC). A 52- and 61-year-old Japanese woman with PBC-CREST overlap syndrome accompanied by Sjögren's syndrome, and Hashimoto's thyroiditis, and Graves' disease, respectively, are reported. They had suffered from Raynaud's phenomena, sclerodactyly, morning stiffness, arthralgia, and sicca symptoms during these several years. They exhibited an increased level of alkaline phosphatase, gamma-glutamyl transpeptidase, positive antibodies against mitochondria and centromere, and hyperglobulinemia without any cholestatic symptoms. Histological findings from liver biopsy specimens were consistent with those of PBC. Clinically, they were diagnosed as both asymptomatic PBC and incomplete CREST syndrome. Their human leukocyte antigen typing showed both DR4 and DR8 positive. The association of the four autoimmune conditions is clinically and etiologically important. Although a combination of these diseases is rare, it is of importance to keep in mind that various autoimmune diseases could occur simultaneously. Of critical importance is that an active diagnostic attitude towards them is admirable, and that early diagnosis and therapy are needed.
19092842 Additive effects of the major risk alleles of IRF5 and STAT4 in primary Sjögren's syndrom 2009 Jan Primary Sjögren's syndrome (SS) shares many features with systemic lupus erythematosus (SLE). Here we investigated the association of the three major polymorphisms in IRF5 and STAT4 found to be associated with SLE, in patients from Sweden and Norway with primary SS. These polymorphisms are a 5-bp CGGGG indel in the promoter of IRF5, the single nucleotide polymorphism (SNP) rs10488631 downstream of IRF5 and the STAT4 SNP rs7582694, which tags the major risk haplotype of STAT4. We observed strong signals for association between all three polymorphisms and primary SS, with odds ratios (ORs) >1.4 and P-values <0.01. We also found a strong additive effect of the three risk alleles of IRF5 and STAT4 with an overall significance between the number of risk alleles and primary SS of P=2.5 x 10(-9). The OR for primary SS increased in an additive manner, with an average increase in OR of 1.78. For carriers of two risk alleles, the OR for primary SS is 1.43, whereas carriers of five risk alleles have an OR of 6.78. IRF5 and STAT4 are components of the type I IFN system, and our findings emphasize the importance of this system in the etiopathogenesis of primary SS.
17636342 End-stage renal failure in adolescence with Sjögren's syndrome autoantibodies SSA and SSB 2007 Oct We describe two adolescents who presented with end-stage renal failure and clinical features suggestive of Sjögren's syndrome (SS). They both demonstrated severe, chronic, tubulointerstitial inflammation on renal biopsy, high-titre antinuclear antibodies, high immunoglobulin A and G concentrations, positive anti-SSA and anti-SSB antibodies, and negative anti-double-stranded DNA antibodies. One had subjective and objective evidence of the sicca complex (dry eyes and/or dry mouth) and fulfilled the commonly accepted SS consensus criteria. The other showed no evidence of the sicca complex but fulfilled modified criteria for juvenile SS. SS may be underrecognised as a cause of end-stage renal failure in childhood.
19000095 Anti-CD20 treatment in primary Sjögren's syndrome. 2008 Dec We performed a search for publications on rituximab (Rtx) in the treatment of primary Sjögren's syndrome (pSS), and assessed the reports for the efficacy of the drug on complaints like sicca symptoms, systemic manifestations and pSS associated lymphoma. We also reviewed the effects on laboratory parameters and potential adverse effects. From the published literature there is little evidence supporting Rtx to have an effect on sicca symptoms, and there is particularly lack of objective improvements in measures of oral and ocular dryness. Systemic manifestations such as fatigue, synovitis, arthralgia, cryoglobulinaemia-related vasculitis, neurological, renal and pulmonary involvement all seem to react favourably to Rtx treatment. The effect on pSS associated non-Hodgkin's lymphoma is also beneficial. Rheumatoid factor concentration is decreasing during Rtx treatment. The levels of anti-SSA and -SSB antibodies are, however, unaltered according to the majority of the studies. The most common complications to Rtx treatment are mild and transient infusion related reactions. Delayed moderate-to-severe reactions are less common, and occur mostly in patients who develop human anti-chimeric antibodies. In conclusion, Rtx is a promising treatment option for severe pSS with systemic complications, but more data from randomized controlled trials are warranted before conclusions on the drug's role can be made with more accuracy.
16728458 Progression of salivary gland dysfunction in patients with Sjogren's syndrome. 2007 Jan BACKGROUND: Salivary gland dysfunction is one of the key manifestations of Sjögren's syndrome. OBJECTIVES: (1) To assess prospectively loss of function of individual salivary glands in patients with primary and secondary Sjögren's syndrome in relation to disease duration and use of immunomodulatory drugs. (2) To study changes in sialochemical and laboratory values and subjective complaints over time. METHODS: 60 patients with Sjögren's syndrome were included in this study. Whole and gland-specific saliva (parotid and submandibular/sublingual (SM/SL)), samples were collected at baseline and after a mean of 3.6 (SD 2.3) years of follow-up. Disease duration was recorded for all patients. RESULTS: Patients with Sjögren's syndrome with short disease duration had significantly higher stimulated flow rates at baseline than those with longer disease duration (p<0.05). When compared with healthy controls, the decrease in SM/SL flow rates at baseline was more prominent than that in parotid flow rates (p<0.05). Over time, there was a significant further decrease of stimulated flow rates, especially of the parotid gland, accompanied by increasing problems with swallowing dry food (p<0.05). The decrease was independent of the use of corticosteroids or disease-modifying antirheumatic drugs (DMARDs). Sialochemical variables remained stable. CONCLUSIONS: Early Sjögren's syndrome is characterised by a decreased salivary gland function (parotis>SM/SL), which shows a further decrease over time, regardless of the use of DMARDs or steroids. Patients with Sjögren's syndrome with longer disease duration are characterised by severely reduced secretions of both the parotid and SM/SL glands. These observations are relevant for identifying patients who would most likely benefit from intervention treatment.
18240266 Effective treatment with oral administration of rebamipide in a mouse model of Sjögren's 2008 Feb OBJECTIVE: To determine whether oral administration of rebamipide, a mucosal protective agent, is effective in the treatment of Sjögren's syndrome (SS) in the NFS/sld mouse model of the disease. METHODS: NFS/sld mice were given daily oral doses of rebamipide (0.3 mg/kg of body weight or 3 mg/kg) or vehicle alone starting from the age of 4 weeks to the age of 8 weeks. The volume of saliva and tears was monitored during and after treatment. After the final dose, histologic features of the tissues, TUNEL+ apoptotic duct cells in affected glands, T cell and cytokine function, and levels of immunoglobulin isotypes and serum autoantibodies were examined. RESULTS: The 3-mg/kg dose of rebamipide prevented the development of autoimmune lesions. The average volume of saliva in rebamipide-treated mice was significantly higher than that in control mice. We found decreased TUNEL+ apoptotic duct cells in the salivary and lacrimal glands of rebamipide-treated mice as compared with control mice. Rebamipide treatment suppressed the activation of CD4+ T cells and Th1 cytokines (interleukin-2, interferon-gamma) associated with impaired NF-kappaB activity. Production of serum autoantibodies, IgM, and IgG1 was clearly inhibited. CONCLUSION: Our findings demonstrate the efficacy of oral administration of rebamipide in the treatment of SS. Rebamipide represents a new therapeutic strategy for the treatment of patients with sicca symptoms caused by SS, as well as for patients with other diseases.
17106166 Mixed connective tissue disease associated with MPO-ANCA-positive polyangiitis. 2006 The patient was a 42-year-old woman diagnosed as having MCTD and Sjögren's syndrome in 1989, and who was taking oral prednisolone. Proteinuria and microscopic hematuria were pointed out for the first time in December 2004. She was referred to our hospital because of massive hemoptysis. Advanced renal failure, anemia and pulmonary alveolar hemorrhage were diagnosed on admission. She was positive for serum MPO-ANCA. The patient was started on a therapy that included steroids, cyclophosphamide and plasmapheresis. However, her respiratory condition was untreatable and she died on the 16th day of hospitalization. The autopsy revealed alveolar hemorrhage in the lungs and crescentic glomerulonephritis. This patient was considered as a rare case of MCTD associated with MPO-ANCA-positive microscopic polyangiitis.
16014676 Basal lamina disorganisation of the acini and ducts of labial salivary glands from patient 2006 Feb OBJECTIVE: To study the expression of laminin and type IV collagen as biomarkers of the organisation of the basal lamina of acini and ducts in labial salivary glands from patients with Sjögren's syndrome, and to relate this organisation to inflammatory cell invasion of acini and ducts. METHODS: Immunohistochemistry for laminin and type IV collagen was undertaken on sections of labial salivary glands from 30 patients with Sjögren's syndrome, 10 control subjects, and 24 controls with chronic sialoadenitis. Immunohistochemistry reaction, alterations to cell morphology, and the presence of inflammatory cells in acini and ducts were evaluated and scored using a semiquantitative method. RESULTS: Changes in the expression of laminin and type IV collagen in the basal lamina of acini and ducts of labial salivary glands from patients with Sjögren's syndrome were more pronounced than in labial salivary glands from control groups. A remarkable characteristic was the disorganisation of the basal lamina in the labial salivary glands in Sjögren's syndrome. The pattern of immunoreactivity of the basal lamina of other structures (for example, blood vessels) did not change. In Sjögren's syndrome, invasion of cytotoxic T lymphocytes was only observed in acini and ducts which had a disorganised basal lamina. CONCLUSIONS: The high state of disorganisation of the basal lamina of acini and ducts could allow invasion of cytotoxic T lymphocytes in Sjögren's syndrome, contributing to cell death and ductal hyperplasia.
18946613 Is HLA-B27 a useful test in the diagnosis of juvenile spondyloarthropathies? 2008 Oct INTRODUCTION: Seronegative spondyloarthritis (SSA) is a type of arthritis that involves joints in the spine, as well as the hips, shoulders, knees and ankles. The diagnosis of juvenile spondyloarthritis is rarely entertained in young children who present with back and leg pain. The aim of the present study was to assess the role of HLA-B27 as a diagnostic marker in children with spondyloarthropathy, and correlation of HLA-B27 with radiological features and tuberculosis. METHODS: Routine haematological and immunological tests were done by standard method and HLA-B27 typing was done by the lymphocytotoxicity method. A total of 70 cases of juvenile spondyloarthropathy were studied from May 2006 to September 2007. It included both males and females. RESULTS: Positivity of HLA-B27 in childhood SSA was only 71.4 percent (50/70). Gender-wise analysis showed that 76.7 percent (46/60) males and 20.0 percent (2/10) of the female patients were HLA-B27 positive. In HLA-B27-positive cases, the sacroiliac, hip, ankle, lower spine and knee joints were more involved. Urinary tract infection, diarrhoea and constipation were more common in HLA-B27-positive cases. None of the HLA-B27 cases were positive for rheumatoid factor; however, C-reactive protein was raised in 60.5 percent. In bilateral/unilateral sacroiliitis diagnosed by radiographs, only 81.5 percent patients were HLA-B27 positive. Tuberculosis was diagnosed in 14.3 percent (10/70) of total cases in which HLA-B27 positivity was seen in 60 percent of cases (6/10). CONCLUSION: Our study concludes that both HLA-B27 and radiological tests should be done in male children suspected to have SSA, because it can indicate early cases of juvenile spondyloarthropathy when radiological changes are not present, and it produces a more severe disease. HLA-B27 positivity probably also predisposes to tuberculosis.
17697366 B cells in Sjögren's syndrome: indications for disturbed selection and differentiation in 2007 Primary Sjögren's syndrome (pSS) is an autoimmune disorder characterized by specific pathological features. A hallmark of pSS is B-cell hyperactivity as manifested by the production of autoantibodies, hypergammaglobulinemia, formation of ectopic lymphoid structures within the inflamed tissues, and enhanced risk of B-cell lymphoma. Changes in the distribution of peripheral B-cell subsets and differences in post-recombination processes of immunoglobulin variable region (IgV) gene usage are also characteristic features of pSS. Comparison of B cells from the peripheral blood and salivary glands of patients with pSS with regard to their expression of the chemokine receptors CXCR4 and CXCR5, and their migratory capacity towards the corresponding ligands, CXCL12 and CXCL13, provide a mechanism for the prominent accumulation of CXCR4+ CXCR5+ memory B cells in the inflamed glands. Glandular B cells expressing distinct features of IgV light and heavy chain rearrangements, (re)circulating B cells with increased mutations of cmu transcripts in both CD27- and CD27+ memory B-cell subsets, and enhanced frequencies of individual peripheral B cells containing IgV heavy chain transcripts of multiple isotypes indicate disordered selection and incomplete differentiation processes of B cells in the inflamed tissues in pSS. This may possibly be related to a lack of appropriate censoring mechanisms or different B-cell activation pathways within the ectopic lymphoid structures of the inflamed tissues. These findings add to our understanding of the pathogenesis of this autoimmune inflammatory disorder and may result in new therapeutic approaches.
17966039 Down-regulation of Fas-ligand mRNA in Sjögren's syndrome patients with enlarged exocrine 2007 Nov We have reported that Sjögren's syndrome (SS) patients with enlarged exocrine glands (EEG) formerly referred to as Mikulicz's disease were defective with Fas-ligand (FasL) expression in PBL and lacrimal glands (LGs). To investigate the mechanisms of reduced FasL expression in SS patients with EEG, FasL mRNA expression level was determined using real-time PCR. The FasL gene promoter region (from - 1197 to - 3) was also amplified using PCR and specific primers. Expression of the FasL mRNA in the LGs and PBLs of three SS patients with EEG was significantly decreased. Direct sequencing revealed a heterozygous point mutation ( - 259T/C) in the FasL gene promoter region in one SS patient with EEG. A luminescent beta-galactosidase (beta-gal) reporter assay using a pbetagal Enhancer Vector demonstrated that beta-gal activity from the vector including the mutant ( - 259C) FasL (pbetagal/mFasL) gene promoter region (735 +/- 42) was similar (p = 0.13) to that from a pbetagal Enhancer Vector without the gene promoter region (603 +/- 66). On the other hand, the beta-gal activity was significantly lower (p < 0.0001) than that from a vector including the wild-type ( - 259T) FasL (pbetagal/wFasL) (3226 +/- 148). In conclusion, the down-regulation of FasL in SS patients with EEG may be due to transcriptional regulation, and the point mutation at - 259T/C in the FasL gene promoter region may lead to the down-regulation of FasL mRNA expression and the lymphoproliferative process observed in SS patients with EEG.
18329935 Onset or exacerbation of cutaneous psoriasis during TNFalpha antagonist therapy. 2008 May The widespread use of TNFalpha antagonists in recent years has led to the recognition of paradoxical adverse effects, defined as the onset or exacerbation of disorders that are usually improved by TNFalpha antagonists. Cutaneous psoriasis is an example, of which several cases have been reported. OBJECTIVE: To identify cases of psoriasis onset or exacerbation during TNFalpha antagonist therapy and to look for potential predictive factors. METHODS: We retrospectively reviewed cases of psoriasis onset or exacerbation during TNFalpha antagonist therapy. For each case we recorded the following data: age, sex, underlying disease, nature of the TNFalpha antagonist, effectiveness in improving the underlying disease, history of psoriasis in the patient or family, time to psoriasis development, type of psoriasis (confirmed by an experienced dermatologist), concomitant treatments, whether the TNFalpha antagonist was stopped or continued, and the outcome of the psoriasis. These data were compared to those in the literature. RESULTS: We identified 12 patients, six men and six women, with a mean age of 45.5 years. The TNFalpha antagonist was adalimumab in four patients, etanercept in six patients, and infliximab in two patients. The underlying disease was ankylosing spondylitis in six cases, rheumatoid arthritis in four, and psoriatic arthritis in two. Mean time from treatment initiation to psoriasis was 4.1 months (range, 1-15 months). A previous history of psoriasis in the patient was noted in six cases, including four of the six patients taking etanercept. TNFalpha antagonist therapy was effective on the underlying disease in 11 of the 12 patients. The drug was discontinued in five patients, of whom four experienced resolution of their psoriasis. In the remaining seven patients, the drug was continued and the skin lesions remained unchanged. Most of the patients had psoriasis vulgaris (plaque psoriasis); palmoplantar pustulosis was a feature in five patients. DISCUSSION: Over 40 cases of psoriasis onset or exacerbation during TNFalpha antagonist therapy have been reported in the literature. The prevalence of this adverse effect has been estimated at 1.5-5% of patients taking TNFalpha antagonists. The findings from our case series are consistent with data in the literature. Psoriasis is a class effect that has been reported with all the currently available TNFalpha antagonists. The skin lesions develop within the first few months of therapy. Patients with a wide range of underlying diseases can be affected. Palmoplantar pustulosis is a common feature. A previous history of psoriasis seems more common in patients who experience psoriasis onset or exacerbation during etanercept therapy (four of six patients in our study and 55% in the literature); thus, previous psoriasis may be a risk factor for psoriasis exacerbation during etanercept therapy.
18226968 Bee venom acupuncture for musculoskeletal pain: a review. 2008 Apr Bee venom (BV) acupuncture (BVA) involves injecting diluted BV into acupoints and is used for arthritis, pain, and rheumatoid diseases. The objective of this systematic review was to evaluate the evidence for the effectiveness of BVA in the treatment of musculoskeletal pain. Seventeen electronic databases were systematically searched up to September 2007 with no language restrictions. All randomized clinical trials (RCTs) of BVA for patients with musculoskeletal pain were considered for inclusion if they included placebo controls or were controlled against a comparator intervention. Methodology quality was assessed and, where possible, statistical pooling of data was performed. A total of 626 possibly relevant articles were identified, of which 11 RCTs met our inclusion criteria. Four RCTs that tested the effects of BVA plus classic acupuncture compared with saline injection plus classic acupuncture were included in the main meta-analysis. Pain was significantly lower with BVA plus classic acupuncture than with saline injection plus classic acupuncture (weighted mean difference: 100-mm visual analog scale, 14.0 mm, 95% CI = 9.5-18.6, P < .001, n = 112; heterogeneity: tau(2) = 0, chi(2) = 1.92, P = .59, I(2) = 0%). Our results provide suggestive evidence for the effectiveness of BVA in treating musculoskeletal pain. However, the total number of RCTs included in the analysis and the total sample size were too small to draw definitive conclusions. Future RCTs should assess larger patient samples for longer treatment periods and include appropriate controls. PERSPECTIVE: Bee venom acupuncture involves injecting diluted BV into acupoints and is used for arthritis, pain, and rheumatoid diseases. A meta-analysis produced suggestive evidence for the effectiveness of BVA in musculoskeletal pain management. However, primary data were scarce. Future RCTs should assess larger patient samples for longer treatment periods and include appropriate controls.
18668563 The arthritis severity locus Cia5d is a novel genetic regulator of the invasive properties 2008 Aug OBJECTIVE: The synovial fibroblast, or fibroblast-like synoviocyte (FLS), has a central role in pannus invasion and destruction of cartilage and bone in rheumatoid arthritis (RA). However, regulation of the FLS remains incompletely understood. The aim of this study was to determine whether the invasive properties of FLS are genetically regulated by arthritis severity loci. METHODS: DA rats (arthritis susceptible) and rat strains congenic for arthritis-protective intervals were studied. Primary FLS cell lines were generated from each strain and used in a well-established FLS invasion model through a collagen-rich barrier. Cells or culture supernatants were analyzed for gene expression, activity of different matrix metalloproteinases (MMPs), cytoskeleton integrity, and cell proliferation. RESULTS: The median number of FLS from DA.F344(Cia5d) rats that invaded through the collagen-rich barrier was reduced 86.5% compared with the median number of invading FLS from DA rats. Histologic examination showed that DA.F344(Cia5d) rats preserved a normal joint without pannus, hyperplasia, or erosions. FLS from DA.F344(Cia5d) rats produced significantly lower levels of active MMP-2 compared with FLS from DA rats, but the levels of proMMP-2 and MMP-2 messenger RNA in DA.F344(Cia5d) rats were similar to those in DA rats. Treatment of FLS from DA rats with an MMP-2 inhibitor reduced cell invasion to a level similar to that in DA.F344(Cia5d) rats, demonstrating that MMP-2 activity accounted for the difference between FLS from these 2 strains. Analysis of MMP-2-activating pathways revealed increased levels of soluble membrane type 1 (MT1)-MMP in DA rats compared with DA.F344(Cia5d) rats. CONCLUSION: These data represent the first evidence for a genetic component in the regulation of FLS invasion. A gene located within the Cia5d interval accounts for this effect and operates via the regulation of soluble MT1-MMP production and MMP-2 activation. These observations suggest novel potential pathways for prognostication and therapy.
16378833 Increase in platelet non-integrin type I collagen receptor in patients with systemic scler 2006 Microvascular injury is one of the major pathogenetic processes involved in systemic sclerosis (SSc). Interaction of the platelet types I and III collagen receptors with their respective ligand in the exposed subendothelial stroma as a result of ongoing microvascular injury in SSc patients results in platelet activation and aggregation with the release of mediators, which contribute to vascular damage and inflammation. We have found that there is a twofold increase in radiolabeled type I collagen binding to washed platelets from patients with SSc compared to platelets obtained from normal volunteers. Western blot analyses showed that the non-integrin platelet type I collagen receptor protein (65 kDa) is increased dramatically in lysates of platelet from patients with SSc. However, the integrin (alpha(2)beta(1)) and other non-integrin receptors such as glycoprotein VI, glycoprotein IV, and the platelet receptor for type III collagen remain unchanged. In addition, platelet lysates from rheumatic disease controls (rheumatoid arthritis, osteoarthritis, gout, and systemic lupus erythematosus) do not show any significant increases. There is no nitrotyrosylation on 65 kDa in patients with SSc compared to controls, suggesting this might also contribute to binding of CI to the 65-kDa CIR. These results suggest that there is a specific increase in the number of platelet type I collagen receptors in SSc patient's platelets. In addition, the activity of nitric oxide synthase is decreased in patients' platelet lysates compared to controls. The increase in platelet expression of the 65-kDa non-integrin platelet type I collagen receptor may explain the enhanced aggregation of platelets from patients with SSc to CI in vitro and microvascular thrombosis in the disease in vivo.
17107772 The pro-inflammatory oxidant hypochlorous acid induces Bax-dependent mitochondrial permeab 2007 Apr At sites of chronic inflammation, such as in the inflamed rheumatoid joint, activated neutrophils release hydrogen peroxide (H(2)O(2)) and the enzyme myeloperoxidase to catalyse the formation of hypochlorous acid (HOCl). 3-chlorotyrosine, a marker of HOCl in vivo, has been observed in synovial fluid proteins from rheumatoid arthritis patients. However the mechanisms of HOCl-induced cytotxicity are unknown. We determined the molecular mechanisms by which HOCl induced cell death in human mesenchymal progenitor cells (MPCs) differentiated into a chondrocytic phenotype as a model of human cartilage cells and show that HOCl induced rapid Bax conformational change, mitochondrial permeability and release of intra-mitochondrial pro-apoptotic proteins which resulted in nuclear translocation of AIF and EndoG. siRNA-mediated knockdown of Bax substantially prevented mitochondrial permeability, release of intra-mitochondrial pro-apoptotic proteins. Cell death was inhibited by siRNA-mediated knockdown of Bax, AIF or EndoG. Although we observed several biochemical markers of apoptosis, caspase activation was not detected either by western blotting, fluorescence activity assays or by using caspase inhibitors to inhibit cell death. This was further supported by findings that (1) in vitro exposure of recombinant human caspases to HOCl caused significant inhibition of caspase activity and (2) the addition of HOCl to staurosporine-treated MPCs inhibited the activity of cellular caspases. Our results show for the first time that HOCl induced Bax-dependent mitochondrial permeability which led to cell death without caspase activity by processes involving AIF/EndoG-dependent pathways. Our study provides a novel insight into the potential mechanisms of cell death in the inflamed human joint.
18698188 Exercise in pediatric rheumatic diseases. 2008 Sep PURPOSE OF REVIEW: The present review discusses the current knowledge about exercise capacity and physical activity in children with rheumatic disease and examines the role of exercise in managing these conditions. RECENT FINDINGS: Recent studies suggest exercise capacity is significantly impaired in a large proportion of children with juvenile idiopathic arthritis and other rheumatic diseases. These deficits are not limited to children with active inflammation. Children, especially girls, with rheumatoid factor positive polyarticular juvenile idiopathic arthritis, have the greatest deficits. Poor fitness and low levels of weight-bearing physical activity contribute to low bone mass and strength. Children and adolescents with juvenile dermatomyositis and systemic lupus erythematosus also exhibit impaired exercise capacity. There is some evidence that structured aerobic and neuromuscular training may improve exercise capacity, functional performance, and quality of life in children and adolescents with rheumatic disease. SUMMARY: A sedentary lifestyle contributes to secondary impairments in aerobic and muscular fitness, bone health, and functional limitations in children and adolescents with rheumatic disease despite advances in the pharmacological management of these inflammatory conditions. Increased levels of moderate to vigorous physical activity and structured exercise may improve exercise capacity, performance of daily activities, and overall quality of life.