Simvastatin inhibits TLR8 signaling in primary human monocytes and spontaneous TNF production from rheumatoid synovial membrane cultures

Simvastatin has been shown to have anti-inflammatory effects that are independent of its serum cholesterol lowering action, but the mechanisms by which these anti-inflammatory effects are mediated have not been elucidated. To explore the mechanism involved, the effect of simvastatin on Toll-like receptor (TLR) signalling in primary human monocytes was investigated. A short pre-treatment with simvastatin dose-dependently inhibited the production of tumor necrosis factor-α (TNF) in response to TLR8 (but not TLRs 2, 4, or 5) activation. Statins are known inhibitors of the cholesterol biosynthetic pathway, but intriguingly TLR8 inhibition could not be reversed by addition of mevalonate or geranylgeranyl pyrophosphate; downstream products of cholesterol biosynthesis. TLR8 signalling was examined in HEK 293 cells stably expressing TLR8, where simvastatin inhibited IKKα/β phosphorylation and subsequent NF-κB activation without affecting the pathway to AP-1. Since simvastatin has been reported to have anti-inflammatory effects in RA patients and TLR8 signalling contributes to TNF production in human RA synovial tissue in culture, simvastatin was tested in these cultures. Simvastatin significantly inhibited the spontaneous release of TNF in this model which was not reversed by mevalonate. Together, these results demonstrate a hitherto unrecognized mechanism of simvastatin inhibition of TLR8 signalling that may in part explain its beneficial anti-inflammatory effects

Resting CD4+ effector memory T cells are precursors of bystander-activated effectors: a surrogate model of rheumatoid arthritis synovial T-cell function.

BACKGROUND: Previously we described a system whereby human peripheral blood T cells stimulated for 8 days in a cytokine cocktail acquired effector function for contact-dependent induction of proinflammatory cytokines from monocytes. We termed these cells cytokine-activated (Tck) cells and found that the signalling pathways elicited in the responding monocytes were identical whether they were placed in contact with Tck cells or with T cells isolated from rheumatoid arthritis (RA) synovial tissue. METHODS: Here, using magnetic beads and fluorescence-activated cell sorting, we extensively phenotype the Tck effector cells and conclude that effector function resides within the CD4+CD45RO+, CCR7-, CD49dhigh population, and that these cells are derived from the effector memory CD4+ T cells in resting blood. RESULTS: After stimulation in culture, these cells produce a wide range of T-cell cytokines, undergo proliferation and differentiate to acquire an extensively activated phenotype resembling RA synovial T cells. Blocking antibodies against CD69, CD18, or CD49d resulted in a reduction of tumour necrosis factor-alpha production from monocytes stimulated with CD4+CD45RO+ Tck cells in the co-culture assay. Moreover, blockade of these ligands also resulted in inhibition of spontaneous tumour necrosis factor-alpha production in RA synovial mononuclear cell cultures. CONCLUSION: Taken together, these data strengthen our understanding of T-cell effector function, highlight the multiple involvement of different cell surface ligands in cell-cell contact and, provide novel insights into the pathogenesis of inflammatory RA disease

Clinical efficacy of tocilizumab in patients with active rheumatoid arthritis in real clinical practice

The previous clinical studies have demonstrated tocilizumab monotherapy to be highly effective in rheumatoid arthritis (RA). The objectives of the present article are to report the efficacy and safety of tocilizumab in patients with active RA in real clinical practice. In total, 61 patients with RA were treated with tocilizumab. Any comorbidities they had, especially infections, were treated thoroughly before they were given the drug. We provided guidance on infection control and prevention. Mean age of the patients was 60.9 ± 12.4 years, and their mean disease duration 10.9 ± 9.2 years. The patients remained on steroids, methotrexate, and tacrolimus as before, but were taken off any other drugs they had been using prior to the treatment. Mean of the 28-joint disease activity score using erythrocyte sedimentation rate was 4.75 ± 1.15 initially and fell to 2.21 ± 0.97 after two doses (n = 50). After four doses, the remission rate was 83.8% (31/37). All patients responded well to the therapy and there was no decrease in the efficacy of tocilizumab during the treatment. Even in the real clinical setting, treatment with tocilizumab can rapidly induce remission in RA in a high proportion of patients and is generally safe and well tolerated. Tocilizumab would seem to be promising as a first-line choice for the treatment of RA

Impact of VIP and cAMP on the regulation of TNF-alpha and IL-10 production: implications for rheumatoid arthritis

Vasoactive intestinal peptide (VIP) is an anti-inflammatory immunomodulatory neuropeptide with therapeutic potential demonstrated for collagen-induced arthritis. The aim of this study was to characterise its potential anti-arthritic effect on human monocytes, macrophages, T cells, and rheumatoid arthritis synovial membrane cells. Monocytes, macrophages, and T cells derived from human peripheral blood were treated with VIP and compared with other cAMP-elevating drugs for a range of activating stimuli. Cytokine production was assessed for cell cultures and, in addition, the ability of VIPs to activate cAMP response element binding protein. VIP partially suppressed monocyte- and macrophage-derived tumour necrosis factor alpha (TNF-alpha) with no effect on IL-10, whereas VIP fails to regulate IL-10 and TNF-alpha production by T lymphocytes. No such modulation of cytokine profile was observed for rheumatoid arthritis synovial membrane cells. Elevation of intracellular cAMP, on the other hand, potently suppressed macrophage TNF-alpha production and modulated T-cell response by inhibiting TNF-alpha and IFN-gamma. VIP's lack of effect on IL-10 and its slight effect on TNF-alpha results from cAMP being rapidly degraded as the phosphodiesterase IV inhibitor, rolipram, rescues cAMP-dependent activation of cAMP response element binding protein. Interestingly, macrophages stimulated with phorbol 12-myristate 13-acetate/ionomycin displayed an augmented IL-10 response upon addition of dibutyryl cAMP, with corresponding downregulation in TNF-alpha, suggesting a complex interaction between protein kinase C and protein kinase A in cytokine regulation. In conclusion, VIP may represent an efficaceous anti-arthritic treatment modulating macrophage and T-cell cytokine profiles when used alongside a phosphodiesterase inhibitor

Validity of the Polar V800 heart rate monitor to measure RR intervals at rest

Purpose To assess the validity of RR intervals and short-term heart rate variability (HRV) data obtained from the Polar V800 heart rate monitor, in comparison to an electrocardiograph (ECG). Method Twenty participants completed an active orthostatic test using the V800 and ECG. An improved method for the identification and correction of RR intervals was employed prior to HRV analysis. Agreement of the data was assessed using intra-class correlation coefficients (ICC), Bland–Altman limits of agreement (LoA), and effect size (ES). Results A small number of errors were detected between ECG and Polar RR signal, with a combined error rate of 0.086 %. The RR intervals from ECG to V800 were significantly different, but with small ES for both supine corrected and standing corrected data (ES 0.999 for both supine and standing corrected intervals. When analysed with the same HRV software no significant differences were observed in any HRV parameters, for either supine or standing; the data displayed small bias and tight LoA, strong ICC (>0.99) and small ES (≤0.029). Conclusions The V800 improves over previous Polar models, with narrower LoA, stronger ICC and smaller ES for both the RR intervals and HRV parameters. The findings support the validity of the Polar V800 and its ability to produce RR interval recordings consistent with an ECG. In addition, HRV parameters derived from these recordings are also highly comparable

Inexperienced clinicians can extract pathoanatomic information from MRI narrative reports with high reproducibility for use in research/quality assurance

<p>Abstract</p> <p>Background</p> <p>Although reproducibility in reading MRI images amongst radiologists and clinicians has been studied previously, no studies have examined the reproducibility of inexperienced clinicians in extracting pathoanatomic information from magnetic resonance imaging (MRI) narrative reports and transforming that information into quantitative data. However, this process is frequently required in research and quality assurance contexts. The purpose of this study was to examine inter-rater reproducibility (agreement and reliability) among an inexperienced group of clinicians in extracting spinal pathoanatomic information from radiologist-generated MRI narrative reports.</p> <p>Methods</p> <p>Twenty MRI narrative reports were randomly extracted from an institutional database. A group of three physiotherapy students independently reviewed the reports and coded the presence of 14 common pathoanatomic findings using a categorical electronic coding matrix. Decision rules were developed after initial coding in an effort to resolve ambiguities in narrative reports. This process was repeated a further three times using separate samples of 20 MRI reports until no further ambiguities were identified (total n = 80). Reproducibility between trainee clinicians and two highly trained raters was examined in an arbitrary coding round, with agreement measured using percentage agreement and reliability measured using unweighted Kappa (<it>k</it>). Reproducibility was then examined in another group of three trainee clinicians who had not participated in the production of the decision rules, using another sample of 20 MRI reports.</p> <p>Results</p> <p>The mean percentage agreement for paired comparisons between the initial trainee clinicians improved over the four coding rounds (97.9-99.4%), although the greatest improvement was observed after the first introduction of coding rules. High inter-rater reproducibility was observed between trainee clinicians across 14 pathoanatomic categories over the four coding rounds (agreement range: 80.8-100%; reliability range <it>k </it>= 0.63-1.00). Concurrent validity was high in paired comparisons between trainee clinicians and highly trained raters (agreement 97.8-98.1%, reliability <it>k </it>= 0.83-0.91). Reproducibility was also high in the second sample of trainee clinicians (inter-rater agreement 96.7-100.0% and reliability <it>k </it>= 0.76-1.00; intra-rater agreement 94.3-100.0% and reliability <it>k </it>= 0.61-1.00).</p> <p>Conclusions</p> <p>A high level of radiological training is not required in order to transform MRI-derived pathoanatomic information from a narrative format to a quantitative format with high reproducibility for research or quality assurance purposes.</p