42 research outputs found

    Elevated formation of pyridinoline cross-links by profibrotic cytokines is associated with enhanced lysyl hydroxylase 2b levels

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    AbstractThe hallmark of fibrosis is the excessive accumulation of collagen. The deposited collagen contains increased pyridinoline cross-link levels due to an overhydroxylation of lysine residues within the collagen telopeptides. Lysyl hydroxylase 2b (LH2b) is the only lysyl hydroxylase consistently up-regulated in several forms of fibrosis, suggesting that an enhanced LH2b level is responsible for the overhydroxylation of collagen telopeptides. The present paper reports the effect of profibrotic cytokines on the expression of collagen, lysyl hydroxylases and lysyl oxidase in normal human skin fibroblasts, as well as the effect on pyridinoline formation in the deposited matrix. All three isoforms of TGF-ÎČ induce a substantial increase in LH2b mRNA levels, also when expressed relatively to the mRNA levels of collagen type I α2 (COL1A2). The TGF-ÎČ isoforms also clearly influence the collagen cross-linking pathway, since higher levels of pyridinoline cross-links were measured. Similar stimulatory effects on LH2b/COL1A2 mRNA expression and pyridinoline formation were observed for IL-4, activin A, and TNF-α. An exception was BMP-2, which has no effect on LH2b/COL1A2 mRNA levels nor on pyridinoline formation. Our data show for the first time that two processes, i.e., up-regulation of LH2b mRNA levels and increased formation of pyridinoline cross-links, previously recognized to be inherent to fibrotic processes, are induced by various profibrotic cytokines

    Association of response to TNF inhibitors in rheumatoid arthritis with quantitative trait loci for CD40 and CD39

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    This study was supported by Medical Research Council (MRC) MR/K015346/1 MATURA study. ARUK 20670 MATURA study. Publisher Copyright: © Author(s) (or their employer(s)) 2019.Objectives We sought to investigate whether genetic effects on response to TNF inhibitors (TNFi) in rheumatoid arthritis (RA) could be localised by considering known genetic susceptibility loci for relevant traits and to evaluate the usefulness of these genetic loci for stratifying drug response. Methods We studied the relation of TNFi response, quantified by change in swollen joint counts (ΔSJC) and erythrocyte sedimentation rate (ΔESR) with locus-specific scores constructed from genome-wide assocation study summary statistics in 2938 genotyped individuals: 37 scores for RA; scores for 19 immune cell traits; scores for expression or methylation of 93 genes with previously reported associations between transcript level and drug response. Multivariate associations were evaluated in penalised regression models by cross-validation. Results We detected a statistically significant association between ΔSJC and the RA score at the CD40 locus (p=0.0004) and an inverse association between ΔSJC and the score for expression of CD39 on CD4 T cells (p=0.00005). A previously reported association between CD39 expression on regulatory T cells and response to methotrexate was in the opposite direction. In stratified analysis by concomitant methotrexate treatment, the inverse association was stronger in the combination therapy group and dissipated in the TNFi monotherapy group. Overall, ability to predict TNFi response from genotypic scores was limited, with models explaining less than 1% of phenotypic variance. Conclusions The association with the CD39 trait is difficult to interpret because patients with RA are often prescribed TNFi after failing to respond to methotrexate. The CD39 and CD40 pathways could be relevant for targeting drug therapy.Peer reviewe

    Regulatory T Cell Responses in Participants with Type 1 Diabetes after a Single Dose of Interleukin-2: A Non-Randomised, Open Label, Adaptive Dose-Finding Trial

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    BACKGROUND: Interleukin-2 (IL-2) has an essential role in the expansion and function of CD4+ regulatory T cells (Tregs). Tregs reduce tissue damage by limiting the immune response following infection and regulate autoreactive CD4+ effector T cells (Teffs) to prevent autoimmune diseases, such as type 1 diabetes (T1D). Genetic susceptibility to T1D causes alterations in the IL-2 pathway, a finding that supports Tregs as a cellular therapeutic target. Aldesleukin (Proleukin; recombinant human IL-2), which is administered at high doses to activate the immune system in cancer immunotherapy, is now being repositioned to treat inflammatory and autoimmune disorders at lower doses by targeting Tregs. METHODS AND FINDINGS: To define the aldesleukin dose response for Tregs and to find doses that increase Tregs physiologically for treatment of T1D, a statistical and systematic approach was taken by analysing the pharmacokinetics and pharmacodynamics of single doses of subcutaneous aldesleukin in the Adaptive Study of IL-2 Dose on Regulatory T Cells in Type 1 Diabetes (DILT1D), a single centre, non-randomised, open label, adaptive dose-finding trial with 40 adult participants with recently diagnosed T1D. The primary endpoint was the maximum percentage increase in Tregs (defined as CD3+CD4+CD25highCD127low) from the baseline frequency in each participant measured over the 7 d following treatment. There was an initial learning phase with five pairs of participants, each pair receiving one of five pre-assigned single doses from 0.04 × 106 to 1.5 × 106 IU/m2, in order to model the dose-response curve. Results from each participant were then incorporated into interim statistical modelling to target the two doses most likely to induce 10% and 20% increases in Treg frequencies. Primary analysis of the evaluable population (n = 39) found that the optimal doses of aldesleukin to induce 10% and 20% increases in Tregs were 0.101 × 106 IU/m2 (standard error [SE] = 0.078, 95% CI = -0.052, 0.254) and 0.497 × 106 IU/m2 (SE = 0.092, 95% CI = 0.316, 0.678), respectively. On analysis of secondary outcomes, using a highly sensitive IL-2 assay, the observed plasma concentrations of the drug at 90 min exceeded the hypothetical Treg-specific therapeutic window determined in vitro (0.015-0.24 IU/ml), even at the lowest doses (0.040 × 106 and 0.045 × 106 IU/m2) administered. A rapid decrease in Treg frequency in the circulation was observed at 90 min and at day 1, which was dose dependent (mean decrease 11.6%, SE = 2.3%, range 10.0%-48.2%, n = 37), rebounding at day 2 and increasing to frequencies above baseline over 7 d. Teffs, natural killer cells, and eosinophils also responded, with their frequencies rapidly and dose-dependently decreased in the blood, then returning to, or exceeding, pretreatment levels. Furthermore, there was a dose-dependent down modulation of one of the two signalling subunits of the IL-2 receptor, the ÎČ chain (CD122) (mean decrease = 58.0%, SE = 2.8%, range 9.8%-85.5%, n = 33), on Tregs and a reduction in their sensitivity to aldesleukin at 90 min and day 1 and 2 post-treatment. Due to blood volume requirements as well as ethical and practical considerations, the study was limited to adults and to analysis of peripheral blood only. CONCLUSIONS: The DILT1D trial results, most notably the early altered trafficking and desensitisation of Tregs induced by a single ultra-low dose of aldesleukin that resolves within 2-3 d, inform the design of the next trial to determine a repeat dosing regimen aimed at establishing a steady-state Treg frequency increase of 20%-50%, with the eventual goal of preventing T1D. TRIAL REGISTRATION: ISRCTN Registry ISRCTN27852285; ClinicalTrials.gov NCT01827735.This is the final version of the article. It first appeared from the Public Library of Science via http://dx.doi.org/10.1371/journal.pmed.100213

    Inducibility or predestination?: Queries and concepts around drug-free remission in rheumatoid arthritis

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    Introduction: Drug-free remission (DFR) and its maintenance have been defined as the most desirable outcome for rheumatoid arthritis (RA) patients. DFR is linked to resolution of arthritis-related symptoms and restoration of normal functioning. However, there is currently no consensus if an optimal strategy, upon the initiation of treatment to the proper drugs withdrawal, is enough to induce it, or whether it is a predetermined condition related to patients’ intrinsic characteristics. Areas covered: This review focuses on two key concepts around DFR. First, we analyze patients’ intrinsic factors that may increase the chance of DFR, regardless of therapeutic choices. Second, we discuss on the evidence that it can be induced thanks to adequate, extrinsic disease management. Finally, we provide a glimpse into consequences of drugs discontinuation. Expert opinion: The early initiation of DMARD and the subsequent strict monitoring and drug adjustments are of primary importance to allow patients to achieve DFR, irrespective of initial treatment strategy. Once remission is obtained and maintained, it is possible to gradually taper and discontinue drugs with no dramatic consequences on the disease course. Among those who stop medication, ACPA-negative patients more often maintain the remission. Thus, DFR might depend on a combination of intrinsic and extrinsic factors

    Earlier is better when treating rheumatoid arthritis: but can we detect a window of opportunity?

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    OBJECTIVES: The window of opportunity (WOO) hypothesis suggests a limited time frame to stop rheumatoid arthritis (RA). We hypothesised that a WOO could either be represented by a hyperbolic ('curved') decline in the chance to achieve the outcome sustained drug-free remission (sDFR) over time, after which achieving sDFR is not possible anymore, or by a more gradual linear decline approaching zero chance to achieve sDFR. METHODS: Patients with RA (symptom duration <2 years) were included from two randomised trials: BehandelStrategieĂ«n (BeSt), n=508 and Induction therapy with Methotrexate and Prednisone in Rheumatoid Or Very Early arthritic Disease (IMPROVED), n=479. Cox-regression was performed to assess the shape of the association between symptom duration and sDFR (Disease Activity Score<1.6, no disease-modifying anti-rheumatic drugs for ≄1 year) for patients starting slow-acting monotherapy (IMPROVED, BeSt) or fast-acting combination therapy (BeSt). Likelihood ratio tests were used to compare the fit of linear and non-linear models in both databases separately. Predictions from the best fitting models were used to assess whether the absolute risk to achieve sDFR approaches zero with increasing symptom duration. RESULTS: In BeSt and IMPROVED, 54/226 and 110/421 patients achieved sDFR with fast-acting treatment, and 53/243 (BeSt) with slow-acting treatment. Non-linear models did not fit better than linear models (fast-acting treatment BeSt p=0.743, IMPROVED p=0.337; slow-acting treatment BeSt p=0.609). After slow-acting monotherapy, linear models declined steeper. None of the models approached zero chance to achieve sDFR over time. CONCLUSIONS: The chance to achieve sDFR decreased gradually over time, and decreased fastest in patients starting slow-acting monotherapy. In both treatment groups, we found no evidence for a WOO within 2 years symptom duration
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