Publications by authors named "Joel A van Roon"

Objectives: To assess to what extent leflunomide (LEF) and hydroxychloroquine (HCQ) therapy in patients with primary Sjögren's syndrome (RepurpSS-I) targets type I IFN-associated responses and to study the potential of several interferon associated RNA-based and protein-based biomarkers to predict and monitor treatment.

Methods: In 21 patients treated with LEF/HCQ and 8 patients treated with placebo, blood was drawn at baseline, 8, 16 and 24 weeks. IFN-signatures based on RNA expression of five IFN-associated genes were quantified in circulating mononuclear cells and in whole blood.

View Article and Find Full Text PDF

Objective: Type 2 conventional dendritic cells (cDC2s) are key orchestrators of inflammatory responses, linking innate and adaptative immunity. Here we explored the regulation of immunological pathways in cDC2s from patients with primary Sjögren's syndrome (pSS).

Methods: RNA sequencing of circulating cDC2s from patients with pSS, patients with non-Sjögren's sicca and healthy controls (HCs) was exploited to establish transcriptional signatures.

View Article and Find Full Text PDF

Objective: To develop a composite responder index in primary Sjögren's syndrome (pSS): the Sjögren's Tool for Assessing Response (STAR).

Methods: To develop STAR, the NECESSITY (New clinical endpoints in primary Sjögren's syndrome: an interventional trial based on stratifying patients) consortium used data-driven methods based on nine randomised controlled trials (RCTs) and consensus techniques involving 78 experts and 20 patients. Based on reanalysis of rituximab trials and the literature, the Delphi panel identified a core set of domains with their respective outcome measures.

View Article and Find Full Text PDF

: Effective treatment for primary Sjögren's syndrome (pSS) is not available. pSS immunopathology involves a variety of immune-cells and dysregulated pathways; targeting several pathways instead of only one could therefore be effective. Treatment with leflunomide (LEF) and hydroxychloroquine (HCQ) might be successful given their unique immunosuppressive properties.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the role of plasmacytoid dendritic cells (pDCs) in systemic sclerosis (SSc), an autoimmune disease characterized by inflammation and fibrosis, focusing on pathways affecting pDC function.
  • Researchers analyzed pDCs from over 1,190 SSc patients and found that lower levels of the transcription factor RUNX3, linked to gene methylation and hypoxia, may contribute to SSc susceptibility.
  • The results indicate that loss of RUNX3 in pDCs leads to increased skin fibrosis in mouse models, highlighting pDCs' significant role in the disease's progression and potential therapeutic targets.
View Article and Find Full Text PDF

Unlabelled: Chronic pain is a major clinical problem that is difficult to treat and requires novel therapies. Although most pain therapies primarily target neurons, neuroinflammatory processes characterized by spinal cord and dorsal root ganglion production of proinflammatory cytokines play an important role in persistent pain states and represent potential therapeutic targets. Anti-inflammatory cytokines are attractive candidates to regulate aberrant neuroinflammatory processes, but the therapeutic potential of these cytokines as stand-alone drugs is limited.

View Article and Find Full Text PDF

Objective: Indoleamine 2,3-dioxygenase (IDO), the rate-limiting enzyme that converts tryptophan to kynurenine, is driven in part by type I and type II interferons (IFNs). Naive T cells are polarized into FoxP3+ Treg cells upon exposure to either IDO+ cells or kynurenine. Recent studies have suggested that the kynurenine pathway reflects a crucial interface between the immune and nervous system.

View Article and Find Full Text PDF

The antiphospholipid syndrome (APS) is a systemic autoimmune disease that is characterized serologically by the presence of antiphospholipid antibodies (aPL) and clinically by vascular thrombosis and obstetric complications. The protein β2 glycoprotein I (β2GPI) is identified as the most important autoantigen in this syndrome. Activation of endothelial cells, thrombocytes and placental tissue by anti-β2GPI antibodies relates to the clinical manifestations of APS.

View Article and Find Full Text PDF

The lifespan of humans has increased drastically over the last decades; considerable effort has been applied to delineate the mechanisms behind aging in order to find strategies for longevity. As the benefits of the gained knowledge might extend to diseases, where accelerated aging is suspected, the role of aging in the systemic autoimmune disease Systemic Lupus Erythematosus (SLE) is of particular interest. In this review the immunological similarities of SLE and aging are analyzed on three levels: the clinical, the cellular and the molecular, in order to find possible common pathological mechanisms.

View Article and Find Full Text PDF

Thymic stromal lymphopoietin (TSLP) is an IL-7-related cytokine that has been studied extensively in atopic diseases and more recently in various rheumatic disorders. It is involved in T cell development in the thymus and promotes homeostatic T cell expansion by classical dendritic cells. However, deregulated TSLP expression in various rheumatic diseases has implicated this cytokine as a strong mediator in immunopathology.

View Article and Find Full Text PDF

Objective: Innate lymphoid cells (ILCs) are a recently discovered group of cells that are essential to epithelial homeostasis and are implicated in psoriasis pathogenesis, yet they have never been reported in psoriatic arthritis (PsA).

Methods: ILC classes and subsets were characterized in the peripheral blood (PB) of healthy controls, patients with psoriasis, and patients with PsA and in the synovial fluid (SF) of patients with PsA and patients with rheumatoid arthritis (RA). Cell surface marker expression and intracellular cytokine production following stimulation were analyzed using flow cytometry.

View Article and Find Full Text PDF

Introduction: The cytokines interleukin (IL)-7 and thymic stromal lymphopoietin (TSLP) signal through the IL-7R subunit and play proinflammatory roles in experimental arthritis and rheumatoid arthritis (RA). We evaluated the effect of inhibition of IL-7R- and TSLPR-signalling as well as simultaneous inhibition of IL-7R- and TSLPR-signalling in murine experimental arthritis. In addition, the effects of IL-7 and TSLP in human RA dendritic cell (DC)/T-cell co-cultures were studied.

View Article and Find Full Text PDF

Objectives: Thymic Stromal Lymphopoietin (TSLP) is a potent immunomodulatory cytokine involved in Th2- and Th17-mediated immune responses in different autoimmune diseases. TSLP expression in relation to disease activity was studied in salivary glands of primary Sjögren's syndrome (pSS) patients as compared to non-SS sicca (nSS) controls.

Methods: Tissue sections of minor salivary glands from pSS and nSS patients were stained with monoclonal antibodies against human TSLP, CD3, CD19 and cytokeratin high molecular weight (CK HMW) or stained for Alcian blue to detect mucus production.

View Article and Find Full Text PDF

Introduction: The aim of this study was to investigate PD-1/PD-L1 involvement in the hyporesponsiveness of rheumatoid arthritis (RA) synovial fluid (SF) CD4 T cells upon stimulation by thymic stromal lymphopoietin (TSLP)-primed CD1c myeloid dendritic cells (mDCs).

Methods: Expression of PD-1 on naïve (Tn), central memory (Tcm) and effector memory (Tem) CD4 T cell subsets was assessed by flow cytometry. PD-L1 expression and its regulation upon TSLP stimulation of mDCs from peripheral blood (PB) and SF of RA patients were investigated by quantitative RT-PCR and flow cytometry.

View Article and Find Full Text PDF

Objective: To determine the levels of thymic stromal lymphopoietin (TSLP) and the numbers of TSLP receptor (TSLPR)-expressing CD1c+ (blood dendritic cell antigen 1-positive) myeloid dendritic cells (MDCs) in the joints as compared with the peripheral blood (PB) of patients with rheumatoid arthritis (RA), as well as to determine the capacity of TSLP to induce MDC-dependent T cell activation.

Methods: TSLP levels were measured in synovial fluid (SF) samples from patients with RA and those with osteoarthritis (OA). MDC numbers in PB and SF samples from RA patients and TSLPR expression on these cells were assessed by fluorescence-activated cell sorter analysis.

View Article and Find Full Text PDF
Article Synopsis
  • The study examines how IL-7 promotes T cell activation and how TLR7 enhances B cell activation, including the role of monocytes/macrophages in this process.
  • The researchers co-cultured B and T cells with specific activators and measured their proliferation and activation markers using various assays.
  • Results showed that TLR7 activation did not affect T cells, but IL-7 significantly enhanced both B and T cell activation, especially in the presence of monocytes/macrophages, leading to increased cytokine and immunoglobulin production.
View Article and Find Full Text PDF

In recent years considerable progress has been made in our understanding of the immunopathology of primary Sjögren's syndrome. Several genetic and environmental risk factors as well as cellular and molecular pathways have been identified, providing multiple targets for therapeutic strategies. Establishment of disease activity scores allows careful monitoring of therapeutic strategies and has set the stage for definition of clinical response criteria.

View Article and Find Full Text PDF

Objectives: To investigate the prognostic value of the lymphocytic focus score (LFS) and the percentages of IgA+, IgM+ and IgG+ plasma cells for disease severity of primary Sjögren syndrome (pSS).

Methods: Medical charts of 174 pSS patients were retrospectively analysed, comparing histology results (LFS and percentages of IgA+, IgM+ and IgG+ plasma cells) with disease outcomes as non-Hodgkin lymphoma (NHL) and clinical scores including cumulative EULAR (European League against Rheumatism) Sjögren syndrome disease activity index (ESSDAI) and the total number of extraglandular manifestations.

Results: The mean LFS was significantly higher in patients developing NHL (3.

View Article and Find Full Text PDF