Anti-C1q Autoantibodies Are Frequently Detected in Patients With Systemic Sclerosis Associated With Pulmonary Fibrosis

BACKGROUND: Anti-C1q autoantibodies (autoAbs) are associated with systemic lupus erythematosus (SLE) but their presence in other rheumatic diseases has not been adequately investigated. OBJECTIVE: We aim to assessanti-C1q autoAbs and circulating immune complexes (CICs) in systemic sclerosis (SSc). METHODS: One hundred twenty four patients with SSc (106 females; median age 59.4 years, range 25-81.4; 75(60.5%) with limited cutaneous SSc[lcSSc], and 49(39.5%) with diffuse cutaneous SSc[dcSSc]), were studied. Twenty-five patients with Sjögren\u27s syndrome (SjS), 29 with rheumatoid arthritis (RA), and 38 patients with systemic lupus erythematosus (SLE) and 53 healthy controls (NC) were also included. ELISAs with high and low salt buffers the former allowing IgGFc binding to C1q, the latter not allowing IgGFc binding and anti-C1q Ab binding to C1q were used to measure anti-C1q Abs and CICs. RESULTS: Anti-C1q Abs were present in20/124 (16.1%) SSc patients [5 had high levels (\u3e80 RU/mL) and 10 patients (50%) had moderate levels (40-80 RU/mL)] compared to 1/25 (4%) SjS, 1/29 (3.4%) RA patients (p CONCLUSIONS: Anti-C1q autoAbs were frequently detected in patients with SSc and their high levels predict the co-occurrence of pulmonary fibrosis or pulmonary arterial hypertension

Spleen Tyrosine Kinase (Syk) Regulates Systemic Lupus Erythematosus (SLE) T Cell Signaling

Engagement of the CD3/T cell receptor complex in systemic lupus erythematosus (SLE) T cells involves Syk rather than the zeta-associated protein. Because Syk is being considered as a therapeutic target we asked whether Syk is central to the multiple aberrantly modulated molecules in SLE T cells. Using a gene expression array, we demonstrate that forced expression of Syk in normal T cells reproduces most of the aberrantly expressed molecules whereas silencing of Syk in SLE T cells normalizes the expression of most abnormally expressed molecules. Protein along with gene expression modulation for select molecules was confirmed. Specifically, levels of cytokine IL-21, cell surface receptor CD44, and intracellular molecules PP2A and OAS2 increased following Syk overexpression in normal T cells and decreased after Syk silencing in SLE T cells. Our results demonstrate that levels of Syk affect the expression of a number of enzymes, cytokines and receptors that play a key role in the development of disease pathogenesis in SLE and provide support for therapeutic targeting in SLE patients

TNF-α and TGF-β Counter-Regulate PD-L1 Expression on Monocytes in Systemic Lupus Erythematosus

Monocytes in patients with systemic lupus erythematosus (SLE) are hyperstimulatory for T lymphocytes. We previously found that the normal program for expression of a negative costimulatory molecule programmed death ligand-1 (PD-L1) is defective in SLE patients with active disease. Here, we investigated the mechanism for PD-L1 dysregulation on lupus monocytes. We found that PD-L1 expression on cultured SLE monocytes correlated with TNF-α expression. Exogenous TNF-α restored PD-L1 expression on lupus monocytes. Conversely, TGF-β inversely correlated with PD-L1 in SLE and suppressed expression of PD-L1 on healthy monocytes. Therefore, PD-L1 expression in monocytes is regulated by opposing actions of TNF-α and TGF-β. As PD-L1 functions to fine tune lymphocyte activation, dysregulation of cytokines resulting in reduced expression could lead to loss of peripheral T cell tolerance

Anti-citrullinated peptides as autoantigens in rheumatoid arthritis-relevance to treatment

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by the presence of rheumatoid factor (RF) and anti-citrullinated protein/peptide autoantibodies (ACPAs). Citrulline derives from arginine by peptidyl arginine deiminases, and ACPAs are directed against different citrullinated antigens, including fibrinogen, fibronectin, alpha-enolase, collagen type II, histones. ACPAs are present in two thirds of RA patients have higher specificity than RF for RA, and are associated with joint radiographic damage and extra-articular manifestations and they are detected years before the onset clinical arthritis. Recent studies suggest that citrullinated antigens are most likely arthritogenic autoantigens in RA. ACPA production is associated with the HIA-DRB1 shared epitope (HLA-DRB1 SE) and accounts for the well-known RA-HLA-DRB1 SE association, as T cells recognize citrullinated peptides. Smoking and periodontitis, known environmental risk factors for RA promote protein citrullination and ACPA production. Cirullinated proteins are capable of inducing arthritis in transgenic mice carrying HLA-DRB1 SE genes, and ACPAs induce macrophage TNF-alpha production, osteoclastogenesis and complement activation. They also induce the formation of neutrophil extracellular traps (NETs). NETs, increased in RA, are a source of citrullinated autoantigens in RA and induce fibroblast interleukin-8 production. This knowledge is likely to have therapeutic implications, as there is a need of matching therapy with patient profile. Abatacept, a T cell activation modulator, is the best therapy for ACPA(+) RA patients, although clinical data are sparse at present. Rituximab, a monoclonal antibody that depletes B cells, is also the best therapy for ACPA(+) RA patients, and clinical data support this view. (C) 2014 Elsevier B.V. All rights reserved

Protein phosphatase 2A is a negative regulator of IL-2 production in patients with systemic lupus erythematosus

Decreased IL-2 production in systemic lupus erythematosus (SLE) represents a central component of the disease immunopathology. We report that the message, protein, and enzymatic activity of the catalytic subunit of protein phosphatase 2A (PP2Ac), but not PP1, are increased in patients with SLE regardless of disease activity and treatment and in a disease-specific manner. Treatment of SLE T cells with PP2Ac-siRNA decreased the protein levels and activity of PP2Ac in a specific manner and increased the levels of phosphorylated cAMP response element–binding protein and its binding to the IL2 and c-fos promoters, as well as increased activator protein 1 activity, causing normalization of IL-2 production. Our data document increased activity of PP2A as a novel SLE disease-specific abnormality and define a distinct mechanism whereby it represses IL-2 production. We propose the use of PP2Ac-siRNA as a novel tool to correct T cell IL-2 production in SLE patients

Early systemic sclerosis-opportunities for treatment

Systemic sclerosis (SSc) is characterized by microvasculopathy (Raynaud's phenomenon and fibrointimal proliferation), presence of autoantibodies and collagen deposition in skin (scleroderma) and internal organs. Microvasculopathy, detected by nailfold capillaroscopy, and disease-specific autoantibodies (anti-topoisomerase I, anti-centromere, anti-RNA polymerase III antibodies) usually appear earlier, even years before scleroderma. At that stage of the disease, immune activation with T cells and B cells promote fibrosis. Diagnosis of SSc has been relied on scleroderma, and by this time, internal organs may have developed fibrosis, a lethal feature with no available treatment. The new EULAR/ACR 2013 criteria for the classification of SSc will help identify SSc patients before fibrosis of internal organs. The early diagnosis of SSc, before the development of fibrosis in internal organs, will allow the introduction of immunosuppressive medications in these patients in a controlled setting (randomized trials). It is anticipated that this approach will change the hitherto grim prognosis of SSc for the better

The Pathophysiologic Role of Monocytes and Macrophages in Systemic Lupus Erythematosus: A Reappraisal

Objectives: To review current developments, regarding the pathophysiologic role of monocytes and macrophages in systemic lupus erythematosus (SLE). Methods: We searched Medline for articles written in the English language using the following terms: monocyte(s) or macrophage(s) and lupus. Although our search spanned the years 1971 to 2008, the majority of the short-listed articles belonged to the period 2000 to 2008. Published literature on phenotypic and functional properties of monocytes/macrophages (Mo/M phi) in SLE was reviewed. References from identified articles were also selected. Currently available experimental data and their relevance to the pathogenesis of SLE are critically discussed. Results: It has traditionally been held that impaired phagocytosis by monocytes and macrophages in SLE allows for the accumulation of apoptotic debris leading to a sequel of autoimmune phenomena. Recent paradigms derived from animal models of systemic autoimmunity, however, has broadened our understanding regarding the possible pathophysiologic roles of Mo/M phi in SLE. Data derived from studies in patients with SLE show multiple aberrations in activation status and secretory functions of circulating and tissue-infiltrating Mo/M phi. Such aberrations may be associated with dysregulation of T-cell function and autoantibody production in SLE. Moreover, emerging evidence suggests that phagocytic capacity and antigen-presenting properties of Mo/M phi are enhanced in some patients with SLE. Conclusions: While defective phagocytosis represents a distinctive feature of monocyte function in some patients with SLE, aberrant activation of the Mo/M phi system may be a more appropriate concept to encompass the broad spectrum of Mo/M phi disorders in SLE. Aberrant function of lupus Mo/M phi appears to play a dynamic role in the initiation and perpetuation of the systemic autoimmune response and organ damage. Delineation of the altered biology of lupus Mo/M phi could provide possible future therapeutic targets for patients with SLE. 2010 Elsevier Inc. All rights reserved. Semin Arthritis Rheum 39:491-50

Progressive multifocal leukoencephalopathy in a patient with systemic sclerosis treated with methotrexate: A case report and literature review

Reactivation of viruses occurs in autoimmune disorders in the setting of certain immunosuppressive drugs. We describe a 54-year-old female with systemic sclerosis and extensive cutaneous calcinosis who had been treated with methotrexate for 18 months and presented with headache and neurological deficits. She was diagnosed with progressive multifocal leukoencephalopathy, a rare disease caused by JC virus. Methotrexate was discontinued and mirtazapine plus mefloquine were added. The patient showed a slow recovery and five years later she had complete resolution of progressive multifocal leukoencephalopathy clinical manifestations. Calcinosis had a limited response to various agents and severely affected daily activities of the patient. This case report, highlights the importance of clinical suspicion for progressive multifocal leukoencephalopathy in every patient with immune-mediated disease, even on weak immunosuppressant, who presents with central nervous system manifestations and also the unmet therapeutic need for systemic sclerosis-associated calcinosis. © The Author(s) 2020

Curcumin for the management of periodontitis and early ACPA-positive rheumatoid arthritis: Killing two birds with one stone

We propose curcumin as a preventive measure to avoid/manage periodontitis (PD), and as a natural immunosuppressant for rheumatoid arthritis (RA). PD, mainly caused by Porphyromonas gingivalis forming biofilm and leading to tooth decay, is a major public health issue and a risk factor for the development of RA in humans. P. gingivalis is able to trigger experimental autoimmune arthritis in animal models and in humans can induce citrullinated peptides, which not only are a source of anti-citrullinated antibodies (ACPAs), but also participate in autoreactive responses and disease development. Curcumin appears to have efficient anti-bacterial activity against P. gingivalis infection and biofilm formation. In addition to antibacterial, anti-oxidant, and anti-inflammatory action, curcumin exerts unique immunosuppressant properties via the inhibition of Th17 pro-inflammatory responses and promotion of regulatory T cells, thus suppressing autoimmunity. We introduce curcumin as a natural product for the management of both PD and RA-related autoreactivity, possibly also as a preventive measure in early RA or individuals at high risk to develop RA. © 2018 by the authors. Licensee MDPI, Basel, Switzerland