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The formation of neutrophil extracellular traps induced by antineutrophil cytoplasmic autoantibodies has been implicated in the pathogenesis of antineutrophil cytoplasmic autoantibody-associated vasculitis. Kraaij et al. now provide evidence that excessive neutrophil extracellular trap formation in vitro induced by sera from patients with antineutrophil cytoplasmic autoantibody-associated vasculitis is associated with active disease but is not dependent on the presence of antineutrophil cytoplasmic autoantibodies., (Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

There is a growing need for disease related biomarkers in Takayasu arteritis (TA).The assessment of pro-inflammatory cytokines and chemokines in TA may provide a better understanding of its pathophysiology, and circulating levels of these mediators may act as biomarkers of disease activity. Serum level of interleukin 6 (IL-6) is a potential biomarker for TA, which is mostly associated with TA status and disease activity. Associations between TA and serum/plasma levels of other cytokines are less clear. mRNA expression of IL-4 and tumor necrosis factor α (TNFα) are constitutively increased in peripheral blood mononuclear cells (PBMC) from TA patients and the expression of both cytokines increases even more after PBMC stimulation in vitro, while the expression of IL-10 mRNA decreases. In addition, circulating T cells from TA patients produce increased levels of both Th1- and Th17-related cytokines upon in vitro stimulation. In the aorta from TA patients, an increased expression of interferon γ (IFNγ), IL-6, IL-12 and IL-17 has been described. Regarding circulating chemokines in TA, serum/plasma levels of IL-8 (CXCL8), CCL2 and CCL5 were shown to be elevated in TA patients compared with healthy controls as well as in TA patients with active disease compared with those in remission. Serum IL-6 seems to be the best biomarker for disease state and disease activity in TA and increased Th1 and Th17 responses are predominant in the pathophysiology of TA., (Copyright © 2017 Elsevier B.V. All rights reserved.)

High mobility group box 1 (HMGB1) has been suggested to be involved in the pathogenesis of many autoimmune diseases. In addition to its nuclear functions, extracellular HMGB1 released from activated, injured or dying cells becomes a proinflammatory mediator via binding to various receptors on the surface of responding cells. HMGB1 interacts with various systems involved in inflammation, such as the complement system and the coagulation system. Thus, HMGB1 could amplify inflammation and enhance immune responses in pathophysiology of certain diseases. In the past years, HMGB1 has been studied in several vasculitides including antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, Kawasaki disease, Henoch-Schönlein purpura, Takayasu arteritis and giant cell arteritis. Several studies showed that circulating HMGB1 levels are higher in patients with active disease compared with healthy controls, and levels are associated with disease severity. Further studies on pathogenetic mechanisms revealed pathogenic roles of HMGB1 in some vasculitides. Here we review clinical and experimental studies dealing with the role of HMGB1 in vascular inflammation, and its relation to the manifestations and prognosis of specific vasculitides, in particular ANCA-associated vasculitis., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Renal lesions in ANCA-associated vasculitis (AAV) show an absence or paucity of immune deposits. Therefore, complement was not considered a major pathogenic factor. Data from an animal model of AAV, however, suggest involvement of the alternative pathway of complement. The paper by Gou et al. demonstrates activation also of the alternative and final common pathways in patients with AAV. Thus, the complement system might be a target for treatment in human AAV.

A group of primary vasculitides is associated with the presence of anti-neutrophil cytoplasmic autoantibodies (ANCA). In these diseases, the contribution of ANCA to disease pathogenesis has been studied extensively. Also, in patients with ANCA-associated vasculitides, the T lymphocyte compartment is dysregulated, as aberrant distribution and function of T cell subsets has been shown. In this review we will discuss the putative role of T lymphocytes in inflammation and granuloma formation, as well as the involvement of B cell compartments in the pathophysiology of ANCA-associated vasculitis., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Refractory vasculitis occurs in 4-5% of patients with anti-neutrophil cytoplasmic antibody associated vasculitis (AAV). Differences between therapies used for refractory disease are mostly reflected in the percentages of complete and partial remissions, but also in the number of serious side effects. Rituximab is considered the most safe second line therapy and should be advocated as a first alternative choice for cyclophosphamide in disease induction in refractory AAV., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The interplay between neutrophils and endothelial cells allows ANCA to become pathogenic and results in uncontrolled inflammation in the vessel wall. This review presents an overall view on neutrophil-endothelial interaction during inflammation with a focus on ANCA-associated vasculitis, and summarizes the effector mechanisms which cause vascular damage in AAV. In addition, potential elements for disease intervention based on this process are discussed., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Pauci-immune necrotizing glomerulonephritis is the most frequent cause of rapidly progressive glomerulonephritis and, in most cases, is associated with antineutrophil cytoplasmic antibodies (ANCA). It is either the renal manifestation of Wegener's granulomatosis, microscopic polyangiitis of Churg-Strauss syndrome, or a renal-limited vasculitis. In this review, the histopathologic changes seen in renal biopsies of patients with pauci-immune glomerulonephritis are described. The authors also describe why the disease is sometimes limited to the kidneys, the clinical course of renal disease, treatment issues, how to deal with disease relapses, and how to prevent them from occurring. Furthermore, the necessity of renal biopsy and rebiopsy, the usefulness of rapid ANCA detection at diagnosis, and serial measurement of ANCA during follow-up are discussed. The effect of dialysis on the disease process and the possibility of renal transplantation after disease remission are also debated., (Copyright 2010 Elsevier Inc. All rights reserved.)

Anti-neutrophil cytoplasmic antibodies, directed against constituents of granules of neutrophils and lysosomes of monocytes, are serological markers of small vessel vasculitides, including Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome and renal-limited vasculitis. These vasculitides are collectively termed ANCA-associated vasculitides (AAV). Environmental factors have been considered important in the development of ANCA, including silica, infection especially with Staphylococcus aureus, and drugs. Accelerated apoptosis of neutrophils induced through intratracheal instillation of silica may act as a trigger in the development of AAV. Inhaled silica may activate alveolar macrophages and not only induce inflammation and activation of fibroblasts, but also stimulate lymphocytes through T-cell receptors and attract neutrophils. Staphylococcus aureus is associated with initiation and relapse of Wegener's granulomatosis. Peptides from complementary PR3 show strong homology with peptides from S. aureus, which could underlie the development of PR3-ANCA. There is increasing recognition that drugs, especially propylthiouracil (PTU), may cause AAV. Patients with PTU-induced AAV have better prognosis than those with primary AAV. The disease spectrum of AAV in various geographic regions is different, which may suggest that the initiating factor in AAV has a different geographical distribution. Differences in genetic background may also be important in determining the response to triggering or initiating factors., (2009 Elsevier B.V. All rights reserved.)

Wegener's Granulomatosis (WG) is a life-threatening autoimmune disease. A pathogenic role for anti-neutrophil cytoplasmic autoantibodies (ANCAs) by inducing necrotizing damage to the vessel wall has been strongly suggested by in vitro and in vivo experimental data. Proteinase 3 (PR3), a serine protease mainly stored in the azurophilic granules of neutrophils, has been identified as a major ANCA-antigen in WG. Elevated expression levels of membrane-bound PR3 (mPR3) has been observed in WG and some other chronic inflammatory diseases, suggesting a pathogenic role of mPR3 by allowing interaction with PR3-ANCA. Recent studies revealed CD177 as a receptor for mPR3 on the neutrophil membrane. However, we recently showed that CD177 negative neutrophils also express mPR3 and are susceptible to PR3-ANCA induced neutrophil activation. Therefore, it is of interest to further investigate the functional consequences of binding of mPR3 to CD177, to explore other binding partners for mPR3 on the neutrophil membrane, and to study the relevance of colocalization of these molecules for disease pathogenesis. This review gives updated information on the mechanism of mPR3 expression and the relevance of colocalization of mPR3 with other molecules on the neutrophil membrane for the pathophysiological events occurring in WG.

Background: Individuals who reach the antibody threshold level of 10IU/l against the surface protein of the hepatitis B virus (HBV) after completion of a series of hepatitis B vaccination are considered to be long-term protected against a clinically manifest HBV infection., Case Report: Here we describe an acute hepatitis B infection in a patient who received five hepatitis B vaccinations. Although his initial response to vaccination was moderate, he finally reached an excellent hepatitis B surface antibody level (anti-HBs) titres of more than 1000 IU/l in response to a booster vaccination with a recombinant DNA vaccine. Nevertheless, he developed full-blown acute hepatitis due to an HBV infection 14years after this booster vaccination. A DNA analysis of the surface protein encoding region followed by phylogenetic analysis showed that our patient was infected with a normal HBV strain that is circulating among men who have sex with men. To our knowledge, this is the first report of a genuine hepatitis B vaccination failure in someone who acquired a high anti-HBs level in response to a recombinant DNA hepatitis B vaccine., Conclusion: Healthcare workers whose response to the initial hepatitis B vaccination is moderate might be vulnerable to hepatitis B virus infection.

Infections are associated with secondary forms of vasculitis. However, there is increasing evidence that microbial agents play a role also in primary systemic vasculitides. For a long time it has been noted that Hepatitis B virus (HBV) is involved in polyarteritis nodosa (PAN) although the incidence of HBV-associated PAN seems to decline. Cryoglobulinemic vasculitis has been shown to be strongly associated with Hepatitis C Virus (HCV) infection, but this is most striking in Southern Europe and less in Northern Europe. Different microbial agents have been suggested to influence disease expression in other primary vasculitides but no specific association has been established. In Wegener's Granulomatosis (WG) chronic carriage of Staphylococcus aureus (S. aureus) is associated with a strongly increased risk for relapsing disease. Various pathogenic pathways for this association have been suggested by clinical and experimental observations. Recent studies even suggest that S. aureus derived peptides, amongst others, may induce proteinase 3-ANCA via idiotypic-anti-idiotypic interactions. Treatment with co-trimoxazole in WG localized to the upper airways may result in (temporary) remission of the disease.

Autoantibodies to complement components are associated with various diseases. Anti-C1q antibodies are present in all patients with hypocomplementemic urticarial vasculitis, but also, with varying prevalence, in other conditions. In SLE, these antibodies are neither sensitive nor specific for this condition. They occur, however, more frequently in (proliferative) lupus nephritis, particularly during active disease. Furthermore, levels of anti-C1q rise, in many cases, prior to a relapse of lupus nephritis, suggesting a pathogenic role for the autoantibodies. Indeed, experimental studies strongly support a pathogenic role for anti-C1q in immune complex-mediated renal disease. In addition, anti-C1q may interfere with the clearance of apoptotic cells, so influencing induction and expression of autoimmunity.

Patients with systemic lupus erythematosus (SLE) show decreased immune responsiveness and are vulnerable for infectious diseases, due to the underlying disease and the frequent use of immunosuppressive drugs. Influenza has a high incidence in the population and is associated with increased morbidity and mortality in immunocompromised patients. Therefore, routine influenza vaccination of SLE patients seems indicated. However, there have been concerns about the safety of influenza vaccination in SLE as vaccination was thought to activate the autoimmune response. Safety of influenza vaccination has been studied, and, as far as SLE patients with quiescent disease are concerned, it is now generally accepted that influenza vaccination is safe. Another point of concern is vaccine efficacy. In immunocompromised patients, the immunogenicity of vaccines may be reduced. In the immune response to influenza (vaccination) both humoral and cell-mediated responses are involved. In SLE, research on the immune response to influenza vaccination has focused on humoral immune responses, demonstrating a blunted humoral response. Future research should focus on cell-mediated immune responses as well, as these are important for clearing of influenza infection and are expected to be impaired in SLE. Because of the decreased immunogenicity of the current influenza vaccine in SLE, new influenza vaccination strategies should be explored to improve vaccination efficacy.

Objective: At present it is unclear whether endothelial activation is systematically present in preeclampsia or restricted to specialized vascular beds. Therefore, this study aimed to investigate the presence of generalized proinflammatory endothelial activation in severe, early-onset preeclampsia in vivo., Methods: During caesarean section, biopsies were obtained from abdominal subcutaneous fat, abdominal fascia, and myometrium from 11 severe, early-onset preeclamptic and 19 healthy pregnant women. Prior to caesarean, section plasma levels of von Willebrand Factor (vWF), sVCAM-1, and C-reactive protein (CRP) were measured by ELISA. Consecutive cryostat sections were stained immunohistochemically for CD31, E-selectin, VCAM-1, and ICAM-1. For subcutaneous fat tissue, endothelial gene expression levels of E-selectin, VCAM-1, ICAM-1, endothelin-1 (ET-1), and endothelial nitric oxide synthase (eNOS) were quantified by real-time RT-PCR, using normalization to the endothelium-specific housekeeping genes CD31 and VE-cadherin., Results: Plasma levels of vWF, sVCAM-1, and CRP were elevated in the preeclampsia group compared to the control group, indicating enhanced endothelial activation and inflammatory response in the severely diseased preeclamptic women. By immunohistochemical analysis, no E-selectin and VCAM-1 expression could be detected in, and no differences in endothelial ICAM-1 staining could be observed between the preeclampsia and the control group for all tissues studied. Endothelial gene expression levels of E-selectin, VCAM-1, ICAM-1, ET-1, and eNOS were comparable between the preeclampsia and control group., Conclusion: Protein and gene expression analysis of E-selectin, VCAM-1, ICAM-1, ET-1, and eNOS, key mediators involved in pro-inflammatory endothelial activation, could not identify endothelial activation in severe, early-onset preeclampsia in the tissues studied. However, elevated plasma levels of markers of endothelial activation and inflammation were observed. These results may suggest that in severe, early-onset preeclampsia pro-inflammatory endothelial cell activation is not a generalized phenomenon, but is likely restricted to (possibly organ-specific) specialized vascular beds.

Background: Recently, the in vivo pathogenic role of anti-neutrophil cytoplasm autoantibodies (ANCA) in ANCA-associated vasculitis has been challenged by Abdel-Salam et al. In their report, they observed that ANCA directed against proteinase 3 (PR3) cannot bind to their target autoantigen PR3 on circulating neutrophils (PMN). Here we present evidence that human PR3-ANCA do specifically bind to PMN that express PR3 on their membrane., Methods: PMN were isolated from donors showing bimodal membrane PR3 expression on their PMN (N= 3). TNFalpha-primed PMN or PMA-stimulated PMN were incubated with serum or plasma from PR3-ANCA-positive patients with Wegener's granulomatosis (WG) (N= 8) or healthy controls (N= 8). Binding of IgG in serum or plasma samples to PMN was assessed by indirect immunofluorescence., Results: Binding of IgG in undiluted plasma or serum from PR3-ANCA-positive WG-patients to PMN was significantly increased compared to plasma or serum from healthy controls. Dilution of plasma and serum showed concentration-dependent binding of IgG. Double staining for PR3 and IgG demonstrated that IgG in plasma or serum from PR3-ANCA-positive patients only bound to those PMN that expressed PR3, and not to PMN that lacked PR3 expression on their membrane., Conclusion: PR3-ANCA in undiluted serum or plasma from PR3-ANCA-positive WG patients bind to TNFalpha- primed and PMA-stimulated PMN that express PR3 on their membrane. Therefore, the hypothesis that PR3-ANCA can bind and activate primed PMN is still the most attractive explanation for the contribution of PR3-ANCA to the pathogenesis of Wegener's granulomatosis.

Objective: Systemic endothelial dysfunction is a central feature in the pathophysiology of preeclampsia. Its cell biologic and molecular basis is poorly understood. One leading hypothesis argues that endothelial dysfunction is caused by (at present largely unknown) circulating factors released from the ischemic placenta. This study investigated the effects of plasma factors of severe, early-onset preeclamptic women versus healthy pregnant women on endothelial gene expression in vitro., Methods: Plasma samples were taken from eight severe early-onset preeclamptic women and eight matched pregnant control women. Primary human umbilical vein endothelial cell (HUVEC) and human glomerular microvascular endothelial cell (hGMEC) cultures were incubated with 20% (vol/vol) plasma for 4, 12, and 24 hours. Identical amounts of RNA isolated from HUVEC from three preeclamptic and three control samples were pooled for each time point, and subsequently hybridized on human 60-mer oligonucleotide microarrays containing 17,000 genes. Gene expression levels of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), interleukin-8 (IL-8), and interleukin-6 (IL-6) in HUVEC and hGMEC were quantified using real-time reverse transcription polymerase chain reaction (RT-PCR)., Results: Microarray analyses of individual genes identified no genes that were up- or down-regulated more than 2.7-fold, and analyses of gene ontologies showed no gene ontology significantly up- or down-regulated in HUVEC by preeclamptic plasma. IL-8 gene expression was modestly induced by preeclamptic plasma after 4, 12, and 24 hours of HUVEC and hGMEC incubation, as identified by real-time RT-PCR. The other genes analyzed did not show altered regulation by preeclamptic plasma factors., Conclusions: In vitro, plasma from preeclamptic patients does not substantially alter endothelial gene expression profile. Only modest induction of IL-8 gene expression was observed. These results indicate that mechanisms other than soluble plasma constituents are likely involved in systemic endothelial cell activation in preeclampsia.

Rises in antineutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3) have predictive potential for a relapse of Wegener's granulomatosis (WG). To assess the value of image analysis for monitoring ANCA levels, we measured PR3-ANCA in a cohort of PR3-ANCA positive patients with WG that were prospectively followed in our clinic and compared findings with other techniques. ANCA levels were measured serially by quantitative image analysis, titration in indirect immunofluorescence (IIF), two different directly coated antigen-specific enzyme-linked immunosorbent assays (ELISA), and a capture ELISA using a PR3-specific monoclonal antibody in 16 consecutive WG patients prior to a renal relapse, and in 16 age- and sex-matched patients with inactive WG. The positive predictive value (PPV) of an increase in ANCA titers by image analysis for relapse was 69% (11 of 16). The PPV of an increase in ANCA was 61% (11 of 18) by IIF, 71% (12 of 17) by a commercial direct ELISA, 63% (12 of 19) by in-house direct ELISA, and 75% (12 of 16) by capture ELISA. The negative predictive value (NPV) of the absence of an increase in ANCA titers by image analysis for relapse was 69% (11 of 16). The NPV of the absence of an increase in ANCA was 64% (9 of 14) by IIF, 73% (11 of 15) by a commercial direct ELISA, 63% (9 of 13) by in-house direct ELISA, and 75% (12 of 16) by capture ELISA. In conclusions, quantitative image analysis is a novel technique based on the principle of IIF to quantify ANCA levels in a single dilution in a patient sample. No major differences were observed between image analysis and the other techniques in their capacity to predict relapses of disease activity.

Objective: Despite the availability of many new imaging procedures, sialography has, after decades of use, maintained its status as the imaging procedure of choice for evaluating the oral component of Sjögren syndrome (SS). In this study, the clinical value of sialography as a diagnostic tool in SS was explored by assessing its diagnostic accuracy, observer bias, and staging potential., Methods: One hundred parotid sialograms were interpreted independently in a blinded fashion by 2 trained and 2 expert observers. Sialograms were derived from a group of consecutive patients referred for diagnostics of SS. Patients were categorized as SS and non-SS by the revised European classification criteria., Results: Trained observers reached a sensitivity of 95 and a specificity of 33% for SS by sialogram, whereas expert observers reached a sensitivity of 87 and a specificity of 84%. There was only "fair" interobserver agreement between trained and expert observers, whereas both expert observers showed "good" agreement with one another, according to Cohen's kappa. Intraobserver agreement was "good" to "very good" for all observers. The 4 different gradations of sialectasia, ie, punctate, globular, cavitary, and destructive, showed a weak but significant correlation with the duration of oral symptoms., Conclusions: This study markedly shows that the diagnostic value of parotid sialography for diagnosing SS greatly depends on the skills of the observer, implying that sialography lacks general applicability as a diagnostic tool in SS and requires specific expertise. Nevertheless, given its potentially high sensitivity and specificity in diagnosing SS as well as its useful staging potential, sialography still has its use in the evaluation of the oral component of SS.

Antineutrophil cytoplasmic autoantibodies (ANCA) directed to proteinase 3 (PR3-ANCA) or myeloperoxidase (MPO-ANCA) are closely associated with the idiopathic systemic necrotizing vasculitides, in particular Wegener's granulomatosis, microscopic polyangiitis and its renal limited manifestation, and Churg Strauss Syndrome. Many in vitro studies show that those ANCA have phlogistic potential, particularly at the interface of neutrophils and endothelial cells. A limited number of studies in experimental animals support their pathogenetic role. However, ANCA alone are not sufficient, as based on clinical and experimental data, and other, probably exogenous factors, seem necessary for disease induction and (re)activation. Among those silica and particularly, the carriage of Staphylococcus aureus have been proposed. Besides, various genetic factors are involved in disease susceptibility. The ANCA-associated vasculitides are systemic autoimmune diseases in which the interplay of autoimmunity with environmental and genetic factors determines their clinical expression.