Anti-nuclear antibodies (ANA) are fundamental for the diagnosis of autoimmune diseases, and have been determined by indirect immunofluorescence assay (IIFA) for decades. As the demand for ANA testing ...increased, alternative techniques were developed challenging the classic IIFA. These alternative platforms differ in their antigen profiles, sensitivity and specificity, raising uncertainties regarding standardisation and interpretation of incongruent results. Therefore, an international group of experts has created recommendations for ANA testing by different methods. Two groups of experts participated in this initiative. The European autoimmunity standardization initiative representing 15 European countries and the International Union of Immunologic Societies/World Health Organization/Arthritis Foundation/Centers for Disease Control and Prevention autoantibody standardising committee. A three-step process followed by a Delphi exercise with closed voting was applied. Twenty-five recommendations for determining ANA (1–13), anti-double stranded DNA antibodies (14–18), specific antibodies (19–23) and validation of methods (24–25) were created. Significant differences between experts were observed regarding recommendations 24–25 (p<0.03). Here, we formulated recommendations for the assessment and interpretation of ANA and associated antibodies. Notably, the roles of IIFA as a reference method, and the importance of defining nuclear and cytoplasmic staining, were emphasised, while the need to incorporate alternative automated methods was acknowledged. Various approaches to overcome discrepancies between methods were suggested of which an improved bench-to-bedside communication is of the utmost importance. These recommendations are based on current knowledge and can enable harmonisation of local algorithms for testing and evaluation of ANA and related autoantibodies. Last but not least, new more appropriate terminologies have been suggested.
Highlights • IL-10 produced by regulatory T-cells has a non-redundant role to maintain intestinal immune homeostasis and to prevent colitis. • IL-10 produced by B helper T-cells promotes autoantibody ...production, and has a pathogenic role in systemic lupus erythematosus. • IL-10 produced early by regulatory T-cells or late by helper T-cells has opposing functions in cytotoxic T-cell responses and cancer.
Patients undergoing long-term highly active antiretroviral therapy treatment are probably at a higher risk of various HIV-related complications. Hyperactivation of The mammalian target of rapamycin ...(mTOR) has been found to contribute to dysregulated apoptosis and autophagy which determine CD4
+-T-cell loss, impaired function of innate immunity and development of neurocognitive disorders. Dysregulated mTOR activation has also been shown to play a key part in the development of nephropathy and in the pathogenesis of HIV-associated malignancies. These studies strongly support a multifunctional key role for mTOR in the pathogenesis of HIV-related disorders and suggest that specific mTOR inhibitors could represent a novel approach for the prevention and treatment of these pathologies.
Abstract Current classification criteria for definite Antiphospholipid Syndrome (APS) require the use of three laboratory assays to detect antiphospholipid antibodies (aCL, anti-β2GPI and LA) in the ...presence of at least one of the two major clinical manifestations (i.e. thrombosis or pregnancy morbidity) of the syndrome. However, several other autoantibodies shown to be directed to other proteins or their complex with phospholipids have been proposed to be relevant to APS but their clinical utility and their diagnostic value remains elusive. This report summarizes the findings, conclusions and recommendations of the “APS Task Force 3—Laboratory Diagnostics and Trends” meeting that took place during the 14th International Congress on Antiphospholipid Antibodies (APLA 2013, September 18–21, Rio de Janeiro, RJ, Brazil).
In vitro studies have documented β2 glycoprotein I (β2GPI) binding to endothelial cells (ECs) and trophoblast using antiphospholipid antibodies. The in vivo binding of β2GPI to these cells and the ...conditions that favor their interaction have not been investigated. We analyzed the in vivo distribution of cyanine 5.5-labeled β2GPI in mice and evaluated the effect of pregnancy and circulating antibodies on its tissue localization. The signal was detected in the liver by whole body scan and ex vivo analysis. The β2GPI failed to bind to the vascular endothelium and reacted only with the ECs of uterine vessels. In pregnant mice the protein was localized on ECs and trophoblast at the embryo implantation sites. Immunized mice showed a similar β2GPI biodistribution to naive mice but the immunized pregnant animals exhibited a significant increase in fetal loss associated with C3 and C9 deposition at the implantation sites. Treatment of mice with LPS after β2GPI-Cy5.5 injection promoted protein localization on gut and brain ECs associated with IgG, C1q, and C9 deposition in immunized mice. These findings indicate that β2GPI binding to EC requires priming with pro-inflammatory factors which is not needed for uterine and placental localization probably dependent on hormonal changes.
β2-glycoprotein I (β2-GPI) is a serum protein widely recognized as the main target of antibodies present in patients with antiphospholipid syndrome (APS). β2-GPI binds to activated endothelial cells, ...platelets and leukocytes, key players in thrombus formation. We developed a new targeted thrombolytic agent consisting of nanobubbles (NB) coated with recombinant tissue plasminogen activator (rtPA) and a recombinant antibody specific for cell-bound β2-GPI. The therapeutic efficacy of targeted NB was evaluated in vitro, using platelet-rich blood clots, and in vivo in three different animal models: i) thrombosis developed in a rat model of APS; ii) ferric chloride-induced mesenteric thrombosis in rats, and iii) thrombotic microangiopathy in a mouse model of atypical hemolytic uremic syndrome (C3-gain-of-function mice). Targeted NB bound preferentially to platelets and leukocytes within thrombi and to endothelial cells through β2-GPI expressed on activated cells. In vitro, rtPA-targeted NB (rtPA-tNB) induced greater lysis of platelet-rich blood clots than untargeted NB. In a rat model of APS, administration of rtPA-tNB caused rapid dissolution of thrombi and, unlike soluble rtPA that induced transient thrombolysis, prevented new thrombus formation. In a rat model of ferric chloride triggered thrombosis, rtPA-tNB, but not untargeted NB and free rtPA, induced rapid and persistent recanalization of occluded vessels. Finally, treatment of C3-gain-of-function mice with rtPA-tNB, that target β2-GPI deposited in kidney glomeruli, decreased fibrin deposition, and improved urinalysis data with a greater efficiency than untargeted NB. Our findings suggest that targeting cell-bound β2-GPI may represent an efficient and thrombus-specific thrombolytic strategy in both APS-related and APS-unrelated thrombotic conditions.
Objectives To assess risk factors for a first thrombotic event in confirmed antiphospholipid (aPL) antibody carriers and to evaluate the efficacy of prophylactic treatments. Methods Inclusion ...criteria were age 18–65 years, no history of thrombosis and two consecutive positive aPL results. Demographic, laboratory and clinical parameters were collected at enrolment, once a year during the follow-up and at the time of the thrombotic event, whenever that occurred. Results 258 subjects were prospectively observed between October 2004 and October 2008. The mean±SD follow-up was 35.0±11.9 months (range 1–48). A first thrombotic event (9 venous, 4 arterial and 1 transient ischaemic attack) occurred in 14 subjects (5.4%, annual incidence rate 1.86%). Hypertension and lupus anticoagulant (LA) were significantly predictive of thrombosis (both at p<0.05) and thromboprophylaxis was significantly protective during high-risk periods (p<0.05) according to univariate analysis. Hypertension and LA were identified by multivariate logistic regression analysis as independent risk factors for thrombosis (HR 3.8, 95% CI 1.3 to 11.1, p<0.05, and HR 3.9, 95% CI 1.1 to 14, p<0.05, respectively). Conclusions Hypertension and LA are independent risk factors for thrombosis in aPL carriers. Thromboprophylaxis in these subjects should probably be limited to high-risk situations.
T helper (Th)-17 cells are increased in systemic sclerosis (SSc). We therefore assessed whether Th17 cells could modulate the inflammatory and fibrotic responses in dermal fibroblasts from healthy ...donors (HD) and SSc individuals.
Fibroblasts were obtained from 14 SSc and 8 HD skin biopsies. Th17 clones were generated from healthy peripheral blood upon enrichment of CC chemokine receptor (CCR)-4/CCR6/CD161 expressing cells. Their cytokine production was assessed by flow cytometry and multiplex beads immunoassay. Fibroblast production of monocyte chemoattractant protein (MCP)-1, interleukin (IL)-8, matrix metalloproteinase (MMP)-1, tissue inhibitor of metalloproteinase (TIMP)-1, MMP-2 and type-I collagen was quantified by enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA), and changes in their transcription levels assessed by real-time PCR. Intracellular signals were dissected by western blot and the use of pharmacological inhibitors. IL-17A, tumor necrosis factor (TNF) and interferon-gamma (IFN-γ) blocking reagents were used to assess the specificity of the observed effects.
IL-17A increased MCP-1, IL-8 and MMP-1 production in a dose-dependent manner while having no effect on type I collagen in HD and SSc fibroblasts both at protein and mRNA levels. Nuclear factor-kappa B (NF-κB) and p38 were preferentially involved in the induction of MCP-1 and IL-8, while MMP-1 was most dependent on c-Jun N-terminal kinase (JNK). Supernatants of activated Th17 clones largely enhanced MCP-1, IL-8 and MMP-1 while strongly inhibiting collagen production. Of note, the production of MCP-1 and IL-8 was higher, while collagen inhibition was lower in SSc compared to HD fibroblasts. The Th17 clone supernatant effects were mostly dependent on additive/synergistic activities between IL-17A, TNF and in part IFN-γ. Importantly, the inhibition of type I collagen production induced by the Th17 clone supernatants was completely abrogated by blockade of IL-17A, TNF and IFN-γ mostly in SSc fibroblasts, revealing an intrinsic resistance to inhibitory signals in SSc.
Our findings demonstrate that in vitro Th17 cells elicit pro-inflammatory responses while restraining collagen production. Thus, the increased Th17 cell number observed in SSc may impact on the inflammatory component of the disease simultaneously potentially providing a protective role against fibrosis.
We monitored the number of intravascular platelet-leukocyte aggregates (PLAs) and thrombotic occlusions (TOs) by intravascular microscopy in the mesentery of rats receiving antiphospholipid (aPL) ...immunoglobulin G (IgG) purified from the sera of patients with antiphospholipid syndrome. aPL IgG had no procoagulant effect, but it caused rapid endothelial deposition of fibrinogen, followed by PLA and TO in rats receiving an intraperitoneal injection of bacterial lipopolysaccharide 3 hours before IgG infusion. Anti-β2-glycoprotein I-depleted aPL IgG failed to induce PLAs and TOs. C3 and C9 colocalized with aPL IgG on the mesenteric vessels. The number of PLAs and TOs was markedly reduced in C6-deficient rats and in animals treated with anti-C5 miniantibody, suggesting the contribution of the terminal complement (C) complex to the aPL antibody-mediated intravascular thrombosis. In conclusion, our data indicate that antibodies to β2-glycoprotein I trigger coagulation subsequent to a priming proinflammatory factor and that the terminal C complex is the main mediator of the coagulation process.
Abstract Objective The objective of this review was to define a core set of recommendations for the treatment of HCV-associated mixed cryoglobulinemia syndrome (MCS) by combining current evidence ...from clinical trials and expert opinion. Methods Expert physicians involved in studying and treating patients with MCS formulated statements after discussing the published data. Their attitudes to treatment approaches (particularly those insufficiently supported by published data) were collected before the consensus conference by means of a questionnaire, and were considered when formulating the statements. Results An attempt at viral eradication using pegylated interferon plus ribavirin should be considered the first-line therapeutic option in patients with mild–moderate HCV-related MCS. Prolonged treatment (up to 72 weeks) may be considered in the case of virological non-responders showing clinical and laboratory improvements. Rituximab (RTX) should be considered in patients with severe vasculitis and/or skin ulcers, peripheral neuropathy or glomerulonephritis. High-dose pulsed glucocorticoid (GC) therapy is useful in severe conditions and, when necessary, can be considered in combination with RTX; on the contrary, the majority of conference participants discouraged the chronic use of low–medium GC doses. Apheresis remains the elective treatment for severe, life-threatening hyper-viscosity syndrome; its use should be limited to patients who do not respond to (or who are ineligible for) other treatments, and emergency situations. Cyclophosphamide can be considered in combination with apheresis, but the data supporting its use are scarce. Despite the limited available data, colchicine is used by many of the conference participants, particularly in patients with mild–moderate MCS refractory to other therapies. Careful monitoring of the side effects of each drug, and its effects on HCV replication and liver function tests is essential. A low-antigen-content diet can be considered as supportive treatment in all symptomatic MCS patients. Although there are no data from controlled trials, controlling pain should always be attempted by tailoring the treatment to individual patients on the basis of the guidelines used in other vasculitides. Conclusion Although there are few controlled randomised trials of MCS treatment, increasing knowledge of its pathogenesis is opening up new frontiers. The recommendations provided may be useful as provisional guidelines for the management of MCS.
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