1,020 research outputs found
Platelets are required for enhanced activation of the endothelium and fibrinogen in a mouse thrombosis model of APS
Antiphospholipid syndrome (APS) is defined by thrombosis, fetal loss, and the presence of antiphospholipid antibodies, including anti-beta 2-glycoprotein-1 autoantibodies (anti-beta 2GP1) that have a direct role in the pathogenesis of thrombosis in vivo. The cellular targets of the anti-beta 2GP1autoantibody/beta 2GP1complex in vivo were studied using a laser-induced thrombosis model of APS in a live mouse and human anti-beta 2GP1 autoantibodies affinity-purified from APS patients. Cell binding of fluorescently labeled beta 2GP1 and anti-beta 2GP1 autoantibodies revealed their colocalization on the platelet thrombus but not the endothelium. Anti-beta 2GP1 autoantibodies enhanced platelet activation, monitored by calcium mobilization, and endothelial activation, monitored by intercellular adhesion molecule-1 expression. When eptifibatide was infused to block platelet thrombus formation, enhanced fibrin generation and endothelial cell activation were eliminated. Thus, the anti-beta 2GP1 autoantibody/beta 2GP1 complex binds to the thrombus, enhancing platelet activation, and platelet secretion leads to enhanced endothelium activation and fibrin generation. These results lead to a paradigm shift away from the concept that binding of the anti-beta 2GP1 autoantibody/beta 2GP1 complex activates both endothelial cells and platelets toward one in which activation of platelets in response to anti-beta 2GP1 autoantibody/beta 2GP1 complex binding leads to subsequent enhanced endothelium activation and fibrin generation
Lessons learned from bone marrow failure in systemic lupus erythematosus: Case reports and review of the literature
© 2017 Elsevier Inc. Objective: In the present review, four new cases of bone marrow failure are presented and the potential contribution of systemic lupus erythematosus (SLE) is discussed. Furthermore, a comprehensive literature review of cases of autoimmune myelofibrosis (AIMF), aplastic anemia (AA), and paroxysmal nocturnal hemoglobinuria (PNH) with concurrent SLE aims to allow their direct comparison. Based on a clearer characterization of reported cases and our own experience, diagnostic and therapeutic strategies of these disorders in SLE are proposed based on lessons learned from the present and previous cases. Methods: A literature search was done in PubMed, accessed via the National Library of Medicine PubMed interface (http://www.ncbi.nlm.nih.gov/pubmed). Using PubMed, a Boolean search of the literature was performed by crossing the keywords âsystemic lupus erythematosus,â AND [âbone marrow fibrosisâ or âbone marrow failureâ or âmyelofibrosisâ or âaplastic anemiaâ or âparoxysmal nocturnal hemoglobinuriaâ]. Results: After a stringent selection of previous cases with a clear diagnosis of SLE, we summarized in the present review 31 cases of AIMF, 26 cases of AA, and 3 cases of PNH. In addition, four new cases illustrate the problem of attribution of bone marrow failure to SLE. Conclusions: The attribution of SLE to bone marrow failure is challenging due to a lack of biomarkers, which complicates treatment decisions. Autoimmune myelofibrosis is likely underreported, but corticosteroids and intravenous immunoglobulin appear to be effective immediate therapies. In AA attributable to SLE, a serum inhibitor of bone marrow precursors should be tested, since plasma exchange has been universally successful in these cases, and a PNH clone should be tested for in the setting of ongoing hemolysis, as complement inhibition may be effective. Further research is warranted to elucidate pathophysiological mechanisms of bone marrow failure in SLE
Thrombus Formation: Direct RealâTime Observation and Digital Analysis of Thrombus Assembly in a Living Mouse by Confocal and Widefield Intravital Microscopy
We have developed novel instrumentation using confocal and widefield microscopy to image and analyze thrombus formation in real time in the microcirculation of a living mouse. This system provides high-speed, near-simultaneous acquisition of images of multiple fluorescent probes and a brightfield channel, and supports laser-induced injury through the microscope optics. Although this imaging facility requires interface of multiple hardware components, the primary challenge in vascular imaging is careful experimental design and interpretation. This system has been used to localize tissue factor during thrombus formation, to observe defects in thrombus assembly in genetically altered mice, to study the kinetics of platelet activation and P-selectin expression following vascular injury, to analyze leukocyte rolling on arterial thrombi, to generate three-dimensional models of thrombi, and to analyze the effect of antithrombotic agents in vivo
Establishment of norms in specific areas of the visual field for critical fusion frequency as determined by a modified stroboscope
Establishment of norms in specific areas of the visual field for critical fusion frequency as determined by a modified stroboscop
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Endothelial diaphragmed fenestrae: in vitro modulation by phorbol myristate acetate
Cultured microvascular endothelial cells isolated from fenestrated capillaries have been shown to express many properties of their in vivo differentiated phenotype, yet they contain very few diaphragmed fenestrae. We show here that treatment of capillary endothelial cells with the tumor promoter, 4 beta-phorbol 12-myristate 13-acetate, induces more than a fivefold increase in the frequency of fenestrae per micron 2 of cell surface, as determined from a quantitative evaluation on freeze-fracture replicas. In quick-frozen, deep-etched preparations, the endothelial fenestrae appeared to be bridged by a diaphragm composed of radial fibers interweaving in a central mesh, as previously observed in vivo. These results indicate that diaphragmed fenestrae are inducible structures, and provide an opportunity to study them in vitro
What Does it Mean to be a British Isles Lupus Assessment Group-Based Composite Lupus Assessment Responder? Post Hoc Analysis of 2 Phase 3 Trials
OBJECTIVE: The British Isles Lupus Assessment Groupâbased Composite Lupus Assessment (BICLA) is a validated global measure of treatment response in systemic lupus erythematosus (SLE) clinical trials. To understand the relevance of BICLA in clinical practice, we investigated relationships between BICLA response and routine SLE assessments, patient-reported outcomes (PROs), and medical resource utilization. METHODS: This was a post hoc analysis of pooled data from the phase III, randomized, placebo-controlled, 52-week TULIP-1 (ClinicalTrials.gov identifier: NCT02446912; n = 457) and TULIP-2 (ClinicalTrials.gov identifier: NCT02446899; n = 362) trials of intravenous anifrolumab (150/300 mg once every 4 weeks) in patients with moderate-to-severe SLE. Changes from baseline to week 52 in clinical assessments, PROs, and medical resource use were compared in BICLA responders versus nonresponders, regardless of treatment assignment. RESULTS: BICLA responders (n = 318) achieved significantly improved outcomes compared with nonresponders (n = 501), including lower flare rates, higher rates of attainment of sustained oral glucocorticoid taper to â€7.5 mg/day, greater improvements in PROs (Functional Assessment of Chronic Illness TherapyâFatigue, Short Form 36 Health Survey), and fewer SLE-related hospitalizations/emergency department visits (all nominal P < 0.001). Compared with nonresponders, BICLA responders had greater improvements in global and organ-specific disease activity (Physicianâs Global Assessment, SLE Disease Activity Index 2000, Cutaneous Lupus Erythematosus Disease Area and Severity Index Activity, and joint counts; all nominal P < 0.001). BICLA responders had fewer lupus-related serious adverse events than nonresponders. CONCLUSION: BICLA response is associated with clinical benefit in SLE assessments, PROs, and medical resource utilization, confirming its value as a clinical trial end point that is associated with measures important to patient care
Declining use of combination infliximab and immunomodulator for inflammatory bowel disease in the community setting.
To describe trends of combination therapy (CT) of infliximab (IFX) and immunomodulator (IMM) for inflammatory bowel disease (IBD) in the community setting.A retrospective study was conducted of all IBD patients referred for IFX infusion to our community infusion center between 04/01/01 and 12/31/14. CT was defined as use of IFX with either azathioprine, 6-mercaptopurine, or methotrexate. We analyzed trends of CT usage overall, for Crohn\u27s disease (CD) and ulcerative colitis (UC), and for the subgroups of induction patients. We also analyzed the trends of CT use in these groups over the study period, and compared the rates of CT use prior to and after publication of the landmark SONIC trial.Of 258 IBD patients identified during the 12 year study period, 60 (23.3%) received CT, including 35 of 133 (26.3%) induction patients. Based on the Cochran-Armitage trend test, we observed decreasing CT use for IBD patients overall (P \u3c 0.0001) and IBD induction patients, (P = 0.0024). Of 154 CD patients, 37 (24.68%) had CT, including 20 of 77 (26%) induction patients. The Cochran Armitage test showed a trend towards decreasing CT use for CD overall (P \u3c 0.0001) and CD induction, (P = 0.0024). Overall, 43.8% of CD patients received CT pre-SONIC vs 7.4% post-SONIC (P \u3c 0.0001). For CD induction, 40.0% received CT pre-SONIC vs 10.8% post-SONIC (P = 0.0035). Among the 93 patients with UC, 19 (20.4%) received CT. Of 50 induction patients, 14 (28.0%) received CT. The trend test of the 49 patients with a known year of induction again failed to demonstrate any significant trends in the use of CT (P = 0.6).We observed a trend away from CT use in IBD. A disconnect appears to exist between expert opinion and evidence favoring CT with IFX and IMM, and evolving community practice
Acthar Gel (repository corticotropin injection) for persistently active SLE: Study design and baseline characteristics from a multicentre, randomised, double-blind, placebo-controlled trial
© 2020 Author(s). Objective SLE is a chronic inflammatory autoimmune disease characterised by the excessive production of autoantibodies, immune complexes and proinflammatory cytokines. Repository corticotropin injection (RCI) is a naturally sourced complex mixture of adrenocorticotropic hormone analogues and other pituitary peptides. RCI is approved by the US Food and Drug Administration for use during an exacerbation or as maintenance therapy in select cases of SLE. This paper discusses the design and baseline characteristics of a multicentre, double-blind, randomised, placebo-controlled, 24-week clinical trial evaluating the effect of RCI in reducing disease activity for patients with persistently active SLE despite moderate-dose corticosteroid use. Methods Efficacy will be evaluated using the SLE Responder Index-4 (SRI-4), SLE Disease Activity Index-2000 (SLEDAI-2K), British Isles Lupus Assessment Group-2004 (BILAG-2004) and Physician\u27s Global Assessment (PGA). The primary efficacy endpoint will be the proportion of SRI-4 responders at week 16. Secondary and exploratory endpoints will include changes in disease activity scores over time, prednisone dose and biomarkers of inflammation and bone turnover. The safety and tolerability profile of RCI will also be evaluated through adverse event profiles, physical examination, clinical laboratory tests and serum cortisol levels. Results Target enrolment for this global study is 270 patients, and as of 15 November 2019, the modified intent-to-treat population included 169 patients. The study cohort had 91.7% women, had a mean age of 39.7 years, mean SLEDAI-2K total score of 9.9, mean BILAG-2004 total score of 18.1, mean PGA of 59.7 and mean prednisone or equivalent daily dose of 11.1 mg. A total of 79.3% and 64.5% of patients were receiving concomitant antimalarial or immunosuppressive therapy, respectively. Conclusions Data from this study will provide valuable insights into the therapeutic role of RCI in refractory SLE, as well as important information regarding its safety profile
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