The mechanisms by which anti-neutrophil cytoplasmic antibodies (ANCAs) may contribute to the pathogenesis of ANCA-associated vasculitis are not well understood. In this study, both polyclonal ANCAs ...isolated from patients and chimeric proteinase 3-ANCA induced the release of neutrophil microparticles from primed neutrophils. These microparticles expressed a variety of markers, including the ANCA autoantigens proteinase 3 and myeloperoxidase. They bound endothelial cells via a CD18-mediated mechanism and induced an increase in endothelial intercellular adhesion molecule-1 expression, production of endothelial reactive oxygen species, and release of endothelial IL-6 and IL-8. Removal of the neutrophil microparticles by filtration or inhibition of reactive oxygen species production with antioxidants abolished microparticle-mediated endothelial activation. In addition, these microparticles promoted the generation of thrombin. In vivo, we detected more neutrophil microparticles in the plasma of children with ANCA-associated vasculitis compared with that in healthy controls or those with inactive vasculitis. Taken together, these results support a role for neutrophil microparticles in the pathogenesis of ANCA-associated vasculitis, potentially providing a target for future therapeutics.
Glomerulonephritis is a common cause of end-stage renal disease. Infiltrating leukocytes interacting with renal cells play a critical role during the initiation and progression of glomerulonephritis, ...but the exact mechanisms are not clearly defined. By using the murine model of nephrotoxic nephritis, we investigated the role of S100A8/A9 myeloid-related protein (MRP) 8/14, calprotectin in promoting glomerulonephritis. In nephrotoxic nephritis, wild-type (WT) mice with glomerulonephritis have elevated serum levels of S100A8/A9, whereas mice deficient in MRP14 ( S100a9 −/− ), and hence S100A8/A9, are significantly protected from disease. By using bone marrow transplants, we showed that MRP14 deficiency is required in both the hemopoietic and intrinsic cells for the protective effect. In vitro , both the WT bone marrow–derived macrophages and renal mesangial cells stimulated with S100A8/A9 secrete IL-6, CXCL1, and tumor necrosis factor α; however, Mrp14−/− cells exhibit significantly blunted proinflammatory responses. The interaction of WT bone marrow–derived macrophages with renal microvascular endothelial cells results in increased levels of monocyte chemotactic protein 1, IL-8, and IL-6 cytokines, which is attenuated in Mrp14−/− bone marrow–derived macrophages. Data shows that S100A8/A9 plays a critical role during glomerulonephritis, exerting and amplifying autocrine and paracrine proinflammatory effects on bone marrow–derived macrophages, renal endothelial cells, and mesangial cells. Therefore, complete S100A8/A9 blockade may be a new therapeutic target in glomerulonephritis.
Patients receiving hemodialysis are at high risk from coronavirus disease 2019 (COVID-19) and demonstrate impaired immune responses to vaccines. There have been several descriptions of their ...immunologic responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, but few studies have described the clinical efficacy of vaccination in patients on hemodialysis.
In a multicenter observational study of the London hemodialysis population undergoing surveillance PCR testing during the period of vaccine rollout with BNT162b2 and AZD1222, all of those positive for SARS-CoV-2 were identified. Clinical outcomes were analyzed according to predictor variables, including vaccination status, using a mixed effects logistic regression model. Risk of infection was analyzed in a subgroup of the base population using a Cox proportional hazards model with vaccination status as a time-varying covariate.
SARS-CoV-2 infection was identified in 1323 patients of different ethnicities (Asian/other, 30%; Black, 38%; and White, 32%), including 1047 (79%) unvaccinated, 86 (7%) after first-dose vaccination, and 190 (14%) after second-dose vaccination. The majority of patients had a mild course; however, 515 (39%) were hospitalized, and 172 (13%) died. Older age, diabetes, and immune suppression were associated with greater illness severity. In regression models adjusted for age, comorbidity, and time period, prior two-dose vaccination was associated with a 75% (95% confidence interval, 56 to 86) lower risk of admission and 88% (95% confidence interval, 70 to 95) fewer deaths compared with unvaccinated patients. No loss of protection was seen in patients over 65 years or with increasing time since vaccination, and no difference was seen between vaccine types.
These data demonstrate a substantially lower risk of severe COVID-19 after vaccination in patients on dialysis who become infected with SARS-CoV-2.
ANCA-associated vasculitis is commonly found in elderly patients, but there are few data concerning outcome and treatment in the highest age groups.
Consecutive patients (N=151) presenting between ...1997 and 2009 were retrospectively included from local registries in six centers in Sweden, the United Kingdom, and the Czech Republic if diagnosed with microscopic polyangiitis or granulomatosis with polyangiitis at age ≥75 years during the study period. Patients were followed until 2 years from diagnosis or death. Data on survival and renal function were analyzed with respect to age, sex, ANCA specificity, renal function, C-reactive protein, comorbidities, and Birmingham Vasculitis Activity Score at diagnosis as well as treatment during the first month.
Median follow-up was 730 days (interquartile range, 244-730). Overall 1-year survival was 71.5% and 2-year survival was 64.6%. Older age, higher creatinine, and lower Birmingham Vasculitis Activity Score were associated with higher mortality in multivariable analysis. Patients who were not treated with standard immunosuppressive therapy had significantly worse survival. Renal survival was 74.8% at 1 year. No new cases of ESRD occurred during the second year. High creatinine at diagnosis was the only significant predictor of renal survival in multivariable analysis.
ANCA-associated vasculitis is a disease with substantial mortality and morbidity among elderly patients. This study showed a better prognosis for those who received immunosuppressive treatment and those who were diagnosed before having developed advanced renal insufficiency.
Objective
COVID‐19 is a novel infectious disease with a broad spectrum of clinical severity. Patients with systemic vasculitis have an increased risk of serious infections and may be at risk of ...severe outcomes following COVID‐19. We undertook this study to establish the risk factors for severe COVID‐19 outcomes in these patients, including the impact of immunosuppressive therapies.
Methods
A multicenter cohort was developed through the participation of centers affiliated with national UK and Ireland vasculitis registries. Clinical characteristics and outcomes are described. Logistic regression was used to evaluate associations between potential risk factors and a severe COVID‐19 outcome, defined as a requirement for advanced oxygen therapy, a requirement for invasive ventilation, or death.
Results
The cohort included 65 patients with systemic vasculitis who developed COVID‐19 (median age 70 years, 49% women), of whom 25 patients (38%) experienced a severe outcome. Most patients (55 of 65 85%) had antineutrophil cytoplasmic antibody–associated vasculitis (AAV). Almost all patients required hospitalization (59 of 65 91%), 7 patients (11%) were admitted to intensive care, and 18 patients (28%) died. Background glucocorticoid therapy was associated with severe outcomes (adjusted odds ratio OR 3.7 95% confidence interval 1.1–14.9; P = 0.047), as was comorbid respiratory disease (adjusted OR 7.5 95% confidence interval 1.9–38.2; P = 0.006). Vasculitis disease activity and nonglucocorticoid immunosuppressive therapy were not associated with severe outcomes.
Conclusion
In patients with systemic vasculitis, glucocorticoid use at presentation and comorbid respiratory disease were associated with severe outcomes in COVID‐19. These data can inform clinical decision‐making relating to the risk of severe COVID‐19 in this vulnerable patient group.
ABSTRACT
Background
Kidney disease is fairly unique due to the lack of symptoms associated with disease activity, and it is therefore dependent on biological monitoring. Dried biofluids, particularly ...dried capillary blood spots, are an accessible, easy‐to‐use technology that have seen increased utility in basic science research over the past decade. However, their use is yet to reach the kidney patient population clinically or in large‐scale discovery science initiatives. The aim of this study was to systematically evaluate the existing literature surrounding the use of dried biofluids in kidney research.
Methods
A systematic literature review was conducted using three search engines and a predefined search term strategy. Results were summarised according to the collection method, type of biofluid, application to kidney disease, cost, sample stability and patient acceptability.
Results
In total, 404 studies were identified and 67 were eligible. In total, 34,739 patients were recruited to these studies with a skew towards male participants (> 73%). The majority of samples were blood, which was used either for monitoring anti‐rejection immunosuppressive drug concentrations or for kidney function. Dried biofluids offered significant cost savings to the patient and healthcare service. The majority of patients preferred home microsampling when compared to conventional monitoring.
Conclusion
There is an unmet need in bringing dried microsampling technology to advance kidney disease despite its advantages. This technology provides an opportunity to upscale patient recruitment and longitudinal sampling, enhance vein preservation and overcome participation bias in research.
We carried out a systematic review of the use of dried biofluids in kidney disease. The majority of studies focused on drug quantification following transplant. However, dried biofluids were comparable with venous samples opening up the possibility to expand to biomarker discovery.
Introduction
The pandemic of coronavirus disease (COVID-19) has highly affected patients with comorbidities and frailty who cannot self-isolate, such as individuals undergoing haemodialysis. The aim ...of the study was to identify risk factors for mortality and hospitalisation, which may be useful in future disease spikes.
Methods
We collected data retrospectively from the electronic medical records of all patients receiving a diagnosis of COVID-19 between 11th March and 10th May 2020 undergoing maintenance haemodialysis at four satellite dialysis units from the Royal Free London NHS Foundation Trust, London, UK. Mortality was the primary outcome, and the need for hospitalization was the secondary one.
Results
Out of 746 patients undergoing regular haemodialysis, 148 symptomatic patients tested positive for SARS-CoV-2 by RT-PCR and were included in the analysis. The overall mortality rate was 24.3%. By univariate analysis, older age, ischaemic heart disease, lower systolic blood pressure, lower body mass index (BMI) and higher frailty scores were associated with higher rates of mortality (all
p
value < 0.05). The laboratory factors associated with mortality were higher values of WBC, neutrophil counts, neutrophil to lymphocyte ratios (NLR), C-reactive protein (CRP), bilirubin, ferritin, troponin, and lower serum albumin level (all
p
value < 0.05). In the logistic regression, mortality was associated with older age and higher CRP, while high levels of NLR and CRP were associated with the need for hospitalization.
Discussion
Haemodialysis patients are susceptible to COVID-19 and have a high mortality rate. Our study identifies prognostic risk factors associated with poor outcome including age, frailty and markers of inflammation, which may support more informed clinical decision-making.
Graphic abstract
This document follows up on a 2017 revised international consensus on anti-neutrophil cytoplasm antibodies (ANCA) testing in granulomatosis with polyangiitis and microscopic polyangiitis and focuses ...on the clinical and diagnostic value of ANCA detection in patients with connective tissue diseases, idiopathic interstitial pneumonia, autoimmune liver diseases, inflammatory bowel diseases, anti-glomerular basement membrane (GBM) disease, infections, malignancy, and during drug treatment. Current evidence suggests that in certain settings beyond systemic vasculitis, ANCA may have clinical, pathogenic and/or diagnostic relevance. Antigen-specific ANCA targeting proteinase-3 and myeloperoxidase should be tested by solid phase immunoassays in any patient with clinical features suggesting ANCA-associated vasculitis and in all patients with anti-GBM disease, idiopathic interstitial pneumonia, and infective endocarditis associated with nephritis, whereas in patients with other aforementioned disorders routine ANCA testing is not recommended. Among patients with autoimmune liver diseases or inflammatory bowel diseases, ANCA testing may be justified in patients with suspected autoimmune hepatitis type 1 who do not have conventional autoantibodies or in case of diagnostic uncertainty to discriminate ulcerative colitis from Crohn’s disease. In these cases, ANCA should be tested by indirect immunofluorescence as the target antigens are not yet well characterized. Many questions concerning the optimal use of ANCA testing in patients without ANCA-associated vasculitis remain to be answered.
Programmed death-1 (PD-1) receptor, an inhibitory costimulatory molecule found on activated T cells, has been demonstrated to play a role in the regulation of immune responses and peripheral ...tolerance. We investigated the role of this pathway in the development of autoimmune diabetes. PD-1 or PD-L1 but not PD-L2 blockade rapidly precipitated diabetes in prediabetic female nonobese diabetic (NOD) mice regardless of age (from 1 to 10-wk-old), although it was most pronounced in the older mice. By contrast, cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) blockade induced disease only in neonates. Male NOD mice also developed diabetes after PD-1-PD-L1 pathway blockade, but NOR mice, congenic to NOD but resistant to the development of diabetes, did not. Insulitis scores were significantly higher and frequency of interferon gamma-producing GAD-reactive splenocytes was increased after PD-1-PD-L1 pathway blockade compared with controls. Interestingly, PD-L1 but not PD-L2 was found to be expressed on inflamed islets of NOD mice. These data demonstrate a central role for PD-1-PD-L1 interaction in the regulation of induction and progression of autoimmune diabetes in the NOD mouse and provide the rationale to develop new therapies to target this costimulatory pathway in this disease.
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