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Rationale: Diffuse alveolar hemorrhage (DAH) is a life-threatening manifestation of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). The PEXIVAS (Plasma Exchange and Glucocorticoids in Severe Antineutrophil Cytoplasmic Antibody-Associated Vasculitis) (NCT00987389) trial was the largest in AAV and the first to enroll participants with DAH requiring mechanical ventilation. Objectives: Evaluate characteristics, treatment effects, and outcomes for patients with AAV with and without DAH. Methods: PEXIVAS randomized 704 participants to plasma exchange (PLEX) or no-PLEX and reduced or standard-dose glucocorticoids (GC). DAH status was defined at enrollment as no-DAH, nonsevere, or severe (room air oxygen saturation of ⩽ 85% as measured by pulse oximetry, or use of mechanical ventilation). Measurements and Main Results: At enrollment, 191 (27.1%) participants had DAH (61 severe, including 29 ventilated) and were younger, more frequently relapsing, PR3 (proteinase 3)-ANCA positive, and had lower serum creatinine but were more frequently dialyzed than participants without DAH (n = 513; 72.9%). Among those with DAH, 8/95 (8.4%) receiving PLEX died within 1 year versus 15/96 (15.6%) with no-PLEX (hazard ratio, 0.52; confidence interval [CI], 0.21-1.24), whereas 13/96 (13.5%) receiving reduced GC died versus 10/95 (10.5%) with standard GC (hazard ratio, 1.33; CI, 0.57-3.13). When ventilated, ventilator-free days were similar with PLEX versus no-PLEX (medians, 25; interquartile range [IQR], 22-26 vs. 22-27) and fewer with reduced GC (median, 23; IQR, 20-25) versus standard GC (median, 26; IQR, 25-28). Treatment effects on mortality did not vary by presence or severity of DAH. Overall, 23/191 (12.0%) with DAH died within 1 year versus 34/513 (6.6%) without DAH. End-stage kidney disease and serious infections did not differ by DAH status or treatments. Conclusions: Patients with AAV and DAH differ from those without DAH in multiple ways. Further data are required to confirm or refute a benefit of PLEX or GC dosing on mortality. Original clinical trial registered with www.clinicaltrials.gov (NCT00987389).
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Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos , Glucocorticoides , Hemorragia , Troca Plasmática , Humanos , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/complicações , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/mortalidade , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/tratamento farmacológico , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/terapia , Masculino , Feminino , Pessoa de Meia-Idade , Hemorragia/terapia , Hemorragia/etiologia , Idoso , Troca Plasmática/métodos , Glucocorticoides/uso terapêutico , Respiração Artificial/estatística & dados numéricos , Pneumopatias/etiologia , Pneumopatias/terapia , Alvéolos Pulmonares , Adulto , Resultado do TratamentoRESUMO
OBJECTIVES: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) commonly presents with diffuse alveolar haemorrhage (DAH) and/or glomerulonephritis. Patients who present with DAH but without kidney involvement have been understudied. METHODS: Patients with DAH diagnosed by bronchoscopy and attributed to AAV over 8.5 years were retrospectively identified through electronic medical records and bronchoscopy reporting software. Patients with end-stage kidney disease (ESKD) or prior kidney transplant were excluded. Characteristics, treatments, and outcomes were abstracted. RESULTS: 30 patients were identified with DAH secondary to AAV. Five with ESKD or prior kidney transplant, and one with concomitant anti-glomerular basement membrane disease, were excluded, leaving 24 patients for analysis. At the time of qualifying bronchoscopy, six patients had no apparent kidney involvement by AAV, while eight of 18 with kidney involvement required dialysis. Of the eight patients dialysed during the initial hospitalisation, four were declared to have ESKD and three died in the subsequent year (one of whom did both). None of the 16 patients without initial dialysis requirement developed kidney involvement requiring dialysis in the subsequent year, though three of the six without initial evidence of kidney involvement by AAV ultimately developed it. No patient without initial kidney involvement died during follow-up. CONCLUSIONS: In our cohort, patients with DAH due to AAV without initial kidney involvement did not develop kidney involvement requiring dialysis or die during the follow-up period, though half of patients without initial evidence of kidney involvement subsequently developed it. Larger studies are warranted to better characterise this population and guide medical management.
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Advances in the diagnosis and treatment of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis have led to continued improvement in survival and prognosis over the course of the last 4 decades. Nevertheless, the most acute and severe disease manifestations, including severe kidney disease and alveolar hemorrhage, continue to be associated with increased early mortality from disease activity or treatment complications as well as risk for the development of end-stage kidney disease (ESKD), which in turn directly affects the overall prognosis of ANCA-associated vasculitis. Plasma exchange (PLEX) has long been proposed and used for these most severe disease manifestations under the assumption that its effects are swift and supported by our understanding of the pathogenic role of ANCA. Yet convincing evidence of a beneficial effect of PLEX in ANCA-associated vasculitis has been lacking, as early studies and small trials have generated conflicting results. The controversy regarding PLEX has been accentuated recently as the largest randomized controlled trial ever conducted in ANCA-associated vasculitis, the Plasma Exchange and Glucocorticoids in Severe ANCA-associated Vasculitis trial, which was specifically designed to evaluate the efficacy of PLEX in patients with severe renal disease or alveolar hemorrhage, failed to show a difference in the combined primary outcome measure of death or ESKD in patients who received PLEX versus those who did not. In light of these disappointing results, we herein review the currently available data on PLEX for ANCA-associated vasculitis and explain why we believe that these data no longer support the use of PLEX in ANCA-associated vasculitis.
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Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/terapia , Hemorragia/etiologia , Falência Renal Crônica/etiologia , Troca Plasmática/efeitos adversos , Plasmaferese/efeitos adversos , Ensaios Clínicos como Assunto , HumanosRESUMO
Portopulmonary hypertension (POPH) is a form of pulmonary arterial hypertension occurring in the setting of portal hypertension with or without hepatic cirrhosis. The presence of both portal and pulmonary vascular disease contributes to complicated hemodynamics and therapeutic challenges, though the severities do not appear to correlate directly. Diagnosis of POPH, and distinction from the commonly observed hyperdynamic state of end-stage liver disease, is typically accomplished with an initial screening transthoracic echocardiogram, followed by right heart catheterization for confirmation of hemodynamic parameters. Though few studies have directly evaluated use in POPH, pulmonary artery-directed therapy is the cornerstone of management, along with consideration of liver transplantation. Perioperative and long-term outcomes are variable, but uniformly worse in the setting of uncontrolled pulmonary pressures. Risk stratification and optimal patient selection for these interventions are areas of ongoing investigation.
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Hipertensão Portal/diagnóstico , Hipertensão Pulmonar/diagnóstico , Anti-Hipertensivos/uso terapêutico , Antagonistas dos Receptores de Endotelina/uso terapêutico , Guanilato Ciclase/fisiologia , Humanos , Hipertensão Portal/epidemiologia , Hipertensão Portal/fisiopatologia , Hipertensão Portal/terapia , Hipertensão Pulmonar/epidemiologia , Hipertensão Pulmonar/fisiopatologia , Hipertensão Pulmonar/terapia , Transplante de Fígado , Inibidores da Fosfodiesterase 5/uso terapêutico , Prostaglandinas/uso terapêuticoRESUMO
PURPOSE OF REVIEW: The role of serial antineutrophil cytoplasmic antibody (ANCA) measurements to guide immunosuppressive therapy in pauci-immune vasculitis is an area of ongoing controversy. Evidence elucidating the relationship between ANCA levels and disease activity continues to grow. RECENT FINDINGS: The finding that proteinase 3-ANCA and myeloperoxidase-ANCA-associated diseases differ genetically has challenged the traditional classification and study of pauci-immune vasculitis. Multiple studies have also found that the clinical features and course of disease differ by ANCA antigen specificity more than clinical diagnosis. Advances in diagnostic assays and new techniques for the evaluation of ANCA levels over time have yielded improved assay performance in specific subsets of patients. In addition, increasing use of rituximab has added to our understanding of the relationship of ANCA levels to B-cell counts and disease relapse, which may differ by treatment regimen. SUMMARY: The relationship between ANCA levels and disease activity is impacted by multiple factors, including antigen specificity, disease manifestations, clinical assay, and therapeutic regimen. Each of these must be taken into account when determining the significance of ANCA levels during long-term follow-up of pauci-immune vasculitis.
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Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos , Anticorpos Anticitoplasma de Neutrófilos/imunologia , Gerenciamento Clínico , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/sangue , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/imunologia , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/terapia , Anticorpos Anticitoplasma de Neutrófilos/sangue , Biomarcadores/sangue , HumanosRESUMO
Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) are pulmonary vascular complications of portal hypertension with divergent clinicopathologic features and management. The presence of intrapulmonary vascular dilatations (IPVDs), detected by agitated saline contrast-enhanced transthoracic echocardiography (cTTE), is an essential feature of HPS but is not typically characteristic of POPH. Although IPVDs have been reported rarely in POPH, the prevalence and significance of this finding have not been systematically studied. We conducted a retrospective chart review of 80 consecutive patients diagnosed with POPH from January 1, 2002 to June 30, 2014 with documentation of cTTE findings, pulmonary hemodynamics, oxygenation, and survival. A total of 34 of the 80 patients (42%) underwent cTTE during initial diagnosis of POPH. IPVDs were detected in 20/34 patients (59%); intracardiac shunting was detected in 9/34 patients (26%; 4 also had IPVDs); and 9 patients (26%) had negative cTTE with no evidence of IPVD or intracardiac shunting. Patients with IPVD had decreased survival as compared to those without IPVD (P = 0.003), a trend that persisted after exclusion of liver transplant recipients (P = 0.07). The IPVD group had a trend toward higher Model for End-Stage Liver Disease score with and without incorporating sodium (MELD or MELD-Na; P = 0.05 for both). The right ventricular index of myocardial performance (RIMP) was lower in the IPVD group (median, 0.4 versus 0.6; P = 0.006). Patients with moderate or large IPVDs (n = 6) had worse oxygenation parameters (partial pressure of arterial oxygen, diffusing capacity of the lung for carbon monoxide, and alveolar-arterial oxygen gradient) as compared to the rest of the cohort. Unexpectedly, IPVDs were frequently documented in POPH and associated with decreased survival. To further understand this observation, we recommend screening for IVPD in all patients with POPH.
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Ecocardiografia/métodos , Síndrome Hepatopulmonar/mortalidade , Pulmão/irrigação sanguínea , Artéria Pulmonar/diagnóstico por imagem , Veias Pulmonares/diagnóstico por imagem , Dilatação Patológica , Feminino , Seguimentos , Síndrome Hepatopulmonar/diagnóstico por imagem , Síndrome Hepatopulmonar/etiologia , Humanos , Hipertensão Portal/complicações , Hipertensão Portal/diagnóstico , Masculino , Pessoa de Meia-Idade , Minnesota/epidemiologia , Prognóstico , Circulação Pulmonar , Estudos Retrospectivos , Taxa de Sobrevida/tendênciasRESUMO
The evolution of metabolic and cardiovascular disease (CVD) complications after liver transplantation (LT) is poorly characterized. We aim to illustrate the prevalence of obesity and metabolic syndrome (MS), define the cumulative incidence of CVD, and characterize risk factors associated with these comorbidities after LT. A retrospective review of 455 consecutive LT recipients from 1999 to 2004 with an 8- to 12-year follow-up was performed. Obesity increased from 23.8% (4 months) to 40.8% (3 years) after LT. Increase in body mass index predicted MS at 1 year after LT (odds ratio, 1.1; P < 0.001, per point). CVD developed in 10.6%, 20.7%, and 30.3% of recipients within 1, 5, and 8 years, respectively. Age, diabetes, hypertension, glomerular filtration rate < 60 mL/minute, prior CVD, ejection fraction < 60%, left ventricular hypertrophy, and serum troponin (TN) > 0.07 ng/mL were associated with CVD on univariate analysis. Age (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.01-1.06; P = 0.019), diabetes (HR, 1.78; 95% CI, 1.09-2.92; P = 0.022), prior history of CVD (HR, 2.46; 95% CI, 1.45-4.16; P < 0.001), and serum TN > 0.07 ng/mL (HR, 1.98; 95% CI, 1.23-3.18; P = 0.005) were independently associated with CVD in the long term. Smoking history (ever), sex, hyperlipidemia, and serum ferritin levels were not predictive of CVD. Tacrolimus use versus noncalcineurin-based immunosuppression (HR, 0.26; 95% CI, 0.14-0.49; P < 0.001) was associated with reduced risk of CVD but not versus cyclosporine (HR, 0.67; 95% CI, 0.30-1.49; P = 0.322). CVD is common after LT. Independent of MS, more data are needed to identify nonconventional risk factors and biomarkers like serum TN. Curbing weight gain in the early months after transplant may impact MS and subsequent CVD in the long term.
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Doenças Cardiovasculares/complicações , Doença Hepática Terminal/cirurgia , Transplante de Fígado/efeitos adversos , Adulto , Biomarcadores , Índice de Massa Corporal , Comorbidade , Ciclosporina/uso terapêutico , Complicações do Diabetes , Doença Hepática Terminal/complicações , Feminino , Taxa de Filtração Glomerular , Humanos , Hipertensão/complicações , Terapia de Imunossupressão , Incidência , Masculino , Síndrome Metabólica/complicações , Pessoa de Meia-Idade , Obesidade/complicações , Razão de Chances , Prevalência , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Tacrolimo/uso terapêuticoRESUMO
BACKGROUND & AIMS: Chronic kidney disease (CKD) after liver transplant (LT) is associated with increased long-term mortality. The impact of gender on CKD before and after LT is unknown. To further define risk factors and analyse gender differences in the incidence and progression of CKD after liver transplant. METHODS: Four hundred and fifty-five consecutive adult primary solitary LT recipients were included. Iothalamate clearance tests performed over time were analysed. RESULTS: Mean age was 51.4 ± 10.4 years with 63% males. A percentage of 29.1% of females and 21.1% of males had a GFR<60 ml/min/1.73 m(2) and 10.2% of females and 5.9% of males had GFR<30 ml/min/1.73 m(2) prior to transplant. At 1 year, 52.6% of recipients tested (69.6% females, 43.0% males) had GFR<60 ml/min/1.73 m(2) and 7.3% (11.6% females, 4.9% males) had GFR<30 ml/min/1.73 m(2) . Pre-LT GFR<60 ml/min/1.73 m(2) [OR 3.28, (1.76-6.10), P ≤ 0.001], female gender (OR 2.96, (1.72-5.10), P < 0.001) and age [OR 1.09, (1.05-1.12), P < 0.001] were independently predictive of stage ≥3 CKD at 1 year post-LT. Female gender [OR 2.52, (1.25-4.71), P = 0.004], age [OR 1.05, (1.02-1.08), P = 0.003] and NASH [OR 2.95, (1.06-8.21), P = 0.039] were independently predictive of ≥stage 3 CKD at 5 years post-LT. Pre-LT diabetes was associated with stage 4 CKD at 5 years [OR 2.91, (1.33-6.36), P = 0.008] post-LT. CONCLUSIONS: In addition to age and pre-LT CKD, female gender and NASH are independent predictors of ≥stage 3 CKD post-LT. Gender-based approaches to optimize modifiable risk factors are needed to improved post-transplant renal function.
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Transplante de Fígado/efeitos adversos , Hepatopatia Gordurosa não Alcoólica/complicações , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/etiologia , Adulto , Feminino , Taxa de Filtração Glomerular/fisiologia , Humanos , Ácido Iotalâmico/farmacocinética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Fatores de Risco , Fatores SexuaisRESUMO
BACKGROUND: Many conditions, including autoimmune disease and idiopathic pulmonary hemosiderosis (IPH), can cause diffuse alveolar hemorrhage (DAH). Little is known about the epidemiology and outcomes in children. OBJECTIVES: This retrospective cohort study sought to describe the etiologies and outcomes of DAH in pediatric patients at a tertiary care center. METHODS: This study involved review of patient records with diagnostic codes or bronchoscopy reports suggestive of pulmonary hemorrhage at a large children's hospital over 11 years (2010-2020). Patients were included if they met criteria for DAH, defined as bilateral pulmonary infiltrates and at least one of the following: (1) hemoptysis, (2) blood visible on bronchoscopic exam without apparent airway source, or (3) DAH noted on biopsy or autopsy. Infants less than 10 days corrected gestational age were excluded. RESULTS: Seventy-one children with DAH were included in the analysis. Cardiovascular disease was the most common etiology. Bleeding diathesis was common, but all patients had other causes of DAH. Patients with IPH were younger than those with autoimmune disease (p < .001). Most (77%) patients required mechanical ventilation, though this was less common among patients with autoimmune disease. Overall mortality was high (37%) but varied based on underlying etiology; mortality was higher in patients with cardiovascular disease (65%) while no deaths were seen in patients with autoimmune disease or IPH (p = .002). Survivors of DAH who performed pulmonary function tests had normal lung function. CONCLUSIONS: DAH frequently causes respiratory failure in children. In our cohort, mortality was highest in patients with cardiovascular disease.
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Proteinase 3 (PR3)-specific antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is one of two major ANCA-associated vasculitis variants and is pathogenically linked to granulomatosis with polyangiitis (GPA). GPA is characterised by necrotising granulomatous inflammation that preferentially affects the respiratory tract. The small vessel vasculitis features of GPA are shared with microscopic polyangiitis. Necrotising granulomatous inflammation of GPA can lead to PR3-ANCA and small vessel vasculitis via activation of neutrophils and monocytes. B cells are central to the pathogenesis of PR3-ANCA-associated vasculitis. They are targeted successfully by remission induction and maintenance therapy with rituximab. Relapses of PR3-ANCA-associated vasculitis and toxicities associated with current standard therapy contribute substantially to remaining mortality and damage-associated morbidity. More effective and less toxic treatments are sought to address this unmet need. Advances with cellular and novel antigen-specific immunotherapies hold promise for application in autoimmune disease, including PR3-ANCA-associated vasculitis. This Series paper describes the inter-related histopathological and clinical features, pathophysiology, as well as current and future targeted treatments for PR3-ANCA-associated vasculitis.
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Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos , Humanos , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/patologia , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/tratamento farmacológico , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/imunologia , Anticorpos Anticitoplasma de Neutrófilos/imunologia , Granulomatose com Poliangiite/imunologia , Granulomatose com Poliangiite/patologia , Granulomatose com Poliangiite/tratamento farmacológico , Granulomatose com Poliangiite/terapia , Mieloblastina/imunologia , Rituximab/uso terapêuticoRESUMO
Rationale & Objective: We sought to elicit patient preferences regarding the use of plasma exchange in antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and its tradeoffs of risk of kidney failure and risk of serious infection. Study Design: Patient survey. Setting & Participants: The online survey was circulated to adults with AAV via kidney and vasculitis networks in Canada, the United Kingdom, and the United States. Outcomes: Respondents reviewed the estimated 1-year risks of kidney failure and serious infection in AAV with and without plasma exchange across 5 serum creatinine categories (150, 250, 350, 450, and 600 µmol/L). For each scenario, participants indicated whether or not they would choose plasma exchange. Analytical Approach: Responses were assessed with multilevel multivariable logistic regression models to identify predictors of respondent choice regarding treatment with plasma exchange. Results: The 470 respondents from the 13 countries (United States 61.7%, United Kingdom 20.0%, Canada 13.8%, and other countries 4.5%) had a mean age of 58.6 (SD 14.3) years, 70.2% women. Respondents were more likely to choose plasma exchange in scenarios at high risk of kidney failure and serious infection (creatinine level of 350 or 450 µmol/L) compared with lower risk scenarios or the highest risk scenario. However, 145 (30.9%) chose plasma exchange across all scenarios, whereas 80 (17.0%) declined plasma exchange across all scenarios. Respondents from the United Kingdom (OR, 2.61; 95% CI, 1.09-6.22) who received previous dialysis (OR, 2.70; 95% CI, 1.12-6.52) or received previous plasma exchange (OR, 5.62; 95% CI, 2.72-11.61) were more likely to choose plasma exchange, whereas older respondents (OR, 0.98; 95% CI, 0.96-0.99 per 1 year increase) were less likely. Limitations: Unclear generalizability to non-English-speaking, older, and less health literate adults, possible responder bias, survivor bias, lack of individualized risk assessments for kidney failure, and serious infection. Conclusions: Patients with AAV do not express a consistent choice for plasma exchange, which highlights the need for shared decision making.
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Bronchoscopy for research purposes is a valuable tool to understand lung-specific biology in human participants. Despite published reports and active research protocols using this procedure in critically ill patients, no recent document encapsulates the important safety considerations and downstream applications of this procedure in this setting. The objectives were to identify safe practices for patient selection and protection of hospital staff, provide recommendations for sample procurement to standardize studies, and give guidance on sample preparation for novel research technologies. Seventeen international experts in the management of critically ill patients, bronchoscopy in clinical and research settings, and experience in patient-oriented clinical or translational research convened for a workshop. Review of relevant literature, expert presentations, and discussion generated the findings presented herein. The committee concludes that research bronchoscopy with bronchoalveolar lavage in critically ill patients on mechanical ventilation is valuable and safe in appropriately selected patients. This report includes recommendations on standardization of this procedure and prioritizes the reporting of sample management to produce more reproducible results between laboratories. This document serves as a resource to the community of researchers who endeavor to include bronchoscopy as part of their research protocols and highlights key considerations for the inclusion and safety of research participants.
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Broncoscopia , Estado Terminal , Humanos , Lavagem Broncoalveolar , Dimercaprol , Seleção de PacientesRESUMO
OBJECTIVE: Proteinase 3 (PR3) is the major antigen for antineutrophil cytoplasmic antibodies (ANCAs) in the systemic autoimmune vasculitis, granulomatosis with polyangiitis (GPA). PR3-targeting ANCAs (PR3-ANCAs) recognize different epitopes on PR3. This study was undertaken to study the effect of mutations on PR3 antigenicity. METHODS: The recombinant PR3 variants, iPR3 (clinically used to detect PR3-ANCAs) and iHm5 (containing 3 point mutations in epitopes 1 and 5 generated for epitope mapping studies) immunoassays and serum samples from patients enrolled in ANCA-associated vasculitis (AAV) trials were used to screen for differential PR3-ANCA binding. A patient-derived monoclonal ANCA 518 (moANCA518) that selectively binds to iHm5 within the mutation-free epitope 3 and is distant from the point mutations of iHm5 was used as a gauge for remote epitope activation. Selective binding was determined using inhibition experiments. RESULTS: Rather than reduced binding of PR3-ANCAs to iHm5, we found substantially increased binding of the majority of PR3-ANCAs to iHm5 compared to iPR3. This differential binding of PR3-ANCA to iHm5 is similar to the selective moANCA518 binding to iHm5. Binding of iPR3 to monoclonal antibody MCPR3-2 also induced recognition by moANCA518. CONCLUSION: The preferential binding of PR3-ANCAs from patients, such as the selective binding of moANCA518 to iHm5, is conferred by increased antigenicity of epitope 3 on iHm5. This can also be induced on iPR3 when captured by monoclonal antibody MCPR2. This previously unrecognized characteristic of PR3-ANCA interactions with its target antigen has implications for studying antibody-mediated autoimmune diseases, understanding variable performance characteristics of immunoassays, and design of potential novel treatment approaches.
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Anticorpos Anticitoplasma de Neutrófilos , Granulomatose com Poliangiite , Humanos , Mieloblastina/genética , Epitopos , Granulomatose com Poliangiite/genética , Anticorpos MonoclonaisRESUMO
Prohibitins (PHB1 and PHB2) are ubiquitously expressed proteins which play critical roles in multiple biological processes, and together form the ring-like PHB complex found in phospholipid-rich cellular compartments including lipid rafts. Recent studies have implicated PHB1 as a mediator of fatty acid transport as well as a membrane scaffold mediating B lymphocyte and mast cell signal transduction. However, the specific role of PHBs in the macrophage have not been characterized, including their role in fatty acid uptake and lipid raft-mediated inflammatory signaling. We hypothesized that the PHB complex regulates macrophage inflammatory signaling through the formation of lipid rafts. To evaluate our hypothesis, RAW 264.7 macrophages were transduced with shRNA against PHB1, PHB2, or scrambled control (Scr), and then stimulated with lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-α), which activate lipid raft-dependent receptor signaling (CD14/TLR4 and TNFR1, respectively). PHB1 knockdown was lethal, whereas PHB2 knockdown (PHB2kd), which also resulted in decreased PHB1 expression, led to attenuated nuclear factor-kappa-B (NF-κB) activation and subsequent cytokine and chemokine production. PHB2kd macrophages also had decreased cell surface TNFR1, CD14, TLR4, and lipid raft marker ganglioside GM1 at baseline and post-stimuli. Post-LPS, PHB2kd macrophages did not increase the concentration of cellular saturated, monounsaturated, and polyunsaturated fatty acids. This was accompanied by decreased lipid raft formation and modified plasma membrane molecular packing, further supporting the PHB complex's importance in lipid raft formation. Taken together, these data suggest a critical role for PHBs in regulating macrophage inflammatory signaling via maintenance of fatty acid composition and lipid raft structure. SUMMARY: Prohibitins are proteins found in phospholipid-rich cellular compartments, including lipid rafts, that play important roles in signaling, transcription, and multiple other cell functions. Macrophages are key cells in the innate immune response and the presence of membrane lipid rafts is integral to signal transduction, but the role of prohibitins in macrophage lipid rafts and associated signaling is unknown. To address this question, prohibitin knockdown macrophages were generated and responses to lipopolysaccharide and tumor necrosis factor-alpha, which act through lipid raft-dependent receptors, were analyzed. Prohibitin knockdown macrophages had significantly decreased cytokine and chemokine production, transcription factor activation, receptor expression, lipid raft assembly and membrane packing, and altered fatty acid remodeling. These data indicate a novel role for prohibitins in macrophage inflammatory signaling through regulation of fatty acid composition and lipid raft formation.
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Proibitinas , Receptores Tipo I de Fatores de Necrose Tumoral , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Lipopolissacarídeos , Receptor 4 Toll-Like/metabolismo , Ácidos Graxos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Transdução de Sinais , Macrófagos , Citocinas/metabolismo , Membrana Celular/metabolismo , Microdomínios da Membrana/metabolismo , Fosfolipídeos/metabolismo , Quimiocinas/metabolismoRESUMO
Introduction: Although the alternative complement pathway has been implicated in the pathogenesis of antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV), the specific nature of its involvement is unclear. This study measured levels of urine and plasma complement fragment Ba at multiple time points in a group of patients with AAV. Methods: The complement fragment Ba was measured by enzyme-linked immunosorbent assay in serial urine and plasma samples from 21 patients with AAV who developed a renal flare, 19 who developed a nonrenal flare, and 20 in long-term remission. Urine Ba levels were corrected for urine creatinine concentration. Changes in Ba levels were modeled using mixed linear-effect models. A logistic regression model was fit to predict a renal flare using Ba levels at the time of flare versus the nonrenal flare and long-term remission groups. Results: Data from 60 patients with AAV were used for this analysis; 53% were male, 93% were White, and 74% had antiproteinase3-ANCA. Urine Ba levels increased at renal flare (P < 0.001) but remained stable during a nonrenal flare or long-term remission. Plasma Ba levels were stable over time in all groups. Urine Ba levels predicted a renal flare with an area under the curve of 0.76 (P < 0.001), with a cutoff of 12.53 ng/mg urine creatinine yielding a sensitivity of 76.2% and a specificity of 68.4%. Conclusion: Urine Ba levels, but not plasma Ba levels, are increased at the time of a renal flare in AAV, suggesting intrarenal complement activation and highlighting the potential use of this biomarker for surveillance of active renal vasculitis.
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CLINICAL QUESTIONS: What is the role of plasma exchange and what is the optimal dose of glucocorticoids in the first 6 months of therapy of patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)? This guideline was triggered by the publication of a new randomised controlled trial. CURRENT PRACTICE: Existing guideline recommendations vary regarding the use of plasma exchange in AAV and lack explicit recommendations regarding the tapering regimen of glucocorticoids during induction therapy. RECOMMENDATIONS: The guideline panel makes a weak recommendation against plasma exchange in patients with low or low-moderate risk of developing end stage kidney disease (ESKD), and a weak recommendation in favour of plasma exchange in patients with moderate-high or high risk of developing ESKD. For patients with pulmonary haemorrhage without renal involvement, the panel suggests not using plasma exchange (weak recommendation). The panel made a strong recommendation in favour of a reduced dose rather than standard dose regimen of glucocorticoids, which involves a more rapid taper rate and lower cumulative dose during the first six months of therapy. HOW THIS GUIDELINE WAS CREATED: A guideline panel including patients, a care giver, clinicians, content experts, and methodologists produced these recommendations using GRADE and in adherence with standards for trustworthy guidelines. The recommendations are based on two linked systematic reviews. The panel took an individual patient perspective in the development of recommendations. THE EVIDENCE: The systematic review of plasma exchange identified nine randomised controlled trials (RCTs) that enrolled 1060 patients with AAV. Plasma exchange probably has little or no effect on mortality or disease relapse (moderate and low certainty). Plasma exchange probably reduces the one year risk of ESKD (approximately 0.1% reduction in those with low risk, 2.1% reduction in those with low-moderate risk, 4.6% reduction in those with moderate-high risk, and 16.0% reduction in those with high risk or requiring dialysis) but increases the risk of serious infections (approximately 2.7% increase in those with low risk, 4.9% increase in those with low-moderate risk, 8.5% increase in those with moderate-high risk, to 13.5% in high risk group) at 1 year (moderate to high certainty). The guideline panel agreed that most patients with low or low-moderate risk of developing ESKD would consider the harms to outweigh the benefits, while most of those with moderate-high or high risk would consider the benefits to outweigh the harms. For patients with pulmonary haemorrhage without kidney involvement, based on indirect evidence, plasma exchange may have little or no effect on death (very low certainty) but may have an important increase in serious infections at 1 year (approximately 6.8% increase, low certainty). The systematic review of different dose regimens of glucocorticoids identified two RCTs at low risk of bias with 704 and 140 patients respectively. A reduced dose regimen of glucocorticoid probably reduces the risk of serious infections by approximately 5.9% to 12.8% and probably does not increase the risk of ESKD at the follow-up of 6 months to longer than 1 year (moderate certainty for both outcomes). UNDERSTANDING THE RECOMMENDATION: The recommendations were made with the understanding that patients would place a high value on reduction in ESKD and less value on avoiding serious infections. The panel concluded that most (50-90%) of fully informed patients with AAV and with low or low-moderate risk of developing ESKD with or without pulmonary haemorrhage would decline plasma exchange, whereas most patients with moderate-high or high risk or requiring dialysis with or without pulmonary haemorrhage would choose to receive plasma exchange. The panel also inferred that the majority of fully informed patients with pulmonary haemorrhage without kidney involvement would decline plasma exchange and that all or almost all (≥90%) fully informed patients with AAV would choose a reduced dose regimen of glucocorticoids during the first 6 months of therapy.
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Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/terapia , Glucocorticoides/administração & dosagem , Troca Plasmática/métodos , HumanosRESUMO
Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) represents a group of small vessel vasculitides characterized by granulomatous and neutrophilic tissue inflammation, often associated with the production of antibodies that target neutrophil antigens. The two major antigens targeted by ANCAs are leukocyte proteinase 3 (PR3) and myeloperoxidase (MPO). AAV can be classified into 3 categories based on patterns of clinical involvement: namely, granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic GPA (EGPA). Clinically, AAV involves many organ systems including the lungs, kidneys, skin, and nervous system. The prognosis of AAV has improved dramatically due to advances in the understanding of its pathogenesis and treatment modalities. This review will highlight some of the recent updates in our understanding of the pathogenesis, clinical manifestations, and treatment options in patients with AAV focusing on kidney involvement.
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Background: The utility of ANCA testing as an indicator of disease activity in ANCA-associated vasculitis (AAV) remains controversial. This study aimed to determine the association of ANCA testing by various methods and subsequent remission and examine the utility of a widely used automated addressable laser-bead immunoassay (ALBIA) to predict disease relapses. Methods: Data from the Rituximab vs. Cyclophosphamide for ANCA-Associated Vasculitis (RAVE) trial were used. ANCA testing was performed by direct ELISA, capture ELISA, and ALBIA. Cox proportional hazards regression models were used to evaluate the association of PR3-ANCA level and subsequent remission or relapse. The ALBIA results are routinely reported as >8 when the value is high. For this study, samples were further titrated. A decrease and increase in PR3-ANCA were defined as a halving or doubling in value, respectively. Results: A decrease in ANCA by ALBIA at 2 months was associated with shorter time to sustained remission (HR 4.52, p = 0.035). A decrease in ANCA by direct ELISA at 4 months was associated with decreased time to sustained remission (HR 1.77, p = 0.050). There were no other associations between ANCA decreases or negativity and time to remission. An increase in PR3-ANCA by ALBIA was found in 78 of 93 subjects (84%). Eleven (14%) had a PR3-ANCA value which required titration for detection of an increase. An increase of ANCA by ALBIA was associated with severe relapse across various subgroups. Conclusions: A decrease in ANCA by ALBIA at 2 months and by direct ELISA at 4 months may be predictive of subsequent remission. These results should be confirmed in a separate cohort with similarly protocolized sample and clinical data collection. A routinely used automated ALBIA for PR3-ANCA measurement is comparable to direct ELISA in predicting relapse in PR3-AAV. Without titration, 14% of the increases detected by ALBIA would have been missed. Titration is recommended when this assay is used for disease monitoring. The association of an increase in PR3-ANCA with the risk of subsequent relapse remains complex and is affected by disease phenotype and remission induction agent.
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Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/diagnóstico , Anticorpos Anticitoplasma de Neutrófilos/sangue , Biomarcadores/sangue , Mieloblastina/imunologia , Testes Sorológicos/métodos , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/tratamento farmacológico , Ciclofosfamida/uso terapêutico , Humanos , Imunoensaio , Imunossupressores/uso terapêutico , Rituximab/uso terapêuticoRESUMO
BACKGROUND: Enterobacter spp. are a common cause of nosocomial pneumonia and treatment can be complicated by AmpC resistance. Carbapenems are the treatment of choice; however, alternatives are needed. Cefepime has been shown to be non-inferior to carbapenems. There are limited data to support the use of piperacillin/tazobactam. The objective of this study was to determine if piperacillin/tazobactam is non-inferior to cefepime or ertapenem for Enterobacter pneumonia treatment. OBJECTIVES: To compare the rate of clinical cure in patients with Enterobacter pneumonia receiving definitive treatment with piperacillin/tazobactam, cefepime, or ertapenem. Secondary outcomes included hospital mortality, infection-related length of stay, duration of mechanical ventilation, recurrent pneumonia, and resistance. METHODS: Retrospective, single-center study. RESULTS: Of 114 patients included, 59 received definitive treatment with piperacillin/tazobactam and 55 received cefepime or ertapenem. There was no difference in the proportion of patients who achieved clinical cure in the piperacillin/tazobactam group compared to the cefepime or ertapenem group (76.3% vs. 87.3%, Pâ¯=â¯0.13). Treatment group was not associated with clinical cure when controlling for confounders in multivariable logistic regression (adjusted odds ratio [OR] 0.59, 95% confidence interval [CI] 0.15-2.37). The rate of recurrent pneumonia was 11.4% in the piperacillin/tazobactam group and 6.7% in the cefepime or ertapenem group (Pâ¯=â¯0.48). Other secondary outcomes did not differ between the groups. CONCLUSIONS: In this retrospective study of patients with Enterobacter pneumonia, clinical cure with piperacillin/tazobactam was comparable to that with cefepime or ertapenem; however, a prospective trial with a larger population is needed to determine if definitive treatment with piperacillin/tazobactam is non-inferior to definitive treatment with cefepime or ertapenem.