Computable phenotype for real-world, data-driven retrospective identification of relapse in ANCA-associated vasculitis

Objective: ANCA-associated vasculitis (AAV) is a relapsing-remitting disease, resulting in incremental tissue injury. The gold-standard relapse definition (Birmingham Vasculitis Activity Score, BVAS>0) is often missing or inaccurate in registry settings, leading to errors in ascertainment of this key outcome. We sought to create a computable phenotype (CP) to automate retrospective identification of relapse using real-world data in the research setting.Methods: We studied 536 patients with AAV and >6 months follow-up recruited to the Rare Kidney Disease registry (a national longitudinal, multicentre cohort study). We followed five steps: (1) independent encounter adjudication using primary medical records to assign the ground truth, (2) selection of data elements (DEs), (3) CP development using multilevel regression modelling, (4) internal validation and (5) development of additional models to handle missingness. Cut-points were determined by maximising the F1-score. We developed a web application for CP implementation, which outputs an individualised probability of relapse.Results: Development and validation datasets comprised 1209 and 377 encounters, respectively. After classifying encounters with diagnostic histopathology as relapse, we identified five key DEs; DE1: change in ANCA level, DE2: suggestive blood/urine tests, DE3: suggestive imaging, DE4: immunosuppression status, DE5: immunosuppression change. F1-score, sensitivity and specificity were 0.85 (95% CI 0.77 to 0.92), 0.89 (95% CI 0.80 to 0.99) and 0.96 (95% CI 0.93 to 0.99), respectively. Where DE5 was missing, DE2 plus either DE1/DE3 were required to match the accuracy of BVAS.Conclusions: This CP accurately quantifies the individualised probability of relapse in AAV retrospectively, using objective, readily accessible registry data. This framework could be leveraged for other outcomes and relapsing diseases.Keywords: Classification; Epidemiology; Outcome Assessment, Health Care; Vasculitis

ANCA vasculitis induction management during the COVID-19 pandemic

As the severe acute respiratory syndrome coronavirus 2 pandemic evolved and became a global health threat, the safety of immunosuppression in antineutrophil cytoplasmic antibody-associated vasculitis (AAV) became of utmost important for clinicians and patients. Although timely initiation of immunosuppressive therapy is critical to quell the acute inflammation and prevent AAV-associated mortality and morbidity, concerns for increased susceptibility to Coronavirus Disease 2019 (COVID-19), delayed viral clearance, and decreased humoral response to infection led to speculation about modification in induction therapy practices may be deployed by physicians caring for patients with AAV. This international retrospective cohort study investigated the influence of the COVID-19 pandemic on AAV induction therapy and patient outcomes in different parts of the world by studying differences in treatment regimens in the United States, United Kingdom, and Europe

Restablishment of Immune Tolerance in ANCA-Associated Vasculitis: Defining a cohort with sustained ANCA negativity and drug free clinical remission

CPCI-S(ISTP)5

Predictors of Renal Outcomes in Sclerotic Class Anti-Neutrophil Cytoplasmic Antibody Glomerulonephritis

Background: The prognostic value of the anti-neutrophil cytoplasmic antibody (ANCA) associated glomerulonephritis (GN) classification has been demonstrated in several cohorts with sclerotic class having the worst renal outcome. Relevant published data on factors predicting outcomes in sclerotic ANCA GN is limited. Methods: Sclerotic ANCA GN patients were recruited from 5 centers worldwide for this retrospective cohort study. We describe the clinical characteristics of this cohort and evaluate predictors of 1-year glomerular filtration rate (GFR) and end-stage renal disease (ESRD). Kidney function at 12 months as measured by Modification of Diet in Renal Disease estimated GFR (eGFR) was modeled by simple and multiple linear regression analyses. We used Cox proportional hazards regression modeling to evaluate ESRD-free survival. Results: Of the 50 patients, 92% were Caucasian and 60% male with a mean age of 61 years. While 72% had renal limited disease, 82% were MPO ANCA positive. Kidney biopsies contained a median of 20 (interquartile range [IQR] 15–34) glomeruli with 96% showing moderate to severe interstitial fibrosis. Overall, 96% of patients received immunosuppressive drug therapy and 16% received plasmapheresis. Treatment response was achieved in all but 1 patient. The median (IQR) eGFR at entry was 14.5 (9–19) mL/min/1.73 m2. Over a median (IQR) follow-up of 33.5 (17–82) months, 26 patients reached ESRD. Ten patients died with 6 of the deaths occurring within the first year of diagnosis. The hazard of progression to ESRD was significantly higher in those with lower GFR at study entry (p = 0.003) and with higher degree of tubular atrophy (p = 0.043). Conclusions: Renal recovery is rare among sclerotic ANCA GN patients requiring dialysis at entry and 12% of patients died in the first year. Entry GFR and tubular atrophy were significant predictors of GFR at 12 months and renal survival in patients with sclerotic class ANCA GN

Characteristics and Outcomes of Patients With Systemic Sclerosis (Scleroderma) Requiring Renal Replacement Therapy in Europe : Results From the ERA-EDTA Registry

Rationale & Objective: Data for outcomes of patients with end-stage renal disease (ESRD) secondary to systemic sclerosis (scleroderma) requiring renal replacement therapy (RRT) are limited. We examined the incidence and prevalence of ESRD due to scleroderma in Europe and the outcomes among these patients following initiation of RRT. Study Design: Registry study of incidence and prevalence and a matched cohort study of clinical outcomes. Setting & Participants: Patients represented in any of 19 renal registries that provided data to the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry between 2002 and 2013. Predictor: Scleroderma as the identified cause of ESRD. Outcomes: Incidence and prevalence of ESRD from scleroderma. Recovery from RRT dependence, patient survival after ESRD, and graft survival after kidney transplantation. Analytical Approach: Incidence and prevalence were calculated using population data from the European Union and standardized to population characteristics in 2005. Patient and graft survival were compared with 2 age- and sex-matched control groups without scleroderma: (1) diabetes mellitus as the cause of ESRD and (2) conditions other than diabetes mellitus as the cause of ESRD. Survival analyses were performed using Kaplan-Meier analysis and Cox regression. Results: 342 patients with scleroderma (0.14% of all incident RRT patients) were included. Between 2002 and 2013, the range of adjusted annual incidence and prevalence rates of RRT for ESRD due to scleroderma were 0.11 to 0.26 and 0.73 to 0.95 per million population, respectively. Recovery of independent kidney function was greatest in the scleroderma group (7.6% vs 0.7% in diabetes mellitus and 2.0% in other primary kidney diseases control group patients, both P Limitations: No data for extrarenal manifestations, treatment, or recurrence. Conclusions: Survival of patients with scleroderma who receive dialysis for more than 90 days was worse than for those with other causes of ESRD. Patient survival after transplantation was similar to that observed among patients with ESRD due to other conditions. Patients with scleroderma had a higher rate of recovery from RRT dependence than controls.Peer reviewe

Genome-wide association study of eosinophilic granulomatosis with polyangiitis reveals genomic loci stratified by ANCA status

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare inflammatory disease of unknown cause. 30% of patients have anti-neutrophil cytoplasmic antibodies (ANCA) specific for myeloperoxidase (MPO). Here, we describe a genome-wide association study in 676 EGPA cases and 6,809 controls, that identifies 4 EGPA-associated loci through conventional case-control analysis, and 4 additional associations through a conditional false discovery rate approach. Many variants are also associated with asthma and six are associated with eosinophil count in the general population. Through Mendelian randomisation, we show that a primary tendency to eosinophilia contributes to EGPA susceptibility. Stratification by ANCA reveals that EGPA comprises two genetically and clinically distinct syndromes. MPO+ ANCA EGPA is an eosinophilic autoimmune disease sharing certain clinical features and an HLA-DQ association with MPO+ ANCA-associated vasculitis, while ANCA-negative EGPA may instead have a mucosal/barrier dysfunction origin. Four candidate genes are targets of therapies in development, supporting their exploration in EGPA

Association of a TNFSF13B (BAFF) regulatory region single nucleotide polymorphism with response to rituximab in antineutrophil cytoplasmic antibody–associated vasculitis

Rituximab is effective at inducing and maintaining remission in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The wide interpatient variability in the duration of B-cell depletion and time to relapse as well as the significant relapse risk after treatment, costs, and adverse event rates necessitate improved patient stratification.This study was supported by the National Institute of Health Research Cambridge Biomedical Research Centre (http://www.cambridge-brc.org.uk). F.A. has been supported by a European Renal Association-European Dialysis and Transplant Association long-term fellowship between September 2012 and September 2013. A.V. and D.M. were supported by the grant “A tailored approach to the immune monitoring and clinical management of viral and autoimmune diseases,” given by the Regione Emilia-Romagna within the Programma di Ricerca Regione-Università 2010–12

Association between age at disease onset of anti-neutrophil cytoplasmic antibody-associated vasculitis and clinical presentation and short-term outcomes

Objectives: ANCA-associated vasculitis (AAV) can affect all age groups. We aimed to show that differences in disease presentation and 6 month outcome between younger- A nd older-onset patients are still incompletely understood. Methods: We included patients enrolled in the Diagnostic and Classification Criteria for Primary Systemic Vasculitis (DCVAS) study between October 2010 and January 2017 with a diagnosis of AAV. We divided the population according to age at diagnosis: <65 years or ≥65 years. We adjusted associations for the type of AAV and the type of ANCA (anti-MPO, anti-PR3 or negative). Results: A total of 1338 patients with AAV were included: 66% had disease onset at <65 years of age [female 50%; mean age 48.4 years (s.d. 12.6)] and 34% had disease onset at ≥65 years [female 54%; mean age 73.6 years (s.d. 6)]. ANCA (MPO) positivity was more frequent in the older group (48% vs 27%; P = 0.001). Younger patients had higher rates of musculoskeletal, cutaneous and ENT manifestations compared with older patients. Systemic, neurologic,cardiovascular involvement and worsening renal function were more frequent in the older-onset group. Damage accrual, measured with the Vasculitis Damage Index (VDI), was significantly higher in older patients, 12% of whom had a 6 month VDI ≥5, compared with 7% of younger patients (P = 0.01). Older age was an independent risk factor for early death within 6 months from diagnosis [hazard ratio 2.06 (95% CI 1.07, 3.97); P = 0.03]. Conclusion: Within 6 months of diagnosis of AAV, patients >65 years of age display a different pattern of organ involvement and an increased risk of significant damage and mortality compared with younger patients

ANCA-associated vasculitis.

The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) are a group of disorders involving severe, systemic, small-vessel vasculitis and are characterized by the development of autoantibodies to the neutrophil proteins leukocyte proteinase 3 (PR3-ANCA) or myeloperoxidase (MPO-ANCA). The three AAV subgroups, namely granulomatosis with polyangiitis (GPA), microscopic polyangiitis and eosinophilic GPA (EGPA), are defined according to clinical features. However, genetic and other clinical findings suggest that these clinical syndromes may be better classified as PR3-positive AAV (PR3-AAV), MPO-positive AAV (MPO-AAV) and, for EGPA, by the presence or absence of ANCA (ANCA+ or ANCA-, respectively). Although any tissue can be involved in AAV, the upper and lower respiratory tract and kidneys are most commonly and severely affected. AAVs have a complex and unique pathogenesis, with evidence for a loss of tolerance to neutrophil proteins, which leads to ANCA-mediated neutrophil activation, recruitment and injury, with effector T cells also involved. Without therapy, prognosis is poor but treatments, typically immunosuppressants, have improved survival, albeit with considerable morbidity from glucocorticoids and other immunosuppressive medications. Current challenges include improving the measures of disease activity and risk of relapse, uncertainty about optimal therapy duration and a need for targeted therapies with fewer adverse effects. Meeting these challenges requires a more detailed knowledge of the fundamental biology of AAV as well as cooperative international research and clinical trials with meaningful input from patients