Epidemiology of granulomatosis with polyangiitis and microscopic polyangiitis in adults in France

Plasmapheresis in ANCA-Associated Vasculitis with Active Kidney Involvement in the United States (2016-2020): A Cross-Sectional Study

Key Points

Background

Plasmapheresis is currently recommended when ANCA-associated vasculitis (AAV) presents with severe kidney and/or lung involvement. This cross-sectional study aimed at describing characteristics of hospitalized patients diagnosed with AAV with severe kidney involvement undergoing plasmapheresis in the United States.

Methods

We defined the study population as adults hospitalized for active kidney involvement with a new diagnosis of AAV (by subtype or unspecified). We established the cohort from the 2016–2020 National Inpatient Sample by International Classification of Diseases, Tenth Revision, Clinical Modification codes. In this cross-sectional study, we described demographic and clinical characteristics, associated inpatient procedures, lengths of stay, hospital costs, and disposition at discharge comparing patients treated and not treated with plasmapheresis.

Results

We identified a total of 975 patients with hospitalized AAV with acute kidney involvement in the United States treated by plasmapheresis over the 5-year period. Demographic characteristics of patients who received plasmapheresis were similar to those in patients who did not (n=5670). There were no regional differences in the proportion of patients who received plasmapheresis; however, plasmapheresis was deployed more frequently among patients admitted to urban teaching hospitals relative to rural and non-teaching hospitals. Patients treated with plasmapheresis were more likely to have had AKI (96% versus 90%, P = 0.0007), AKI requiring dialysis (52% versus 16%, P < 0.001), hypoxia (40% versus 16%, P < 0.0001), and respiratory failure requiring mechanical ventilation (13% versus 3%, P = 0.0003).

Conclusions

During 2016–2020, plasmapheresis was deployed in approximately 20% of patients being admitted for AAV and acute kidney involvement in the United States. As standards of care and practice evolve, the role of plasmapheresis in the management of AAV with acute kidney involvement will require further study.

Large-vessel involvement in ANCA-associated vasculitis: A multicenter case-control study

OBJECTIVE

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) primarily affects small vessels. Large-vessel involvement (LVI) is rare. We aimed to describe the characteristics of LVI, to identify associated risk factors, and to describe its therapeutic management.

METHODS

This multicenter case-control (1:2) study included patients with AAV according to the ACR/EULAR classification and LVI as defined by the Chapel Hill nomenclature, together with controls matched for age, sex, and AAV type.

RESULTS

We included 26 patients, 15 (58 %) of whom were men, with a mean age of 56.0 ± 17.1 years. The patients had granulomatosis with polyangiitis (n = 20), or microscopic polyangiitis (n = 6). The affected vessels included the aorta (n = 18; 69 %) supra-aortic trunks (n = 9; 35 %), lower-limb arteries (n = 5; 19 %), mesenteric arteries (n = 5; 19 %), renal arteries (n = 4; 15 %), and upper-limb arteries (n = 2; 8 %). Imaging showed wall thickening (n = 10; 38 %), perivascular inflammation (n = 8; 31 %), aneurysms (n = 5; 19 %), and stenosis (n = 4; 15 %). Comparisons with the control group revealed that LVI was significantly associated with neurological manifestations (OR=3.23 [95 % CI: 1.11-10.01, p = 0.03]), but not with cardiovascular risk factors (OR=0.70 [95 % CI: 0.23-2.21, p = 0.60]), or AAV relapse (OR=2.01 [95 % CI: 0.70-5.88, p = 0.16]). All patients received corticosteroids, in combination with an immunosuppressant in 24 (92 %), mostly cyclophosphamide (n = 10, 38 %) or rituximab (n = 9, 35 %).

CONCLUSION

Regardless of distinctions based on vessel size, clinicians should consider LVI as a potential manifestation of AAV, with the aorta commonly affected. The risk of developing LVI appears to be greater for clinical phenotypes of AAV with neurological involvement. Standard AAV treatment can be used to manage LVI.

Evolution of therapeutic management of patients with ANCA associated vasculitis in France after licensing Rituximab use

INTRODUCTION

In 2013, rituximab was approved in France for the treatment of ANCA-associated vasculitis (AAV). The aim of the study was to compare the treatment and health events of adult incident patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), included before rituximab approval (over 2010-2012, Group 1) and those included after rituximab approval (over 2014-2017, Group 2).

METHOD

Data were extracted from the French National Health Insurance database (SNDS) including outpatient health care consumption and hospital discharge forms. Comparisons between inclusion periods were performed using Wilcoxon and χ² tests. Kaplan-Meier method was used to model the duration of treatment induction, maintenance, and off-drug periods. Fine and Gray tests were used to compare treatment phase durations.

RESULTS

A total of 694 GPA and 283 MPA patients were included in Group 1, while 668 GPA and 463 MPA patients were included in Group 2. Between the two inclusion periods, the proportions of patients treated with rituximab increased in the induction and maintenance phases whereas treatment with azathioprine declined. These proportions remained stable in the case of methotrexate, cyclophosphamide, and glucocorticoid-treated patients. Frequency of first-time hospitalized infections, diabetes and renal failure during the first year after inclusion increased for both groups.

LIMITATIONS OF THE STUDY

This is a retrospective study based on claims data including only 76% of people covered by health insurance in France. The period studied includes the learning phase of using rituximab. This study lacks biological data and precise quantitative analysis for the use of steroids, therefore the criteria for establishing diagnosis and therapeutic choice were unknown.

CONCLUSIONS

Introduction of rituximab reduced the use of azathioprine without affecting the use of glucocorticoids or cyclophosphamide.

Using an artificial intelligence tool incorporating natural language processing to identify patients with a diagnosis of ANCA-associated vasculitis in electronic health records

BACKGROUND

Because anti-neutrophil cytoplasmatic antibody (ANCA)-associated vasculitis (AAV) is a rare, life-threatening, auto-immune disease, conducting research is difficult but essential. A long-lasting challenge is to identify rare AAV patients within the electronic-health-record (EHR)-system to facilitate real-world research. Artificial intelligence (AI)-search tools using natural language processing (NLP) for text-mining are increasingly postulated as a solution.

METHODS

We employed an AI-tool that combined text-mining with NLP-based exclusion, to accurately identify rare AAV patients within large EHR-systems (>2.000.000 records). We developed an identification method in an academic center with an established AAV-training set (n = 203) and validated the method in a non-academic center with an AAV-validation set (n = 84). To assess accuracy anonymized patient records were manually reviewed.

RESULTS

Based on an iterative process, a text-mining search was developed on disease description, laboratory measurements, medication and specialisms. In the training center, 608 patients were identified with a sensitivity of 97.0 % (95%CI [93.7, 98.9]) and positive predictive value (PPV) of 56.9 % (95%CI [52.9, 60.1]). NLP-based exclusion resulted in 444 patients increasing PPV to 77.9 % (95%CI [73.7, 81.7]) while sensitivity remained 96.3 % (95%CI [93.8, 98.0]). In the validation center, text-mining identified 333 patients (sensitivity 97.6 % (95%CI [91.6, 99.7]), PPV 58.2 % (95%CI [52.8, 63.6])) and NLP-based exclusion resulted in 223 patients, increasing PPV to 86.1 % (95%CI [80.9, 90.4]) with 98.0 % (95%CI [94.9, 99.4]) sensitivity. Our identification method outperformed ICD-10-coding predominantly in identifying MPO+ and organ-limited AAV patients.

CONCLUSIONS

Our study highlights the advantages of implementing AI, notably NLP, to accurately identify rare AAV patients within large EHR-systems and demonstrates the applicability and transportability. Therefore, this method can reduce efforts to identify AAV patients and accelerate real-world research, while avoiding bias by ICD-10-coding.

Epidemiology of systemic vasculitis

PURPOSE OF REVIEW

Epidemiology of vasculitides exhibit geographic variation and data from some parts of the world are still scarce. Increased recognition of these rare diseases and improvement in diagnosis and patient care may lead to changes in their epidemiology. In this review, we aimed to highlight the most recent work on the epidemiology of systemic vasculitis.

RECENT FINDINGS

New data from countries where information on the epidemiology of giant cell arteritis, Takayasu arteritis and Behçet syndrome were limited have revealed that these conditions are not as rare as previously believed. The incidence rates during the coronavirus disease 2019 pandemic highlight the link between Kawasaki disease and respiratory pathogens. The use of different classification criteria hampers the comparison of true incidence and prevalence rates in antineutophil cytoplasmic antibody (ANCA)-associated vasculitis and its subtypes between geographies and over time.

SUMMARY

Recent studies have highlighted the epidemiology of vasculitides in different parts of the world and changing trends. Standardization of study design and disease definitions is needed to improve the reliability and comparability of the results.

The Role of Neutrophils in ANCA-Associated Vasculitis: The Pathogenic Role and Diagnostic Utility of Autoantibodies

Recent years have brought progress in understanding the role of the neutrophil, dispelling the dogma of homogeneous cells mainly involved in the prime defence against pathogens, shedding light on their pathogenic role in inflammatory diseases and on the importance of antineutrophil-cytoplasmic antibodies' pathogenic role in ANCA-associated vasculitides vasculitis (AAV). Myeloperoxidase (MPO) and proteinase 3 (PR3) expressed in neutrophil granulocytes are the most common targets for ANCAs and contribute to the formation of MPO-ANCAs and PR3-ANCAs which, released to the bloodstream, become an excellent diagnostic tool for AAV. In this study, we focus on increasing the clinical and experimental evidence that supports the pathogenic role of ANCAs in AAV. Additionally, we discuss the diagnostic utility of ANCAs for disease activity and prognosis in AAV. Understanding the central role of ANCAs in AAV is crucial for advancing our knowledge of these complex disorders and developing targeted therapeutic strategies in the era of personalized medicine.

Profile, Healthcare Resource Consumption and Related Costs in ANCA-Associated Vasculitis Patients: A Real-World Analysis in Italy

INTRODUCTION

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are rare autoimmune diseases triggering inflammation of small vessels. This real-world analysis was focused on the most common AAV forms, granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), to describe patients' demographic and clinical characteristics, therapeutic management, disease progression, and the related economic burden.

METHODS

A retrospective analysis was conducted on administrative databases of a representative sample of Italian healthcare entities, covering approximately 12 million residents. Between January 2010 and December 2020, adult GPA patients were identified by payment waiver code or hospitalization discharge diagnosis, and MPA patients by payment waiver code with or without hospitalization discharge diagnosis. Clinical outcomes were evaluated through AAV-related hospitalizations, renal failure onset, and mortality. Economic analysis included healthcare resource utilization deriving from drugs, hospitalizations, and outpatient specialist services. The related mean direct costs year/patient were also calculated in patients stratified by presence/absence of glucocorticoid therapy and type of inclusion criterion (hospitalization/payment waiver code).

RESULTS

Overall, 859 AAV patients were divided into GPA (n = 713; 83%) and MPA (n = 146; 17%) cohorts. Outcome indicators highlighted a clinically worse phenotype associated with GPA compared to MPA. Cost analysis during follow-up showed tendentially increased expenditures in glucocorticoid-treated patients versus untreated (overall AAV: €8728 vs. €7911; GPA: €9292 vs. €9143; MPA: €5967 vs. €2390), mainly driven by drugs (AAV: €2404 vs. €874; GPA: €2510 vs. €878; MPA: €1881 vs. €854) and hospitalizations.

CONCLUSION

Among AAV forms, GPA resulted in a worse clinical picture, higher mortality, and increased costs. This is the first real-world pharmaco-economic analysis on AAV patients stratified by glucocorticoid use on disease management expenditures. In both GPA and MPA patients, glucocorticoid treatment resulted in higher healthcare costs, mostly attributable to medications, and then hospitalizations, confirming the clinical complexity and economic burden for management of patients with autoimmune diseases under chronic immunosuppression.

Classification and epidemiology of vasculitis: Emerging concepts

The recent publication of the American College of Rheumatology (ACR)-European Alliance of Associations for Rheumatology (EULAR) classification criteria for large vessel vasculitis and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) has provided modern criteria for the classification of these conditions, which incorporate contemporary methods of investigation and diagnosis. Further validation is required in independent cohorts, especially from populations that were not well represented in the development cohort. Studies of the occurrence of large vessel vasculitis report that Takayasu arteritis is a rare disease in most populations, and giant cell arteritis is the most common vasculitis in older populations. The incidence of AAV appears to have plateaued, but the prevalence is increasing as a result of lower mortality. The new classification criteria may affect the reported incidence and prevalence, and studies will be needed to confirm this. The impact of COVID-19 on the occurrence of the vasculitides is not completely known, but there is evidence of reduced occurrence of Kawasaki disease and IgA-associated vasculitis following lockdowns with reduced transmission of possible trigger infectious agents.