#2532 Patient characteristics and treatment patterns in ANCA-associated vasculitis: an observational study based on the DEMONSTRATE database, Uppsala, Sweden

Abstract Background and Aims ANCA-associated vasculitis (AAV) are rare but severe autoimmune conditions characterized by inflammation and damage to small- and medium-sized blood vessels. Any organ can be affected by inflammation, including the kidneys, lungs, and upper respiratory tract. Using an extensive observational data source (DEMONSTRATE), this study aimed to explore the management of AAV in clinical practice by evaluating patient characteristics and treatment trends. Method This observational study, utilizing the DEMONSTRATE database, identified all patients aged 18 years or older in Region Uppsala, Sweden, with at least two recorded diagnoses of AAV between January 1, 2007, and December 31, 2022. Diagnoses were based on ICD codes M31.3 (granulomatosis with polyangiitis, GPA) and M31.7 (microscopic polyangiitis, MPA). The study population was restricted to patients diagnosed within the specialties of Nephrology, Rheumatology, Ear-Nose-Throat, Pulmonary Medicine, and Internal Medicine. Descriptive statistics were applied to analyze patient characteristics and treatment patterns for AAV, focusing on two distinct time periods, 2016–2018 and 2019–2022, to evaluate potential changes in treatment approaches over time. Results A total of 150 patients were identified: 83 (55%) with GPA and 67 (45%) with MPA. Patients diagnosed with GPA were generally younger, with a median age of 63.9 years (IQR 55.6–73.1), compared to a median age of 71.9 years (IQR 64.4–77.7) for patients with MPA (Table 1). GPA was predominantly diagnosed in Rheumatology department, while MPA was primarily diagnosed in Nephrology department (Table 1). Patients with MPA had a higher comorbidity burden compared to those with GPA, with higher rates of heart failure (20.9% vs. 3.6%), hypertension (67.2% vs. 37.3%), and diabetes (26.9% vs. 15.7%). At the time of diagnosis, MPA patients also had substantially lower median eGFR levels (25.8, IQR 19.1–44.9) compared to GPA patients (67.9, IQR 43.6–84.4), reflecting more severe kidney involvement at diagnosis. Around the time of diagnosis, there was an increase in the use of intravenous corticosteroids from 2016–2018 (45.2% of patients) to 2019–2022 (73.5% of patients). Similarly, rituximab use increased from 16.1% (2016–2018) to 49.0% (2019–2022), while cyclophosphamide use showed a slight decrease from 38.7% (2016–2018) to 34.7% (2019–2022) (Fig. 1). Conclusion These findings suggest a shift in treatment for AAV patients in region Uppsala, with more use of intravenous corticosteroids and rituximab in recent years. The study also highlights differences in patient characteristics and comorbidity profiles between patients with GPA and MPA, which may influence treatment decisions and outcomes.