P179 Glucocorticoid exposure and link to serious adverse events in patients with ANCA-associated vasculitis

Abstract Background Remission induction in ANCA-associated vasculitis (AAV) is with high dose glucocorticoids (GC) and immunosuppressants. Patients are exposed to high GC dose and/or prolonged low dose. EULAR/EDTA guidelines target 7.5-10mg at 3 months but acknowledge this is often achieved later. This study used UK real world practice data to examine the scale of GC exposure and associated clinical risks in AAV. Methods The study utilised the Clinical Practice Research Datalink (CPRD) - Hospital Episode Statistics (HES) linked database. AAV patients were identified using specific READ and ICD codes and followed between 01/01/1997 and 01/01/2018. GP prescriptions were used to describe periods of continuous GC use, stop and restart and when high dose (> 30mg/day) and low dose (<30mg/day) was prescribed. Diagnostic codes indicative of infections and adverse events linked to GCs were used to estimate rates in the AAV population using a generalized linear model with a Poisson distribution. Results 450 AAV patients with at least one GC prescription were analysed. The median dose decreased to 9.3 mg (IQR 5.0 - 17.0) at 6 months and 5.1 mg (0.00 - 10.0) at 12 months,50% patients were taking > 10mg at 5 months and 25% were still > 10mg at 12 months. However, within 6 months of achieving 10mg/day, 50% relapse to needing dose >10mg, 75% within 2 years and 90% within 6 years. In adjusted Poisson model (age, gender, year of diagnosis before/after 2013) the rate of infection in AAV patients taking high dose was 2.59 times (CI95 1.95, 3.45) that of those on low dose and lower in those not taking GCs (IRR 0.27 (0.22-0.34)). Increased risk of new onset cardiovascular disease (IRR 2.55 (0.92, 7.04)) and new onset renal disease (IRR 3.4 (1.29-8.96)) were higher in patients receiving high dose. Conclusion AAV patients have significant exposure to high dose GCs and in real world practice, GC dose remains higher than recommended in current clinical guidelines. High dose GCs are associated with high risk of infection and new cardiovascular disease and renal disease. This creates a significant patient burden and has implications for healthcare resource use. Disclosures P. Spearpoint: Corporate appointments; Employee of Vifor Pharma. C. Sammon: Corporate appointments; Employee of PHMR. A. Ramirez de Arellano Serna: Corporate appointments; Employee of Vifor Pharma. P. Rutherford: Corporate appointments; Employee of Vifor Pharma. Shareholder/stock ownership; Vifor Pharma.