P0388ABC-R ANCA STUDY ESTABLISHMENT OF AN ANATOMOPATHOLOGICAL BIOLOGICAL AND CLINICAL PROGNOSTIC SCORE IN THE MANAGEMENT OF ANCA VASCULITIS WITH RENAL IMPAIRMENT

Background and Aims Glomerulonephritis is common in ANCA associated vasculitis (GN-AAV). There is extensive published data on the renal prognosis of these conditions. However, few authors have described predictive factors for end-stage renal disease (ESRD) in patients with GN-AAV. Many authors suggest that renal biopsy should be abandoned in patients whose diagnosis would be established by antibody positivity alone. The aim of the study was to establish a prognostic score for renal damage during ANCA vasculitis and demonstrate need for prognostic renal biopsy. Method One Hundred and eighteen patients referred to 2 french nephrology departments in Lyon between January 2003 and January 2019 were retrospectively analysed. Patients were randomly divided in 2 cohorts at a ratio of 70/30: training and validation cohorts. ESRD was defined as glomerular filtration rate (eGFR) ≤ 15mL/min/1.73m2,need of chronic dialysis or renal transplantation. Results Of the 118 patients, 38 (32.20%) developed ESRD. We identified 3 criteria associated with development of ESRD in patients with GN-AAV. One point was assigned to each criterion according to a threshold value: eGFR at the time of renal biopsy ≤ 15 mL/min; percentage of sclerotic glomeruli ≥ 11% and percentage of normal glomeruli < 20%. A new prognostic renal score was established in patients with GN-AAV. It classifies patients into 3 categories at risk of developing ESRD: low (≤ 1 point), moderate (2 points) and high (3 points). Conclusion Two of the three criteria of our score are histological. Biopsy remains, when possible, an essential tool for diagnosis and especially to predict renal prognosis of ANCA vasculitis with renal impairment.