#464 Survey results on the utility of the Renal Risk Score and Histopathological Classification of ANCA-glomerulonephritis

Abstract

Abstract Background and Aims The importance of kidney biopsy in ANCA-associated glomerulonephritis (AAV) is widely recognized: both the Berden classification and the ANCA renal risk score (ARRS) are widely used and reliable predictors of prognosis. AAV phenotypes, outcomes and treatment have changed over the last decades: whether and how the existing classification and ARRS need to be updated is a matter of discussion. A survey to assess the current use of the classification and ARRS in clinical practice was conducted on behalf of the newly formed “Working Group on classifications and risk scores”. Method An online survey was sent to the active members of the European Vasculitis Society (EUVAS) between September 13th and September 27th, 2023. The survey used an internet platform, contained 12 multiple-choice and 2 open questions and results were analyzed anonymously. Results 76 of 295 EUVAS members replied to the questionnaire: 40 (52.6%) were nephrologists, 25 (32.9%) rheumatologists, 4 (5.3%) pathologists and 7 (9.3%) “others”. Their level of expertise was high, with 61 (80.3%) physicians encountering more than 10 new-diagnosed AAV patients per year. A total of 64 (84.2%) responders usually performed a kidney biopsy in suspected AAV patients, considering the pathological examination a useful tool for prognosis (89.5%), diagnosis (85.5%) and treatment (81.6%). More than 90% of responders indicated they discuss kidney biopsy results in a multidisciplinary meeting involving both clinicians and pathologists. Both the Berden classification and the ARRS are known by around 70% of experts in the field; the first being commonly used by clinicians in everyday practice (70.1% vs 52.5%, p = 0.08). Both systems were considered useful on a scale from 0 to 10, with a median grade of 7 [(IQR 5-8) vs (IQR 6-8), p = 0.21]. Suggested improvements were further standardizations and simplicity. New parameters (e.g., extraglomerular involvement, laboratory and clinical features) and biomarkers should be considered for future inclusion. Conclusion A survey assessing the current use of the Berden classification and ARRS in clinical practice showed that both systems are widely used among vasculitis clinicians and that the ideal system should be able to guide treatment decisions. The validation of pathological systems for targeted treatment decisions is an unmet need.