[KDIGO-Update: Treatment of ANCA vasculitis]

Antineutrophil Cytoplasmic Antibody (ANCA)-associated Vasculitis (AAV) is a life-threatening systemic autoimmune disease. Break of tolerance against either proteinase 3 or myeloperoxidase is key to the disease etiology. Innate and adaptive immune cells cooperate and contribute to the inflammatory necrotizing small-vessel vasculitis. AAV can affect every organ and frequently affects the kidneys. Necrotizing crescentic glomerulonephritis is associated with worse patient outcome. Anti-inflammatory and immunosuppressive treatments are effective in inducing acute vasculitis remission but are associated with treatment-related morbidity and mortality. In 2024, Kidney Disease: Improving Global Outcomes (KDIGO) provided an update of the Clinical Practice Guideline for the Management of AAV patients with kidney manifestation. A major aspect of the update is the consequent reduction of glucocorticoid exposure to diminish glucocorticoid toxicity. The C5a receptor blocker avacopan allows significant reduction of the cumulative glucocorticoids during AAV induction treatment, while increasing sustained remission and improving the glomerular filtration rate. Therefore, avacopan is now considered in the guideline as an alternative to glucocorticoids. Other topics covered by the KDIGO experts are the use of cyclophosphamide and rituximab or combinations thereof in patients with severe kidney involvement for inducing AAV remission. Moreover, considerations for the use of plasma exchange are provided.