ANCA-associated vasculitis: overview and practical issues of diagnosis and therapy from a European perspective.

Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) is a heterogeneous group of rare diseases characterized by necrotizing inflammation predominantly of small vessels and the presence of these circulating antibodies. AAV comprises three important diseases, namely granulomatosis with polyangiitis, microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis, which affect multiple organ systems, significantly affecting patients' quality of life and survival. The diagnosis is established according to the clinical manifestations, detectable ANCA, and histopathology findings. Primary treatment strategies are adapted to the severity of the disease and based on immunosuppression with corticosteroids and cyclophosphamide, with increasing adoption of new, less toxic agents aimed at sustained remission of the disease, such as rituximab, methotrexate, and mycophenolate mofetil. Several international medical organizations have proposed recommendations for diagnosing and managing these diseases to standardize the procedures. In this study, we provide an up-to-date European perspective on AAV management, compiling current and relevant information regarding its epidemiology, symptoms, diagnosis, treatment strategies, and prognosis.