ANCA-associated vasculitis (AAV) involves small- to medium-sized blood vessels. AAV is classified into three heterogeneous syndromes: granulomatosis with polyangiitis (GPA); microscopic polyangiitis (MPA); and eosinophilic granulomatosis with polyangiitis (EGPA). The relevant target antigens of ANCA are proteinase 3 (PR3) and myeloperoxidase (MPO). Antibodies specific for PR3 and MPO are called PR3-ANCA and MPO-ANCA, respectively. MPO-ANCA is detected in 50–70% of patients with MPA and 40–50% of patients with EGPA. PR3-ANCA is detected in 80–90% of patients with GPA. Therapeutic apheresis is used in elderly patients with associated RPGN or pulmonary bleeding, who are at high risk for infections and are intolerant to standard immunosuppressive treatments. Apheresis is indicated for rapidly progressive glomerulonephritis with severe renal impairment (Cr > 5.8 mg/dL) [1].