MPO and anti-neutrophil cytoplasmic antibody-associated vasculitis: These days, data from MAINRITSAN3 point in the direction of treatment for a total 4 years for PR3-ANCA-associated vasculitis and initially severe and relapsing MPO-ANCA-associated vasculitis, and 2 years for newly diagnosed severe MPO-ANCA-associated vasculitis (Fig. 2).