MPO and anti-neutrophil cytoplasmic antibody-associated vasculitis: A large international cohort study by Kronbichler et al. showed several clinical and laboratory factors were identified as "more" associated with renal involvement in ANCA-associated vasculitis, which included fatigue, weight loss, high C-reactive protein, low complement 3, myeloperoxidase, and proteinase 3-ANCA [5].