Hasegawa J, et al. – Given to the research kidney biopsy was a gold standard for diagnosis of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). This study wanted to reveal whether vasculitis could be detected from AAV patients with minor urinary abnormalities. Overall renal vasculitis (crescentic glomeruli and/or small renal artery vasculitis) was detected less frequently in minor urinary abnormalities group than major urinary abnormalities group. Study outcomes suggested the effectiveness of renal biopsy as a useful tool for histological diagnosis of ANCA–associated vasculitis in ANCA–positive patients with minor urinary abnormalities.