Morita S, et al. - In patients with otitis media associated with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), experts evaluated the presence of myeloperoxidase (MPO)-deoxyribonucleic acid (DNA) complex as a surrogate marker of neutrophil extracellular traps (NETs) in the middle ear fluid, and clarified the association between its quantifiable level and hearing outcome. This was the first analysis that aimed to reveal the presence of elevated levels of MPO-DNA complex in the middle ear fluid, suggesting the pathogenic role of NETs in otitis media associated with AAV. Compared with the controls, the quantifiable levels of MPO-DNA complex in patients with AAV were significantly higher. Regardless of ANCA status, NETs could be a valuable biomarker for use in clinical decision-making and predicting hearing outcome.