Neutrophil extracellular traps (NETs) are characterized by the presence of 
extracellular DNA fibers studded with antimicrobial proteins, including 
myeloperoxidase (MPO). Although NETs play an important role in the innate immune 
system, the scattered extracellular enzymes, such as MPO, pose risks to the 
host. Therefore, NETs are strictly regulated by DNase I in the serum, which 
prevents them from persisting. Recent studies have demonstrated that 
dysregulation of NETs could be involved in the pathogenesis of autoimmune 
diseases, including systemic lupus erythematosus. In this review, we interpret 
the association of disordered NETs with autoimmune diseases, especially 
propylthiouracil-induced MPO-ANCA-associated vasculitis.