MPO and myositis disease: Coexistent autoantibodies were also examined in 37 patients (54.3%), including anti-nuclear/myositis/ganglioside antibody profiles, anti-myeloperoxidase (MPO)/protease 3 (PR3)/acetylcholine receptors (AchR)/aquaporin 4 (AQP4) antibodies, and 19 patients (51.4%) were shown to exhibit the coexistence of other autoantibodies.