The P-ANCA-positive APS patients had major vascular events, including pulmonary emboli, and thrombocytopenia, while the anti-MPO/elastase patient had lupus-like phenotype with mouth ulcers, alopecia, Raynaud’s phenomenon, pulmonary emboli, leukopenia and thrombocytopenia. Here, MPO is linked to systemic lupus erythematosus.