In addition, p-ANCA can be directed against antigens other than MPO and is observed in a variety of autoimmune disorders including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Sjogren’s syndrome (SS), polymyositis (PM) and dermatomyositis (DM) [8]. Here, MPO is linked to systemic lupus erythematosus.