There are various well-known predisposing risk factors for development of venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT), and several studies reported that autoimmune disorder is one of important risk factors for development of VTE [1,2]. Furthermore, autoimmune disorder is thought to be a relatively strong risk factor for VTE recurrence, and extended anticoagulation therapy are recommended for prevention of VTE recurrence in patients with autoimmune disorders[3].
