A Case of Systemic Lupus Erythematosus With Sole Anti-phosphatidylserine/Prothrombin Complex Antibodies Complicated by Vertebral Artery Dissection

Cerebrovascular diseases commonly complicate systemic lupus erythematosus (SLE); however, vertebral artery dissection is rare. Although cerebrovascular diseases in SLE are often associated with antiphospholipid antibodies (aPL), such as lupus anticoagulant (LAC), anticardiolipin antibodies (aCL), and anti-β2 glycoprotein-I antibodies, reports of cases with sole positive anti-phosphatidylserine/prothrombin complex antibodies (aPS/PT) are also rare. Herein, we report the case of a 44-year-old woman with SLE who had sole positive aPS/PT results and presented with vertebral artery dissection. The patient, who had previously undergone bypass surgery of the right superficial temporal and middle cerebral arteries for moyamoya vessels, was found to have an asymptomatic left vertebral artery dissection during a follow-up examination. The patient also had a malar rash. Laboratory examination revealed hypocomplementemia and positive results for antinuclear and anti-Smith antibodies. LAC, aCL, and anti-β2 glycoprotein-I antibodies were negative; however, aPS/PT of immunoglobulin G was positive. The patient was diagnosed with SLE with sole positive aPS/PT result complicated by left vertebral artery dissection and moyamoya vessels. We initiated treatment with methylprednisolone pulse therapy, followed by oral prednisolone and intravenous cyclophosphamide. The patient's condition improved without sequelae. This case suggests that even though patients with SLE presenting with vascular complications lack LAC, aCL, and anti-β2 glycoprotein-I antibodies, other aPLs should be investigated.