A case of catastrophic antiphospholipid antibody syndrome complicated with systemic lupus erythematosus, double positive for anti-cardiolipin/β₂ glycoprotein I and anti-phosphatidylserine/prothrombin autoantibodies.

A 16-year-old male with severe thrombocytopenia and progressive multiple organ infarctions was diagnosed as having catastrophic antiphospholipid syndrome (CAPS) complicated with systemic lupus erythematosus, and was successfully treated with combination of anticoagulants, corticosteroids, plasma exchange, and intravenous cyclophosphamide. Antibodies to phosphatidylserine/prothrombin (PS/PT) complex and cardiolipin (CL)/β(2)-glycoprotein I (β(2)GPI) were simultaneously detected, indicating that the different pathways of both PS/PT and CL/β(2)GPI might be associated with the radical manifestation of CAPS.