Outcome of Disseminated Intravascular Coagulation without Documented Antiphospholipid Antibody Successfully Treated with Rituximab

ABSTRACT

Catastrophic antiphospholipid syndrome (APS) is defined as a rare, life-threatening autoimmune disorder leading to multiorgan failure. Probable APS, with clinical manifestations similar to APS without antiphospholipid antibodies, was suggested to be seronegative catastrophic APS. The triggering factors of catastrophic APS are various, including infection, trauma, malignancy, and surgery. In approximately 40% of patients, catastrophic APS develops from an unknown cause. We report a case of seronegative catastrophic APS due to an unknown origin. A 20-year-old man presented with cough, abdominal pain, skin lesions, tunnel vision, and watery diarrhea without fever. His symptoms and laboratory test suggested disseminated intravascular coagulation. Considering seronegative catastrophic APS, we treated with intravenous steroid and intravenous immunoglobulin, but the effects were limited. After weekly treatment with rituximab, an immune-modulating agent, his laboratory findings including thrombocytopenia and coagulation tests, returned to normal. We conclude that rituximab can be an effective treatment for seronegative catastrophic APS.