Rituximab Twice Weekly for Refractory Thrombotic Thrombocytopenic Purpura in a Critically Ill Patient with Acute Respiratory Distress Syndrome.

Thrombotic thrombocytopenic purpura (TTP) is a rare, serious, life-threatening disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and hypercoagulability. The etiology is a deficiency of ADAMTS13 which is usually caused by acquired antibodies. Plasma exchange and steroids is the standard of care in the treatment of TTP.