Successful remission of thrombotic thrombocytopenic purpura with rituximab in a patient with undifferentiated connective tissue disorder.

Thrombotic thrombocytopenic purpura (TTP) is rarely associated with undifferentiated connective tissue disorder. We present a patient with TTP, undifferentiated connective tissue disorder, and very high titer of anti-ribonucleoprotein antibodies. Her TTP did not respond to intravenous methylprednisolone and cyclophosphamide requiring her to remain dependent on plasmapheresis. Her disease remitted successfully after 4 doses of rituximab given at weekly intervals and she remained in continuous remission 6 months after therapy. We propose early and aggressive use of B-cell depletion therapy in TTP associated with autoimmune disorders.