title: Rituximab induces remission of cerebral ischemia caused by thrombotic thrombocytopenic purpura.
abstract: OBJECTIVE
  This report describes the experience of a case of atypical thrombotic thrombocytopenic purpura (TTP) whose diagnosis was based on severe deficiency of the von Willebrand factor (vWF) cleaving metalloprotease ADAMTS13.
  
  
  METHODS
  The level of ADAMTS13 activity, the titer of the inhibitors of this protease and the size distribution of vWF multimers in plasma samples were analysed in a patient with recurrent episodes of dizziness and blurred vision.
  
  
  RESULTS
  In the absence of thrombocytopenia or microangiopathic hemolysis, diagnosis of TTP was established by demonstration of very low ADAMTS13 activity levels and the presence of inhibitors of this protease. After rituximab therapy decreased the inhibitor titer and increased the ADAMTS13 level, the patient has had no relapse of ischemic symptoms in the following 16 months.
  
  
  CONCLUSIONS
  Acute neurological deficits may occur in TTP without concurrent thrombocytopenia or microangiopathic hemolysis. The role of rituximab for patients with TTP deserves further exploration.
authors.affiliation: Division of Hematology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY 10467, USA. htsai@montefiore.org
authors.forename: Han-Mou
authors.initials: HM
authors.lastname: Tsai
authors.forename: Keith
authors.initials: K
authors.lastname: Shulman
mesh_terms: D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; D000328:Adult; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000494:pharmacology; D058846:Antibodies, Monoclonal, Murine-Derived; D001323:Autoantibodies / Q000097:blood / Q000187:drug effects; D002545:Brain Ischemia / Q000188:drug therapy* / Q000209:etiology; D005260:Female; D006801:Humans; D008666:Metalloendopeptidases / Q000172:deficiency / Q000187:drug effects / Q000276:immunology; D009422:Nervous System Diseases / Q000209:etiology; D011697:Purpura, Thrombotic Thrombocytopenic / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D012074:Remission Induction; D000069283:Rituximab
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D001323:Autoantibodies; D000069283:Rituximab; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human