Rituximab induces remission of cerebral ischemia caused by thrombotic thrombocytopenic purpura.
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.
Tsai
Han-Mou
HM
Division of Hematology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY 10467, USA. htsai@montefiore.org
Shulman
Keith
K
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
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D001323:Autoantibodies; D000069283:Rituximab; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human