title: Rituximab for thrombotic thrombocytopenic purpura: benefit of early administration during acute episodes and use of prophylaxis to prevent relapse.
abstract: BACKGROUND
  Rituximab has been documented in the treatment of acute (≤ 3 days from admission), relapsed/refractory thrombotic thrombocytopenic purpura (TTP) and given as prophylaxis in selected cases to prevent acute relapse. The precise timing of rituximab in acute TTP has not been determined.
  
  
  OBJECTIVE
  To perform a retrospective analysis of rituximab use in a large TTP referral center over an 8-year period.
  
  
  METHODS
  We assessed response to treatment and outcome for all patients treated with rituximab, including 91 patients presenting with 104 episodes of acute TTP and 15 patients given rituximab as prophylaxis to prevent relapse. In the acute TTP group we assessed the benefit of giving early (≤ 3 days from admission) vs. later (> 3 days) rituximab.
  
  
  RESULTS
  In acute de novo TTP, previously untreated with rituximab, rituximab was given ≤ 3 days from admission to 54 patients and > 3 days from admission to 32 patients. Earlier administration (≤ 3 days) was associated with faster attainment of remission (12 vs. 20 days, P < 0.001), fewer plasma exchanges (16 vs. 24, P = 0.03) and shorter hospital stay (16 vs. 23 days, P = 0.01). Eighty-two patients (95%) achieved complete remission within 14 days (4-52 days); four patients died acutely. Eleven out of 82 (13.4%) relapsed at a median of 24 months (4-49 months). Rituximab prophylaxis was associated with normalization of ADAMTS13 levels within 3 months in all but one case, with only one acute relapse at follow-up.
  
  
  CONCLUSIONS
  Although limited by being retrospective and non-randomized, this study demonstrates the potential benefit of early administration of rituximab in acute TTP, and prophylactic use to prevent acute relapse.
authors.affiliation: Haemostasis Research Unit, University College London, UK. j.westwood@ucl.ac.uk
authors.forename: J-P
authors.initials: JP
authors.lastname: Westwood
authors.forename: H
authors.initials: H
authors.lastname: Webster
authors.forename: S
authors.initials: S
authors.lastname: McGuckin
authors.forename: V
authors.initials: V
authors.lastname: McDonald
authors.forename: S J
authors.initials: SJ
authors.lastname: Machin
authors.forename: M
authors.initials: M
authors.lastname: Scully
mesh_terms: D051722:ADAM Proteins / Q000097:blood; D000071120:ADAMTS13 Protein; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage* / Q000009:adverse effects; D015415:Biomarkers / Q000097:blood; D002648:Child; D018572:Disease-Free Survival; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage* / Q000009:adverse effects; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011697:Purpura, Thrombotic Thrombocytopenic / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D012008:Recurrence; D012042:Registries; D012189:Retrospective Studies; D000069283:Rituximab; D062606:Tertiary Care Centers; D013997:Time Factors; D016896:Treatment Outcome; D006113:United Kingdom; D055815:Young Adult
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D015415:Biomarkers; D007155:Immunologic Factors; D000069283:Rituximab; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human