A systematic review of randomized controlled trials for plasma exchange in the treatment of thrombotic thrombocytopenic purpura

Transfus Med. 2007 Feb;17(1):17-35. doi: 10.1111/j.1365-3148.2006.00720.x.


The mainstay of treatment for thrombotic thrombocytopenic purpura (TTP) is plasma exchange (PE). A systematic review was undertaken to summarize the randomized controlled trial (RCT) evidence, to date, on PE as treatment for TTP. Seven randomized RCTs were identified till May 2005. A statistical reduction in mortality was found in patients receiving PE compared with patients receiving plasma infusion (relative risk 0.31, 95% confidence interval 0.12-0.79). No statistical difference in mortality was found in trials comparing different replacement fluids for PE. There were few differences in the response to treatment and the resolution of the presenting signs of TTP in any trial. Lack of data prevented a full assessment of the incidence of adverse events. None of the studies included measured patients' quality of life. Further research is required to determine the benefits and side effects associated with different replacement fluids for PE. It is recommended that there should be consistency in the diagnostic criteria, measurement of clinical outcomes and length of follow up. Continued support of existing TTP patient registries and establishment of new registries would facilitate this.

Publication types

  • Comparative Study
  • Review
  • Systematic Review

MeSH terms

  • Blood Transfusion
  • Detergents / pharmacology
  • Factor VIII
  • Fibrinogen
  • Humans
  • Methylene Blue / pharmacology
  • Plasma / drug effects
  • Plasma Exchange* / adverse effects
  • Plasma Exchange* / methods
  • Purpura, Thrombotic Thrombocytopenic / mortality
  • Purpura, Thrombotic Thrombocytopenic / therapy*
  • Randomized Controlled Trials as Topic / statistics & numerical data
  • Remission Induction
  • Research Design
  • Single-Blind Method
  • Solvents / pharmacology
  • Treatment Outcome


  • Detergents
  • Solvents
  • cryoprecipitate coagulum
  • Factor VIII
  • Fibrinogen
  • Methylene Blue