title: Platelet transfusion in thrombotic thrombocytopenic purpura.
abstract: BACKGROUND
  Platelet (PLT) transfusion has been considered contraindicated in patients with thrombotic thrombocytopenic purpura (TTP). However, adverse clinical outcomes and death in patients with TTP after receiving PLT transfusion were based on case reports prior to routine use of plasma exchange (PEX) therapy. PLT transfusions are often required by the interventional radiologist before the insertion of a central venous catheter. In this study, we evaluate whether PLT transfusions are harmful in patients with TTP undergoing PEX.
  
  
  METHODS
  We retrospectively reviewed the records of consecutive patients with the clinical diagnosis of TTP who received PEX at our institution between January 2004 and September 2014. An adverse event was defined as any complication including seizures, cerebrovascular accident, bleeding, thrombosis, myocardial infarction or death for any reason within 30 days from the PLT transfusion. Analyses were performed on only patients with ADAMTS13 activity <10%.
  
  
  RESULTS
  Our cohort included 110 patients with the clinical diagnosis of TTP. Fifty-five patients had ADAMTS13-deficient TTP, 23 of whom received PLT at some point during disease course. The patients who received PLT transfusion were not different from those who did not in terms of age, gender, race, haematocrit, PLT count, creatinine, LDH and complications. The three patients who received PLT and died had malignancy and complicated disease course. None of them died from a thrombotic event.
  
  
  CONCLUSIONS
  All deaths in the transfused group happened in very ill patients that had alternative causes of death. PLT transfusions in patients with TTP do not appear harmful in regard to thrombotic complications.
authors.affiliation: Department of Pathology and Immunology, Washington University, St Louis, MO, USA.
authors.forename: Z K
authors.initials: ZK
authors.lastname: Otrock
authors.affiliation: Department of Pathology and Immunology, Washington University, St Louis, MO, USA.
authors.forename: C
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Pathology and Immunology, Washington University, St Louis, MO, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Grossman
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017713:Platelet Transfusion / Q000009:adverse effects*; D011697:Purpura, Thrombotic Thrombocytopenic / Q000628:therapy*
keywords: adverse events; plasma exchange; platelet transfusion; thrombotic thrombocytopenic purpura