title: Relative safety of pooled whole blood-derived versus single-donor (apheresis) platelets in the United States: a systematic review of disparate risks.
abstract: BACKGROUND
  Risks of transfusion-transmitted infections (TTIs), transfusion-associated sepsis (TAS), and transfusion-related acute lung injury (TRALI) were compared between pooled whole blood-derived (PWBD) and single-donor platelets (PLTs) transfused in the United States.
  
  
  METHODS
  The literature was searched for estimates of the risk of TTIs and TAS and of the effect on bacterial contamination of PLTs of process improvements, bacterial culture, and surrogate methods to detect bacteria. Seven studies published between January 2005 and December 2008 and comparing bacterial contamination frequency between PWBD and single-donor PLTs after implementing bacterial culture testing of both components were subjected to meta-analysis. The three retrieved studies diagnosing TRALI based on the 2004 consensus definition in settings transfusing both PWBD and single-donor PLTs were not amenable to meta-analysis and were assessed qualitatively.
  
  
  RESULTS
  Under a best-case scenario, if 100% (from the current 12.5%) of PLT doses were provided as PWBD PLTs, the number of additional transmissions of human immunodeficiency virus, hepatitis C virus, hepatitis B virus, bacteria, or a novel pathogen annually could be 1.2, 1.3, 9.0, 105.3, or 69.2 to 252.6, respectively. Compared with single-donor PLTs, US PLT pools of five concentrates have a 5.6-fold higher risk of bacterial contamination (summary odds ratio, 5.58; 95% confidence interval, 2.60-11.98; p < 0.05). The three studies that diagnosed TRALI based on the consensus definition did not demonstrate a difference in risk between PWBD and single-donor PLTs.
  
  
  CONCLUSIONS
  TTIs and TAS determine the relative safety of PWBD versus single-donor PLTs. The available limited data do not support a higher risk of TRALI from single-donor (compared with PWBD) PLTs.
authors.affiliation: Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA. vamvakase@cshs.org
authors.forename: Eleftherios C
authors.initials: EC
authors.lastname: Vamvakas
mesh_terms: D001781:Blood Component Removal / Q000009:adverse effects* / Q000706:statistics & numerical data*; D001782:Blood Donors / Q000706:statistics & numerical data; D001803:Blood Transfusion / Q000706:statistics & numerical data*; D006801:Humans; D007239:Infections / Q000097:blood / Q000453:epidemiology* / Q000635:transmission*; D012307:Risk Factors; D065227:Transfusion Reaction; D014481:United States / Q000453:epidemiology