title: Repeated exposure rather than the total volume of transfused components may influence the incidence of allergic transfusion reactions.
abstract: BACKGROUND
  The plasma fraction of blood components has an essential role in the etiology of allergic transfusion reactions (ATRs). The difference of incidences of ATRs between fresh-frozen plasma (FFP) and platelet concentrates (PCs), in which plasma is the main component, is not clearly understood. This study compares the frequency of ATRs to FFP versus PCs on both first and subsequent (nonfirst) transfusions and considers the factors influencing the risk of ATRs.
  
  
  METHODS
  Five hospitals agreed to systematically collect and share 2 years of data (January 2010 through December 2011). This was a retrospective observational analysis of data including the number of transfusion episodes and ATRs for FFP and PCs on first-transfusion patients (without transfusion history) and previously transfused patients.
  
  
  RESULTS
  The incidence of ATRs to PCs (2.51%) was significantly higher than to FFP (1.68%) on subsequent transfusions (p < 0.001). On the other hand, there were no significant differences in the incidences of ATRs to FFP (2.67%) and PCs (2.82%) on first transfusions. This discrepancy was most pronounced among males: FFP versus PCs on first transfusions, 2.02% versus 2.60% (p = 0.30); and on subsequent transfusions, 1.58% versus 2.46% (p = 0.0007). Among females, FFP versus PCs on first transfusions was 3.59% versus 3.13% (p = 0.61) and on subsequent transfusions was 1.87% versus 2.61% (p = 0.029).
  
  
  CONCLUSIONS
  Repeated exposure rather than the total volume of transfused components may influence the incidence of ATRs.
authors.affiliation: Department of Transfusion Medicine, Aichi Medical University, Nagakute, Japan.
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Kato
authors.affiliation: Department of Transfusion Medicine, Aichi Medical University, Nagakute, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakayama
authors.affiliation: Department of Transfusion Medicine, Aichi Medical University, Nagakute, Japan.
authors.forename: Motoaki
authors.initials: M
authors.lastname: Uruma
authors.affiliation: Division of Transfusion and Cell Therapy, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Okuyama
authors.affiliation: Department of Transfusion Medicine & Cell Therapy, Keio University, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Handa
authors.affiliation: Department of Blood Transfusion, Osaka University Hospital, Suita, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tomiyama
authors.affiliation: Division of Transfusion Medicine, Shinshu University Hospital, Matsumoto, Japan.
authors.forename: Shigetaka
authors.initials: S
authors.lastname: Shimodaira
authors.affiliation: Department of Transfusion Medicine, Aichi Medical University, Nagakute, Japan.|Japanese Red Cross Hokkaido Block Blood Center, Sapporo, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Takamoto
mesh_terms: D016913:Blood Component Transfusion / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D015994:Incidence; D008297:Male; D010949:Plasma / Q000276:immunology; D017713:Platelet Transfusion / Q000009:adverse effects; D012189:Retrospective Studies