title: Clinical utility of the basophil activation test for analysis of allergic transfusion reactions: a pilot study.
abstract: OBJECTIVE
  In previous studies, we demonstrated that the basophil-activating effects of supernatants found in residual-transfused platelet concentrates (PC-SNs) on whole blood basophils in cases of allergic transfusion reactions (ATRs) could be assessed by the basophil activation test (BAT) in terms of allergen/IgE dependency. However, in these studies, the basophils were derived from third-party healthy volunteers. In this study, we performed BAT using patients' own blood basophils to analyse ATRs.
  
  
  METHODS
  The BAT was performed in two cases of severe ATRs using residual PC-SNs and the patients' own basophils in the presence and absence of dasatinib, an inhibitor of IgE-mediated basophil activation.
  
  
  RESULTS
  In both cases, PC-SNs exhibited basophil-activating activity against the patients' basophils, but not against basophils from third-party healthy volunteers. In addition, basophil activation was inhibited in the presence of dasatinib, indicating that the basophils were activated in an allergen/IgE-dependent manner. Of note, the basophils in Case 2, but not in Case 1, were activated by PC-SNs from some unrelated non-haemolytic transfusion reaction cases.
  
  
  CONCLUSIONS
  This pilot study indicates that the BAT may be useful in clarifying the causal relationship between ATRs and transfused blood as well as in elucidating the mechanisms behind ATRs considering the allergen/IgE-dependent pathway.
authors.affiliation: Division of Hematology and Stem Cell Transplantation, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Okamura
authors.affiliation: Japanese Red Cross Kinki Block Blood Center, Ibaraki, Osaka, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Matsuyama
authors.affiliation: Japanese Red Cross Kinki Block Blood Center, Ibaraki, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yasui
authors.affiliation: Japanese Red Cross Kinki Block Blood Center, Ibaraki, Osaka, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Hirayama
authors.affiliation: Division of Hematology and Stem Cell Transplantation, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ikeda
mesh_terms: D001491:Basophils / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D000069439:Dasatinib / Q000494:pharmacology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D017713:Platelet Transfusion / Q000009:adverse effects*; D012720:Severity of Illness Index; D065227:Transfusion Reaction / Q000209:etiology* / Q000473:pathology; D053802:Tryptases / Q000097:blood
chemical_list: D007073:Immunoglobulin E; D053802:Tryptases; D000069439:Dasatinib
keywords: allergic transfusion reactions; anaphylaxis; basophil activation test