Incidence of transfusion-related adverse reactions per patient reflects the potential risk of transfusion therapy in Japan

Objectives: To describe the frequency of adverse reactions (ARs) after transfusion on both per transfused patient and per transfused unit bases. Methods: We performed a retrospective analysis of data available from records of 6 hospitals on the total number of transfusions and documented ARs between January 2008 and December 2009 for RBCs, fresh-frozen plasma (FFP), and platelet concentrates (PCs). Results: The incidence of ARs to RBCs, FFP, and PCs per transfused unit was 0.6%, 1.3%, and 3.8%, respectively. The incidence of ARs to RBCs, FFP, and PCs per patient was 2.6%, 4.3%, and 13.2%, respectively-almost 3-fold higher. Most RBC-ARs were febrile nonhemolytic transfusion reactions and allergic reactions, whereas most FFP-ARs and PC-ARs were allergic reactions. Conclusions: The incidence of ARs per transfused patient may reflect better the potential risk of transfusion with blood components, taking into account the characteristics of the transfused patient.