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.