血小板輸血によるアナフィラキシー反応回避のために COBE Spectra Leukoreduction System による白血球除去血小板製剤を使用した2症例

Life-threatening anaphylactic transfusion reaction, a rare side-effect of platelet transfusion, has been reported in patients who lack various plasma proteins such as IgA and the fourth complement component (C4). However, the cause of these reactions has in most cases not been determined.We experienced two patients with hematological disorders who developed severe anaphylactic reactions after several platelet transfusions with a leukocyte removal filter. C3, C4 and immunoglobulins A, G and M levels in their sera were normal. Anti-platelet, plasma anti-IgA, and C4 and C9 antibodies were negative.The COBE Spectra Leukoreduction System (LRS) produces platelet concentrates (PC) that contain less than 0.5×106 residual white blood cells. Since anaphylactic reaction to plasma protein was unlikely in our cases, we transfused LRS-PC without a leukocyte removal filter. Both patients received frequent infusions of LRS-PC without further complications.Although the cause of the anaphylactic reactions in these two cases remains unknown, LRS-PC transfusion was useful in avoiding anaphylactic reaction associated with platelet transfusions through leukocyte removal filters.