赤血球Ｍ・Ａ・Ｐ中におけるＹｅｒｓｉｎｉａ ｅｎｔｅｒｏｃｏｌｉｔｉｃａの増殖とエンドキシン及び上清ヘモグロビンの産生について

Abstract

Contamination of Yersinia enterocolitica (Y. e.) in preserved red cell concentrates with an additive solution (RC-MAP) has been gathering recent concern. It is useful to detect contamination of RC-MAP with Y. e. at an early stage of storage. Since Y. e. proliferates to produce endotoxin and free hemoglobin (Hb) in plasma, we examined the relation of proliferated amount of Y. e. to production of endotoxin and free Hb in RC-MAP stored at 4°C for 42 days, in comparison to that in RC-MAP without Y. e. as a control.Y. e. was inoculated to give a concentration of 115-130CFU/ml into whole blood (n=5) at two hours after collection. The proliferation of Y. e. in RC-MAP was recognized at 10 days after the inoculation and endotoxin was also found at the same time. However, the endotoxin could not be detected earlier than the proliferation of Y. e. The increase of free Hb in plasma was not recognized before Y. e. had proliferation above 107-108CFU/ml, while there was one sample with no increase of free Hb in plasma in spite of the presence of Y. e. at 108CFU/ml.The color changes of RC-MAP from outward appearance occurred 2-3 weeks after Y. e. had proliferated to 108CFU/ml.These findings indicate that the amount of endotoxin and free Hb in plasma do not predict the contamination of Y. e. in RC-MAP in advance, although testing for them just before transfusion may be helpful to prevent transfusion-related sepsis due to Y. e. Further studies are required to find other measures to detect Y. e. in contaminated RC-MAP.