Irradiation and prolonged storage of red cells are associated with increased adverse events.

BACKGROUND: Red blood cell (RBC) transfusion is associated with the most transfusion-related adverse events (AE). Recent clinical studies showed no significant difference in transfusion-associated mortality between fresh and older RBCs. However, the impact of storage duration as well as irradiation on nonfatal yet much more common complications has not been fully investigated. MATERIALS/METHODS: In this retrospective study of RBC transfusion-associated AEs, a total of 188,562 units of leucocyte-reduced RBCs were transfused in approximately 5·5 years. After excluding washed, deglycerolized, autologous or directed RBCs and RBCs transfused during a massive transfusion protocol, 149,052 units were analysed. Attributes of RBCs including storage time, collection method, CMV serological status and gamma irradiation, as well as the recipient's gender, were analysed. A total of 358 RBC transfusion AEs were categorized into allergic and non-allergic reactions and analysed. RESULTS: Univariate and multivariate logistic analyses showed that irradiated RBCs were associated with a significantly increased frequency of non-allergic reactions (OR (95% CI): 1·89 (1·52, 2·35); P < 0·001). There was a significant association between the frequency of non-allergic reactions and the storage time of irradiated RBCs (OR (95% CI): 1·024 (1·001, 1·048); P = 0·042). In contrast, there was no association between the frequency of allergic reactions and the storage time of irradiated RBCs or between the age of non-irradiated RBCs and the frequency of non-allergic reactions. CONCLUSIONS: Prolonged storage of irradiated RBCs was associated with a significant increase in non-allergic transfusion reactions. Overall, the irradiated RBCs appeared to cause more non-allergic reactions compared with non-irradiated RBCs.

Prolonged platelet storage associated with increased frequency of transfusion-related adverse events.

BACKGROUND: Platelets (PLTs) have been associated with the highest rate of transfusion-associated adverse events (AEs) among all blood products. Most of PLT-associated AEs are considered to have an inflammatory mechanism. However, it is still unclear whether prolonged storage of platelets is associated with an increased rate of transfusion-related AEs, especially in the era of universal prestorage leucoreduction. METHODS/MATERIALS: In this retrospective study, 52 649 PLT products consisting of about 80% apheresis PLTs and 20% whole blood-derived (WBD) PLTs were transfused to 9415 patients from July 2011 to March 2017. All the PLTs were leucoreduced prior to storage. All but 69 units of the apheresis PLTs were irradiated and none of WBD PLTs were irradiated. During this period, a total of 284 AEs that were reported to the transfusion service were analysed. RESULTS: Univariate and multivariate logistic analyses showed that apheresis/irradiated PLTs and PLT age were associated with a significantly increased frequency of inflammation type AEs (OR (95% CI): 2·24 (1·32, 4·15) and 1·30 (1·12, 1·52), respectively). There was a significant increase in the frequency of inflammation AEs associated with prolonged storage of apheresis/irradiated PLTs [OR (95% CI): 1·26 (1·03, 1·53)]. In contrast, there was no association between allergic symptoms and PLT age. Moreover, the frequency of transfusion AEs associated with apheresis/irradiated PLTs (57·2/10 000) was significantly higher than that of WBD/nonirradiated PLTs (26·0/10 000) (P < 0·01). CONCLUSION: Prolonged storage of apheresis/irradiated PLTs was associated with a higher frequency of inflammation AEs. Apheresis/irradiated PLTs caused more AEs than WBD/nonirradiated PLTs.

Chemopreventive and growth inhibitory effects of selenium.

There is very convincing evidence that a high dietary level of selenium substantially reduces the incidence of a wide variety of animal cancers. The human epidemiological evidence is less clear cut, but overall suggests that selenium may be protective: the evidence is strongest in men in relation to gastro-intestinal cancers. There is evidence that dietary selenium compounds reduce the formation of DNA adducts by carcinogens. Selenium compounds also inhibit growth in vitro and induce apoptosis. In general, there is a good correlation between the effectiveness of selenium compounds in chemoprevention and growth inhibition, implying that the mechanisms of growth inhibition and chemoprevention may be similar and that a major factor in the chemopreventive effects of selenium compounds in vivo is their ability to retard outgrowth of pre-malignant cells. Various hypotheses have been advanced as to how selenium compounds might prevent tumour cell growth. One is that they cause apoptosis by inducing oxidative stress. However, we have shown that the most potent selenium compound, selenodiglutathione (SDG), a natural metabolite of selenite, does not induce oxidative stress, at least not in the same way as other oxidants such as H2O2 and diamide. Firstly, a partially selenium-resistant variant cell line does not show increased resistance to H2O2. Moreover, SDG does not induce widespread tyrosine phosphorylation, including MAP and SAP kinases, like other oxidants such as H2O2 and diamide and its effects are not reversed by pretreatment with the tyrosine kinase inhibitor, herbimycin. Our experiments with the selenium-resistant variant suggest that a novel selenium-binding protein may be involved in growth inhibition by selenium.