The effect of gamma irradiation on platelet redox state during storage

Abstract

Background As a method with insignificant adverse effects on in vitro quality of platelet concentrates (PCs), gamma irradiation is applied to abrogate the risk of transfusion‐associated graft‐vs‐host disease in vulnerable recipients. However, there is some evidence of lower posttransfusion responses and proteomic alterations in gamma‐irradiated platelets (PLTs), which raises some questions about their quality, safety, and efficacy. Since reactive oxygen species (ROS) are considered as markers of PLT storage lesion (PSL), the study presented here investigated oxidant state in gamma‐irradiated PCs. Study Design and Methods PLT‐rich plasma PC was split into two bags, one kept as control while other was subjected to gamma irradiation. Within 7 days of storage, the levels of intra‐PLT superoxide, H2O2, mitochondrial ROS, P‐selectin expression, and phosphatidylserine (PS) exposure were detected by flow cytometry while intracellular reduced glutathione (GSH), glucose concentration, and lactate dehydrogenase (LDH) activity were measured by enzymocolorimetric method. Results GSH decreased, while ROS generation and LDH activity increased, during storage. Gamma irradiation significantly attenuated GSH whereas increased ROS generation in earlier and later stages of storage associated with either P‐selectin or PS exposure increments. Conclusion Gamma irradiation can significantly increase cytosolic ROS generation in two distinct phases, one upon irradiation and another later in longer‐stored PCs. While earlier ROS influx seems to be governed by direct effect of irradiation, the second phase of oxidant stress is presumably due to the storage‐dependent PLT activation. Intriguingly, these observations were also in line with early P‐selectin increments and increased PS exposure in longer‐stored PLTs. Given the mutual link between ROS generation and PLT activation, further investigation is required to explore the effect of gamma irradiation on the induction of PSL.

Gamma and X‐ray irradiation do not affect the in vitro quality of refrigerated apheresis platelets in platelet additive solution (PAS‐E)

“…Proteomic investigations have shown that gamma irradiation alters the platelet proteome 61,62 . Furthermore, gamma irradiated platelets show evidence of greater oxidative stress than non‐irradiated components 49,61 . While ROS accumulation was not directly measured in this study, many of the quality parameters assessed are endpoint markers of ROS damage, including receptor shedding, degranulation, mitochondrial dysfunction and potentiation of aggregation 50 .…”

“…The negative effects of irradiation are reportedly exerted by damage to nuclear DNA, a direct deleterious effect on cell membrane integrity or through the accumulation of reactive oxygen species (ROS). 49,50 Irradiation appears to have little impact on the standard metabolic (pH, glucose, lactate) or activation (CD62P, annexin-V) parameters during conventional platelet storage. [15][16][17][18][19][20] However, given the membrane alterations initiated by cold storage, including cytoskeletal modifications, alteration in microtubules, and ultimately a significant morphological change, 48,51,52 it seemed plausible that irradiation of platelets that had undergone these coldinduced modifications may result in further detrimental changes to the platelets, especially during extended storage.…”

“…61,62 Furthermore, gamma irradiated platelets show evidence of greater oxidative stress than non-irradiated components. 49,61 While ROS accumulation was not directly measured in this study, many of the quality parameters assessed are endpoint markers of ROS damage, including receptor shedding, degranulation, mitochondrial dysfunction and potentiation of aggregation. 50 Our results demonstrate that irradiation did not impact any of these parameters in the context of extended cold storage.…”

“…The negative effects of irradiation are reportedly exerted by damage to nuclear DNA, a direct deleterious effect on cell membrane integrity or through the accumulation of reactive oxygen species (ROS) 49,50 . Irradiation appears to have little impact on the standard metabolic (pH, glucose, lactate) or activation (CD62P, annexin‐V) parameters during conventional platelet storage 15–20 .…”

The in vitro quality of X‐irradiated platelet components in PAS‐E is equivalent to gamma‐irradiated components

“…400 × 10 9 platelets/unit). Interestingly, while several studies have shown that gamma irradiated platelets show evidence of greater oxidative stress than non‐irradiated components, 18,19 this does not seem to translate to significant alterations in the standard metabolic (pH, glucose, lactate) or activation (CD62P, annexin‐V) parameters. While markers of ROS damage were not investigated in this study, some differences were observed between irradiated and non‐irradiated components, with irradiation potentiating ADP‐induced aggregation and improving GPIbα retention.…”