Effect of concurrent pathogen reduction (amotosalen/UVA) and gamma/x-ray irradiation on biochemical characteristics of apheresis platelets in additive solution.

Background: Pathogen reduction (PR) may be used as an alternative to gamma or x-ray irradiation (I) to prevent transfusion associated graft versus host disease (TA-GVHD) if the pathogen reduction technology has been shown to inactivate residual lymphocytes. However, as I is considered the gold standard for reducing the risk of TA-GVHD, some centers continue to perform I in addition to PR. This study investigated the effect of concurrent pathogen reduction and irradiation (PR/I) on the biochemical characteristics of apheresis platelets at day 1, 5, and 7 of storage at room temperature.

Methods: We compared in vitro characteristics of apheresis platelets (PLTs), PR PLTs, I PLTs, and PR/I PLTs at storage day 1, 5, and 7. PLTs from six healthy volunteers were suspended in 65% PAS-3/35% plasma prior to splitting and treatment with PR, I, or PR/I. Parameters measured were: PLT loss, mean PLT volume (MPV), pH, glucose consumption, lactate production, CD62P, annexin V binding, PLT aggregation, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS).

Results: PR/I PLTs did not show significant changes in measured parameters when compared to PR PLTs. However, when compared to control PLTs, PR and PR/I PLTs showed significant declines in PLT content, pH, MMP, aggregation and significant increases in MPV, CD62P, annexin V binding, and ROS production, mostly on day 7 of storage. Irradiation did not cause significant changes in measured parameters in comparison to control PLTs.

Conclusions/summary: While PR impacts PLTs' biochemical characteristics and function, irradiation of PR PLTs did not cause additional significant changes.