Beschreibung:
<jats:sec><jats:title>Background</jats:title><jats:p>Residual white blood cells (<jats:styled-content style="fixed-case">WBC</jats:styled-content>s) in cellular blood components induce a variety of adverse immune events, including nonhemolytic febrile transfusion reactions, alloimmunization to <jats:styled-content style="fixed-case">HLA</jats:styled-content> antigens, and transfusion‐associated graft‐versus‐host disease (<jats:styled-content style="fixed-case">TA</jats:styled-content>‐<jats:styled-content style="fixed-case">GVHD</jats:styled-content>). Pathogen reduction (<jats:styled-content style="fixed-case">PR</jats:styled-content>) methods such as the ultraviolet <jats:styled-content style="fixed-case">C</jats:styled-content> (<jats:styled-content style="fixed-case">UVC</jats:styled-content>) light‐based <jats:styled-content style="fixed-case">THERAFLEX UV</jats:styled-content>‐<jats:styled-content style="fixed-case">P</jats:styled-content>latelets system were developed to reduce the risk of transfusion‐transmitted infection. As <jats:styled-content style="fixed-case">UVC</jats:styled-content> light targets nucleic acids, it interferes with the replication of both pathogens and <jats:styled-content style="fixed-case">WBC</jats:styled-content>s. This preclinical study aimed to evaluate the ability of <jats:styled-content style="fixed-case">UVC</jats:styled-content> light to inactivate contaminating <jats:styled-content style="fixed-case">WBC</jats:styled-content>s in platelet concentrates (<jats:styled-content style="fixed-case">PC</jats:styled-content>s).</jats:p></jats:sec><jats:sec><jats:title>Study Design and Methods</jats:title><jats:p>The in vitro and in vivo function of <jats:styled-content style="fixed-case">WBC</jats:styled-content>s from <jats:styled-content style="fixed-case">UVC</jats:styled-content>‐treated <jats:styled-content style="fixed-case">PC</jats:styled-content>s was compared to that of <jats:styled-content style="fixed-case">WBC</jats:styled-content>s from gamma‐irradiated and untreated <jats:styled-content style="fixed-case">PC</jats:styled-content>s by measuring cell viability, proliferation, cytokine secretion, antigen presentation in vitro, and xenogeneic <jats:styled-content style="fixed-case">GVHD</jats:styled-content> responses in a humanized mouse model.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p><jats:styled-content style="fixed-case">UVC</jats:styled-content> light was at least as effective as gamma irradiation in preventing <jats:styled-content style="fixed-case">GVHD</jats:styled-content> in the mouse model. It was more effective in suppressing <jats:styled-content style="fixed-case">T</jats:styled-content>‐cell proliferation (>5‐log reduction in the limiting dilution assay), cytokine secretion, and antigen presentation than gamma irradiation.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>The <jats:styled-content style="fixed-case">THERAFLEX UV</jats:styled-content>‐<jats:styled-content style="fixed-case">P</jats:styled-content>latelets (<jats:styled-content style="fixed-case">M</jats:styled-content>aco<jats:styled-content style="fixed-case">P</jats:styled-content>harma) <jats:styled-content style="fixed-case">PR</jats:styled-content> system can substitute gamma irradiation for <jats:styled-content style="fixed-case">TA</jats:styled-content>‐<jats:styled-content style="fixed-case">GVHD</jats:styled-content> prophylaxis in platelet (<jats:styled-content style="fixed-case">PLT</jats:styled-content>) transfusion. Moreover, <jats:styled-content style="fixed-case">UVC</jats:styled-content> treatment achieves suppression of antigen presentation and inhibition of cytokine accumulation during storage of <jats:styled-content style="fixed-case">PC</jats:styled-content>s, which has potential benefits for transfusion recipients.</jats:p></jats:sec>