Red blood cell concentrates treated with the amustaline (S-303) pathogen reduction system and stored for 35 days retain post-transfusion viability: results of a two-centre study

Background and ObjectivesPathogen reduction technology using amustaline (S-303) was developed to reduce the risk of transfusion-transmitted infection and adverse effects of residual leucocytes. In this study, the viability of red blood cells (RBCs) prepared with a second-generation process and stored for 35 days was evaluated in two different blood centres. Materials and MethodsIn a single-blind, randomized, controlled, two-period crossover study (n = 42 healthy subjects), amustaline-treated (Test) or Control RBCs were prepared in random sequence and stored for 35 days. On day 35, an aliquot of Cr-51/Tc-99m radiolabeled RBCs was transfused. In a subgroup of 26 evaluable subjects, 24-h RBC post-transfusion recovery, mean life span, median life span (T-50) and life span area under the curve (AUC) were analysed. ResultsThe mean 24-h post-transfusion recovery of Test and Control RBCs was comparable (83<bold></bold>2 5<bold></bold>2 and 84<bold></bold>9 +/- 5<bold></bold>9%, respectively; P = 0<bold></bold>06) and consistent with the US Food and Drug Administration (FDA) criteria for acceptable RBC viability. There were differences in the T-50 between Test and Control RBCs (33<bold></bold>5 and 39<bold></bold>7 days, respectively; P < 0<bold></bold>001), however, these were within published reference ranges of 28-35 days. The AUC (per cent surviving x days) for Test and Control RBCs was similar (22<bold></bold>6 and 23<bold></bold>1 per cent surviving cells x days, respectively; P > 0<bold></bold>05). Following infusion of Test RBCs, there were no clinically relevant abnormal laboratory values or adverse events. ConclusionRBCs prepared using amustaline pathogen reduction meet the FDA criteria for post-transfusion recovery and are metabolically and physiologically appropriate for transfusion following 35 days of storage.