Sanne de Bruin

146 Chapter 6 in alkaline additive solutions results in chloride shifts from intracellular to extracellu- lar, with an opposite flux of hydroxyl ions into the RBC. The hydroxyl ions increase the intracellular pH and thereby activate PFK. An experimental additive solution PAGGGM (phosphate-adenine-glucose-guanosine-gluconate-mannitol) showed better in vitro preservation of 2,3-DPG levels and higher ATP levels throughout storage but is not tested in vivo so far 18 . We hypothesized that: 1) storing RBCs in PAGGGM results in improved RBC metabolism during storage which in turn would improve post-transfusion survival; 2) storing RBCs in PAGGGM changes expression of eat-me and don’t eat me signals on stored RBCs.To investigate these hypotheses we performed a randomized controlled trial, comparing RBCs stored in SAGMwith RBCs in PAGGGM. To this end, differentially biotinylated RBCs were used, which allowed the post transfusion quantification, isolation and phenotypic analysis of donor RBCs. In this manner, the metabolic status of the donor RBCs before and on different time points after transfusion was assessed by metabolomics. In ad- dition, the expression of several “eat me” and “don’t eat me” markers were quantified on the transfused cells. Material and methods Study design An open label randomized controlled trial was conducted to study the effect of storage time and additive solution on the PTR of RBCs. Subjects were randomly allocated to receive autologous biotinylated RBC products stored in saline-adenine-glucose-man- nitol (SAGM) or the experimental additive solution phosphate-adenine-glucose-gua- nosine-gluconate-mannitol (PAGGGM). Volunteers received 2 and 35- days stored RBC concentrates. Twenty healthy male subjects were recruited. Prior to inclusion, each subject was screened by a research physician and was approved as an autologous blood donor by the national blood bank. Screening included a health questionnaire, physical examina- tion, electrocardiogram and blood examination. Healthy males between the age of 18 and 35 were included. Potential subjects who used medication on doctor prescription, with alcohol and/or drugs abuse, donated/lost >500 ml of blood three months before start of study or had abnormalities during the medical screening were excluded from study participation. Participants were compensated for time lost and received travel allowance.