Donor Variation In Biological Mediators During Storage Of Packed Red Blood Cells

Introduction During routine storage, packed red blood cells (PRBC) undergo numerous biochemical and biophysical changes collectively referred to as the “RBC storage lesion”. A number of factors reported to accumulate during the routine storage of PRBCs are hypothesized to mediate inflammatory cell responses and contribute to poor patient outcomes following transfusion. In addition, donor variability in red blood cell (RBC) characteristics and onset of the storage lesion has been reported. We investigated changes in levels of potential biological response modifies in the supernatant (SN) of PRBC relevant to storage, and, variance between donations. Methods Cytometric bead array was utilised to quantify a panel of 32 potential biological response modifiers (BRMs) in the SN of PRBC during storage. Potential BRMS were analysed in the SN of 8 leukodepleted PRBC units at weekly intervals (D2, D7, D14, D21, D28, D35, D42). The CBA panel was comprised of soluble(s) CD40 Ligand, sCD62E, sCD62L, sCD14, sCD54 (ICAM-1), sCD106 (VCAM-1), CXCL9, VEGF, Fractalkine (CX3CL1), IL-1β, IL-6, IL-8, IL-10, IL-12p70, TNF-α, MIP-1α, MIP-1β, IP-10, RANTES, sCD62P, IL-1α, IL-2, IL-3, IL-4, IL-5, IL-7, IL-9, IL-13, IFN-α, IFN-γ, angiogenin, MCP-1. Storage related changes were analysed using ANOVA (95% CI). Donor variance was indicated by fold difference and range. “High” sub population of donations compared to remaining donations at each time point using Mann-Whitney (95% CI). Results Of the 32 potential BRMs studied, angiogenin, sCD14, sCD106 (VCAM-1), sCD62L, sCD62P, ICAM-1, IL-1α, IP-10, RANTES and IL-9 were consistently detected in all units throughout the time course. There was no evidence of a storage related increase in these biological mediators during storage of the PRBC, although angiogenin levels significantly declined during storage (P<0.001, ANOVA). Of particular interest, the concentrations of these nine biological mediators varied greatly between the individual PRBC units. ICAM-1, VCAM-1 and IL-1α concentrations each varied 10 fold between units (range 1000 – 10 000 pg/mL for each), sCD14 varied 5 fold (range 20 000 - 100 000 pg/mL), sCD62L varied 4.4 fold (range 9000 – 40 000 pg/mL), and sCD62P varied 6.5 fold (range 200 -1300 pg/ml). In addition, it was apparent that a sub population (3/8) of the units assessed consistently had the highest levels of ICAM-1, sCD106 (VCAM-1), sCD14, sCD62L, IL-1α, sCD62P and angiogenin. For sCD62P, in particular, this “high” sub population had significantly different levels of sCD62P at each time point compared to the other five units (P<0.05 at each time point). The remaining BRMs studied were at the limits of detection (<20 pg/mL) for every unit at each time point, and no storage related changes were evident. Conclusions There was minimal change in the BRMs studied relevant to storage duration of the PRBC units. The most notable differences in the levels of biological mediators present in PRBC SN were due to donor-to-donor variation. These data suggest high levels of BRMs and potential immune modulation in transfusion recipients may be the result of donor-associated differences rather than storage-associated differences in blood components. Disclosures: No relevant conflicts of interest to declare.