Hypothermic storage of leukoreduced red blood cells for greater than 21 days is a safe alternative to irradiation

Abstract

Background Irradiation of red blood cells (RBCs) inactivates residual donor T lymphocytes to prevent transfusion‐associated graft‐vs‐host disease (TA‐GVHD) but can have adverse effects on recipients and inventory management. Reported incidence of TA‐GVHD is lower when leukoreduced RBCs and older blood products are transfused; therefore, the impact of leukoreduction and storage was evaluated as an alternative prevention strategy. Study Design and Methods Effectiveness of leukoreduction filters on white blood cell (WBC) proliferation was evaluated by filtering buffy coat (BC) products and isolating residual WBCs. Additionally, leukoreduced RBCs were spiked with 5 × 106 WBCs on Day 21 of hypothermic storage, then stored and processed on Days 7, 14, and 21 to obtain residual WBCs to investigate the impact of hypothermic storage on their viability and proliferative ability. Viability of residual WBCs was assessed by staining with annexin V and an antibody cocktail for flow cytometry analysis. Proliferative ability was assessed by placing carboxyfluorescein diacetate succinimidyl ester–labeled residual WBCs into culture for 6 days with phytohemagglutinin before flow cytometry assessment. Results Filtration of BC units depleted WBCs, particularly T lymphocytes, to 0.001% ± 0.003% cells/unit, although proliferative activity remained consistent with prefiltration levels of WBCs. WBCs in stored RBCs remained viable even on Day 21 of storage; however, the proliferative activity decreased to 0.24% ± 0.41%. Conclusions Hypothermic storage of RBCs for 21 days or more is sufficient to inactivate T lymphocytes, which may help prevent TA‐GVHD when irradiated RBCs are not available.

Irradiated red blood cell transfusion is associated with an increased risk of deep vein thrombosis in trauma patients: a case control study

“…Blood irradiation (usually with γ-rays) can inactivate the immune activity of lymphocytes; consequently, irradiated blood is usually used in transplant patients to prevent transfusion-related graft-versus-host disease [27]. However, in China, irradiation is mostly carried out by blood centers, and medical institutions usually prestore a certain amount of irradiated RBCs.…”