Impact of haematocrit, storage duration and recipient sex on post-transfusion recovery of red blood cells in a murine model.

Background and objectives: During cold storage, red blood cells (RBCs) undergo progressive biochemical and structural changes, known as the storage lesion, which affects their function and post-transfusion recovery (PTR). While anticoagulants and additive solutions help mitigate these effects, they also influence unit haematocrit. The impact of haematocrit on PTR remains unclear. This study investigates how storage of haematocrit, storage duration and recipient sex influence PTR.

Materials and methods: Using transgenic mice with RBCs expressing fluorescent proteins, leukoreduced RBC units were prepared and stored at 60% or 75% haematocrit for 1, 6 or 11 days. Before transfusion, freshly collected RBCs were added to stored units to facilitate PTR calculations. RBC units were then transfused into female or male recipient mice and PTR was evaluated at multiple time points.

Results: PTR decreased with storage duration. Haematocrit had no significant effect on PTR for RBC units stored up to 6 days. However, after 11 days of storage, a higher haematocrit was associated with reduced PTR. Additionally, female recipients exhibited significantly lower PTR than male recipients, regardless of unit haematocrit.

Conclusion: Haematocrit and recipient sex influence PTR for RBC units stored for a long time. These findings highlight the need to consider both factors when optimizing RBC storage and transfusion strategies.