Sickle cell disease (SCD) patient status and blood storage conditions might influence donor red blood cell (RBC) deformability and hemolysis, being clinically relevant factors for RBC transfusions, according to a new study published in Transfusion.

“The current study shows preliminary evidence that RBCs stored under hypoxic conditions may have improved ex vivo deformability and reduced hemolysis after exposure to plasma from adults with SCD,” the authors explained. “Together, HRBCs [RBCs stored under hypoxic conditions] in steady-state plasma maximized donor red cell ex vivo function and survival.”

Hypoxic storage performed better than conventional storage conditions in preserving RBC deformability when donor cells were exposed to plasma from patients with SCD. Relative deformability was 0.036 higher in RBCs stored under hypoxic conditions compared with RBCs stored under conventional conditions. This observation was independent of the plasma type.

Moreover, patients with SCD who had frequent vaso-occlusive crises and were hospitalized due to crisis at the time of blood sample collection had reduced donor RBC deformability and increased levels of hemolysis postincubation, regardless of the storage conditions. Mean donor RBC hemolysis was 0.33% higher after incubation with severe acute-phase symptoms plasma compared with steady-state plasma. Previous studies have shown that inflamed plasma from patients with SCD during crises may damage donor RBCs.

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The authors identified the storage condition of the donor RBCs as the most significant contributor for the relative flow outcome, whereas patient condition was the most significant contributor to hemolysis. However, these results might have been influenced by the relatively low number of nonpaired patient samples, hemoglobin A1c percent, reticulocyte percent, and platelet count.

This study enrolled 18 patients with SCD, including 9 hospitalized for vaso-occlusive crises. The authors used a microfluidic multiplexed microcapillary network device to assess the flow of patient plasma samples.

RBC deformability is a key aspect in SCD. Strategies to maximize RBC deformability could be valuable to improve RBC transfusions.


Karafin MS, Field JJ, Ilich A, et al. Hypoxic storage of donor red cells preserves deformability after exposure to plasma from adults with sickle cell disease. Transfusion. Published online October 30, 2022. doi:10.1111/trf.17163