Abstract: Objective We evaluated the quality of leukocyte-reduced suspended red blood cells (SRBCs) with storage time by detecting hemolysis rate, bacterial growth, biochemical indicators and indexes of energy metabolism, membrane damage and oxidative stress at 4 ℃. Methods On the day of collection, 50 mL of whole blood was collected from 10 volunteers as test specimens. Leukoreduction filters were used for the removal of leukocytes and the plasma was removed as much as possible on the day of collection. We added erythrocyte preservation solution according to a ratio of preservative solution per 200 mL of whole blood and stored at 4℃ until the end of study. The hemolysis rate, ATP/2, 3-DPG, Na⁺/K⁺/GLU/LDH/pH, PS/CD47 and MDA/SOD were tested on day 0, 7, 14, 21, 28, 35 and 42 of storage. Bacterial growth was measured on day 0, 14, 28 and 42 of storage. Results The hemolysis rate progressively increased with storage, which increased from 0.03% to 0.4% at from day 0 to 42. There were statistically significant differences compared to day 0 (P<0.001), but none of them exceeded the national standard requirements. There was no bacterial growth. Na⁺, GLU and pH decreased with increasing K⁺ and LDH levels in supernatant. ATP began to decrease on Day 14, dropping to 36.4% on Day 21 and to 13.2% at the end. There were significant differences compared to day 0 (P<0.001). 2, 3-DPG began to decline on day 7, decreased to 57.5% on day 28 and 44.0% on day 42. At the end of storage, external exposure of membrane phosphatidylserine (PS) increased to 0.83%, and the mean fluorescence intensity of CD47 decreased to 60.8%. There was no change in MDA value during storage. Activities of SOD decreased on day 28, with statistical difference compared to Day 0 (P<0.001). Conclusion By evaluating the quality of leukocyte-reduced SRBCs stored at 4 ℃, we suggested that the optimal storage period of leukocyte-reduced SRBCs was within two weeks, because indexes of biochemical, energy metabolic and oxygen-carrying capacity were basically maintained in two weeks.

Key words: Leukocyte-reduced suspended red blood cells, Storage, Quality evaluation