Hemolysis of red blood cells during processing and storage.

Background: During processing and storage, red blood cells (RBCs) undergo changes and cell injury resulting in hemolysis. Mostly, the separation of whole blood in top-and-bottom quadruple bag systems with break openings takes less than 4 minutes. However, longer separation times are not uncommon. The aims were to investigate whether hemolysis is increased in RBCs with longer separation time (RBCs(>6 min)) compared to regular RBCs (RBCs(reg)), to measure hemolysis increase during storage and to study whether frequency of hemolytic donations is donor dependent.

Study Design And Methods: RBCs(>6 min) (n = 172) and 172 matched controls were tested for hemolysis on Days 1 and 21 RBC units from each group were stored at 4 ± 2°C and tested again after 5 weeks. Donor dependency was retrospectively investigated for 100 hemolytic RBC units.

Results: RBCs(>6 min) exhibited a higher mean hemolysis rate than RBCs(reg) (0.058% vs. 0.033%). Four RBC units were hemolytic (>0.8%), all RBCs(>6 min) (2.36%). During storage, hemolysis in both groups increased with 0.24%. Hemolysis frequency did not seem to be donor dependent.

Conclusions: Increased separation time is a useful screening tool for potentially increased hemolysis rate in RBCs. Hemolysis rate increased during storage equally in both groups. Hemolysis frequency appears donor independent.