Phosphatidylethanolamine is progressively exposed in RBCs during storage

Area of Science:

• Hematology
• Cell Biology
• Biochemistry

Background:

• Red blood cell (RBC) circulation decreases with storage age, but clearance mechanisms are unclear.
• Phosphatidylethanolamine (PE) is a phospholipid exposed on aged cells, acting as a phagocytosis ligand.
• Understanding RBC aging is crucial for transfusion efficacy.

Purpose of the Study:

• To quantify phosphatidylethanolamine (PE) exposure on donor RBCs during storage.
• To utilize the novel PE-specific probe, duramycin, for accurate measurement.
• To compare PE exposure with phosphatidylserine (PS) exposure over time.

Main Methods:

• AS-1 preserved RBC units were sampled weekly for six weeks.
• Duramycin was used to label and quantify PE exposure via flow cytometry.
• Phosphatidylserine (PS) exposure was assessed for comparative analysis.

Main Results:

• PE exposure on RBCs increased significantly with storage duration, reaching nearly 20% by 42 days.
• Increased PE exposure correlated with higher vesiculation and cell-free hemoglobin release.
• Phosphatidylserine (PS) exposure was considerably lower, at approximately 5% by 42 days.

Conclusions:

• Phosphatidylethanolamine (PE) exposure is a more prominent marker of RBC aging than phosphatidylserine (PS).
• Increased PE exposure during storage is linked to RBC vesiculation and hemoglobin release.
• These findings contribute to understanding RBC clearance and transfusion outcomes.