Frozen red cells.

Area of Science:

• Blood banking and transfusion medicine
• Cryopreservation of biological materials
• Infectious disease transmission control

Background:

• Historically, frozen red blood cells (RBCs) were favored in the 1970s to overcome storage limitations and reduce transfusion reactions.
• The process offered incidental benefits like white cell and plasma depletion, potentially lowering alloimmunization and disease transmission risks.

Observation:

• Modern filtration techniques now efficiently remove white cells, offering similar benefits to freezing at lower costs.
• Enhanced donor screening for Hepatitis B virus (HBV), HIV, and the use of ALT assays for non-A, non-B hepatitis have drastically reduced transfusion-transmitted infections.
• New resuspension solutions are emerging, enabling extended refrigerated storage and rejuvenation of RBCs, surpassing the convenience of freezing.

Findings:

• The primary goal of long-term RBC storage via freezing has been achieved.
• The practical and economic feasibility of widespread RBC freezing has diminished due to advancements in alternative methods.
• Current screening and filtration technologies have made the benefits of frozen RBCs less critical for routine transfusion.

Implications:

• Frozen RBCs are unlikely to be widely adopted in the civilian market due to cost and inconvenience.
• Their use may be limited to specialized applications like storing rare blood types and potentially preventing Cytomegalovirus (CMV) transmission.
• The evolution of blood banking practices has rendered the original rationale for extensive RBC freezing largely historical.