Fresh versus old blood: are there differences and do they matter?

Area of Science:

• Hematology
• Transfusion Medicine
• Cellular Biology

Background:

• The transfusion of stored red blood cells (RBCs) is a common medical practice with debated clinical outcomes.
• Stored RBCs undergo significant biochemical and cellular alterations, termed the storage lesion.
• Existing evidence from retrospective studies presents conflicting results regarding the safety and efficacy of transfusing older RBCs.

Purpose of the Study:

• To review the clinical background and basic science of RBC storage.
• To explore the potential biological mechanisms by which stored RBCs may affect recipient health.
• To identify challenges in current research investigating the effects of RBC transfusion.

Main Methods:

• Review of existing clinical trials and basic science literature on RBC storage.
• Analysis of the 'storage lesion' and its components.
• Discussion of factors complicating hypothesis testing in transfusion research.

Main Results:

• The effects of transfusing stored RBCs remain controversial, with studies reporting varied outcomes.
• Stored RBCs undergo substantial changes, leading to the formation of biologically active substances.
• Several hypotheses exist regarding how these changes might impact recipient biology.

Conclusions:

• The RBC storage lesion is complex and presents challenges for research.
• Donor variability and recipient-specific conditions further complicate the assessment of stored RBC safety.
• Prospective clinical trials are crucial but face significant hurdles in fully elucidating the impact of stored RBC transfusion.