Liquid storage of granulocytes

Area of Science:

• Hematology
• Transfusion Medicine
• Cellular Biology

Background:

• Neutrophils are critical immune cells, but their storage duration is limited compared to other blood components.
• Assessing neutrophil viability and function post-storage is crucial for effective transfusion therapy.

Purpose of the Study:

• To evaluate methods for assessing neutrophil storage quality.
• To determine optimal storage conditions and duration for granulocyte concentrates.
• To identify sensitive indicators of neutrophil damage during storage.

Main Methods:

• Utilized various functional assays including cell counts, morphology, dye exclusion, oxygen consumption, and specific enzyme activities.
• Assessed neutrophil functions such as chemotaxis, phagocytosis, and microbial killing.
• Investigated different storage media (whole blood, plasma, synthetic) and conditions (pH, temperature, agitation).

Main Results:

• Neutrophil function loss during storage mirrors the reverse of their maturation sequence, with chemotaxis being the most sensitive indicator.
• In vitro studies suggest a storage limit of approximately 24 hours, though in vivo data indicates this may be optimistic.
• Ideal storage conditions identified as pH 7.2, room temperature (20-24°C), and no agitation.
• Neither donor glucocorticoid premedication nor unit irradiation improved storage potential.
• Granulocyte concentrates collected via filtration leukapheresis are unsuitable for storage.

Conclusions:

• Neutrophil storage is challenging, requiring careful consideration of functional integrity.
• Optimal storage conditions can extend viability for short periods, but functional assays are critical for quality control.
• Further research into synthetic storage media and improved collection methods is warranted for enhanced granulocyte transfusion efficacy.