Doctoral dissertation: Red blood cell products may affect immune cells regardless of storage time
The doctoral dissertation of Licentiate of Medicine Eva Laurén examined the storage properties of red blood cell products and their effects on immune cells under cell culture conditions. In Finland, red blood cell products can be stored for up to 35 days before being used in blood transfusions. The study provides new information on the quality of red blood cells during storage and supports efforts to target transfusions to patients who benefit from them the most.
During storage, changes occur in red blood cells, such as variation in cell shape and the formation of extracellular vesicles. Extracellular vesicles are nanosized, membrane-bound particles released from cells that can influence the function of other cells through their molecular content. Vesicles have been thought to be associated with adverse effects of blood transfusions, such as fever and inflammatory reactions or transfusion-related acute lung injury.
The dissertation found that the phospholipid composition of red blood cells and the vesicles released from them is similar and does not change significantly during storage.
In addition, the study showed that both fresh and longer-stored red blood cells can affect immune cell function under laboratory conditions. The significance of this finding at the level of the patient’s immune system requires further research.
Blood transfusions used more cautiously in Finland
The study also examined the use of red blood cells in southern Finland between 2011 and 2016. The results show that the use of red blood cells in patient care had decreased and that the threshold for administering transfusions had increased compared to earlier practices. According to current understanding, red blood cell transfusion should most often be given only when the patient’s hemoglobin level falls below 70–80 g/l.
Red blood cell transfusion is a valuable and often necessary treatment, but due to potential adverse effects, its use should be carefully considered. Regular evaluation of blood product use is important to ensure that each donated unit is directed to patients who benefit from it the most.
Licentiate of Medicine Eva Laurén will defend her dissertation titled “Studies of storage lesions and usage of red blood cells” on Friday, April 17, 2026, at 12:00 at Biomedicum, Lecture Hall 3.
Supervisors:
Adjunct Professor Erja Kerkelä, Finnish Red Cross Blood Service
Professor Emeritus Ville Pettilä, HUS / University of Helsinki
Opponent:
Adjunct Professor Marja-Kaisa Auvinen, Akademiska Sjukhuset / Uppsala University
