Investigations on the deformability of human red blood cells stored in different preservative solutions

Deformability changes of red blood cells stored either as whole blood or as different resuspensions in sucrose-free or sucrose-containing media were characterized by measuring red cell filterability during 36 days of storage. For whole blood and SAG-resuspensions only a slight increase of the filterability index was observed during the first 3 weeks; after 36 days it was elevated 1.4-fold (whole blood) and 1.8-fold (SAG-resuspension). In contrast, a strong deformability loss (increase of the filterability index to more than the 6-fold) was observed for red blood cells stored in sucrose-containing CDS-AG medium. This deformability loss is caused by an increase of the internal viscosity (at least 4-fold) due to the shrinkage of red blood cells by more than 20%. After incubation for 1 h in fresh plasma no changes of filterability could be found. The in vivo behavior of such rigid cells is discussed with regard to references about the posttransfusion survival.