Albumin reverses the echinocytic shape transformation of stored erythrocytes.

The storage of red blood cells (RBCs) leads to storage lesions, which have a negative impact on the clinical outcome after transfusion. A hallmark of storage lesions is echinocytosis. Albumin may reverse this shape transformation, which was the topic of this study. Echinocytosis was generated by incubation of blood for 48 h at room temperature or in RBC units stored 48 days at 5°C. Human serum albumin was diluted in phosphate-buffered saline. RBCs were fixed in 1% glutaraldehyde and examined by light and scanning electron microscopy. The degree of echinocytosis was quantified by calculating the morphological index. Incubation and storage of RBCs led to an echinocytic shape transformation, which was reversible upon incubation in albumin solutions. This process was time-, concentration- and hematocrit-dependent. Treating RBC units at the end of their shelf-life by adding 20% albumin or washing them in 0.2% albumin reversed all degrees of echinocytosis towards discocytosis. In conclusion, albumin has the capacity to reverse echinocytosis generated by RBC storage. This observation may improve the quality of RBC units stored for longer periods of time.