Traditional and emerging technologies for washing and volume reducing blood products

Abstract

Millions of blood components including red blood cells, platelets, and granulocytes are transfused each year in the United States. The transfusion of these blood products may be associated with adverse clinical outcomes in some patients due to residual proteins and other contaminants that accumulate in blood units during processing and storage. Blood products are, therefore, often washed in normal saline or other media to remove the contaminants and improve the quality of blood cells before transfusion. While there are numerous methods for washing and volume reducing blood components, a vast majority utilize centrifugation-based processing, such as manual centrifugation, open and closed cell processing systems, and cell salvage/autotransfusion devices. Although these technologies are widely employed with a relatively low risk to the average patient, there is evidence that centrifugation-based processing may be inadequate when transfusing to immunocompromised patients, neonatal and infant patients, or patients susceptible to transfusion-related allergic reactions. Cell separation and volume reduction techniques that employ centrifugation have been shown to damage blood cells, contributing to these adverse outcomes. The limitations and disadvantages of centrifugation-based processing have spurred the development of novel centrifugation-free methods for washing and volume reducing blood components, thereby causing significantly less damage to the cells. Some of these emerging technologies are already transforming niche applications, poised to enter mainstream blood cell processing in the not too distant future.

Dynamics of shape recovery by stored red blood cells during washing at the single cell level

“…8,10,[15][16][17][18] A majority of shape changes occurred within the initial 10 minutes of RBCs being exposed to the washing solution, which is on par with our previous studies [15][16][17][18] and agrees well with the time it typically takes to wash a unit of RBCs using a conventional centrifugation-based cell processor. 39 Outside of hypothermic storage, normal RBCs can be transformed into echinocytes by incubation with sodium salicylate, a well-known echinocytogenic agent, and such a transformation is fully reversible upon exchange of the suspending medium. 5,9 Unlike exposure to sodium salicylate, the effect of hypothermic storage on shape of individual RBCs in a population is highly heterogeneous.…”

“…There is of course a rather substantial difference between our single-cell washing method and how RBC units would be washed in practice-in the current research and clinical settings washing of stored RBCs is typically performed using a high-volume centrifuge or a centrifugation-based automated cell processor. 39 Centrifugation subjects stored RBCs to substantial mechanical forces, damaging the cells and causing excessive hemolysis. Although this mechanical washing is known to improve the overall morphology of RBC units, damaged cells continue to release free Hb and potassium into the suspending medium, reaching the prewash levels within 24 hours after the procedure.…”

“…The conventional washing procedure involves adding washing solution to the RBC unit which is then centrifuged to replace the supernatant with a fresh solution and is typically performed using a high-volume centrifuge or an automated cell processor. 39 The differences in Hct of the suspension, the mechanical forces applied, the washing solution used, and the temperature at which washing is performed all could have an impact on how the shape of individual RBCs evolves throughout this process. Thus, care should be taken when extending interpretation of our findings in the context of shape recovery for RBCs preserved with alternative storage systems, washed in different solutions and/or under different conditions.…”

An In Vitro Pilot Study Comparing the Novel HemoClear Gravity-Driven Microfiltration Cell Salvage System with the Conventional Centrifugal XTRA™ Autotransfusion Device

“…Moreover, autologous blood transfusion is widely accepted as the preferred option where possible due to numerous advantages over allogeneic blood [ 3 , 5 – 7 ]. However, limited by the availability and affordability of current cell salvage devices, autologous transfusion is mostly confined to fully equipped hospital operating rooms [ 4 , 8 , 9 ]. Due to the high capital investment, extensive training requirements, and expensive consumables, cell salvage is merely cost-effective in settings where hemorrhage is anticipated [ 10 ].…”

“…Additionally, the need for electricity and ponderous design makes these devices unpractical in low-resource settings [ 8 , 11 , 12 ]. HemoClear (HemoClear BV, Zwolle, Netherlands) presents a novel simplistic gravity-driven device for washing shed blood and concentrating RBCs, with the potential to counteract global blood shortage.…”