Deborah Chen

Assessing the influence of component processing and donor characteristics on quality of red cell concentrates using quality control data.

Quality control (QC) data collected by blood services are used to monitor production and to ensure compliance with regulatory standards. We demonstrate how analysis of quality control data can be used to highlight the sources of variability within red cell concentrates (RCCs).

Non-invasive spectroscopy of transfusable red blood cells stored inside sealed plastic blood-bags.

After being separated from (donated) whole blood, red blood cells are suspended in specially formulated additive solutions and stored (at 4 °C) in polyvinyl chloride (PVC) blood-bags until they are needed for transfusion. With time, the prepared red cell concentrate (RCC) is known to undergo biochemical changes that lower effectiveness of the transfusion, and thus regulations are in place that limit the storage period to 42 days. At present, RCC is not subjected to analytical testing prior to transfusion. In this study, we use Spatially Offset Raman Spectroscopy (SORS) to probe, non-invasively, the biochemistry of RCC inside sealed blood-bags. The retrieved spectra compare well with conventional Raman spectra (of sampled aliquots) and are dominated by features associated with hemoglobin. In addition to the analytical demonstration that SORS can be used to retrieve RCC spectra from standard clinical blood-bags without breaking the sterility of the system, the data reveal interesting detail about the oxygenation-state of the stored cells themselves, namely that some blood-bags unexpectedly contain measurable amounts of deoxygenated hemoglobin after weeks of storage. The demonstration that chemical information can be obtained non-invasively using spectroscopy will enable new studies of RCC degeneration, and points the way to a Raman-based instrument for quality-control in a blood-bank or hospital setting.

The effect of timing of gamma-irradiation on hemolysis and potassium release in leukoreduced red cell concentrates stored in SAGM

While irradiation of red cell concentrates (RCC) prevents graft‐versus‐host disease in susceptible transfusion recipients, it also damages red blood cells (RBC). To understand the ability of irradiation regulations to prevent transfusion of inferior units, we irradiated 980 RCC in saline‐adenine‐glucose‐mannitol (SAGM) using various combinations of pre‐irradiation age and post‐irradiation storage times, and measured hemolysis and extracellular potassium levels. We observed unacceptably high hemolysis (>0·8%) in some RCC and elevated extracellular potassium levels in all gamma‐irradiated RCC. This suggests that more restrictive storage times should be considered for RCC in SAGM.

Pathogen inactivation by riboflavin and ultraviolet light illumination accelerates the red blood cell storage lesion and promotes eryptosis: MIRASOL TREATMENT AND ERYPTOSIS

Pathogen reduction treatment using riboflavin and ultraviolet light illumination (Mirasol) effectively reduces the risk of transfusion‐transmitted infections. This treatment is currently licensed for only platelets and plasma products, while its application to whole blood (WB) to generate pathogen‐inactivated red blood cells (RBCs) is under development. RBC storage lesion, constituting numerous morphologic and biochemical changes, influences RBC quality and limits shelf life. Stored RBCs further show enhanced susceptibility to RBC programmed cell death (eryptosis) characterized by increased cytosolic Ca2+‐provoked membrane phosphatidylserine (PS) externalization.

Introducing the red cell storage lesion

The storage of red blood cells under standard blood‐banking conditions leads to a decline in red cell quality and function known as the red cell storage lesion. These changes are linked to alterations in cellular biochemical processes, biomechanical effects and damage from oxidation. Although storage‐related alterations in red cells can be readily measured in the laboratory, the clinical impact of the storage lesion is not as easy to demonstrate. While some immediate differences between fresh and stored cells can be measured, red cells recover in the circulation to some degree upon transfusion with a concomitant reduction in the effect of the storage lesion. The clinical literature is inconsistent with studies arguing that long‐term stored red cells have a clinical impact and other studies including recent randomized controlled trials have failed to show any effect of the storage lesion on patient outcomes. Amelioration of the storage lesion will require further development of novel storage processes as well as an increased understanding of the role that donor‐specific factors play in product quality.

An investigation of red blood cell concentrate quality during storage in paediatric‐sized polyvinylchloride bags plasticized with alternatives to di‐2‐ethylhexyl phthalate (DEHP)

Di‐2‐ethylhexyl phthalate (DEHP) is a blood bag plasticizer. It is also a toxin, raising concerns for vulnerable populations, for example, neonates and infants. Here, the in vitro quality of red cell concentrates (RCC) stored in paediatric bags formulated with alternative plasticizers to DEHP was compared.

Identification of potential protein quality markers in pathogen inactivated and gamma-irradiated red cell concentrates.

Post‐collection manipulations (PCMs) aim to increase blood product safety. However, PCMs improve safety at a cost to quality, causing elevated hemolysis. As hemolysis is linked to red blood cell membrane integrity, a quantitative proteomics approach was employed to assess membrane proteome alterations induced by PCMs.

Proteomic analysis of red blood cells from donors exhibiting high hemolysis demonstrates a reduction in membrane-associated proteins involved in the oxidative response

The development of hemolysis during ex vivo hypothermic storage is multifaceted. Standardization of collection and production processes is used to minimize variability in biologics manufacturing and to maximize product quality. However, the influence of various donor characteristics on product quality is often difficult to evaluate and to control. Using a proteomic approach, we aimed to decipher relevant donor characteristics that may predict red blood cell (RBC) quality during storage.

Raman spectroscopy of stored red blood cells: evaluating clinically-relevant biochemical markers in donated blood

Modern transfusion medicine relies on the safe, secure, and cost-effective delivery of donated red blood cells (RBCs). Once isolated, RBCs are suspended in a defined additive solution and stored in plastic blood bags in which, over time, they undergo chemical, physiological, and morphological changes that may have a deleterious impact on some patients. Regulations limit the storage period to 42 days and the cells do not routinely undergo analytical testing before use. In this study, we use Raman spectroscopy to interrogate stored RBCs and we identify metabolic and cell-breakdown products, such as haemoglobin and membrane fragments, that build-up in the blood bags as the cells age. Our work points the way to the development of an instrument which could quickly and easily assess the biochemical nature of stored RBC units before they are transfused.