The effect of storing whole blood at 22 degrees C for up to 24 hours with and without rapid cooling on the quality of red cell concentrates and fresh-frozen plasma

Evaluation of platelet concentrates prepared using different methods after overnight holding (18-24 h) of whole blood at room temperature

BACKGROUND AND OBJECTIVES

Regulatory requirement of fixed holding time (6 h) of whole blood (WB) at room temperature, that is, 22-24°C (RT) results in sub-optimal component separation. The aim was to evaluate the platelet concentrates (PC) prepared by both platelet rich plasma (PRP) and buffy coat (BC) methods after overnight hold (18-24 h) at RT.

MATERIALS AND METHODS

A prospective experimental study was performed. A total of 48 WB units collected were divided into four groups (12 each) control-1 (C1) and test-1 (T1) for PRP and control-2 (C2) and test-2 (T2) for the BC method. Control groups were processed within 6 h, and in test groups, components were prepared after overnight hold, followed by evaluation of quality parameters.

RESULTS

Irrespective of the method used, all PCs had similar volume, platelet yield, swirling, no bacterial contamination, RBC contamination, PaO2 and PaCO2 levels. PCs in the T1 group had significant differences in glucose and MPV values on d1, which were resolved by d5 of storage. PCs in T2 has significant differences in pH, glucose, and MPV levels throughout storage. PRBC in test and control groups had similar quality parameters till d42 of storage. FFPs in all tests were noninferior to the concurrent control groups till 3 months of storage.

CONCLUSION

Overnight holding of WB had no lasting deleterious changes. Though a few biochemical parameters in the test groups were significantly different, they can be accepted to improve the logistics of component separation. Overall PRP method seemed to have a better result than the BC method after an overnight hold.

The compound effect of irradiation and familial pseudohyperkalemia on potassium leak from red blood cells

BACKGROUND

Familial pseudohyperkalemia (FP) is a rare asymptomatic condition characterized by an increased rate of potassium leak from red blood cells (RBC) on refrigeration. Gamma irradiation compromises RBC membrane integrity and accelerates potassium leakage. Here, we compared the effect of irradiation, applied early or late in storage, on FP versus non-FP RBC.

STUDY DESIGN

Five FP and 10 non-FP individuals from the National Institute for Health Research Cambridge BioResource, UK, and three FP and six non-FP individuals identified by Australian Red Cross Lifeblood consented to the study. Blood was collected according to standard practice in each center, held overnight at 18-24°C, leucocyte-depleted, and processed into red cell concentrates (RCC) in Saline Adenine Glucose Mannitol. On Day 1, RCC were split equally into six Red Cell Splits (RCS). Two RCS remained non-irradiated, two were irradiated on Day 1 and two were irradiated on Day 14. RBCs were tested over cold storage for quality parameters.

RESULTS

As expected, non-irradiated FP RCS had significantly higher supernatant potassium levels than controls throughout 28 days of storage (p < .001). When irradiated early, FP RCS released potassium at similar rates to control. When irradiated late, FP RCS supernatants had higher initial post-irradiation potassium concentration than controls but were similar to controls by the end of storage (14 days post-irradiation). No other parameters studied showed a significant difference between FP and control.

DISCUSSION

FP does not increase the rate of potassium leak from irradiated RBCs. Irradiation may cause a membrane defect similar to that in FP RBCs.

Metabolic reprogramming under hypoxic storage preserves faster oxygen unloading from stored red blood cells

Stored red blood cells (RBCs) incur biochemical and morphological changes, collectively termed the storage lesion. Functionally, the storage lesion manifests as slower oxygen unloading from RBCs, which may compromise the efficacy of transfusions where the clinical imperative is to rapidly boost oxygen delivery to tissues. Recent analysis of large real-world data linked longer storage with increased recipient mortality. Biochemical rejuvenation with a formulation of adenosine, inosine, and pyruvate can restore gas-handling properties, but its implementation is impractical for most clinical scenarios. We tested whether storage under hypoxia, previously shown to slow biochemical degradation, also preserves gas-handling properties of RBCs. A microfluidic chamber, designed to rapidly switch between oxygenated and anoxic superfusates, was used for single-cell oxygen saturation imaging on samples stored for up to 49 days. Aliquots were also analyzed flow-cytometrically for side-scatter (a proposed proxy of O2 unloading kinetics), metabolomics, lipidomics and redox proteomics. For benchmarking, units were biochemically rejuvenated at four weeks of standard storage. Hypoxic storage hastened O2 unloading in units stored to 35 days, an effect that correlated with side-scatter but was not linked to post-translational modifications of hemoglobin. Although hypoxic storage and rejuvenation produced distinct biochemical changes, a subset of metabolites including pyruvate, sedoheptulose 1-phosphate, and 2/3 phospho-D-glycerate, was a common signature that correlated with changes in O2 unloading. Correlations between gas-handling and lipidomic changes were modest. Thus, hypoxic storage of RBCs preserves key metabolic pathways and O2 exchange properties, thereby improving the functional quality of blood products and potentially influencing transfusion outcomes.

Effect of parachute delivery on red blood cell (RBC) and plasma quality measures of blood for transfusion

Background

Parachute airdrop offers a rapid transfusion supply option for humanitarian aid and military support. However, its impact on longer‐term RBC survival is undocumented. This study aimed to determine post‐drop quality of RBCs in concentrates (RCC), and both RBCs and plasma in whole blood (WB) during subsequent storage.

Study design and methods

Twenty‐two units of leucodepleted RCC in saline, adenine, glucose, mannitol (SAGM) and 22 units of nonclinical issue WB were randomly allocated for air transportation, parachute drop, and subsequent storage (parachute), or simply storage under identical conventional conditions (4 ± 2°C) (control). All blood products were 6–8 days post‐donation. Parachute units were packed into Credo Cubes, (Series 4, 16 L) inside a PeliCase (Peli 0350) and rigged as parachute delivery packs. Packs underwent a 4‐h tactical flight (C130 aircraft), then parachuted from 250 to 400 ft before ground recovery. The units were sampled aseptically before and after airdrop at weekly intervals. A range of assays quantified the RBC storage lesion and coagulation parameters.

Results

Blood units were maintained at 2–6°C and recovered intact after recorded ground impacts of 341–1038 m s⁻². All units showed a classical RBC storage lesion and increased RBC microparticles during 42 days of storage. Fibrinogen and clotting factors decreased in WB during storage. Nevertheless, no significant difference was observed between Control and Parachute groups. Air transportation and parachute delivery onto land did not adversely affect, or shorten, the shelf life of fresh RBCs or WB.

Discussion

Appropriately packaged aerial delivery by parachute can be successfully used for blood supply.

A comparison of the effect of X and gamma irradiation on red cell storage quality

BACKGROUND AND OBJECTIVES

Irradiation of red cell components is indicated for recipients at risk of transfusion-associated graft vs. host disease. Current technologies available comprise of a gamma (γ) or an x source of radiation. The benefits of x vs. γ include non-radioactivity and hence no decay of the source. We aimed to compare the effect of the two technologies on red cell component storage quality post-irradiation.

MATERIALS AND METHODS

Paired units of red cell concentrates (RCC), neonatal red cell splits (RCS), red cells for intra-uterine transfusion (IUT) or neonatal exchange transfusion (ExTx) were either γ- or x-irradiated. Units were sampled and tested for five storage parameters until the end of shelf life. Equivalence analysis of storage quality parameters was performed for pairs of the same components (RCC, RCS, IUT or ExTx) that were either γ- or x-irradiated.

RESULTS

Nearly all component comparisons studied showed equivalence between γ and x irradiation for haemolysis, ATP, 2,3-DPG, potassium release and lactate production. The exceptions found that were deemed non-equivalent were higher haemolysis with x irradiation for ExTx, lower 2,3-DPG with x irradiation for RCS irradiated early and higher ATP with x irradiation for IUT. However, these differences were considered not clinically significant.

CONCLUSION

This study has demonstrated that a range of red cell components for use in different age groups are of acceptable quality following x irradiation, with only small differences deemed clinically insignificant in a few of the measured parameters.

Familial pseudohyperkalemia induces significantly higher levels of extracellular potassium in early storage of red cell concentrates without affecting other standard measures of quality: A case control and allele frequency study

BACKGROUND

Familial pseudohyperkalemia (FP) is characterized by an increased rate of potassium leakage in refrigerated red cells and is associated with the minor allele of the single nucleotide polymorphism rs148211042 (R723Q) in the ABCB6 gene. The study aims were to obtain the minor allele frequencies of ABCB6 variants and to measure supernatant potassium accumulation, and other red cell storage parameters, in red cell concentrates (RCC) from carriers of variant rs148211042 under standard blood bank conditions.

STUDY DESIGN

Whole blood units were collected from 6 FP individuals and 11 controls and processed into RCC in additive solution. RCC were sampled and tested over cold storage for full blood count, extracellular potassium, glucose, lactate, microvesicle release, deformability, hemolysis, pH, adenosine triphosphate, and 2,3-diphosphoglycerate.

RESULTS

Screening of genotyped cohorts identified that variant rs148211042 is present in 1 in 394 British citizens of European ancestry. FP RCC had significantly higher supernatant potassium at all time points from day 3 onwards (p < .001) and higher mean cell volume (p = .032) than controls. The initial rate of potassium release was higher in FP RCC; supernatant potassium reached 46.0 (23.8-57.6) mmol/L (mean [range]) by day 5, increasing to 68.9 (58.8-73.7) mmol/L by day 35. Other quality parameters were not significantly different between FP RCC and controls.

CONCLUSION

These data suggest that if a blood donor has FP, reducing the RCC shelf-life to 5 days may be insufficient to reduce the risk of hyperkalemia in clinical scenarios such as neonatal large volume transfusion.

Effect of storage of plasma in the presence of red blood cells and platelets: re-evaluating the shelf life of whole blood

BACKGROUND

There is renewed interest in administering whole blood (WB) for the resuscitation of patients with bleeding trauma. The shelf life of WB was established decades ago based on the viability of red blood cells. However, plasma quality during WB storage is not established.

STUDY DESIGN AND METHODS

White blood cell- and platelet-reduced WB (WB-PLT) was prepared using standard processes and compared to WB processed using a platelet-sparing WBC reduction (WB + PLT) filter. WB (± PLT) was held at 2 to 6°C for 35 days alongside control units of red blood cells (RBCs) in saline, adenine, glucose, and mannitol and liquid plasma. A series of assays explored the coagulation potential and RBC quality.

RESULTS

While fibrinogen and α2-antiplasmin remained unaffected by storage, other factors varied between components or over time at 2 to 6°C. At 14 days factor V, factor VII, α₂ -antiplasmin and free protein S antigen remained on average greater than 0.50 IU/mL or 50%, as appropriate, in WB ± PLT. Factor VIII was on average 0.49 IU/mL in WB+PLT, and 0.56 IU/mL for WB-PLT. Free protein S activity decreased significantly in all arms but remained on average greater than 40% at Day 14. Contact activation was not demonstrated before Day 14. Thrombin generation in plasma remained relatively stable to Day 35 in all arms.

CONCLUSIONS

Clotting factor activity remained at or above a mean of 0.5 IU/mL, or 50%, at Day 14 for factor V, factor VII, factor VIII, free protein S, fibrinogen, and α2-antiplasmin in all arms. Further data on platelet function in WB+PLT is needed to inform its shelf life.

Rejuvenation of RBCs: validation of a manufacturing method suitable for clinical use

BACKGROUND

Rejuvenation of stored red blood cells (RBCs) increases levels of adenosine 5'-triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG) to those of fresh cells. This study aimed to optimize and validate the US-approved process to a UK setting for manufacture and issue of rejuvenated RBCs for a multicenter randomized controlled clinical trial in cardiac surgery.

STUDY DESIGN AND METHODS

Rejuvenation of leukoreduced RBC units involved adding a solution containing pyruvate, inosine, phosphate, and adenine (Rejuvesol, Zimmer Biomet), warming at 37°C for 60 minutes, then "manual" washing with saline adenine glucose mannitol solution. A laboratory study was conducted on six pools of ABO/D-matched units made the day after donation. On Days 7, 21, and 28 of 4 ± 2°C storage, one unit per pool was rejuvenated and measured over 96 hours for volume, hematocrit, hemolysis, ATP, 2,3-DPG, supernatant potassium, lactate, and purines added (inosine) or produced (hypoxanthine) by rejuvenation. Subsequently, an operational validation (two phases of 32 units each) was undertaken, with results from the first informing a trial component specification applied to the second. Rejuvenation effects were also tested on crossmatch reactivity and RBC antigen profiles.

RESULTS

Rejuvenation raised 2,3-DPG to, and ATP above, levels of fresh cells. The final component had potassium and hemolysis values below those of standard storage Days 7 and 21, respectively, containing 1.2% exogenous inosine and 500 to 1900 μmoles/unit of hypoxanthine. The second operational validation met compliance to the trial component specification. Rejuvenation did not adversely affect crossmatch reactivity or RBC antigen profiles.

CONCLUSION

The validated rejuvenation process operates within defined quality limits, preserving RBC immunophenotypes, enabling manufacture for clinical trials.

General overview of blood products in vitro quality: Processing and storage lesions

Blood products are issued from blood collection. Collected blood is immediately mixed with anticoagulant solutions that immediately induce chemical and/or biochemical modifications. Collected blood is then transformed into different blood products according to various steps of fabrication. All these steps induce either reversible or irreversible "preparation-related" lesions that combine with "storage-related" lesions. This short paper aims to provide an overview of the alterations that are induced by the "non-physiological" processes used to prepare blood products that are used in clinical practice.

Laboratory assessment of the quality of adult and neonatal red cell concentrates manufactured from whole blood, exchange transfusion or intrauterine transfusion red cell units

BACKGROUND

We evaluated the quality of red cell components in additive solution over 42 days of storage when re-manufactured from neonatal exchange transfusion (ExTx) or intrauterine transfusion (IUT) units on day 7 for issue to adults, neonates or infants.

MATERIALS AND METHODS

Red cell concentrates (RCC) manufactured from WB were compared to RCC re-manufactured from ExTx or IUT on day 7, and red cell splits (RCS) manufactured from WB were compared to RCS re-manufactured from ExTx or IUT on day 7. All components were stored at 2-6°C and tested throughout storage until day 42 for in vitro parameters of red cell quality. One RCS manufactured from each of WB, ExTx or IUT, was irradiated on day 14 and tested on day 28 along with a non-irradiated RCS from the same unit.

RESULTS

All the re-manufactured arms had no worse haemolysis, red cell microvesicle (RCMV) release or ATP over storage compared to controls. All arms complied with the 0·8% haemolysis UK specification, except for re-manufactured RCS from the IUT arm irradiated on day 14 and tested on day 28. Re-manufactured units had significantly decreased potassium levels compared to control over storage (P < 0·001 all).

CONCLUSION

RCC or RCS re-manufactured from ExTx or IUT units on day 7 are suitable for transfusion up to the standard day 35 of storage. Re-manufactured RCS from ExTx units (but not IUT), may be irradiated up to day 14 and stored for 14 days post-irradiation.

A Comparison of Red Cell Rejuvenation versus Mechanical Washing for the Prevention of Transfusion-associated Organ Injury in Swine

Background

We evaluated the effects of two interventions that modify the red cell storage lesion on kidney and lung injury in experimental models of transfusion.

Methods

White–landrace pigs (n = 32) were allocated to receive sham transfusion (crystalloid), 14-day stored allogeneic red cells, 14-day red cells washed using the red cells washing/salvage system (CATS; Fresenius, Germany), or 14-day red cells rejuvenated using the inosine solution (Rejuvesol solution; Zimmer Biomet, USA) and washed using the CATS device. Functional, biochemical, and histologic markers of organ injury were assessed for up to 24 h posttransfusion.

Results

Transfusion of 14 day red cells resulted in lung injury (lung injury score vs. sham, mean difference −0.3 (95% CI, −0.6 to −0.1; P = 0.02), pulmonary endothelial dysfunction, and tissue leukocyte sequestration. Mechanical washing reduced red cell–derived microvesicles but increased cell-free hemoglobin in 14-day red cell units. Transfusion of washed red cells reduced leukocyte sequestration but did not reduce the lung injury score (mean difference −0.2; 95% CI, −0.5 to 0.1; P = 0.19) relative to 14-day cells. Transfusion of washed red cells also increased endothelial activation and kidney injury. Rejuvenation restored adenosine triphosphate to that of fresh red cells and reduced microvesicle concentrations without increasing cell-free hemoglobin release. Transfusion of rejuvenated red cells reduced plasma cell-free hemoglobin, leukocyte sequestration, and endothelial dysfunction in recipients and reduced lung and kidney injury relative to 14-day or washed 14-day cells.

Conclusions

Reversal of the red cell storage lesion by rejuvenation reduces transfusion-associated organ injury in swine.

Temperature-dependent haemolytic propensity of CPDA-1 stored red blood cells vs whole blood - Red cell fragility as donor signature on blood units

BACKGROUND

To preserve cellular integrity and avoid bacterial growth, storage and transfer of blood and blood products follow strict guidelines in terms of temperature control. We evaluated the impact of ineligible warming of whole blood donations on the quality of blood components.

MATERIALS AND METHODS

One-hundred and twenty units of whole blood (WB) from eligible blood donors were collected in CPDA-1 and stored at 4±2 °C. During shipment to the blood processing centre, a gradual warming up to 17 °C was recorded within a period of less than eight hours. The warmed units were processed to packed red blood cells (PRBCs) or stored as WB units at 4±2 °C. In-bag haemolysis, osmotic fragility (mean corpuscular fragility, MCF) and bacterial growth were assessed in blood and blood components throughout the storage period.

RESULTS

Normal basal and early storage levels of haemolysis were recorded in both PRBC and WB units. Thereafter, PRBCs exhibited higher average in-bag haemolysis and MCF index compared to the WB units throughout the storage. Moreover, 14.3 and 52.4% of the PRBC units exceeded the upper permissible limit of 0.8% haemolysis at the middle (1.220±0.269%) or late (1.754±0.866%) storage period, respectively. MCF index was similar in all PRBCs at the middle of storage but significantly lower in the non-haemolysed compared to the haemolysed units of PRBCs on the last days. The fragility of stored RBCs was proportional to the donor-related values of day 2 samples (r=0.861, p<10^-32). In the qualified PRBCs, MCF was correlated with haemolysis at every time point of the storage period (r=0.332, p<0.050). Bacterial growth was detected by blood culture in two units of PRBCs.

DISCUSSION

Transient, gradient warming of whole blood from 4 to 17 °C led to increased incidence of in-bag haemolysis in PRBC but not in WB units. Haemolysis is a multi-parametric phenotype of stored blood, and MCF is a donor-related and highly dynamic measure that can, in part, predict the storage lesion.

Critical re-appraisal of blood component quality after overnight hold of whole blood outside current room temperature limits

BACKGROUND AND OBJECTIVES

According to European guidelines, the temperature of whole blood (WB) has to be maintained at 20-24°C until processing within 24 h, but in blood bank practice, WB is frequently held at temperatures between 18-25°C. We aimed to assess the impact of these small temperature deviations on the quality of the blood components.

MATERIALS AND METHODS

After rapid cooling, 7 WB units were held overnight at 18°C and 8 units at 25°C, reflecting worst case holding conditions, and separated into a red cell concentrate (RCC), plasma and buffy coat (BC). RCCs were filtered at test temperature and stored for 42 days at 2-6°C. BCs were processed to single-BC platelet concentrates (sPC) and stored up to Day 8 at 20-24°C.

RESULTS

After overnight hold at 18°C, 2,3-DPG in WB decreased by 34 ± 9%, while at 25°C the decrease was 82 ± 6%. Accordingly, the 2,3-DPG levels in the RCCs in the 25°C group were significantly lower than in the 18°C group (2·2 ± 1·4 vs. 10·4 ± 2·9 μmol/g Hb). RCCs and sPCs in the 25°C group showed higher initial lactate levels and lower pH compared to the 18°C group, but these differences levelled off at the end of storage. RCCs showed small differences in ATP levels and haemolysis. Plasma in both groups showed comparable Factor VIII:C levels.

CONCLUSION

The temperature of WB during overnight hold strongly affects initial 2,3-DPG levels of RCCs and supports the maintenance of temperature limits between 20 and 24°C. Other in vitro effects of the temperature deviations were small and of no practical relevance.

Quality Assessment of Established and Emerging Blood Components for Transfusion

Blood is donated either as whole blood, with subsequent component processing, or through the use of apheresis devices that extract one or more components and return the rest of the donation to the donor. Blood component therapy supplanted whole blood transfusion in industrialized countries in the middle of the twentieth century and remains the standard of care for the majority of patients receiving a transfusion. Traditionally, blood has been processed into three main blood products: red blood cell concentrates; platelet concentrates; and transfusable plasma. Ensuring that these products are of high quality and that they deliver their intended benefits to patients throughout their shelf-life is a complex task. Further complexity has been added with the development of products stored under nonstandard conditions or subjected to additional manufacturing steps (e.g., cryopreserved platelets, irradiated red cells, and lyophilized plasma). Here we review established and emerging methodologies for assessing blood product quality and address controversies and uncertainties in this thriving and active field of investigation.

Thawed and liquid plasma--what do we know?

There is increasing interest in the use of liquid or frozen plasma thawed and stored for extended periods (>24 h) to reduce wastage and to improve rapid availability of plasma in massive transfusion protocols advocating the early use of plasma in trauma by some centres. There is now a body of studies that have assessed individual coagulation factors during storage of thawed plasma. These show that factor VIII (FVIII) is the worst affected factor and that its activity is mainly lost during the first 24 h following thawing. However, for most factors studied, there is a continual decline during further storage. The few studies that have assessed thrombin generation in thawed plasma have shown variable results. Extended storage of plasma is associated with an increase in levels of DEHP in the component and could theoretically increase the risk of bacterial contamination, although the latter does not appear to have been an issue in countries that have adopted the use of thawed plasma. There are no clinical studies relating to the efficacy of extended-thawed plasma, and therefore, the potential reduction in its efficacy must be balanced with the clinical need for the component.

The effects of an overnight holding of whole blood at room temperature on haemoglobin modification and in vitro markers of red blood cell aging

BACKGROUND

Some effects of the red blood cell (RBC) storage lesion are well documented whereas others are not. Whether a period of room temperature hold (RTH) during RBC production enhances the RBC storage lesion has remained controversial. In this study, we compared whole blood (WB)-derived RBCs produced after 24-h RTH with rapidly cooled (RC) RBCs and tested them for classical metabolic markers and signs of oxidative damage.

STUDY DESIGN AND METHODS

SAGM-RBCs were prepared from mixed and split pairs (n = 12) of WB units. RBCs prepared after a 24-h period of RTH on day+1 after collection (RTH-RBCs) were compared with RC-RBCs. All RBCs were stored at 4°C for 42 days with assay of in vitro variables on days+1, +15, +22, +29 and +42. The study examined standard quality parameters, glutathione, catalase and superoxide dismutase (SOD) activities, and indicative markers of oxidative cell damage including post-translational haemoglobin modification, malondialdehyde (MDA), and phosphatidylserine expression.

RESULTS

RTH-RBCs exhibited decreased levels of potassium (1·98 ± 0·26 vs. 5·23 ± 0·65 mmol/l) and of 2,3-diphosphoglycerate (2,3-DPG) on day+1 compared with RC-RBCs. Haemolysis rate on day+42 was higher in RTH-RBCs than in RC-RBCs (0·52 ± 0·13 vs. 0·37 ± 0·12%). The phosphatidylserine expression amounted to 0·25 ± 0·20% in RTH-RBCs and 0·07 ± 0·12% in RC-RBCs. Haemoglobin modification was not different between both RBC groups. RTH-RBCs showed slightly higher MDA concentration on days +29 and +42.

CONCLUSIONS

RC-RBCs and RTH-RBCs show only small differences of classical in vitro parameters and no relevant differences in antioxidative metabolism and oxidative haemoglobin modification. These findings do not explain the loss observed in in vivo survival studies with RBCs.

Microparticle profile and procoagulant activity of fresh-frozen plasma is affected by whole blood leukoreduction rather than 24-hour room temperature hold

BACKGROUND

Microparticles (MPs) are small phospholipid-containing vesicles that have procoagulant properties. MPs are thought to contribute to the hemostatic potential of plasma. This study investigated the effects of whole blood (WB) hold time and leukoreduction (LR) on the MP profile and hemostatic potential of fresh-frozen plasma (FFP).

STUDY DESIGN AND METHODS

WB units (n=12) from healthy donors were divided into two pairs and each pair was held at 20 to 24°C for 6 or 24 hours. At the designated hold time, 1 unit from the pair was LR while the other unit was not LR. FFP was prepared by standard procedures, aliquoted, and frozen. The MP content was determined by flow cytometry using an absolute count assay and specific labels for red blood cells (CD235a), platelets (CD41), and phosphatidylserine (PS). The hemostatic potential was determined by thrombelastography (TEG) and coagulation factor assays.

RESULTS

Compared to non-LR-FFP, LR-FFP had significantly lower numbers of MPs, particularly CD41+ MPs and PS-positive MPs (p<0.03). LR-FFP, compared to non-LR-FFP, had a slower clot formation time (p=0.002); lower clot strength (p<0.001); and lower Factor (F)VIII, FXII, and fibrinogen levels (p<0.01). With longer WB hold time, the TEG profile was unchanged, although FVIII levels were decreased as expected (p<0.01). On average FFP units met quality requirements.

CONCLUSION

LR of WB resulted in lower hemostatic potential of FFP in conjunction with depletion of MPs and coagulation factors. Longer WB hold time did not significantly affect the hemostatic potential of FFP as measured by TEG. Acceptable hemostatic quality was maintained for all FFP processing conditions studied.

Impact of constant storage temperatures and multiple warming cycles on the quality of stored red blood cells

BACKGROUND

Red blood cells (RBCs) are routinely stored in liquid state at temperatures below 6°C, and RBC unit core temperature should not exceed 10°C during transport. Since the critical temperature of 10°C was chosen mostly arbitrarily, this study investigated the effect of both constant temperature settings as well as multiple rewarming cycles on stored RBCs with respect to morphology, biochemical parameters and haemolysis.

MATERIALS AND METHODS

Buffy coat-depleted filtered RBCs were used as standard products. RBCs were stored at 1-6°C (reference group, n = 12), 13 and 22°C (test groups, n = 12 each) or stored at 1-6°C and warmed up five times to 10, 13, or 22°C for a period of 24 h each. Various biochemical parameters were measured weekly. RBCs were further investigated using electron microscopy.

RESULTS

Red blood cells stored constantly at 13 or 22°C showed stable haemolysis rates until day 28 and day 14, respectively. RBCs stored at 1-6°C with five warming-up periods to 10, 13 or 22°C each lasting 24 h (total 120 h) did not exceed the limit of the haemolysis rate at the end of storage. Differently shaped erythrocytes were found in all samples, but more crenate erythrocytes appeared after 42 days of storage independent of temperature profiles.

CONCLUSION

Red cells can be kept at constant temperatures above 6°C without apparent harmful effects at least until day 14, whereas multiple warming cycles for no longer than 24 h at 10, 13 or 22°C with subsequent cooling do not cause quality loss as assessed using the in vitro assays employed in this study.

The 30 minute rule for red blood cells: in vitro quality assessment after repeated exposure to 30°C

BACKGROUND

Red blood cells (RBC) may be out of temperature control only for 30 minutes before they must be discarded, but evidence for this rule is weak. We investigated the effect on RBC quality of multiple exposures to 30°C.

STUDY DESIGN AND METHODS

RBC units made after 24 hours of whole blood ambient hold were pooled and split into adult and pediatric units and exposed to permitted deviations (5-hr core temperature 10°C, 12-hr surface temperature 10°C). Test units were exposed to 30°C once, twice, or three times on each of Days 15, 17, and 21, for 30 or 60 minutes. Negative controls were not exposed to 30°C; positive control was exposed to 30°C for 24 hours.

RESULTS

Adult units exposed once for 30 or 60 minutes (×3 occasions) showed no more hemolysis than negative control. Units exposed to 30°C for two or three periods of 60 minutes showed more hemolysis from Day 28. Hemolysis in pediatric units exposed for 30 minutes (×3) was not increased but units exposed to one or two periods of 60 minutes (×3) showed higher hemolysis. No differences were seen in supernatant potassium. ATP remained at an acceptable level on Day 28 in all but positive controls.

CONCLUSIONS

There was no evidence of significant damage to RBC after exposure to 30°C for three periods of 30 minutes. Multiple exposures of 60 minutes caused limited damage but this was within current regulatory limits if there were three or fewer exposures, suggesting that a 60-minute rule may be feasible.

Repeated short-term warming of red blood cell concentrates has minimal effect on their quality

BACKGROUND AND OBJECTIVES

Blood components must be stored under controlled temperature conditions, for reasons of component quality and safety. However, there are occasions when components may be exposed to conditions outwith the defined limits. This study aimed to generate prospective data on the effect of red cell exposure to extremes of temperature.

MATERIALS AND METHODS

Study 1: red cell concentrates (RCC) in saline, adenine, glucose and mannitol (SAGM), made after ambient overnight hold of whole blood, were exposed to either +22°C or -2°C for up to three periods of 3 h on days 3, 8 and 15 of storage, followed by a 5 h exposure on day 29. Study 2: RCC in SAGM were exposed to 25°C for 24 or 48 h from day 2. In vitro markers of cell quality were measured during storage to 43 days, and compared with control units that had been stored at 2-6°C.

RESULTS

Multiple short-term exposures to +22°C or -2°C did not cause any significant changes to pH, haemolysis, supernatant potassium, cellular ATP, 2,3-DPG, or deformability, when compared to control units. Exposure of RCC to 25°C for 24 or 48 h caused a significant fall in pH, ATP, and deformability.

CONCLUSION

Red cells may be damaged by prolonged exposure to warm temperatures, but repeated short-term exposure to 22°C or -2°C does not appear to affect the in vitro quality of RCC. It is important to note that no bacterial growth studies were performed during this study.

Platelet concentrates prepared after a 20- to 24-hour hold of the whole blood at 22°C

BACKGROUND

The Food and Drug Administration (FDA) requires that red blood cells must be refrigerated within 8 hours of whole blood collection. Longer storage of whole blood at 22°C before component preparation would have many advantages.

STUDY DESIGN AND METHODS

Two methods of holding whole blood for 20 to 24 hours at room temperature were evaluated, refrigerated plates or a 23°C incubator. After extended whole blood storage, platelet (PLT) concentrates were prepared from PLT-rich plasma on Day 1 postdonation, and the PLTs were stored for 6 more days. On Day 7 of PLT storage, blood was drawn from each subject to prepare fresh PLTs. The stored and fresh PLTs were radiolabeled and transfused into their donor.

RESULTS

Eleven subjects' whole blood was stored using refrigerated butanediol plates (Compocool, Fresenius), and 10 using an incubator. Poststorage PLT recoveries averaged 47 ± 13% versus 53 ± 11% and survivals averaged 4.6 ± 1.7 days versus 4.7 ± 0.9 days for Compocool versus incubator storage, respectively (p = NS). With all results, poststorage PLT recoveries averaged 75 ± 10% of fresh and survivals 57 ± 13% of fresh; PLT recoveries met FDA guidelines for poststorage PLT viability but not survivals.

CONCLUSION

Seven-day poststorage PLT viability is comparable when whole blood is stored for 22 ± 2 hours at 22°C using either refrigerated plates or an incubator to maintain temperature before preparing PLT concentrates.

Red cell concentrate storage and transport temperature

BACKGROUND AND OBJECTIVES

This study investigated the current U.K. guidelines for storage and transport of red cell concentrates (RCC) in saline, adenine, glucose and mannitol (SAGM). The guidelines stipulate storage at 2-6 °C but allow exposure to between 1-10 °C core temperature in a single occurrence of less than 5 h and a surface temperature of 2-10 °C for no more than 12 h during transportation.

METHODS AND MATERIALS

Twenty RCC units in SAGM were selected on the day of blood collection (day 0) and in vitro quality was tested pre- and post-temperature deviation at 10 °C and up to day 42 of storage. Each group of 10 RCC units was incubated for either 12 h or for both 5 and 12 h.

RESULTS

Haemolysis was below the 0·8% U.K. limit at day 42 in all units, although there was an unexpected trend towards lower haemolysis in packs incubated for 5 and 12 h rather than just 12 h alone. Supernatant potassium was significantly higher than reference data on day 35 (P < 0·05) with a maximum of 58 mmol L(-1) and day 42 (P < 0·001). All units incubated at 10 °C had comparable levels of adenosine triphosphate and, 2,3-diphosphoglycerate to reference data from previous studies, throughout storage.

CONCLUSION

These results suggest that exposure to 10 °C for 12 h or for 5 and 12 h did not adversely affect in vitro red cell quality for the remainder of the components shelf life.

Manufacture of red cells in additive solution from whole blood refrigerated for 5 days or remanufactured from red cells stored in plasma

BACKGROUND AND OBJECTIVES

To investigate methods for the production of red cell concentrates (RCC) in saline, adenine, glucose and mannitol (SAG-M), from whole blood or red cells stored in plasma for 5 or 6 days and to provide evidence that exchange transfusion RCC in citrate phosphate dextrose (CPD) plasma or citrate, phosphate, dextrose, adenine (CPDA-1) plasma are of comparable quality.

METHODS AND MATERIALS

Ten RCC in SAG-M were produced following the remanufacture of red cells in CPD plasma on day 5/6 or after 5 days hold as leucodepleted CPD whole blood. In addition, 10 RCC in CPD plasma and 9 in CPDA-1 plasma were stored without further processing. Units were assessed for red cell parameters including haemolysis, adenosine triphosphate (ATP), 2,3-diphosphoglycerate (2,3-DPG) and extracellular potassium.

RESULTS

Units in SAG-M produced by remanufacture of RCC in plasma or by delayed manufacture of whole blood had comparable levels of haemolysis, ATP and 2,3-DPG. Furthermore, these units underwent biochemical changes similar to reference SAG-M units, with the exception of haemolysis which was greater at the end of shelf life and supernatant potassium which was lower following remanufacture. As expected, the decline in ATP was greater in red cells stored in CPD plasma compared with CPDA-1 plasma. In general, units in CPD plasma were of similar quality at day 28 compared to those in CPDA-1 plasma at day 35.

CONCLUSIONS

RCC produced following the remanufacture of RCC in plasma or the delayed manufacture of whole blood are of acceptable in vitro quality and should be assigned the same shelf life as standard RCC in SAG-M.

Ambient overnight hold of whole blood prior to the manufacture of blood components

Blood services routinely separate whole blood into components that are then stored under different conditions. The storage conditions used for whole blood prior to separation must therefore be a compromise between the needs of the red cells (which benefit from refrigeration) and plasma and platelets (which are better preserved at ambient temperature). For many years, the approach has been to manufacture plasma and platelet components on the day of blood collection, and to refrigerate any unprocessed blood for manufacture into red cell components on the following day. However, this can make it challenging to maintain adequate stocks of all components. The European practice of 'ambient hold' of whole blood for up to 24 hours prior to processing allows greater flexibility in blood component manufacture, and the data reviewed suggest there is relatively little impact on the quality of red cell or plasma components, and an improvement in the quality of platelet components.

Evaluation of the properties of components prepared and stored after holding of whole blood units for 8 and 24 hours at ambient temperature

BACKGROUND

The capability of holding whole blood (WB) units at ambient temperature, overnight, should help in platelet (PLT) concentrate preparation logistics. We summarize the results of a study conducted in the early 1990s that compared, in particular, PLT and red blood cell (RBC) in vivo viability properties following storage after preparation after 8- and 24-hour WB hold periods.

STUDY DESIGN AND METHODS

Individuals donated units of WB on two occasions. Centrifugation at 20 to 24°C to separate PLTs and additive system RBC placement at 1 to 6°C was completed 8 hours after phlebotomy or after 24 hours in randomized order. Components were not leukoreduced. Studies including in vitro biochemical and hematologic analyses and autologous in vivo RBC and PLT evaluations were conducted at two sites.

RESULTS

RBC 24-hour in vivo (mean ± SD) recoveries (single-label approach), after 35 days of storage, were 79.2 ± 4.3 and 79.4 ± 3.9% (n = 9; p > 0.05), with WB holding periods of 8 and 24 hours, respectively. With 42 days of storage, recovery after a 24-hour hold was slightly less than with an 8-hour hold (72.9 ± 6.5% vs. 76.0 ± 5.4%; n = 17; p < 0.05). RBC 2,3-diphosphoglycerate acid levels were substantially less after the 24-hour hold compared to after the 8-hour hold (n = 18; p < 0.05). PLT recovery after 5 days of storage with 8- and 24-hour hold periods were similar, 51.1 ± 14.9 and 50.6 ± 17.7%, respectively (n = 18; p > 0.05). The PLT survival variable and in vitro properties reflecting storage quality also showed no significant difference.

CONCLUSION

RBC and PLT in vivo variables, and most in vitro variables, were not significantly different after storage with WB holding times of 8 and 24 hours except for a slight diminution of RBC recovery with the 24-hour hold after 42 days of storage.

Effect of additive solutions on red blood cell (RBC) membrane properties of stored RBCs prepared from whole blood held for 24 hours at room temperature

BACKGROUND

The quality of RBC components is influenced by collection, processing and storage conditions. Regulations require that whole blood (WB) units be refrigerated within 8 hours and processed into RBCs within 24 hours of collection. Overnight room temperature hold of WB has logistical advantages, but the effect on RBC quality has not been fully investigated. RBC additive solutions were compared for their ability to provide improved quality of RBCs prepared from WB held at room temperature for 24 hours.

STUDY DESIGN AND METHODS

Leukocyte-reduced RBCs were prepared from WB held at 20°C on cooling plates for 24 hours prior to processing. RBCs were stored in additive solutions, SAG-M (control), Erythrosol-4, and PAGGSM, under standard blood banking conditions and sampled during 49 days of storage. Stored RBCs were evaluated for RBC shape and microparticle (MP) accumulation using flow cytometry. Osmotic fragility, adhesion of RBCs to endothelium under shear stress conditions (0.5 dyne/cm(2) ), and routine RBC quality parameters were assessed.

RESULTS

RBCs stored in Erythrosol-4 and PAGGSM had decreased cell size, reduced osmotic fragility, and decreased accumulation of glycophorin A-positive MPs and annexin V-binding MPs compared with RBCs stored in SAG-M. RBCs stored in erythrosol-4 had increased adherence to endothelium at days 42 and 49 compared with RBCs stored in SAG-M or PAGGSM.

CONCLUSION

RBCs stored in PAGGSM or Erythrosol-4 had improved retention of RBC membrane and osmotic resilience. The development of new additive solutions may offer improved quality of RBC components prepared from WB held overnight at room temperature.

Active cooling of whole blood to room temperature improves blood component quality

BACKGROUND

Many countries use cooling plates to actively cool collected whole blood (WB) to room temperature. Until now, no paired comparison had been performed, and it was our aim to compare the effect of active versus no active cooling on the in vitro quality of WB and subsequently prepared blood components.

STUDY DESIGN AND METHODS

Two units of WB were pooled and divided shortly after donation. One unit was placed under a butane-1,4-diol plate to obtain active cooling; the other was placed in an insulated box with other warm units to mimic worst-case holding conditions. WB was held overnight and processed into a white blood cell (WBC)-reduced red blood cells (RBCs), buffy coat (BC), and plasma. The BCs were further processed into platelet (PLT) concentrates. RBCs were stored for 42 days, and PLT concentrates for 8 days (n = 12 paired experiments).

RESULTS

After overnight storage, ATP content of the RBCs was 4.9 ± 0.3 µmol/g Hb for actively cooled WB versus 4.5 ± 0.4 µmol/g Hb for not actively cooled WB (p < 0.001). On Day 42 of storage, RBCs prepared from this WB contained 3.1 ± 0.3 µmol ATP/g Hb with active cooling versus 2.6 ± 0.3 µmol/g Hb without (p < 0.001). Hemolysis on Day 42 was 0.35 ± 0.08% with active cooling and 0.67 ± 0.21% without (p < 0.001). No effect was observed on the in vitro quality of plasma, BC, or PLT concentrates.

CONCLUSIONS

Active cooling of WB results in improved ATP levels and less hemolysis in WBC-reduced RBCs, although the clinical implications are unclear. It has no effect on the in vitro quality of plasma or PLT concentrates.

Instituting a thawed plasma procedure: it just makes sense and saves cents

BACKGROUND

The objectives of this time-series study were to elucidate the impact of a thawed plasma standard operating procedure (TP SOP) on plasma wastage and on cost savings.

STUDY DESIGN AND METHODS

This study compared plasma wastage for 1 year before versus 1 year after implementation of a TP SOP.

RESULTS

The plasma wastage and discard declined 79.7 and 64.9%, respectively, with a cost savings of $15,654.79 during the 1 year after implementation of the TP SOP. The risk that a unit of plasma would be wasted decreased 86.2% from Year 1 to Year 2 and the risk that a unit of plasma would be discarded decreased 76.3% from Year 1 to Year 2.

CONCLUSION

Our study showed the positive, sustained, impact of implementing a TP SOP. Twelve months after introducing the SOP our Blood Bank and Transfusion Medicine Services' plasma wastage and discard were dramatically reduced, saving thousands of dollars. Initiating a TP SOP just makes sense; it is easy to implement, conserves plasma, and saves cents.

Prion reduction of red blood cells: impact on component quality

BACKGROUND

A filter has been developed (P-Capt, MacoPharma) to remove infectious prions from red blood cells (RBCs). We sought to assess 1) its operational use, 2) the quality of filtered components, and 3) whether filtration resulted in any significant changes to blood group antigens.

STUDY DESIGN AND METHODS

A total of 272 leukoreduced RBC units, including units processed using "top-and-top" (TAT) and "bottom-and-top" (BAT) methods, were prion reduced using the P-Capt filter. All RBCs were assessed using standard in vitro tests of RBC quality. Changes to blood group antigen expression were also investigated, including the exposure of cryptantigens and the ability of filtered RBCs to be crossmatched.

RESULTS

Ninety-nine percent of TAT units and 58% of BAT units had a hemoglobin (Hb) content of more than 40 g. Hemolysis increased immediately after filtration, but units remained within UK specification throughout storage. Prion reduction resulted in the loss of 7 to 8 g of Hb and reductions in hematocrit of 6% to 9% due to the filter containing 40 mL of saline, adenine, glucose, and mannitol. Other RBC quality data, including extracellular potassium, 2,3-diphosphoglycerate, and adenosine triphosphate were similar to historical control data. There was no evidence of any immunologic changes of clinical relevance to the RBC membrane after filtration.

CONCLUSIONS

Prion filtration does not appear to have a detrimental effect on basic in vitro measures of RBC quality or on blood group antigens as assessed by in vitro methods. However, prion filtration using the P-Capt filter results in loss of Hb.