Cold storage of whole blood in an additive solution containing apoptotic and necrotic inhibitors.

BACKGROUND: Whole blood (WB) reigns superior to component therapy for the treatment of hemorrhagic shock on the battlefield. Though cold storage of WB offers a shelf life of 21 to 35 days, storage lesions and the potential for blood wastage remain. Storing WB in an additive solution (AS) containing apoptotic inhibitors may help preserve blood cell viability and improve blood quality over extended cold storage. STUDY DESIGN AND METHODS: Non-leukoreduced WB was obtained from healthy individuals and dosed with: AS, AS+Necrostatin-1 (AS+N1), AS+Boc-D-fmk (AS+B; apoptosis inhibitor), AS+Q-VD-OPh (AS+Q; apoptosis inhibitor), and Control (0.9% saline). Blood bags were kept refrigerated (1°-6°C) for 21 days. Bags were tested on days 0, 7, 14, and 21 for complete blood count, metabolism, clot formation, aggregation function, platelet activation, and red blood cell quality. RESULTS: Platelet count was better preserved in all AS-containing samples. All groups displayed increased glucose consumption and lactate production with storage. Furthermore, all groups displayed a similar decline in clot strength (max amplitude) over the 21-day storage period. Bags that received AS displayed greater preservation of GPIIb expression and lower phosphatidylserine exposure. P-selectin expression was increased in all AS groups. DISCUSSION: Treatment of hemorrhagic shock with WB transfusion is logistically simpler than component therapy. Results from our study suggest that refrigerated WB stored with an AS containing apoptotic and necrotic inhibitors helps better preserve platelet count but does not improve platelet function. The future development of WB ASs is warranted to optimize both platelet quality and hemostatic function.

Efficacy and safety of platelet additive solution-E stored platelet concentrates.

INTRODUCTION: In 2018, platelet (PLT) additive solution-E (PAS-E) was introduced. The implementation of PAS-E was expected to diminish the number of allergic reactions in recipients following a PLT transfusion. Here, we evaluated the efficacy and safety of transfusions with PLTs stored in PAS-E. STUDY DESIGN AND METHODS: After implementation of PAS-E, data were collected from 2 cohorts of patients with hematological disorders as well as oncology patients, receiving PLTs in PAS-E. A similar patient group in a recent RCT, receiving PLTs in plasma, was used as a historical control group for both cohorts. Endpoints were corrected count increments (CCIs), bleeding scores (only reported in cohort 1), and the incidence of adverse reactions. RESULTS: In cohort 1, the mean 1-h CCI was 14.3 ± 6.9, and the 24-h CCI was 8.7 ± 5.6. In cohort 2, the 1-h CCI was 11.6 ± 7.8 and the 24-h CCI was 7.0 ± 6.1. In the control group, the 1-h CCI was 15.4 ± 5.5 and 24-h CCI 8.7 ± 4.8. Bleeding complications of WHO grade ≥2 occurred in 40% of patients in cohort 1 compared to 44% in plasma PCs. The incidence of adverse reactions was 1.2% in the two PAS-E cohorts, compared to 3.0% in plasma PCs. National hemovigilance data showed a significant reduction in allergic reactions with PAS-E PC transfusions as compared to plasma PCs with an odds ratio of 0.46 (CI 95% 0.37-0.58). CONCLUSION: The CCIs of PLTs in PAS-E were decreased compared to plasma PCs, but clinically acceptable. Allergic transfusion reactions were decreased in PAS-E PCs compared to plasma PCs.

Effects of pre-freeze pathogen reduction with riboflavin and UV light on red cells stored post-thaw in AS-3 additive solution.

BACKGROUND: Pathogen reduction technology (PRT) may improve the safety of RBCs for transfusion. As the Czech Republic considers PRT, we asked what effects riboflavin and UV light PRT pre-freezing has on the post-thaw recovery and properties of cryopreserved RBCs (CRBCs) after deglycerolization and liquid storage. STUDY DESIGN AND METHODS: 24 Group O whole blood (WB) units were leukoreduced and then treated with riboflavin and UV light PRT (Mirasol, Terumo BCT, USA) before cryopreservation (T-CRBC); 20 similarly-collected units were untreated controls (C-CRBC). Units were processed to RBCs and then cryopreserved with 40% glycerol (wt/vol), frozen at -80°C, stored >118 days, reconstituted as deglycerolized RBC units in AS-3, and stored at 4 ± 2°C for 21 days. One treated unit sustained massive hemolysis during the post-thaw wash process and was removed from data analysis. The remaining units were assessed pre-PRT, post-PRT, and post-thaw-wash on days 0, 7, 14, and 21 for hematocrit, volume, hemoglobin per transfusion unit, pH, % hemolysis, hemoglobin in the supernatant, potassium, phosphorus, NH3 , osmolality, ATP, and 2,3-diphosphoglycerate. RESULTS: PRT with leukoreduction caused a 5% loss of RBC followed by a 24% freeze-thaw-wash related loss for a total 28% loss but treated units contained an average of 45 g of hemoglobin, meeting European Union guidelines for CRBC. T-CRBCs displayed higher post-wash hemolysis, potassium, and ammonia concentrations, and lower ATP at the end of storage. CONCLUSIONS: Cryopreserved RBCs from Riboflavin and UV light-treated WB meet the criteria for clinical use for 7 days after thawing and provide additional protection against infectious threats.

The role of sodium citrate during extended cold storage of platelets in platelet additive solutions.

BACKGROUND: Cold-stored platelets are increasingly being used to treat bleeding. Differences in manufacturing processes and storage solutions can affect platelet quality and may influence the shelf life of cold-stored platelets. PAS-E and PAS-F are approved platelet additive solutions (PAS) in Europe and Australia, or the United States respectively. Comparative data are required to facilitate international transferability of laboratory and clinical data. STUDY DESIGN AND METHODS: Single apheresis platelets from matched donors (n = 8) were collected using the Trima apheresis platform and resuspended in either 40% plasma/60% PAS-E or 40% plasma/60% PAS-F. In a secondary study, platelets in PAS-F were supplemented with sodium citrate, to match the concentration in PAS-E. Components were refrigerated (2-6°C) and tested over 21 days. RESULTS: Cold-stored platelets in PAS-F had a lower pH, a greater propensity to form visible (and micro-) aggregates, and higher activation markers compared to PAS-E. These differences were most pronounced during extended storage (14-21 days). While the functional capacity of cold-stored platelets was similar, the PAS-F group displayed minor improvements in ADP-induced aggregation and TEG parameters (R-time, angle). Supplementation of PAS-F with 11 mM sodium citrate improved the platelet content, maintained the pH above specifications and prevented aggregate formation. DISCUSSION: In vitro parameters were similar during short-term cold storage of platelets in PAS-E and PAS-F. Storage in PAS-F beyond 14 days resulted in poorer metabolic and activation parameters. However, the functional capacity was maintained, or even enhanced. The presence of sodium citrate may be an important constituent in PAS for extended cold storage of platelets.

Platelet storage: Progress so far.

There is a crucial need for platelet transfusion during an emergency-surgery and treatment of platelet disorders. The unavailability of donors has furthermore increased the demand for platelet storage. Platelets have limited shelf life due to bacterial contamination and storage lesions. Temperature, materials, oxygen availability, media, platelet processing and manufacturing methods influence the platelet quality and viability during storage. The conception of various platelet additive solutions along with the advent of plastic storage during the 1980s led to enormous developments in platelet storage strategies. Cold storage of platelets gained attention despite its inability to contribute to platelet survival post-transfusion as it offers faster haemostasis. Several developments in platelet storage strategies over the years have improved the quality and shelf-life of stored platelets. Despite the progress, the efficacy of platelets during storage beyond a week has not been achieved. Antioxidants as additives have been explored in platelet storage and have proven to enhance the efficacy of platelets during prolonged storage. However, the molecular interactions of antioxidants in platelets can provide a better understanding of their mechanism of action. Optimization of dosage concentrations of antioxidants is also a critical parameter to be considered as they tend to exhibit toxicity at certain levels. This review provides comprehensive insights into the critical factors affecting platelet storage and the evolution of platelet storage. It also emphasizes the role of antioxidants as additives in platelet storage solutions and their future prospects towards better platelet banking.

A novel, quantitative clot retraction assay to evaluate platelet function.

Blood platelets are crucial to prevent excessive bleeding following injury to blood vessels. Platelets are crucial for the formation of clots and for clot strength. Platelet activation involves aggregation, attachment to fibrin and clot retraction. Most assays that address platelet function measure platelet aggregation, not clot retraction. Here, we describe a 96-well-based clot retraction assay that requires a relatively short runtime and small sample volume. The assay involves continuous optical density monitoring of platelet-rich plasma that is activated with thrombin. The data can be analyzed using time-series analytical tools to generate quantitative information about different phases of clot formation and clot retraction. The assay demonstrated good repeatability and reproducibility and was robust to different calcium concentrations. Impairment of platelet bioenergetics, actin polymerization, fibrin interaction, and signaling significantly affected clot retraction and was detected and showed good agreement with light transmission aggregometry, suggesting that clot retraction is predictive of platelet function. Using this microplate clot retraction assay, we showed a significant difference in platelets stored in autologous plasma compared with platelet additive solution after 7 days of room temperature storage.

Platelets are cell fragments in the blood that are necessary for clot formation. They are crucial to preventing excessive bleeding following trauma. To form clots, platelets clump (aggregate) and attach to fibrin protein and cells inside the blood vessels to form strong web-like structures. Platelets also contract to pull the edges of the wound close. Most measurements of platelet function involve aggregation. This paper focuses on platelet contraction. Here, we describe a new assay to measure platelets contraction that is repeatable and reproducible. The assay uses standard and common laboratory equipment and can be performed by most laboratory personnel and has the potential to detect clinical pathologies of clot formation. The assay could be developed for bedside patient care where platelet function could be assessed rapidly and assist in the diagnosis of coagulation and platelet disorders.

Gamma and X-ray irradiation do not affect the in vitro quality of refrigerated apheresis platelets in platelet additive solution (PAS-E).

BACKGROUND: Platelet refrigeration (cold storage) provides the advantages of an extended shelf life and reduces the risk of bacterial growth, compared to platelets stored at room temperature (RT). However, processing modifications, such as irradiation, may further improve the safety and/or alter the quality of cold-stored platelets. Platelet components are irradiated to prevent transfusion-associated graft versus host disease (TA-GvHD) in high-risk patients; and while irradiation has little effect on the quality of RT-stored platelet components, there is no data assessing the effect irradiation has following cold storage. STUDY DESIGN AND METHODS: Triple-dose apheresis platelets were collected in 40% plasma/60% PAS-E, using the TRIMA apheresis platform, and refrigerated (2-6°C) within 8 h of collection. On day 2, one of each component was gamma or X-ray irradiated or remained non-irradiated. Platelets were tested over 21 days. RESULTS: The platelet concentration decreased by approximately 20% in all groups during 21 days of storage (p > .05). Irradiation (gamma or X-ray) did not affect platelet metabolism, and the pH was maintained above the minimum specification (>6.4) for 21 days. The surface phenotype and the composition of the supernatant was similar in non-irradiated and irradiated platelets, regardless of the source of radiation. Functional responses (aggregation and clot formation) were not affected by irradiation. DISCUSSION: Gamma and X-ray irradiation do not affect the in vitro quality of platelet components stored in the cold for up to 21 days. This demonstrates the acceptability of irradiating cold-stored platelets, which has the potential to improve their safety for at-risk patient cohorts.

In vitro storage characteristics of neonatal platelet concentrates after addition of 20% PAS-E.

BACKGROUND AND OBJECTIVES: An observed decline in end-of-storage pH in plateletpheresis-derived platelet concentrates for neonatal use suspended in 100% autologous plasma was expected to be reversed by the addition of a platelet additive solution, (PAS)-E, increasing unit volume by approximately 20%. This study determined the impact on other in vitro storage parameters to ensure the expected increase in pH did not mask an adverse impact on component quality. STUDY DESIGN AND METHODS: For each replicate, one of a pair from a double adult dose plateletpheresis collection had approximately 50 ml of PAS-E added on Day 3 of storage. Its unmodified twin served as a control. Each adult dose was split into four neonatal storage packs and tested on Days 3, 6, 7 and 8. Three of 12 replicates were from donors with a history of low pH at end of storage and reflected the worst-case scenario for the new components. A further experiment evaluated whether any differences were simply due to the increased unit volume. RESULTS: In the nine randomly selected collections, pH on Day 8 was approximately 0.4 units higher in the test units. Platelet activation tended to be lower, with CD62P surface expression on Day 8 of 54.6 ± 9.9% compared to 65.8 ± 10.7% for controls (p < 0.001). Test units from donors with historically low pH retained pH22°C levels above 6.8 compared to controls (<6.4 on Day 8). CONCLUSION: The addition of 20% PAS-E by volume increased the buffering capacity of the units whilst maintaining other in vitro storage characteristics.

Dual preparation of plasma and platelet concentrates in platelet additive solution from platelet concentrates in plasma using a novel filtration system.

BACKGROUND AND OBJECTIVES: Platelet concentrates suspended in a platelet additive solution (PAS-PC) are associated with a reduction in allergic response and are suitable for preparing pathogen-inactivated PC. We aimed to develop an efficient platform for the dual preparation of PAS-PC and platelet-poor plasma. MATERIALS AND METHODS: PAS-PC was prepared in six steps by using a hollow-fibre system based on cross-flow filtration: priming, loading PC, loading PAS, collection of filtered liquid (flow-through) and collection of platelets by washing with PAS followed by washing with air. In this study, the efficacy of platelet and plasma protein recovery and characteristics of recovered PAS-PC and flow-through plasma were analysed in detail. RESULTS: Recoveries of platelet in PAS-PC and plasma protein in the flow-through were 95.4% ± 3.7% and 61.6% ± 5.0%, respectively. The residual plasma protein in PAS-PC was 34.1% ± 2.8%. Although the expression level of CD62P, a platelet activation marker, in recovered platelets was approximately 1.2-fold of that in original platelets, swirling patterns were well retained, and aggregation in PAS-PC was not visible. Agonist-induced aggregabilities, platelet morphology and hypotonic shock recovery were conserved. The patterns of plasma protein and lipoprotein in the flow-through were comparable with those in the original PCs. The multimeric pattern analysis of VWF remained unaltered. CONCLUSION: We propose a highly efficient preparation system that enables the simultaneous production of PAS-PC and platelet-poor plasma. It also achieves a high recovery of functionally well-retained platelets with very low activation.

The in vitro quality of X-irradiated platelet components in PAS-E is equivalent to gamma-irradiated components.

BACKGROUND: Blood components are irradiated to inactivate lymphocytes in an effort to prevent transfusion-associated graft versus host disease. Although gamma irradiators are commonly used, they are subjected to rigorous health, safety, and compliance regulations, compared with X-irradiators which have the advantage of only emitting radiation while the machine is switched on. While the effects of gamma irradiation on platelet components are well known, there is little or no data comparing the effects of X- and gamma-irradiation on the quality of these components. Therefore, this study examined the in vitro quality of platelet components (pooled and apheresis) following X- or gamma-irradiation. STUDY DESIGN AND METHODS: Whole-blood-derived (pooled) and apheresis platelet components in platelet additive solution (n = 20 pairs for each type) were irradiated (X vs. gamma). In vitro platelet quality was tested prior to irradiation (day 1) and subsequently on days 2, 5, and 7. Non-irradiated components were tested on day 5 in parallel as reference controls. Metabolic parameters, surface expression of glycoproteins and activation markers (CD62P and annexin-V binding), and agonist-induced aggregation were measured. RESULTS: All components met Council of Europe specifications. There were no statistical differences in any in vitro quality measurements between X- and gamma-irradiated pooled or apheresis platelet components. CONCLUSION: X- and gamma-irradiation have similar effects on the in vitro quality of stored blood components, indicating that either technology represents a suitable option for irradiation of platelet components.

Refrigeration of apheresis platelets in platelet additive solution (PAS-E) supports in vitro platelet quality to maximize the shelf-life.

BACKGROUND: Refrigeration, or cold-storage, of platelets may be beneficial to extend the limited shelf-life of conventionally stored platelets and support transfusion protocols in rural and military areas. The aim of this study was to compare the morphologic, metabolic, and functional aspects of apheresis platelets stored at room-temperature (RT) or cold conditions, in either plasma or supplemented with platelet additive solution (PAS). STUDY DESIGN AND METHODS: Double-dose apheresis platelets were collected in either 100% plasma or 40% plasma/60% PAS-E using the Trima apheresis platform. One component from each group was either stored at RT (20-24°C) or refrigerated (2-6°C). Platelets were tested over a 21-day period. RESULTS: The platelet concentration decreased by approximately 30% in all groups during 21 days of storage (p > .05). Cold-storage reduced glycolytic metabolism, and the pH was maintained above the minimum specification (>6.4) for 21 days only when platelets were stored in PAS. The surface phenotype and the composition of the supernatant were differentially affected by temperature and storage solution. Functional responses (aggregation, agonist-induced receptor activation, clotting time) were improved during cold-storage, and the influence of residual plasma was assay dependent. CONCLUSION: In vitro platelet quality is differentially affected by storage time, temperature, and solution. Cold-storage, particularly in PAS, better maintains key metabolic, phenotypic, and functional parameters during prolonged storage.

Cold-stored platelets have better preserved contractile function in comparison with room temperature-stored platelets over 21 days.

Although it is well established that transfusion of platelets in cases of severe bleeding reduces mortality, the availability of platelets is hampered by harsh restrictions on shelf life due to elevated risks of microbial contamination and functional losses with room temperature-stored platelets (RTP) kept at 22°C. In contrast, many recent studies have shown that 4°C cold-stored platelets (CSP) are able to overcome these shortcomings leading to the recent Food and Drug Administration licensure for 14-day stored CSP when conventional platelets are unavailable. This work expands the evidence supporting superiority of CSP function by assaying the less explored platelet-mediated clot retraction of RTP and CSP in either autologous plasma (AP) or platelet additive solution (PAS) for up to 21 days. The results demonstrate that CSP have better preservation of contractile function, exhibiting retraction for up to 21 days in both AP and PAS and forming highly ordered fibrin scaffolds similar to those of fresh platelets. In contrast, RTP stored in AP showed impaired contractile function by Day 5 with no retraction after 10 days, whereas PAS-stored RTP retained contractile function for up to 21 days. Collectively, these findings support extended storage of CSP and suggest that storage in PAS can mitigate functional losses in RTP.

Preventing adverse reactions in pediatric transfusions using washed platelet concentrate.

Blood transfusion is an important form of supportive care in children; however, transfusion-associated adverse reactions (TARs) are a problem. As with adults, allergic transfusion reactions (ATRs) and febrile non-hemolytic transfusion reactions (FNHTRs) are major TARs, and the frequency of ATRs caused by platelet concentrate (PC) tends to be particularly high. The plasma component of the blood product is thought to be a major factor in the onset of TARs such as ATR and FNHTR. By contrast, in children, age, underlying disease, and number of blood transfusions may be relevant patient-related factors. Although acetaminophen or diphenhydramine may be used prophylactically to prevent TARs, there is no clear evidence of their effectiveness. Volume-reduced PC is used to prevent TARs; however, it may be difficult to maintain the quality of platelets. Plasma-replaced PC stored with platelet additive solution raises the concern that TARs cannot be completely prevented by residual plasma. Washed PC removes most of the plasma, so it can effectively prevent ATR and FNHTR. The recent development of platelet additive solution [M-sol, bicarbonate Ringer's solution supplemented with acid-citrate-dextrose formula A (BRS-A)] in Japan has enabled the maintenance of the quality of platelets for long periods. The clinical use of washed PC in Japan has therefore progressed. Washed PC with M-sol or BRS-A for pediatric patients can effectively prevent TARs without diminishing the transfusion effect. The supply of washed PC has begun from the Japanese Red Cross Society, and it has become possible to use washed PC at all medical institutions in Japan.

Extended storage of thawed platelets: Refrigeration supports postthaw quality for 10 days.

BACKGROUND: Cryopreservation of platelets with dimethylsulfoxide (DMSO) at -80°C increases their shelf life from days to years. Once thawed, platelets are stored at room temperature (RT), and the shelf life is limited to 4-6 hours. However, refrigeration (cold storage) may facilitate a prolongation of the shelf life of thawed platelets. STUDY DESIGN AND METHODS: ABO-matched buffy coat-derived platelets (30% plasma/70% SSP+) were cryopreserved at -80°C in 5%-6% DMSO. Paired cryopreserved platelet components were thawed, resuspended in 30% plasma/70% SSP+, and then stored at either 20°C-24°C with agitation (RT) or at 2°C-6°C (cold). In vitro platelet quality was assessed over 10 days of postthaw storage. RESULTS: During postthaw storage, the platelet concentration of RT-stored components decreased significantly more than components in cold storage (Day 10 RT 58 ± 10 × 109 /unit vs Day 10 cold 142 ± 16 × 109 /unit; P < .0001). Cold storage reduced the metabolic rate of thawed platelets. During storage, the surface glycoprotein ([GP] Ibα, GPVI, GPIIb, GPIIIa) and activation marker (P-selectin and phosphatidylserine) profile of cold platelets was closer to freshly thawed platelets (Day 0) than those stored at RT. Thromboelastography (reaction time) demonstrated that the procoagulant nature of cryopreserved platelets was preserved during 10 days of cold storage, while RT-stored thawed platelets displayed a gradual prolongation of the time taken to initiate clot formation. CONCLUSION: Cold storage of thawed platelets preserves the platelet phenotype and function for up to 10 days, compared to thawed platelets stored at RT. Thus, cold storage of thawed platelets may represent a simple approach to extend the postthaw shelf life.

Rejuvenation solution as an adjunct cold storage solution maintains physiological haemoglobin oxygen affinity during early-storage period of red blood cells.

BACKGROUND: Red blood cell (RBC) units accumulate morphologic and metabolic lesions during storage before transfusion. Pyruvate-inosine-phosphate-adenine (PIPA) solutions (Rejuvesol, Biomet, Warsaw, IN) can be incubated with RBC units to mitigate storage lesions. This study proposes a PIPA treatment process, termed cold 'rejuvenation', using Rejuvesol as an adjunct additive solution, to prevent biomechanical storage lesions while avoiding the 1 h PIPA incubation required with standard PIPA treatment. We compared the efficacy of cold to standard 'rejuvenation' in improving metabolic lesions that occur during cold storage of RBCs, without altering function. METHODS: Twelve leucoreduced, A-positive RBC units were obtained. Each unit was aliquoted into either control (standard storage), washed (W), standard rejuvenation (SR) or cold rejuvenation (CR) groups, the latter two requiring washing. A volume-adjusted dose of Rejuvesol was instilled into the CR group upon receipt (Day 3). After 15 days of storage, p50, RBC deformability, in-bag haemolysis and mechanical fragility were analysed. 'Any treatment' is defined as W, SR and CR, with comparisons in reference to control. RESULTS: Higher p50s were seen in rejuvenated groups (>30 mmHg vs. <19 mmHg; P < 0·0001). Any treatment significantly increased elongation index (P = 0·034) but did not significantly increase in-bag haemolysis (P = 0·062). Mechanical fragility was not significantly different between groups (P = 0·055) at baseline, but the control (CTL) group was more fragile after 2 h in a cardiac bypass simulation than any treatment (P < 0·0001). CONCLUSIONS: This study demonstrates that rejuvenation (standard or cold) prevents the leftward p50 shift of storage lesions without detrimental effect on RBC deformity, in-bag haemolysis or mechanical fragility.

The impact of red blood cell manufacturing variables on bacterial growth dynamics: a pilot study.

BACKGROUND AND OBJECTIVES: Bacterial contamination of red blood cells (RBC) remains a rare but serious clinical concern. Despite the low temperature storage of RBC, some bacteria can proliferate. The impact of RBC additive solutions (AS), manufacturing method or donor sex on bacterial growth/survival in RBC was addressed in this pilot study. MATERIALS AND METHODS: Using a partial pool-and-split design, bacterial growth/survival was assessed in intentionally inoculated RBC, manufactured separately from male and female donors using three different manufacturing methods (two whole blood [WB] filtration methods; one RBC filtration method), and resuspended in one of four AS: SAGM, PAGGSM, AS-1 or AS-3. At the beginning of storage, RBC were inoculated with 10 CFU/ml of either Klebsiella pneumoniae, Staphylococcus epidermidis, Yersinia enterocolitica or Propionibacterium acnes. Manufacturing, inoculation, storage (until day 42) and monitoring of bacterial growth were conducted at two sites: Canadian Blood Services and Héma-Québec. RESULTS: Yersinia enterocolitica was the only bacterium that proliferated during storage at both sites. RBC tested at Canadian Blood Services had higher bacterial concentrations than those at Héma-Québec (P = 0·0044). At Héma-Québec, where two different manufacturing methods were used, Y. enterocolitica reached significantly higher bacterial concentrations in AS-3 RBC (WB filtration method) compared to units prepared in the other three AS (RBC filtration method; P < 0·05). Bacterial survival/growth dependent on donor sex was not uniformly noted. CONCLUSION: Only one of four bacteria grew under RBC storage conditions. The results indicate that RBC manufacturing variables, rather than AS or donor sex, affect bacterial growth in RBC.

Comparison of human platelet lysate alternatives using expired and freshly isolated platelet concentrates for adipose-derived stromal cell expansion.

Pooled human platelet lysate (pHPL) has been used to expand adipose-derived stromal cells (ASCs) and can be formulated using fresh or expired buffy coats (BCs) which are then resuspended in either plasma or an additive solution. Not much is known about the effects that expired products and additive solutions have on ASC expansion, and the need for quality control and release criteria has been expressed. This pilot study compared proliferation, cell size, morphology and immunophenotype of ASCs expanded in the different pHPL alternatives versus foetal bovine serum (FBS). Quality control criteria were assessed prior to and during the manufacture of the pHPL alternatives. ASCs were then expanded in 1%, 2.5%, 5% or 10% of the different pHPL alternatives or in 10% FBS. Cell size, morphology, cell number and immunophenotype were measured using microscopy and flow cytometry. The majority of the pHPL alternatives were within the recommended ranges for the quality control criteria. ASCs expanded in the pHPL alternatives were smaller in size, displayed a tighter spindle-shaped morphology, increased cell growth and had a similar immunophenotype (with the exception of CD34 and CD36) when compared to ASCs expanded in FBS. Here we report on the effects that expired BC products and additive solutions have on ASC expansion. When taken together, our findings indicate that all of the pHPL alternatives can be considered to be suitable replacements for FBS for ASC expansion, and that expired BC products can be used as an alternative to fresh BC products.

Assessment of Time-Dependent Platelet Activation Using Extracellular Vesicles, CD62P Exposure, and Soluble Glycoprotein V Content of Platelet Concentrates with Two Different Platelet Additive Solutions.

Novel analytical measures are needed to accurately monitor the properties of platelet concentrates (PCs). Since activated platelets produce platelet-derived extracellular vesicles (EVs), analyzing EVs of PCs may provide additional information about the condition of platelets. The prospect of using EVs as an auxiliary measure of platelet activation state was investigated by examining the effect of platelet additive solutions (PASs) on EV formation and platelet activation during PC storage. The time-dependent activation of platelets in PCs with PAS-B or with the further developed PAS-E was compared by measuring the exposure of CD62P by flow cytometry and the content of soluble glycoprotein V (sGPV) of PCs by an immunoassay. Changes in the concentration and size distribution of EVs were determined using nanoparticle tracking analysis. A time-dependent increase in platelet activation in PCs was demonstrated by increased CD62P ex-posure, sGPV content, and EV concentration. Using these strongly correlating parameters, PAS-B platelets were shown to be more activated compared to PAS-E platelets. Since the EV concentration correlated well with the established platelet activation markers CD62P and sGPV, it could potentially be used as a complementary parameter for platelet activation for PCs. More detailed characterization of the resulting EVs could help to understand how the PC components contribute the functional effects of transfused PCs.

Quality of irradiated and non-irradiated plateletpheresis concentrates stored in platelet additive solution.

INTRODUCTION: Platelet additive solutions (PAS) allow to maintain platelet storage properties in platelet concentrates (PCs). The aim of the present study was to evaluate the in-vitro quality of irradiated and non-irradiated PCs, suspended in PAS, over a storage period of 6 days. METHODS: Plateletpheresis donors fulfilling current eligibility criteria underwent plateletpheresis with the MCS+ blood cell separator. The PAS SSP+ was used to store platelets (PLT) for up to 6 days. Aliquots were drawn from the PCs after collection, at day 4, 5 and 6 of storage. A battery of tests was performed to analyse the quality of the PCs: PLT count, mean PLT volume (MPV), PLT activation marker CD 62, swirl, RBC and WBC contamination, pH, citrate, glucose, lactate and lactate dehydrogenase. RESULTS: An average of 2.53 ±â€¯0.21 × 1011 PLT were collected in a product volume of 231 ±â€¯5 mL in irradiated and 233 ±â€¯6 mL in non-irradiated PCs, respectively. RBC- and WBC-contamination were within the allowed ranges. Δ CD62 steadily decreased in irradiated and non-irradiated PCs while the pH was well maintained over storage time. Glucose and lactate levels of irradiated and non-irradiated PCs showed characteristic pattern of PC storage within acceptable ranges. CONCLUSION: Our data demonstrate that parameters of PC quality were well maintained over a storage period of 6 days using PAS. Irradiation had no impact on the quality of PCs. The product quality of irradiated and non-irradiated PCs met national and European guidelines.

Platelet Additive Solutions: A Review of the Latest Developments and Their Clinical Implications.

Summary Platelet additive solutions (PASs) have undergone many reformulations in order to further improve platelet storage. Studies of platelets stored in PAS-F (containing acetate, magnesium and potassium as key constituents) showed that platelets may be stored for 13 days with recovery and survival outcomes that are equal or even superior to 7-day stored platelets in plasma. Clinically, patients transfused with platelets in PAS have fewer allergic reactions, while for febrile reactions data are conflicting. Transfusion-related acute lung injury (TRALI) occurs less frequently if PAS is used for buffy coat-derived platelets, but for apheresis platelets there is no difference. For PAS-B and PAS-C, corrected count increments (CCIs) are lower than for platelets stored in plasma, but for PAS-E (like PAS-F also with acetate, magnesium and potassium but with additional phosphate), though limited data is available in the literature, the CCIs seem to be comparable to those observed for platelets in plasma. With platelets in PAS, there is an accumulated dilution effect of anticoagulant and PAS as well as a loss of number and function (due to storage and/or pathogen inactivation treatment) of platelets, of which it is not clear how this impacts clinical outcomes of patients undergoing massive transfusion. Worst-case in vitro studies, where the entire plasma fraction is replaced by supernatant of platelets in PAS, do show an effect on the ability of reconstituted whole blood to clot, but in a more realistic scenario, functional clotting parameters are not different. In this review, recent laboratory and clinical data are discussed, focusing on studies published after 2010.