Platelet concentrates from fresh or overnight-stored blood, an international study

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.

Evaluation of platelets componentized with the Reveos Automated Blood Processing System and stored for 7 days at room temperature in a non-Di(2-ethylhexyl) phthalate (DEHP) platelet pooling set

BACKGROUND

Platelet concentrates (PCs) used for transfusion can be produced by apheresis or derived from whole blood (WB). The Reveos device is the first US Food and Drug Administration-approved automated blood processing system that can produce PCs. In this work, we evaluated the quality and function of Reveos-collected PCs stored for 7 days at room temperature.

STUDY DESIGN AND METHODS

WB was collected from healthy donors and componentized on the day of collection (Fresh) or after an overnight hold (Overnight). PCs were produced (n = 7 Fresh; n = 6 Overnight), stored at room temperature in plasma, and evaluated on days 1 and 7 for quality metrics, platelet activation, clot formation, and aggregation response.

RESULTS

Platelet count was comparable between Fresh and Overnight PCs. A drop in pH was reported in Fresh day 7 PCs (p < .001, vs. day 1) but not in Overnight. Overnight units displayed the lowest levels of P-selectin expression (p = .0008, vs. day 7 Fresh). Reduced clot strength and increased lysis were observed in both Fresh and Overnight units on day 7 (vs. day 1). Overnight-hold PCs resulted in the highest clot strength on day 7 (p = .0084, vs. Fresh). No differences in aggregation were reported between groups.

CONCLUSION

Reveos-processed PCs produced from overnight-hold WB performed better in hemostatic function assays and displayed reduced activation compared to fresh WB-derived PCs, although both PC groups maintained platelet quality throughout storage. Utilization of overnight WB for PC preparation with Reveos holds promise as an alternative method of producing platelets for transfusion purposes.

Assessment of the soluble proteins HMGB1, CD40L and CD62P during various platelet preparation processes and the storage of platelet concentrates: The BEST collaborative study

BACKGROUND

Structural and biochemical changes in stored platelets are influenced by collection and processing methods. This international study investigates the effects of platelet (PLT) processing and storage conditions on HMGB1, sCD40L, and sCD62P protein levels in platelet concentrate supernatants (PCs).

STUDY DESIGN/METHODS

PC supernatants (n = 3748) were collected by each international centre using identical centrifugation methods (n = 9) and tested centrally using the ELISA/Luminex platform. Apheresis versus the buffy coat (BC-PC) method, plasma storage versus PAS and RT storage versus cold (4°C) were investigated. We focused on PC preparation collecting samples during early (RT: day 1-3; cold: day 1-5) and late (RT: day 4-7; cold: day 7-10) storage time points.

RESULTS

HMGB1, sCD40L, and sCD62P concentrations were similar during early storage periods, regardless of storage solution (BC-PC plasma and BC-PC PAS-E) or temperature. During storage and without PAS, sCD40L and CD62P in BC-PC supernatants increased significantly (+33% and +41%, respectively) depending on storage temperature (22 vs. 4°C). However, without PAS-E, levels decreased significantly (-31% and -20%, respectively), depending on storage temperature (22 vs. 4°C). Contrastingly, the processing method appeared to have greater impact on HMGB1 release versus storage duration. These data highlight increases in these parameters during storage and differences between preparation methods and storage temperatures.

CONCLUSIONS

The HMGB1 release mechanism/intracellular pathways appear to differ from sCD62P and sCD40L. The extent to which these differences affect patient outcomes, particularly post-transfusion platelet increment and adverse events, warrants further investigation in clinical trials with various therapeutic indications.

Comparison of in-vitro and in-vivo parameters of whole blood derived random donor platelets (RDP) after over-night hold with RDP prepared after 2-h hold: Single centre report from India

BACKGROUND

Random Donor Platelet (RDP) derived from whole blood is the major source of platelets in India. At our centre, we prepare RDPs by buffy coat method after a holding period of 2-hours (THRDP) as per current regulatory guidelines. Overnight hold of buffy coats before RDP preparation (OHRDP) would logistically optimise the manpower usage at our centre. The aim of this study was to compare both in-vitro as well as in-vivo parameters of OHRDPs with THRDPs.

METHODOLOGY

Hematological (Platelet, leucocyte counts), physical (pH and Swirling) and biochemical parameters (pO2, pCO2, lactate, bicarbonate and glucose) as well as platelet activation markers were tested in THRDPs and OHRDPs each at Day-1 and Day-5 as in-vitro studies. Separately, in-vivo study was done where Corrected count increment (CCI) and percentage platelet recovery (PPR) were considered. All parameters were expressed as Mean ± Standard deviation and were analysed using paired t-test with level of significance, p < 0.05.

RESULTS

OHRDPs had higher platelet counts and lower leucocytes and CD62 P expression than THRDPs. All other markers were well within the quality control range in both groups. No significant differences were seen in the two groups when comparing CCI and PPR.

CONCLUSION

OHRDPs were found to be as good or better as compared to the THRDPs in the in-vitro part of our study. Additionally, there were no significant differences between the two groups when they were compared in vivo. This makes us conclude that overnight hold of buffy coats may be implemented at our center.

Comparative analysis of platelet concentrates prepared after two hours and overnight storage of buffy coat at room temperature

INTRODUCTION

The overnight storage of the buffy coat (BC) at room temperature has logistic and operational advantages for the blood centre. The present study aimed to evaluate the impact of an overnight hold (stored) of BC at room temperature in comparison with the 2-hour hold (fresh) of buffy coats on the platelet concentrate (PC) characteristics.

METHODS

A total of 60 BCs were included in the study, 30 PCs (fresh) were prepared after two hours holding time of the BCs and the other 30 PCs (stored) were prepared after the overnight BC storage at room temperature. The primary endpoint of PCs evaluation was the platelet yield, volume, pH, WBC count, RBC count, and platelet swirling in the PC and the secondary endpoints were glucose concentration, lactate, LDH, and sterility of the PCs. All the tests were performed on the day+1 of the blood collection.

RESULTS

There was no difference concerning the volume, RBC count, and swirling between the two groups (P>0.05). The PCs from the fresh BC had higher pH and glucose concentration (P<0.05). On the other hand, the overnight hold of BC produced higher platelet counts, WBC counts, lactate, and LDH levels (P<0.05). All the 60 PCs did not record any bacterial growth on the culture media for the sterility results.

CONCLUSION

The overnight hold of BC produces a higher platelet yield with higher storage lesions. This may also allow better supervision, ensuring better quality control.

Donor platelet and leukocyte count as predictive factors of the quality of platelet concentrates obtained from whole blood by semiautomated fractionation

Platelet concentrates (PCs) obtained from whole blood are produced by fractionation of the buffy coat (BC) or the platelet-rich plasma. Despite the improvements in the technologies used for the hemocomponent fractionation, the proportion of PCs that do not accomplish the quality requirements is high. This study aimed to determine whether the basal platelet and leukocyte counts are predictive factors of the quality of the PCs obtained from BC by semiautomated fractionation. Quality control registers of 196 PCs were analyzed. Gender- and age-dependence of the blood cell count and the characteristics of PCs were evaluated. Platelet yield and residual leukocytes in the PCs were correlated with the platelet and leukocyte counts and the age of the donors. Predictive efficacy was assessed, and an optimal cut-off was established. The proportions of PCs accepted and rejected by using or not the optimal cut-off were compared. 50.0% of the PCs accomplished all the quality control requirements. Female donors had a higher basal platelet count than males. A correlation was observed between basal platelets and platelet yield, but not between basal leukocytes and residual leukocytes. The basal platelet count predicted the quality of the PCs. A cut-off of 231,000 platelets/mm³ was established, but it did not improve the proportion of accepted PCs. In conclusion, we found that the basal platelet count is correlated with the platelet yield. The basal leukocyte count is not correlated with the residual leukocytes. The established cut-off for the basal platelet count did not improve the proportion of accepted PCs.

Clotting functional stability of withdrawing blood in storage for acute normovolemic hemodilution: a pilot study

Purpose

This study was conducted to time-course changes of clotting function of withdrawing blood for acute normovolemic hemodilution (ANH).

Methods

Twelve enrolled patients who underwent ANH from August, 2018 to January, 2019. Blood was withdrawn into blood collection pack and shaken at 60–80 rpm for 24 h in room temperature. Clot formation was evaluated using rotational thromboelastometry (ROTEM™) just after blood withdrawal (control) and 4, 8, 12 and 24 h after blood withdrawal. We compared with the control value and each value of extrinsically-activated test with tissue factor (EXTEM), intrinsically-activated test using ellagic acid (INTEM) and fibrin-based extrinsically activated test with tissue factor (FIBTEM).

Results

Maximum clot firmness (MCF) of FIBTEM did not change significantly. MCF of EXTEM was significantly decreased time-dependent manner but all MCF of EXTEM were within a normal range. Maximum percent change in MCF of EXTEM was 12.4% [95% confidence interval (CI): 9.0–15.8%]. The difference in the maximum clot elasticity (MCE) between EXTEM and FIBTEM (MCE_EXTEM−MCE_FIBTEM) was significantly decrease from 8 h after blood withdrawal. Maximum percent change in MCE_EXTEM−MCE_FIBTEM was 30.2% (95% CI:17.6–42.9%) at 24 h after blood withdrawal.

Conclusion

Even though the MCE significantly decreased in a time-dependent manner, MCF of FIBTEM and EXTEM was normal up to 24 h storage. The blood of ANH can use for the purpose of hemostasis at least 8 h stored at room temperature after blood withdrawal. Future studies are needed to elucidate the clinical impact on the patient after delayed transfusion of ANH blood with regard to patient’s hemostasis.

Electronic supplementary material

The online version of this article (10.1007/s00540-020-02856-x) contains supplementary material, which is available to authorized users.

Platelet Immobilization on Supported Phospholipid Bilayers for Single Platelet Studies

The worldwide cardiovascular disease (CVD) epidemic is of grave concern. A major role in the etiology of CVDs is played by the platelets (thrombocytes). Platelets are anuclear cell fragments circulating in the blood. Their primary function is to catalyze clot formation, limiting traumatic blood loss in the case of injury. The same process leads to thrombosis in the case of CVDs, which are commonly managed with antiplatelet therapy. Platelets also have other, nonhemostatic functions in wound healing, inflammation, and tissue regeneration. They play a role in the early stages of atherosclerosis and the spread of cancer through metastases. Much remains to be learned about the regulation of these diverse platelet functions under physiological and pathological conditions. Breakthroughs in this regard are expected to come from single platelet studies and systems approaches. The immobilization of platelets at surfaces is advantageous for developing such approaches, but platelets are activated when they come in contact with foreign surfaces. In this work, we develop and validate a protocol for immobilizing platelets on supported lipid bilayers without activation due to immobilization. Our protocol can therefore be used for studying platelets with a wide variety of surface-sensitive techniques.

Preparation of red blood cell concentrates and plasma units from whole blood held overnight using a hollow-fibre separation system

BACKGROUND

The ErySep system represents an alternative to centrifuge-based whole blood (WB) separation, using gravity and filtration through hollow-fibres (0·2 µm pore size) to produce red blood cell (RBC) and plasma components. The aim of this study was to characterise the quality of ErySep RBC and plasma units compared with standard products from WB held overnight.

METHODS/MATERIALS

Two ABO-compatible WB units (n = 24) were pooled and split to produce matched products. One of the WB units was separated into components using the ErySep system (ErySep; n = 12), whereas the other units were separated by centrifugation (control; n = 12). RBC units were stored at 2-6 °C and assessed for in vitro quality over 42 days of storage. Plasma was frozen at -30 °C and tested upon thawing.

RESULTS

Processing WB with the ErySep system took longer than controls. The ErySep RBC units were of an appropriate volume (307 ± 17 mL) and contained sufficient Hb (50 ± 2 g unit(-1) ). ErySep RBC components contained more microparticles relative to controls at expiry. The plasma volume, total protein, coagulation factor activity (fibrinogen, FV, FVIII) and number of microparticles was lower in the ErySep units compared with controls.

CONCLUSION

Following overnight hold of WB, the ErySep system was capable of producing RBC components that met specifications. However, the ErySep plasma components did not meet quality specifications.

Evaluation of Random Donor Platelets Produced from Buffy Coat Stored for 24 h at Ambient Temperature: Should This be Implemented in India?

Whole blood derived platelets are made from platelet rich plasma (PRP) method or buffy coat (BC) method. In India majority of random donor platelets (RDPs) are prepared by PRP method. However, BC method offers the advantage of less platelet activation and fewer WBC contamination. Presently in India RDPs are prepared within 8 h of whole blood collection, whereas, in Europe this time limit is up to 24 h. Our aim was to evaluate the platelet count, WBC contamination, platelet CD62P expression, and biochemical parameters of RDPs prepared from BC within 8 h and within 24 h of collection. We prepared 40 units of RDP by the BC method from whole blood stored at room temperature within 8 h of collection (fresh BC), and another 40 units from BC stored at 22 °C for <24 h (stored BC). We analyzed the platelet counts, CD62P expression, WBC counts, glucose levels, pH, PO2, PCO2 in both the groups of RDPs, 24 h after respective preparation. The platelet counts from stored BC was higher in fresh BC. CD62P expression was low in stored BC compared to fresh BC. There were no differences of pH, pO2, pCO2 and glucose levels in fresh BC and stored BC. WBC contamination was more in fresh BC. Our study stored BC contained higher platelet counts, less WBC contamination and less platelet activation. We conclude that RDP prepared from stored BC is the better method for RDP production.

A comparison study of the blood component quality of whole blood held overnight at 4°c or room temperature

Background. The use of plasma frozen within 24 hrs is likely to increase. Whole blood (WB) and buffy coats (BCs) can be held for a few hrs or overnight before processing. Methods. Twenty-four bags of WB for plasma and 12 bags for platelet (PLT) concentrates were collected. The fresh frozen plasma (FFP) was prepared within 6 hrs. I-FP24 and II-FP24 samples were prepared either from leukodepleted WB that was held overnight or from WB that was held overnight before leukodepletion. The PLT concentrates (PCs) were prepared from BCs within 6 hrs (PC1) and within 18 to 24 hrs (PC2). The typical coagulation factors and some biochemical parameters were determined. Results. Compared to the FFP samples, the levels of FVII and FVIII in the I-FP24 and II-FP24 samples decreased significantly. The pH, Na⁺, LDH, and FHb levels differed significantly between II-FP24 and FFP. Compared to PC1, PC2 exhibited lower pH, pO₂, and Na⁺ levels, a higher PLT count, and increased pCO₂, K⁺, Lac, and CD62P expression levels. Conclusion. FP24 is best prepared from WB that was stored overnight at 4°C and then leukodepleted and separated within 24 hrs. PCs are best produced from BCs derived from WB that was held overnight at room temperature.

Standardization of CD62P measurement: results of an international comparative study

BACKGROUND AND OBJECTIVES

Despite long being a mainstay in describing platelet activation via degranulation, interlaboratory variation remains an issue in measurement of membrane CD62P by flow cytometry. Our objective was to identify actions that may minimize this variation.

MATERIALS AND METHODS

Sixteen laboratories participated in an international comparative study. Two sets of platelet samples were prepared in one laboratory. Set 1 was stained and fixed; set 2 was fixed and required staining at participating laboratories. A single-staining method was used, and platelet populations were selected based on forward scatter/side scatter characteristics. Calibration beads were used to standardize measurement across different instruments.

RESULTS

There was a large discrepancy in reported CD62P values among study sites [interlaboratory coefficient of variance (CV): 36-78%]. When electronic data were re-analysed by a single analyst using a consistent gating strategy and a stable reference point, variation decreased markedly (CV < 12%), indicating a problem with isotype control samples, possibly related to sample fixation or shipment.

CONCLUSION

Consensus regarding gating strategies and use of a reliable reference point would greatly improve agreement in interlaboratory CD62P measurement.

Evaluation of platelet function during extended storage in additive solution, prepared in a new container that allows manual buffy-coat platelet pooling and leucoreduction in the same system

BACKGROUND

A novel and practical storage container designed for manual buffy-coat pooling and leucodepletion was evaluated to assess its filtration performance and to analyse the quality of stored leucoreduced buffy-coat-derived platelet pools.

MATERIALS AND METHODS

To analyse the grifols leucored transfer PL system, blood was collected from random donors into standard triple bag systems, and fractionated using standard procedures to obtain buffy-coats. Ten leucodepleted platelet pools were prepared each from five units of buffy-coats in additive solution. Concentrates were stored for 10 days at 22 °C on an end-over-end agitator. On days 0, 5, 7, and 10 of storage, samples were tested using standard in vitro platelet parameters.

RESULTS

The use of this novel system for volume reduction and leucodepletion of buffy-coats resuspended in additive solution led to platelet pools that met the European requirements. pH was maintained well, declining from an initial value of 7.11±0.04 to 6.88±0.08 after 10 days. Parameters of cell lysis, response to a hypotonic stimulus and aggregation induced by agonists (arachidonic acid, ristocetin, collagen or thrombin receptor activating peptide) were also well-preserved. During storage, the quality profile of the platelet pools remained very similar to that previously reported in platelet concentrates in terms of metabolism, platelet activation (CD62, CD63, sCD62), expression of glycoproteins Ib and IIb/IIIa, capacity of glycoprotein IIb/IIIa to become activated upon ADP stimulation, and release of biological response modifiers (sCD40L and RANTES).

DISCUSSION

This new system allows the preparation of leucodepleted buffy-coat platelet pools in additive solution with good preservation of platelet function. The logistics of the procedure are relatively simple and it results in good-quality components, which may reduce costs and ease the process of buffy-coat pooling and leucocyte reduction in transfusion services.