Differences in levels of platelet-derived microparticles in platelet components prepared using the platelet rich plasma, buffy coat, and apheresis procedures

Comparative analysis of the quality of platelet concentrates produced by apheresis procedures, platelet rich plasma, and buffy coat

BACKGROUND

Platelet concentrates (PCs) could be prepared using either whole-blood processes or apheresis instruments. During collection, processing and storage, some biochemical and functional changes occur, which may result in quality reduction. Quality evaluation of PCs may be helpful for the precise control of platelet (PLT) inventory to reduce the risk of refractoriness and adverse effects caused by platelet transfusion.

STUDY DESIGN AND METHODS

The study was aimed to evaluate the quality of PCs which were produced by five processes: apheresis (AP) procedures (using three different cell separators: Amicus, Trima Accel and MCS+ instruments), platelet rich plasma (PRP), and buffy coat (BC). A total of 100 PCs (20 of each group) were assessed in respect of routine quality control, morphology, size distribution, destroyed and activated platelets, and production of platelet-derived microparticles (PMPs).

RESULTS

All PCs have satisfied the recommended quality of volume, platelet count, residual WBC count, residual RBC count, pH, and sterility according to the Chinese Technical Manual. There was no difference among the 5 groups in morphology and size of PLT and PMPs. Dynamic light scattering test showed that apheresis PCs showed peaks around 10-20 nm, but not whole blood-derived PCs. PCs prepared by Amicus had the relatively high percentage of destroyed platelet, activated platelets and PMPs than other groups.

DISCUSSION

The data suggested high heterogeneity of PMPs, destroyed and activated platelets in PCs produced by different processes, which might be helpful to manage the platelet inventory for targeted use.

Extracellular vesicles: effectors of transfusion-related acute lung injury

Respiratory transfusion reactions represent some of the most severe adverse reactions related to receiving blood products. Of those, transfusion-related acute lung injury (TRALI) is associated with elevated morbidity and mortality. TRALI is characterized by severe lung injury associated with inflammation, pulmonary neutrophil infiltration, lung barrier leak, and increased interstitial and airspace edema that cause respiratory failure. Presently, there are few means of detecting TRALI beyond clinical definitions based on physical examination and vital signs or preventing/treating TRALI beyond supportive care with oxygen and positive pressure ventilation. Mechanistically, TRALI is thought to be mediated by the culmination of two successive proinflammatory hits, which typically comprise a recipient factor (1st hit-e.g., systemic inflammatory conditions) and a donor factor (2nd hit-e.g., blood products containing pathogenic antibodies or bioactive lipids). An emerging concept in TRALI research is the contribution of extracellular vesicles (EVs) in mediating the first and/or second hit in TRALI. EVs are small, subcellular, membrane-bound vesicles that circulate in donor and recipient blood. Injurious EVs may be released by immune or vascular cells during inflammation, by infectious bacteria, or in blood products during storage, and can target the lung upon systemic dissemination. This review assesses emerging concepts such as how EVs: 1) mediate TRALI, 2) represent targets for therapeutic intervention to prevent or treat TRALI, and 3) serve as biochemical biomarkers facilitating TRALI diagnosis and detection in at-risk patients.

Blood Donors with Thalassemic Trait, Glucose-6-Phosphate Dehydrogenase Deficiency Trait, and Sickle Cell Trait and Their Blood Products: Current Status and Future Perspective

The use of blood products for different medical purposes has increased in recent years. To meet increasing demand, some blood centers allow volunteer donors with thalassemic trait, glucose-6-phosphate dehydrogenase deficiency (G6PD) trait, and sickle cell trait (SCT) to donate blood if their hemoglobin values fall within acceptable ranges and show no signs of hemolysis. Currently, there are no standard guidelines or policies regarding the use or management of blood products obtained from these donors. However, in recent years, there has been advanced research on eligible donors who have these underlying conditions. In this review, we summarize the current knowledge from in vitro and in vivo studies regarding donor characteristics, changes in physical and biochemical parameters in blood products during processing and storage, and posttransfusion efficacy of blood products. In addition, we discuss some unresolved issues concerning blood products from thalassemic trait, G6PD-deficiency trait, and SCT donors.

Irreversible alteration of extracellular vesicle and cell-free messenger RNA profiles in human plasma associated with blood processing and storage

The discovery and utility of clinically relevant circulating biomarkers depend on standardized methods that minimize preanalytical errors. Despite growing interest in studying extracellular vesicles (EVs) and cell-free messenger RNA (cf-mRNA) as potential biomarkers, how blood processing and freeze/thaw impacts the profiles of these analytes in plasma was not thoroughly understood. We utilized flow cytometric analysis to examine the effect of differential centrifugation and a freeze/thaw cycle on EV profiles. Utilizing flow cytometry postacquisition analysis software (FCMpass) to calibrate light scattering and fluorescence, we revealed how differential centrifugation and post-freeze/thaw processing removes and retains EV subpopulations. Additionally, cf-mRNA levels measured by RT-qPCR profiles from a panel of housekeeping, platelet, and tissue-specific genes were preferentially affected by differential centrifugation and post-freeze/thaw processing. Critically, freezing plasma containing residual platelets yielded irreversible ex vivo generation of EV subpopulations and cf-mRNA transcripts, which were not removable by additional processing after freeze/thaw. Our findings suggest the importance of minimizing confounding variation attributed to plasma processing and platelet contamination.

Storage Duration and Red Blood Cell-Derived Microparticles in Packed Red Blood Cells Obtained from Donors with Thalassemia

OBJECTIVE

To address the effects of storage duration on red blood cell (RBC)-derived microparticles (RMPs) in packed RBCs from donors who have thalassemia.

MATERIALS AND METHODS

Packed RBCs were prepared according to laboratory routine. The quantity of RMPs was determined using FACSCalibur and counting beads.

RESULTS

Across durations of storage, the packed RBCs from donors with thalassemia (n = 28) and healthy volunteers (n = 104) showed average RMPs to be 47,426 (10,139‒127,785) particles/μL vs 49,021 (13,033‒126,749) particles/μL, respectively (P = .63). The peak RMP levels in donors with thalassemia and healthy volunteers, respectively, were shown in products from storage days 34 and 38. Both groups showed a trend toward a positive association between RMP concentration and the duration of storage in packed RBC bags stored under blood bank conditions.

CONCLUSION

Our results suggest that storage-induced RMP release has similar effects in stored packed RBCs obtained from both donors with thalassemia and healthy volunteers.

Extracellular vesicles in the transfusion medicine field: The potential of proteomics

In transfusion centres, blood components are divided and stored following specific guidelines. The storage temperature and time vary among the blood cells but all of them release extracellular vesicles (EVs) under blood bank conditions. The clinical impact of such vesicles in blood components for transfusion is an object of debate, but should be considered and is being investigated. In this context, proteomics is an excellent tool to study the cargo and composition of EVs derived from red blood cells and platelets, since such vesicles are enriched in lipids and proteins. The development of quantitative mass spectrometry techniques and the evolution of bioinformatics have allowed the identification of novel EVs biomarkers for different diseases. In this context, the application of high coverage proteomic tools to the analysis of EVs in the transfusion medicine field would provide information about storage lesions and possible transfusion adverse reactions. This viewpoint article approaches the potential of proteomics to investigate the impact of EVs in blood bank transfusion components, especially red blood cells and platelets.

Effects and Side Effects of Platelet Transfusion

Aside from their canonical role in hemostasis, it is increasingly recognized that platelets have inflammatory functions and can regulate both adaptive and innate immune responses. The main topic this review aims to cover is the proinflammatory effects and side effects of platelet transfusion. Platelets prepared for transfusion are subject to stress injury upon collection, preparation, and storage. With these types of stress, they undergo morphologic, metabolic, and functional modulations which are likely to induce platelet activation and the release of biological response modifiers (BRMs). As a consequence, platelet concentrates (PCs) accumulate BRMs during processing and storage, and these BRMs are ultimately transfused alongside platelets. It has been shown that BRMs present in PCs can induce immune responses and posttransfusion reactions in the transfusion recipient. Several recent reports within the transfusion literature have investigated the concept of platelets as immune cells. Nevertheless, current and future investigations will face the challenge of encompassing the immunological role of platelets in the scope of transfusion.

Cell-Derived Microparticles in Blood Products from Blood Donors Deficient in Glucose-6-Phosphate Dehydrogenase

OBJECTIVE

To quantitate the microparticles (MPs) in whole blood and blood products obtained from blood donors who are deficient in glucose-6-phosphate dehydrogenase (G6PD).

METHODS

The current study analyzed whole blood and blood components prepared from 49 blood donors with G6PD deficiencies and 98 with G6PD-normal results. Packed red blood cells (PRBCs), platelet concentrate (PC), and plasma were prepared according to transfusion laboratory procedures. MP concentrations were determined using a flow cytometer.

RESULTS

Blood components prepared from donors with G6PD deficiency were characterized by higher red blood cell-derived MP (RMP) concentration in PRBCs (25,526 vs 18,738 particles/µL) but lower concentrations of platelet-derived MPs (PMPs; in whole blood and PC), leukocyte-derived MPs (LMP; in whole blood and plasma) and total MP (in PC), compared with those from donors with G6PD-normal test results.

CONCLUSIONS

These results suggest that differences in G6PD status may account for variation in RMP levels during processing.

Quantitation of phosphatidylserine-exposing platelets and platelet-derived microparticles in platelet products: A new strategy to improve efficacy of platelet transfusion

Platelet transfusion is an effective therapy to prevent or treat bleeding. Considering the different clinical purposes of transfusion, it is necessary to assess the quality of platelet products prepared in transfusion laboratories. So far, there is no solution to the problem of how best to do this. Here, we summarize the quantitation of phosphatidylserine (PS)-exposing platelets and platelet-derived microparticles (PMPs) in platelet products using previously reported data. Because PS promotes the assembly and enhances the activity of coagulation factors, classifying platelet products according to their concentrations of PS-exposing platelets and PMPs will improve the therapeutic treatment of transfusion recipients.

Cell-Derived Microparticles in Blood Products from Thalassemic Blood Donors

OBJECTIVE

To determine the number of cell-derived microparticles (MPs) in blood products obtained from donors who have thalassemia.

METHODS

Packed red blood cells (PRBCs), plasma, and platelet concentrate (PC) were prepared according to routine procedures. We used flow cytometry to quantitate the concentration of MPs.

RESULTS

The results of a comparison of MP levels in unprocessed whole blood showed that the concentration of all MPs in the donors without thalassemia trait (n = 255) was higher than in donors with thalassemia trait (n = 70). After processing, increased concentrations of MPs were documented in both groups. Among the blood components, PRBC showed higher platelet-derived MP concentrations in donors with thalassemia than in donors without thalassemia. However, PC showed higher concentrations of total MPs in donors without thalassemia than in donors with that condition.

CONCLUSIONS

Our results suggest little influence of thalassemia-trait status on changes in MP concentrations in blood components.

Comparison of the platelet activation status of single-donor platelets obtained with two different cell separator technologies

BACKGROUND

The microparticle content (MP%) of apheresis platelets-a marker of platelet activation-is influenced by donor factors and by external stressors during collection and storage. This study assessed the impact of apheresis technology and other factors on the activation status (MP%) of single-donor apheresis platelets.

STUDY DESIGN AND METHODS

Data from six US hospitals that screened platelets by measuring MP% through dynamic light scattering (ThromboLUX) were retrospectively analyzed. Relative risks (RRs) were derived from univariate and multivariable regression models, with activation rate (MP% ≥15% for plasma-stored platelets; ≥10% for platelet additive solution [PAS]-stored platelets) and MP% as outcomes. Apheresis platform (Trima Accel vs Amicus), storage medium (plasma vs PAS), pathogen reduction, storage time, and testing location were used as predictors.

RESULTS

Data were obtained from 7511 platelet units collected using Trima (from 16 suppliers, all stored in plasma, 20.0% were pathogen-reduced) and 2456 collected using Amicus (from four different collection facilities of one supplier, 65.0% plasma-stored, 35.0% PAS-stored, none pathogen-reduced). Overall, 30.0% of Trima platelets were activated compared to 45.6% of Amicus platelets (P < .0001). Multivariable analysis identified apheresis platform as significantly associated with platelet activation, with a lower activation rate for Trima than Amicus (RR: 0.641, 95% confidence interval [CI]: 0.578; 0.711, P < .0001) and a 6.901% (95% CI: 5.926; 7.876, P < .0001) absolute reduction in MP%, when adjusting for the other variables.

CONCLUSION

Trima-collected platelets were significantly less likely to be activated than Amicus-collected platelets, irrespective of the storage medium, the use of pathogen reduction, storage time, and testing site.

Blood microparticles are a component of immune modulation in red blood cell transfusion

Patients may display alloimmunization following transfusion. Microparticles (MPs) released into the blood are present in transfusion products. We show that MPs can modulate the immune system, CD4⁺ T-cell, and humoral responses, through their concentration, cellular origin and phenotype, and should therefore be considered to reduce the immune impact of transfusion.

Affordable, Reliable Dual-Platform Approach to Quantitating Phosphatidylserine-Exposing Platelets in Platelet Components

OBJECTIVE

To compare the number of phosphatidylserine (PS)-exposing platelets obtained using the dual-platform approach and bead-based flow cytometry.

METHODS

Platelets were enumerated using the ADVIA 2010i instrument (Siemens AG). The numbers and percentages of PS-exposing platelets in 175 platelet products were determined using a FACSCalibur flow cytometer (Becton, Dickinson and Company) and counting beads.

RESULTS

Our results showed good correlation (r2 = 0.96; P <.001) between the PS-exposing platelets obtained using counting beads and the dual-platform approach. The results of Bland-Altman analysis showed a bias of +46,449 cells per µL and a limit of agreement (LOA) from -197,863 to 290,762 cells per µL. Also, 8 measurements (5.0%) revealed a number of PS-exposing platelets outside the LOA ranges. Further, 21 measurements (12.0%) revealed greater than 2-fold changes in the number of PS-exposing platelets.

CONCLUSIONS

The results suggest that the dual-platform approach is affordable and reliable for quantitating PS-exposing platelets as part of monitoring the quality of platelet products.

Quantitation of Cell-Derived Microparticles in Blood Products and Its Potential Applications in Transfusion Laboratories

Cell-derived microparticles (MPs) are small fragments released from various cells when they are activated or undergo apoptosis. In the field of transfusion medicine, a number of studies have documented increased levels of MPs in blood products, which have been associated with multiple factors, including donor variability, blood component processing, and storage. In addition, transfusions that contain high levels of MPs are linked to posttransfusion complications. Considering the clinical importance of MP levels, transfusion laboratories should routinely screen blood products for them. However, this practice is not yet applied routinely, perhaps in part because of a lack of understanding of how to apply MP data to transfusion medicine. We describe the methods used to quantitate MPs in blood components and discuss the application of these quantitative data in routine transfusion laboratories in order to manage quality, improve the outcomes of transfusions, and minimize their complications.

Leukocyte-rich PRP versus leukocyte-poor PRP - The role of monocyte/macrophage function in the healing cascade

The mechanism of action of Platelet Rich Plasma (PRP) is thought to be related to the biomolecules present in α-granules. However, for the healing process to occur, an inflammatory phase is also deemed necessary. Leukocytes present in the inflammatory phase release both pro- and anti-inflammatory molecules. The latter may play an important role in the process of "inflammatory regeneration". Thus, we propose that in the context of healing, both platelets and leukocytes play an important role, specifically due to the macrophage's plasticity to switch from the M1 to M2 fraction. Therefore, we propose that PRP products derived from the buffy coat may be more beneficial than detrimental from a standpoint of the regenerative potential of PRP.

Effects of donor age, donor sex, blood-component processing, and storage on cell-derived microparticle concentrations in routine blood-component preparation

BACKGROUND

A number of factors cause increases in the number of cell-derived microparticles (MPs) in blood components. However, the overall effects of these factors on the concentration of MPs during routine blood-component preparation have not fully been elucidated.

AIM

To evaluate the effects of donor age, donor sex, blood-component preparation, and storage on MP concentrations.

METHODS

Flow cytometry was used to quantitate the number of whole blood-derived MPs.

RESULTS

The total MP concentration was similar in male and female donors (26,044 ± 1254 particles/μL vs. 27,696 ± 1584 particles/μL). The total MP concentration did not differ significantly among the different age groups: 18-30 years (28,730 ± 1600 particles/μL), 31-40 years (24,972 ± 5947 particles/μL), and 41-58 years (25,195 ± 1727 particles/μL). However, the total number of MPs in fresh plasma (152,110 ± 46,716 particles/μL) was significantly higher (p <  0.05) than that in unprocessed whole blood (26,752 ± 985 particles/μL), fresh packed red blood cells (PRBCs) (28,574 ± 1028 particles/μL), and platelet concentrate (PC) (33,072 ± 1858 particles/μL). Furthermore, the total numbers of MPs in stored PRBCs and fresh-frozen plasma (FFP) were significantly higher (p <  0.05) than those in fresh PRBCs and fresh plasma, respectively.

CONCLUSIONS

The study suggests that donor factors, blood-component processing and storage contribute to the MP concentration in routine blood-product preparation. The findings can improve quality control and management of blood-product manufacturing in routine transfusion laboratories.

Microparticles in Hematological Malignancies: Role in Coagulopathy and Tumor Pathogenesis

Microparticles (MP) are submicron vesicles released from various cells in response to activation, injury or apoptosis. They contain different structural and functional proteins and RNAs, which contribute to physiological intercellular "crosstalk" and to the pathogenesis of various diseases including cancer. In hematological malignancies, these MPs participate in the initiation and propagation of thrombosis through different pathways. They have a role in the angiogenesis, malignant cell survival and metastasis. MPs act as a mediator of resistance of leukemic cells to chemotherapy. The number of MPs is one of the prognostic factors following stem cell transplant, and studies have also found they contribute to the pathogenesis of graft versus host disease. MPs are being tested as therapeutic options in leukemias and graft versus host disease. Future studies should help us understand the interactions between MPs and cancer cells better, thereby opening new approaches for treatment of hematological malignancies.

Pathogen reduction technologies: The pros and cons for platelet transfusion

The transfusion of platelets is essential for diverse pathological conditions associated with thrombocytopenia or platelet disorders. To maintain optimal platelet quality and functions, platelets are stored as platelet concentrates (PCs) at room temperature under continuous agitation-conditions that are permissive for microbial proliferation. In order to reduce these contaminants, pathogen reduction technologies (PRTs) were developed by the pharmaceutical industry and subsequently implemented by blood banks. PRTs rely on chemically induced cross-linking and inactivation of nucleic acids. These technologies were initially introduced for the treatment of plasma and, more recently, for PCs given the absence of a nucleus in platelets. Several studies verified the effectiveness of PRTs to inactivate a broad array of bacteria, viruses, and parasites. However, the safety of PRT-treated platelets has been questioned in other studies, which focused on the impact of PRTs on platelet quality and functions. In this article, we review the literature regarding PRTs, and present the advantages and disadvantages related to their application in platelet transfusion medicine.