Platelet Yield Research Articles

Effect of double dose plateletpheresis on target yield and donor platelet recovery

IntroductionThe demand for apheresis platelets has increased in the recent past and the shrinking donor pool has shifted the trend to collection of double-dose or higher yield of platelets. ObjectiveThe present study aimed to determine the effect of double-dose plateletpheresis on the target yield and donor platelet recovery. MethodsThe study was conducted on 100 healthy plateletpheresis donors, 50 of whom were in the study group, which underwent double-dose plateletpheresis (DDP), and 50 of whom were in the control group for single-donor plateletpheresis. Pre- and post-procedure samples of donors were subjected to a complete blood count. The DDP product was sampled for platelet yield and then split into two parts. Platelet yield, collection efficiency, collection rate, recruitment factor and donor platelet loss were calculated. ResultsThe mean platelet yield in the SDP was 4.09 ± 1.15 × 1011 and in the DDP, 5.93 ± 1.04 × 1011. There was a significant correlation between the pre-donation platelet count and platelet yield. The total of platelets processed for the SDP were 5.42 ± 1.08 × 1011 and for the DDP, 7.94 ± 0.77 × 1011. The collection efficiency was 71.93 ± 25.14% in the SDP and 72.94 ± 16.28% in the DDP, while the collection rates were 0.78 × 1011 and 0.94 × 1011 per minute, respectively. The average recruitment factor observed was 0.98 in the SDP, while it was 0.99 in the DDP. The mean platelet loss observed in the SDP was 35.55 ± 8.53% and in the DDP, 37.76 ± 8.65%. ConclusionThe double-dose plateletpheresis supplements the platelet inventory in developing countries where the apheresis donor pool is limited. It is prudent to ensure stringent donor selection criteria for donors donating high-yield platelet products, thus enhancing donor safety and retention.

Remodelling whole blood processing through automation and pathogen reduction technology at the Luxembourg Red Cross

In 2014–2015, the Luxembourg Red Cross (LRC) implemented a fully automated system (FAS) able to process 4 whole blood units simultaneously, and a pathogen reduction technology (PRT) based on riboflavin and ultraviolet light to improve safety of platelet concentrates (PCs). In this observational study, the impact of both technologies to enable this centralised blood transfusion centre to provide safe and timely blood components supply for the whole country was analysed. Standard quality control parameters for blood components, productivity and safety were compared from data collected with the conventional semi- automated buffy coat method and with FAS/PRT. The FAS decreased processing time when compared with the buffy coat method and facilitated the daily routine at the LRC. Red blood cell concentrates, plasma units and PCs prepared with both methods were conform to the European Directorate for the Quality of Medicines & HealthCare specifications. PCs prepared by FAS showed high yields, with decreased variability when the device-related software (T-Pool Select) was used. PRT had minimal impact on platelet yields and product quality and induced no increase in transfusion reaction notifications. The FAS and PRT transformed the daily routine of blood component manufacture by allowing increased productivity and efficiency, notwithstanding resource containment and without impacting quality, yet promoting safety.

Internal quality control in blood and component bank in a tertiary healthcare center in Northern India

Quality control describes steps taken by blood and component bank to ensure that tests are performed correctly. Primary goal of quality control is transfusion of safe quality of blood. It is to ensure availability of efficient supply of blood and blood components. Internal quality control is the backbone of quality assurance program.To analyze the internal quality control of blood components in modern blood banking as an indicator of our blood bank performance.An observational cross sectional study conducted at the Blood and Component Bank, JN Medical College and Hospital from 2018 to 2020. Each blood component was arbitrarily chosen during the study on monthly basis. Selection criteria was 1.0% of total collection or minimum 4 bags per month. Packed red cells were evaluated for hemoglobin, hematocrit, RBC count; platelet concentrates for pH, yield and culture; fresh frozen plasma and cryoprecipitate were evaluated for unit volume, factor VIII and fibrinogen concentration.The mean HCT of packed red cells was 65.75+7.42%, volume was 238+26.25ml, Hb was 20.5+0.15g/dL and RBC count of 5.89x10+0.30x10. The mean platelet yield was 5.7x10, pH was ≥6.8+0.175 and volume was 82.5+13.75ml; cultures were negative and swirling was present in all the platelet units tested. Mean factor VIII and fibrinogen levels were found to be 95.25 +7.37and 307.5+41.37gm/l for FFP respectively. Mean volume, PT and APTT were 215+32.5ml, 14.15+0.325 sec and 29.50+1.5 sec respectively.The quality control of blood components ensures the timely availability of a blood component of high quality with maximum efficacy and minimal risk to potential recipients.

Leukodepletion Filters-Derived CD34+ Cells As a Cell Source to Study Megakaryocyte Differentiation and Platelet Formation.

The in vitro expansion and differentiation of human hematopoietic progenitors into megakaryocytes capable of elongating proplatelets and releasing platelets allows an in-depth study of the mechanisms underlying platelet biogenesis. Available culture protocols are mostly based on hematopoietic progenitors derived from bone marrow or cord blood raising a number of ethical, technical, and economic concerns. If there are already available protocols for obtaining CD34 cells from peripheral blood, this manuscript proposes a straightforward and optimized protocol for obtaining CD34+ cells from leukodepletion filters readily available in blood centers. These cells are isolated from leukodepletion filters used in the preparation of blood transfusion products, corresponding to eight blood donations. These filters are meant to be discarded. A detailed procedure to collect hematopoietic progenitors identified as CD34+ cells from these filters is described. The method to obtain mature megakaryocytes extending proplatelets while discussing their phenotypic evolution is also detailed. Finally, the protocol present a calibrated pipetting method, to efficiently release platelets that are morphologically and functionally similar to native ones. This protocol can serve as a basis for evaluating pharmacological compounds acting at various steps of the process to dissect the underlying mechanisms and approach the in vivo platelet yields.

New design to remove leukocytes from platelet-rich plasma (PRP) based on cell dimension rather than density

Platelet-rich plasma (PRP) can stimulate the proliferation of stem cells and have a positive effect on tissue repair. Although many commercialized PRP preparation kits are already on the market, first-line clinical workers are still not satisfied with most of the PRP kits. The work of commercial PRP kits is based on the density of blood elements. However, the blood elements are very close in density which makes the separation challenging. Therefore, the mentioned commercialized kits are generally contaminated by leucocytes and erythrocyte. In this study, a home-designed PRP device was developed to use a separation membrane with adequate cut-off pore size of 5 μm, 3 μm and 2 μm for the groups of H5M, H3M, and H2M, respectively, to be placed in the middle of the centrifuge tube. The home-designed H2M showed a very promising results regardless of the final volume (1.82 ± 0.09 ml), platelet yield (8.39 ± 0.44%), Red Blood Cells (0%), White Blood Cells (0%), and Relative Concentration of Platelet Increment value (225.09%). Further, it showed a good result in cell viability and cytotoxicity and confirmed a good multilineage potentials. The concentration in PRP prepared by group H2M was relatively stable and far above average. All the fibrin fibers were linked together as bridging strands or strings and turned into an inter-connected porous structure for nutrients transportation and regenerative cell migration. We believe that the home-designed group H2M should have a great potential to develop into the final product to meet the requirements of first-line clinical workers.

Factors affecting the quantity and quality of platelet-rich plasma and platelet-derived growth factor-BB: an observational study

Abstract Objective: Platelet-rich plasma (PRP) releases growth factors upon activation, which in turn accelerates healing and regeneration of the target tissue. However, PRP composition may vary according to the patient's demographics, and wider applications of PRP warrant product standardization. The current study aimed to examine variables influencing the platelet-derived growth factor BB (PDGF-BB) concentration in PRP. Methods: This observational study was conducted in the Department of Pathology and Dentistry at Swami Rama Himalayan University, a tertiary care hospital in northern India from December 2016 to November 2017. PRP was prepared from 40 mL of whole blood from 35 individuals (22 women, 13 men). Platelet counts, platelet indices (platelet distribution width, mean platelet volume) and PDGF-BB levels were measured, and platelet yield, platelet dose, and growth factor dose in PRP were also calculated. All parameters were analyzed using Pearson's correlation coefficient. The association between PDGF-BB and PRP platelet count was evaluated using logistic regression. This study was approved by the Ethics Committee of Swami Rama Himalayan University (SRHU/HIMS/ETHICS/2016/103) on September 7, 2016. Results: The mean platelet count, PDGF-BB concentration, platelet yield, platelet dose, and growth factor dose in PRP were 1317 × 109/L, 30 ± 9.89ng/mL, 71.62 ± 28.34%, 6.5 ± 3.5 × 109, and 159.62 ± 52.39ng/mL, respectively. Linear regression analysis indicated that PRP platelet counts were a good predictor for PGDF-BB (P < 0.05; adjusted R 2 = 0.96. PRP platelet count was significantly positively correlated with PDGF-BB concentration (r = 0.74, P < 0.001), platelet yield (r = 0.80, P < 0.001), platelet dose (r = 1, P < 0.001), and growth factor dose (r = 0.74, P < 0.001). Conclusions: PRP has wide clinical applications associated with its healing and regenerative properties, and both the quality and quantity of PRP thus need to be standardized as per the requirements. Evaluating variables affecting PRP will thus aid pathologists and clinical practitioners.

Generation and manipulation of human iPSC-derived platelets.

The discovery of iPSCs has led to the ex vivo production of differentiated cells for regenerative medicine. In the case of transfusion products, the derivation of platelets from iPSCs is expected to complement our current blood-donor supplied transfusion system through donor-independent production with complete pathogen-free assurance. This derivation can also overcome alloimmune platelet transfusion refractoriness by resulting in autologous, HLA-homologous or HLA-deficient products. Several developments were necessary to produce a massive number of platelets required for a single transfusion. First, expandable megakaryocytes were established from iPSCs through transgene expression. Second, a turbulent-type bioreactor with improved platelet yield and quality was developed. Third, novel drugs that enabled efficient feeder cell-free conditions were developed. Fourth, the platelet-containing suspension was purified and resuspended in an appropriate buffer. Finally, the platelet product needed to be assured for competency and safety including non-tumorigenicity through in vitro and in vivo preclinical tests. Based on these advancements, a clinical trial has started. The generation of human iPSC-derived platelets could evolve transfusion medicine to the next stage and assure a ubiquitous, safe supply of platelet products. Further, considering the feasibility of gene manipulations in iPSCs, other platelet products may bring forth novel therapeutic measures.

Effect of Donor Variables on Platelet Yield Among Donor Undergoing Plateletpheresis at Transfusion Medicine Department, Dhaka Medical College Hospital (Experience of 350 Procedures)

Background: The platelet transfusions help in prevention of bleeding related complications and thus prevents morbidity and mortality in thrombocytopenic patients. Platelet transfusion plays an important role in the treatment of haematological, oncological, surgical, and transplant patients. Platelets are transfused by two methods i) by fractionation of whole blood and ii) by platelet apheresis. Over the last decade there has been a trend towards the use of SDPs rather than pooled random donor platelets in thrombocytopenic patients. Optimization of platelet yield is an emerging issue to identify factors which may help in selecting donors to obtain higher platelet yields in shorter time and consequently better clinical outcome.
 Objective: The quality of single donor platelets (SDP) in terms of yield influences the platelet recovery in the recipient. The aim was to identify the SDP donor factors that influence platelet yield.
 Methods: The study was undertaken at transfusion medicine department, DMCH from 1st January 2017 to 31st December 2017. The study included 350 plateletpheresis procedures. All procedures were performed according to manufacturer’s manual and standard operating procedure.
 Results: During the period of study, 350 platelet pheresis donors were studied. All of the donors were male. Platelet yield showed high statistical significance with pre donation platelet count and its indices. (p=0.000). Statistical significant negative correlation was seen between pre donation Hb concentration and the platelet yield. (p =0.005). No statistical significance was seen height (p=0.933), weight (p=0.760) of donor on platelet yield.
 Conclusion: Platelet recovery in the patient is influenced by the transfused dose of platelets, which in turn is dependent on the quality of the platelet product in terms of yield. Various donor factors such as pre donation platelet count and haemoglobin concentration may affect platelet yield.
 J Dhaka Medical College, Vol. 28, No.2, October, 2019, Page 179-183

Are donor predonation variables related to the quality of single donor platelets? – A tertiary care center experience

Introduction: Platelets are the most common product collected by apheresis. The product obtained is called single donor platelets (SDPs). The quality of the SDP is determined by the platelet yield (that is platelet count of the SDP product), which in turn directly influences the patient recovery. Materials and Methods: In the present study, donor demographic and complete blood count parameters were studied and their influence on the yield of the SDP was analyzed. With such an analysis, a better quality product (with a good platelet yield) can be obtained consequently improving clinical outcome. This would allow prolonging intervals between transfusions. Results: Parameters such as height, weight, and body mass index did not statistically influence the platelet yield in this study, unlike the results obtained by past studies. The most consistent parameter found to influence the platelet yield was platelet count of the donor. Healthy donors with high platelet counts can yield better platelet yield in SDPs in a shorter time and therefore improve the clinical outcome in patients with thrombocytopenia. Conclusion: It is important to consider hematological characteristics of the donors on an individual basis so as to ensure a good quality of the plateletpheresis product.

Incidence and severity of adverse events among platelet donors: A three-year retrospective study.

Adverse events (AEs) are unfortunate consequences of platelet donation. This study reports the incidence and severity of AEs and the associated risk factors in platelet donation at a major blood donation center in Riyadh, Saudi Arabia.A review of donation records was conducted between 2014 and 2017. Eligible study participants were 5007 platelet donors who had donated 7969 times. Each donation was accounted for as a single study subject. Participants’ characteristics were described and analyzed as potential contributing factors to adverse events.The average age of platelet donors was 30.0±7.3 years. First-time donors comprised (n = 3,100, 61.9%) of the sample, and 1907 (38.1%) were multiple donors (periodic/routine). Their average BMI was 28.6 ± 4.9 kg/m2. Most donors have blood type “O” and Rheo “positive”. The range of blood volume processed was 0 to 5273 ml, while the procedure duration ranged from 0 to 90 minutes. The average platelet yield was 3.8 ± 3.5 ∗1011 platelets per unit, and the average collected volume was 257.6 ± 86.1 ml. Incidence of AEs was 4.2%, of which 91.3% were mild and 8.7% were severe. AEs were vascular injuries (65.3%), vasovagal reactions (11.6%), and citrate toxicity (5.3%). AEs were associated with first-time donation, adj.OR (95%CI) = 1.5 (1.1–1.8) and lower BMI, adj. OR (95% CI) = 1.4 (1.1–1.8). Citrate toxicity was present in severe forms, unlike vascular injuries and vasovagal reactions that tended to be milder. Donors with hemoglobin levels above 16 g/dl, adj. OR (95% CI) = 1.3 (1.1–1.7) and platelet levels below 250,000, adj. OR (95% CI) = 1.3 (1.1–1.6) were more likely to contract AEs than others.Reporting adverse events is essential to establish a benchmark for the annual incidence rates to be compared against local and international figures. Blood donor centers should also take notice of blood donors characteristics that are associated with higher incidence and more severe forms of AEs during or after platelet donation.

Comparison of Two Preparation Methods for Platelet-Rich Plasma Eye Drops for Release of Growth Factors and De-Epithelization Rabbit Model.

Purpose To compare two platelet-rich plasma (PRP) preparation methods (double spin (D-PRP) and TriCell PRP (T-PRP)) for eye drops, concentration yields of platelets and other cells, release of growth factors, and efficacy of the de-epithelization rabbit model. Methods PRP was extracted by D-PRP and T-PRP from 30 ml blood from healthy adults. After extraction, platelets and leukocytes were counted. D-PRP and T-PRP were preserved during A: 1 h storage at room temperature, B: 1 h storage at −20°C, C: 24 h storage at 4°C, and D: 24 h storage at −20°C. Platelet-derived growth factor (PDGF) was measured. Freezing/thawing PRP eye drops and control were instilled in the de-epithelization rabbit model four times per day for 5 days. Histology was compared between eyes treated with control, D-PRP, and T-PRP. Results 14 ml of D-PRP and 4 ml of T-PRP were extracted from 30 ml whole blood samples. D-PRP and T-PRP had 41.36 ± 8.43 × 104 and 67.02 ± 13.55 × 104 platelets and 0.41 ± 0.24 × 103/ml and 10.09 ± 4.29 × 103/ml leucocytes, respectively. In the four storage methods, PDGF concentrations in T-PRP were higher than those in D-PRP eye drops. Freezing/thawing D-PRP and T-PRP increased PDGF concentrations. Histology showed corneal epithelium thickness in T-PRP-treated eyes after healing (38.41 ± 9.10 μm) was significantly higher than that in control-treated (27.77 ± 4.76 μm) and D-PRP-treated eyes (18.32 ± 3.14 μm) (P < 0.05). There was no corneal damage with inflammation in corneal stroma and epithelium of all tested groups. Electron microscopy revealed strong adhesion between cell junctions in T-PRP-treated eyes. Conclusions Freezing/thawing of PRP extracted with the T-PRP kit may result in high platelet and leukocyte concentration and produce high PDGF concentration. PRP eye drops including leucocytes could increase thickness of corneal epithelium without corneal inflammation.

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

IntroductionThe 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. MethodsA 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. ResultsThere 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. ConclusionThe 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.

Assessment of software-derived predictive algorithms for platelet yield and blood cell count after apheresis.

Algorithms have been developed to predict the platelet yield after apheresis from the donor's data, as well as the effect on the blood cell count, to extract an acceptable platelet number without affecting the donor. However, the evaluation of these algorithms has not been widely reported. This study aimed to assess the accuracy of the predictive algorithms of the Trima Accel v. 6 blood collection system. Platelet concentrates (PCs) obtained by apheresis were analyzed. Platelet count and hematocrit were compared pre- and post-apheresis. Calculated post-apheresis platelet count (CPAPC), hematocrit (CPAH), and platelet yield (CPY), and their actual values were correlated. The bias of the algorithms was assessed with Bland-Altman plots, and the prediction of the extraction of single or double platelet products was evaluated. Two hundred and seventy-nine PCs were analyzed. Post-apheresis platelet count (PAPC) and hematocrit were decreased. A moderate correlation was observed between CPY and the actual yield, with a negative bias, and a trend to increase alongside the magnitude of the measurements. CPAPC and CPAH were strongly correlated with their actual values without bias. Prediction of single or double platelet product extraction showed a significant agreement with the actual outcomes. The predictive algorithm for the platelet yield showed bias, and a trend to underestimate the actual platelet yields when they are higher. The algorithms for the prediction of the PAPC and hematocrit did not show bias, proving their accuracy. Prediction of a single or double platelet product extraction has a strong agreement with the APY.

Platelet Rich Plasma - Platelet Counts and Application - A Literature Review

Platelet rich plasma (PRP) is a novel method of using plasma concentrated with platelets for wound healing and tissue regeneration. Platelet rich plasma is prepared from the venous blood using a differential centrifugation technique. It involves a separation spin and a concentration spin, yielding platelet rich plasma. PRP products have been classified into 4 types depending upon major cell constituent and fibrin density upon activation. These are as follows: Pure PRP, Leukocyte and PRP, Pure PRF, Leukocyte and PRF. PRF differs from PRP in that it is rich in a high density fibrin network after activation. PRP is abundant in a variety of growth factors such as VEGF, PDGF, TGF, EGF, and Interleukin-1. Literature consists of reports by different authors about the platelet yield of PRP centrifuged by different systems. A number of factors have also been quoted to influence the platelet concentration in platelet rich plasma. Hence, the aim of this review is to discuss the platelet concentration in PRP centrifuged by different systems and to observe for variations if any.

Plateletpheresis in the Era of Automation: Optimizing Donor Safety and Product Quality Using Modern Apheresis Instruments.

The increases in major surgeries, transplantations and speciality clinics have significantly increased the utilization of platelet concentrates including single donor platelets (SDP). The advantages of SDP or apheresis platelet have been discussed elaborately by previous authors as compared to random donor platelets. Here we share our experiences of plateletpheresis procedures using the modern apheresis machines with regards to product quality and donor safety. This study included 3016 procedures of plateletpheresis (1397 on Amicus and 1619 on Trima accel cell separators) on eligible donors using recommended apheresis kits. A target yield of 3 × 1011 was set as the end point of each procedure. Donor details, procedure details and donor adverse reactions if any were documented. Statistical analysis was done using the SPSS statistical package (version 13, USA). Of the total 6276 donors screened 2049 (32.6%) were deferred due to various reasons. Out of remaining 4227 eligible donors; 3016 (71.4%) underwent plateletphereis procedures based on the requirement of SDP by the patients. Mean pre-procedure platelet count and hematocrit in donors were 188.3 × 106/mL and 41.7% respectively. Mean procedure time in Amicus (76.6min) was significantly more than the Trima accel (64.3min) (p = 0.02). Platelet yield by Trima accel and Amicus was 2.96 × 1011 and 3.08 × 1011 respectively (p = 0.061). A total of 40 donors (1.33%) suffered adverse effect during or after apheresis procedures. While the modern plateletpheresis devices are both donor and user friendly at the same time they provide quality product consistently in lesser time.

Utilità clinica dei fattori di crescita nel plasma ricco di piastrine (PRP). Analisi dell'efficacia di differenti metodi di preparazione

Background and aim Over the past few years, the use of blood components for non-infusion or non-transfusion procedure has rapidly expanded to various clinical applications in different speciality fields. PRP has a high concentration of platelets that make it functional for the repair and regeneration processes of damaged tissues. These effects depend on the fact that growth factors are present in the alpha granules of the platelets, able not only to stimulate tissue regeneration, but also to field a striking local anti-inflammatory response, called chemotaxis. The main identified growth factors that trigger and promote tissue regeneration processes are TGF-β (Transforming Growth Factor beta), VEGF (Vascular Endothelial Growth Factor) and PDGF (Platelet Derived Growth Factor). The purpose of this study is to compare the characteristic parameters of the blood components for non-infusion use obtained with the various possible preparation methods: this study will be able to identify the parameters for the best therapeutic effect on the patients treated, in terms of effectiveness and durability. Materials and methods The type of blood component to prepare, for the treatment of patients, is chosen by the transfusion doctor, based on their clinical characteristics, such as age, venous access and concomitant pathologies, choosing between the PRP Single Device (PRP-SD), the PRP by apheresis (PRP-AFE), the PRP homologous (PRP-OMO) and the Leuco-platelet apheresis (L-PRP). Results Control blood count was performed on all patients treated with the PRP before sampling and subsequently, on the blood component. The results has been compared with the data reported in literature, in order to identified the most effective PRP preparation method, in terms of platelet yield and of leukocyte. Conclusions The literature’s data show that the number of platelets and leukocytes present in the PRP greatly influences the patient's outcome. The results obtained have showed a variety of platelets and leukocytes contained in the PRP prepared with the various processing methods. The PRP-SD is the blood component capable of guaranteeing the best therapeutic effect, in terms of efficacy and durability. Keywords: PRP, Growth factors, Platelets, Leukocytes.

Blood component separation of pathogen-reduced whole blood by the PRP method produces acceptable red cells but platelet yields and function are diminished.

This study evaluated blood components processed by the platelet rich plasma (PRP) method from fresh whole blood (FWB) treated with a pathogen reduction technology (PRT). The effects of storage temperature on PRT treated platelet concentrates (PCs) were also examined. PRT was performed using riboflavin and ultraviolet light on FWB in citrate phosphate dextrose anticoagulant. Following PRT, red blood cells (RBCs), PCs, and plasma for fresh frozen plasma (FFP), were isolated by sequential centrifugation. RBCs were stored at 4°C, FFP at -80°C, and PC at 22°C or at 4°C. Components were assayed throughout their storage times for blood gases, chemistry and CBC, hemostatic function as well as platelet (PLT) and RBC integrity. Component processing following PRT resulted in a significant drop in platelet recovery. Most PRT-PC bags fell below AABB guidelines for platelet count. PRT-PC also showed a decrease in clot strength and decreased aggregometry response. Platelet caspases were activated by PRT. Storage at 4°C improved platelet function. In PRT-FFP, prothrombin time and partial thromboplastin time (PT and aPTT) were prolonged; factors V, VII, VIII, and XI, protein C, and fibrinogen were significantly decreased. Free hemoglobin was elevated two-fold in PRT-RBC. Blood components isolated by the PRP method from PRT-treated WB result in a high percentage of PC that fail to meet AABB guidelines. FFP also shows diminished coagulation capacity. However, PRT-RBC are comparable to control-RBC. PRT-WB retains acceptable hemostatic function but alternatives to the PRP method of component separation may be more suitable.

Optimization of a rapid one-step platelet-rich plasma preparation method using syringe centrifugation with and without carprofen

BackgroundCarprofen and platelet-rich plasma (PRP) are widely used in small animal clinical practice. Separation layers have been used during blood centrifugation to increase platelet yield. The objectives of this study were to (1) identify the optimal centrifugation force for the one-step PRP preparation, (2) determine whether there is an advantage to using carprofen in one-step PRP preparation, and (3) compare platelet morphology from one-step PRP preparation with and without carprofen. We hypothesized that injectable carprofen (emulsion formula) could be used successfully as the separation layer in PRP preparation.ResultsSamples from 14 healthy dogs were used to determine the optimal centrifugation force using one-step PRP preparation in a disposable syringe without carprofen, with forces set at 300, 500, 700, 900, 1100, 1300, and 1500 xg for 5 min. Optimum centrifugation force, plasma volume, and platelet concentrations of one-step PRP preparation were found and recovered at 900 xg, 1.9 ± 0.28 ml, and 260.50 ± 58.39 X 103 cell/μl, respectively. Samples from 12 healthy dogs were used to determine the optimal force (with forces set at 300, 500, 700, and 900 xg) for 5 min using one-step PRP preparation with carprofen. Optimum centrifugation force, plasma volume, and platelet concentrations for one-step PRP preparation with carprofen were found and recovered at 500 xg, 0.62 ± 0.16 ml and 948.50 ± 261.40 X 103 cell/μl, respectively. One-step PRP preparation with carprofen increased the platelet yield from baseline by 1.76 and 4.95 fold, respectively. Samples from 3 healthy dogs were used to observe platelet morphologies after centrifugation by scanning electron microscopy. Images of platelets on glass slides from both preparation methods revealed pseudopods emerging from the margins of the discoid platelets.ConclusionsOne-step PRP centrifugation both with and without carprofen increased the platelet yield, but using carprofen (emulsion formula) as a separation layer resulted in a higher platelet yield. The clinical usefulness of PRP products from these methods should be further investigated.

Predicting yields in autologous MNC apheresis for ATMP manufacture: applying a kinetic model for HPC apheresis

Background & Aim In cancer immunotherapy autologous MNC apheresis provides the source material for various advanced therapy medicinal products (ATMPs). Predicting cell yields would facilitate complex therapeutic regimens. Therefore an algorithm for CD34+ HPC yield in stem cell collection was applied but failed because of considerable cell recruitment during leukapheresis. Methods, Results & Conclusion Methods 41 patients were subjected to 46 autologous MNC leukapheresis procedures with a continous flow cell separator (Spectra Optia, V11.0, CMNC programme, TerumoBCT). Blood counts and quantification of lymphocyte subpopulations were done before and after leukapheresis as well as in the apheresis product on a hematology analyzer (Sysmex K21) and a flow cytometer (FACS Verse, BD). From the results and the apheresis key data cell yields, collection efficiency (CE2) and recruitment were calculated. Furthermore, relevant data were entered into a kinetic model validated for prediction of CD34+ HPC yields in HPC apheresis. Results The yields in 46 procedures averaged to vital TNC s 1.3*10E10, lymphocytes 6.8*10E9, CD3+ T cells 3.8 *10E9, NK cells (NKs) 7.2*10E8, platelets (PLT) 16.7*10E10, respectively. Though in 29/46 separations peripheral blood CD34+ HPCs were below 1/µl, they were detectable in the corresponding apheresis products containing on average 3.8*10E7 CD34+ HPCs. The collection efficiency (CE2) amounted to 0.64 for lymphocytes, 0.61 for CD3+ T cells, 0.74 for NKs. CE2 for CD3+ and NK cells were independent from their blood count. In the model validated for the prediction of CD34+ HPC yields described by Humpe et al. the calculated amounts overestimated PLT yields (3.0fold), but underscored the harvests of NK, CD3+ T cells and lymphocytes 0.5fold each. This is probably related to the recruitment which averaged 2.7 for lymphocytes, NK and CD3+T cells each and 1.1 for PLT. As described earlier in healthy donors, cell recruitment and loss were significantly correlated. Conclusion Yields in MNC leukapheresis cannot be predicted using a kinetic model validated for the prediction of CD34+ HPC collection. This is caused by a considerable, but highly variable recruitment of cells into the apheresis product representing a novel kind of liquid biopsy. In cancer immunotherapy autologous MNC apheresis provides the source material for various advanced therapy medicinal products (ATMPs). Predicting cell yields would facilitate complex therapeutic regimens. Therefore an algorithm for CD34+ HPC yield in stem cell collection was applied but failed because of considerable cell recruitment during leukapheresis. 41 patients were subjected to 46 autologous MNC leukapheresis procedures with a continous flow cell separator (Spectra Optia, V11.0, CMNC programme, TerumoBCT). Blood counts and quantification of lymphocyte subpopulations were done before and after leukapheresis as well as in the apheresis product on a hematology analyzer (Sysmex K21) and a flow cytometer (FACS Verse, BD). From the results and the apheresis key data cell yields, collection efficiency (CE2) and recruitment were calculated. Furthermore, relevant data were entered into a kinetic model validated for prediction of CD34+ HPC yields in HPC apheresis.