Apheresis Machine Research Articles

Comparison study between two apheresis machines: Cobe® Spectra versus Spectra Optia® - a single center experience

Comparison study between two apheresis machines: Cobe® Spectra versus Spectra Optia® - a single center experience

Certification of donor apheresis nurses: Keys to develop an effective training program

Within Sanquin Blood Supply, a training program to train apheresis nurses was developed. The parts of the work for which qualification should be necessary was analysed. Based on this analysis, a modular program with theoretical and practical information and knowledge was developed. The modular program consists of two sections: a theoretical and technical / practical. The theoretical section consists of by the project group identified themes including basic hematology (e.g. the characteristics, kinetics, physiology and function of blood cells), basic apheresis physiology, indications for apheresis procedures, criteria for donors apheresis, difficulties and risks of procedures as well as the actions to be taken in case of side effects, and introduction to the apheresis machine available, including the mechanism of the machine. The program for the technical / practical section consists of machine and procedure knowledge (in theory and practise) and troubleshooting. To conclude each individual module, tests in theory and capability to perform procedures are taken. Each trainee needs to demonstrate to have sufficient insight and skill to master all the relevant critical features of the work. Also a text-book for the trainee was written. This educational program provides an approach to educate and test apheresis donor nurses. The combination of theoretical and practical components and monitoring of the progression are an important basis.

Simultaneous Therapeutic Plasma Exchange in Parallel with Cardiopulmonary Bypass for Prevention of HLA-Antibody Mediated Rejection in a Pediatric Double-Transplant Patient

Therapeutic plasma exchange (TPE) has been used peri-operatively to prevent antibody-mediated rejection (AMR) in pre-sensitized solid organ transplant patients. Intraoperative TPE during cardiopulmonary bypass (CPB) has been reported in neonates receiving ABO-incompatible cardiac transplants, as well as in adults undergoing cardiac surgery. To our knowledge, intraoperative TPE in parallel with CPB (TPE-CPB) for prevention of human leukocyte antigen (HLA)-AMR has not been reported in pediatric cardiac transplantation. A 13 year old female with dilated cardiomyopathy, status post orthotopic cardiac transplant at 5 months of age, presented for cardiac re-transplantation due to end-stage heart failure and renal transplantation for end stage renal disease. Histocompatibility testing was weakly positive for antibodies to HLA-DQ6, with weakly positive donor crossmatch. In order to minimize ischemic time of the donor heart, TPE was performed while on CPB, immediately prior to cardiac transplantation. Apheresis machine access and return lines were connected via stopcocks to the CPB via proximal and distal ports, respectively, on the venous/low pressure side of the CPB circuit, before the CPB pump and oxygenator. The apheresis access line pressure alarm was set to 10 mm Hg less than the CPB pump pressure, to avoid pressure alarms and apheresis pump shutdown. The procedure was well tolerated, without complications. The subsequent renal transplant was uneventful. Post-operatively, no AMR was seen, and the patient continues to have good cardiac and renal function. Intraoperative TPE-CPB is feasible and safe, and may be considered for reduction of HLA antibody level immediately prior to cardiac transplantation in pediatric patients.

Allogeneic single‐donor cryoseal produced from fresh‐frozen quarantine apheresis plasma as alternative for multidonor or autologous fibrin sealants

Fibrin sealant is a human blood product consisting of two components: cryoprecipitate and thrombin. Commercial fibrin sealants are produced from multidonors, increasing the viral risk, and contain fibrinolytic inhibitors such as tranexamic acid or bovine aprotinin. Autologous fibrin sealants reduce the viral risk and are mostly produced during a surgical procedure or well in advance. Alternatively, the allogeneic single-donor fibrin sealant cryoseal can be used. In this study cryoseal was characterized and the manufacturing consistency of the production process was investigated. Cryoseal was produced from plasma collected on apheresis machines using a commercial device. In a research setting the protein composition and recovery were determined. Also, the manufacturing consistency of the production process was tested in a research setting as well as in a routine setting. In the research setting all produced cryoseal met the quality control requirements of a clotting time of less than 10 seconds and the presence of Factor (F)XIII (qualitative). In the routine setting, one procedure per year did not meet these requirements. The protein composition showed the following mean ± standard deviation (%recovery) results: thrombin 25.7 ± 11.1 IU/mL, fibrinogen 19.9 ± 4.6 (15%) mg/mL, FVIII 15.6 ± 5.4 (44%) IU/mL, FXIII 2.7 ± 0.7 (6%) IU/mL, and plasminogen 1.8 ± 0.2 (4%) U/mL. In both research and routine settings the production process resulted in a consistent product. The cryoseal manufacturing process resulted in a consistent product, which meets the predetermined specifications. The single-donor origin and the absence of fibrinolytic inhibitors make cryoseal a good alternative for multidonor and autologous fibrin sealants.

Hematologic Changes After Total Body Irradiation and Autologous Transplantation of Hematopoietic Peripheral Blood Progenitor Cells in Dogs With Lymphoma

Dogs with and without lymphoma have undergone hematopoietic cell transplantation in a research setting for decades. North Carolina State University is currently treating dogs with B- and T-cell lymphoma in a clinical setting with autologous peripheral blood progenitor cell transplants, using peripheral blood CD34+ progenitor cells harvested using an apheresis machine. Complete blood counts were performed daily for 15 to 19 days posttransplantation to monitor peripheral blood cell nadirs and subsequent CD34+ cell engraftment. This study documents the hematologic toxicities of total body irradiation in 10 dogs and the subsequent recovery of the affected cell lines after peripheral blood progenitor cell transplant, indicating successful CD34+ engraftment. All peripheral blood cell lines, excluding red blood cells, experienced grade 4 toxicities. All dogs had ≥ 500 neutrophils/μl by day 12, while thrombocytopenia persisted for many weeks. All dogs were clinically normal at discharge.

Autologous Peripheral Blood Stem Cell Transplantation in Children with Refractory or Relapsed Lymphoma: Results of Children’s Oncology Group Study A5962

This prospective study was designed to determine the safety and efficacy of cyclophosphamide, BCNU, and etoposide (CBV) conditioning and autologous peripheral blood stem cell transplant (PBSCT) in children with relapsed or refractory Hodgkin and non-Hodgkin lymphoma (HL and NHL). Patients achieving complete remission (CR) or partial remission (PR) after 2 to 4 courses of reinduction underwent a granulocyte-colony stimulating factor (G-CSF) mobilized PBSC apheresis with a target collection dose of 5 × 10⁶ CD34(+)/kg. Those eligible to proceed received autologous PBSCT after CBV (7200 mg/m², 450-300 mg/m², 2400 mg/m²). Forty-three of 69 patients (30/39 HL, 13/30 NHL) achieved a CR/PR after reinduction. Thirty-eight patients (28 HL, 10 NHL) underwent PBSCT. All initial 6 patients who received BCNU at 450 mg/m² experienced grade III or IV pulmonary toxicity compared to none of the subsequent 32 receiving 300 mg/m² (P < .0001). The probability of overall survival (OS) at 3 years for all patients is 51% and for transplanted patients is 64%. The 3-year event-free survival (EFS) is 38% (45% for HL; 30% NHL). The 3-year EFS in transplanted patients is 66% (65% HL; 70% NHL). Initial duration of remission of ≥12 versus <12 months was associated with a significant increase in OS (3 years OS 70% versus 34%) (P = .003). BCNU at 300 mg/m(2) in a CBV regimen prior to PBSCT is well tolerated in relapsed or refractory pediatric lymphoma patients. A short duration (<12 months) of initial remission is associated with a poorer prognosis. Last, a high percentage of patients achieving a CR/PR after reinduction therapy can be salvaged with CBV and autologlous PBSCT.

Extended Storage of Autologous Apheresis Platelets (Plts) in Plasma and Plasmalyte.

Abstract 2108Poster Board II-85Background: The FDA has proposed that, at the end of storage, radiolabeled autologous plt recoveries and survivals should be 67% and 58% respectively, of the same donor's “fresh” plt recovery and survival results. Methods: Using 98 normal subjects, 3 different variables were evaluated to determine their effects on post-storage plt recoveries and survivals; i.e., storage solution (plasma and Plasmalyte), apheresis machine [Haemonetics MCS+ (H), Cobe Spectra (CS), or Cobe Trima (CT)], and storage bag (H, CS, or CT). Autologous plts were collected and either infused “fresh” or stored under the conditions of interest. The fresh and stored plts were alternately radiolabeled with either 51Cr or 111In prior to transfusion. Results: Plasma Storage. Both H and CS collected apheresis plts can be stored for 8 days and meet FDA requirements with no differences in post-storage plt recoveries or survivals between the 2 machines (see table). After 9 days of storage, 2 of 5 units (1 H and 1 CS) had pH's of <6.2, and these plts had recoveries of 36% and 26% and survivals of 1.1 and 0.9 days, respectively.Apheresis MachineStorage Time (Days)Storage BagNPLATELET RECOVERYPLATELET SURVIVAL%% of “Fresh”Days% of “Fresh”Plt Storage In Plasma:H8H1052 ± 879 ± 165.3 ± 1.778 ± 16CS8CS1054 ± 1175 ± 84.7 ± 1.462 ± 22Plt Storage In Plasmalyte:H7H1052 ± 10ND6.0 ± 0.9NDCS7CS1547 ± 18*ND4.3 ± 1.5*NDCT7CT1040 ± 15**69 ± 215.0 ± 1.6**64 ± 20H9H455 ± 1182 ± 206.6 ± 1.293 ± 39CS9CS527 ± 16**ND3.6 ± 1.9**NDCT9CT932 ± 19***58 ± 353.7 ± 1.6***48 ± 23CT9H1044 ± 1378 ± 165.0 ± 0.759 ± 7H13H1049 ± 1073 ± 114.6 ± 1.069 ± 19CS13CS538 ± 10****ND2.6 ± 0.9****NDCS13H542 ± 14****ND4.6 ± 2.2****NDData reported as average ±1 S.D.*Four units had post-storage pH's of <6.0.**One unit had a post-storage of pH <6.0.***Two units had post-storage pH's of 6.1. One other unit had a pH of 6.0 and was not injected.****CS apheresis plts were collected from 5 subjects, and half of the collection was stored in CS bags, and half in H bags. One collection had a pH <6.0 in both bags and was not injected.Plasmalyte Storage. For the H collections, the plts were elutriated using Plasmalyte instead of plasma, and, for the CS and CT collections, the plts were concentrated during collection and re-suspended in Plasmalyte. For all the collections, the final Plasmalyte concentration was 80% with 20% residual plasma. As shown in the table, H collected plts met FDA criteria for 13 days versus 7 days of storage for both CS (FDA criteria not directly tested) and CT collected plts. Even after 7 days of storage, H collected plts were significantly better than CS or CT collected plts with respect to survival (p=0.05), and, after 9 days of storage, H collected plts were significantly better than CS and CT collected plts for both recoveries (p=0.003) and survivals (p<0.001). Recoveries of CS collected plts were better than CT collected plts after 7 days of storage (p=0.01), but the rest of the CS and CT plt recovery and survival data at 7 and 9 days of storage were not different. To determine whether the better results achieved with H plts were because of the machine and/or the storage bag, experiments were performed storing CT or CS collected plts in H bags for 9 or 13 days, respectively. When stored in H bags versus CT bags, 9-day stored CT collected plts had better survivals (p=0.03). Again, CS collected plts stored for 13 days showed a trend for better survivals when stored in H versus CS bags. These data show that both the apheresis machine as well as the storage bag affect the results with the predominant effect being the storage bag. H bag is a ES 3049 PVC compound, and CS and CT bags are PVC with a citrate plasticizer. Low post-storage pH's were found at any storage interval for CS and CT collected plts mainly when stored in their respective bags. pH's <6.2 reduced recoveries by 29% points and survivals by 3.0 days. Therefore, all statistical comparisons between groups were adjusted for the effects of low pH. Conclusion: Apheresis plts can be stored in plasma for 8 days and meet FDA guidelines for plt viability with comparable results between machines and bags. Plt storage in Plasmalyte is effected by both the method of collection as well as the storage bag with the best results achieved with H plts stored in H bags. H plts stored in H bags meet FDA guidelines for 13 days of storage The importance of these results is that extended plt storage can be achieved by using the appropriate combination of storage solution, collection machine, and storage bag. Disclosures:Slichter:Gambro BCT: Research Funding. Off Label Use: Plasmalyte was used as a platelet storage solution.

A single apheresis procedure in the donor may be enough to complete an allograft using the "Mexican method" of non-ablative allografting.

Since 1999, in Mexico we have been using a regimen to conduct allografts that involves non-myeloablative conditioning and peripheral blood stem cells (PBSC) and have introduced some changes with the main goal of decreasing the cost of the procedure. We analysed the salient apheresis features of a group of 175 allogeneic peripheral blood stem cell transplants conducted in two institutions in a 7-year period. The grafts were conducted using the "Mexican" non-myelo ablative conditioning regimen employing oral busulphan, i.v. cyclophosphamide and i.v. fludarabine. In all instances, the apheresis machine employed was the Baxter CS3000 Plus and donors were mobilised with filgrastim. The apheresis procedures were performed on days 0, +1 and +2, the end-point of collection being 5,000 mL of blood/m2 in each procedure. Three apheresis sessions were planned but the number was adjusted according to the cell yield. The final number of allografted CD34 cells ranged between 0.5 and 25.4 x 10(6)/Kg of the recipient's body weight (median, 5.2 x 10(6)/Kg). One to three apheresis procedures were needed to obtain a product containing more than 0.5 x 10(6) CD34 cells/Kg of the recipient, the median being two procedures; in 72 cases (41%) a single apheresis procedure was sufficient to obtain the target number of CD34 cells. The volumes of apheresis ranged between 50 and 600 mL (median, 400 mL). Since the median cost of each apheresis procedure is 900 USD, the fact that two apheresis procedures was spared in 72 cases and one apheresis was spared in another 65 cases, led to a total saving of approximately 188,100 USD. It can be concluded that, in many cases, allogeneic transplants can be completed with a single apheresis session and that there are considerable financial benefits from this practice.

A Single Apheresis Procedure in the Donor May Be Enough to Complete an Allograft Using the “Mexican Method” of Non-Ablative Allografting

Background. Since 1999, in Mexico we have been using a regimen to conduct allografts that involves non-myeloablative conditioning and peripheral blood stem cells (PBSC) and have introduced some changes with the main goal of decreasing the cost of the procedure. Materials and methods. We analysed the salient apheresis features of a group of 175 allogeneic peripheral blood stem cell transplants conducted in two institutions in a 7-year period. The grafts were conducted using the “Mexican” non-myelo ablative conditioning regimen employing oral busulphan, i.v. cyclophosphamide and i.v. fludarabine. In all instances, the apheresis machine employed was the Baxter CS3000 Plus and donors were mobilised with filgrastim. The apheresis procedures were performed on days 0, +1 and +2, the end-point of collection being 5,000 mL of blood/m2 in each procedure. Three apheresis sessions were planned but the number was adjusted according to the cell yield. Results. The final number of allografted CD34 cells ranged between 0.5 and 25.4 x 10/Kg of the recipient’s body weight (median, 5.2 x 10/Kg). One to three apheresis procedures were needed to obtain a product containing more than 0.5 x 106 CD34 cells/Kg of the recipient, the median being two procedures; in 72 cases (41%) a single apheresis procedure was sufficient to obtain the target number of CD34 cells. The volumes of apheresis ranged between 50 and 600 mL (median, 400 mL). Conclusions. Since the median cost of each apheresis procedure is 900 USD, the fact that two apheresis procedures was spared in 72 cases and one apheresis was spared in another 65 cases, led to a total saving of approximately 188,100 USD. It can be concluded that, in many cases, allogeneic transplants can be completed with a single apheresis session and that there are considerable financial benefits from this practice.

Comparison of the Fresenius COM.TEC with the COBE Spectra for the Collection and Processing of Peripheral Blood Progenitor Cells for Autologous Transplantation

BACKGROUND: The Fresenius COM.TEC is a newer automated leukapheresis device with a software feature that predicts the CD34+ cell yield in peripheral blood progenitor cell (PBPC) collections. There is little published information comparing the collection efficacy of PBPC on the Fresenius COM.TEC with other apheresis machines, including the COBE Spectra.AIM: To compare the collection and cell processing parameters of PBPC collected on the Fresenius COM.TEC with those collected on the COBE Spectra.METHODS: A prospective, single institution study of patients undergoing PBPC collection following mobilisation with chemotherapy and G-CSF was performed. Patients were alternately assigned to have the 1st day of PBPC collection performed on either the COBE Spectra (Version 6.0, MNC) or the Fresenius COM.TEC (Version 4.02, Auto MNC), dependent upon the availability of trained operators for the Fresenius COM.TEC. Patients were scheduled to have 3 blood volumes processed during leukapheresis.RESULTS: Overall, 28 patients had PBPC collected on the COBE Spectra and 20 on the Fresenius COM.TEC. All collections except one were commenced when the peripheral blood CD34+ cell count was ≥10 × 106/L. Two patients on the COBE Spectra and 6 patients on the Fresenius COM.TEC had collections terminated after processing of only 2 blood volumes due to operational requirements. The median volume of PBPC collected on the Fresenius COM.TEC (328mL) was significantly higher than that collected on the COBE Spectra (257mL; p=0.015). This impacted upon the requirement for plasma reduction within the processing laboratory. There was no significant difference in the median number of total nucleated cells, total CD34+ cells or total platelets collected on the 2 machines. Collection efficiency of CD34+ cells was also similar on both machines. Regardless of apheresis machine used, there was a high degree of correlation between predicted and actual yield of total CD34+ cells. However an increased level of red cell contamination in PBPC collected on the Fresenius COM.TEC (median total red cells of 280.2 × 109) compared with the COBE Spectra (median total red cells of 154.3 × 109; p = 0.005) was observed. Also, there was significantly less overall recovery of viable CD34+ cells after laboratory processing of PBPC collected on the Fresenius COM.TEC (median of 73% recovery) compared with the COBE Spectra (median of 89% recovery; p= 0.0004). Of note, technical difficulty was experienced in the processing laboratory with plasma reduction of 7 PBPC products collected on the Fresenius COM.TEC, necessitating deviation from standard operating procedure and re-centrifugation at elevated g force (1000g) to ensure adequate sedimentation of nucleated and CD34+ cells. It is unclear whether the difficultly in plasma reduction in the Fresenius products may have contributed to the reduced recovery of progenitor cells post cryopreservation and thawing.CONCLUSION: Although the Fresenius COM.TEC collects CD34+ cells with similar efficiency to that of the COBE Spectra, PBPC are collected in a larger volume with a higher level of red cell contamination. Furthermore, the recovery of CD34+ cells post cryopreservation and thawing is lower for PBPC collected on the Fresenius COM.TEC. Insufficient patients with collections performed on the COM.TEC have been infused to determine any effect on engraftment kinetics. This study underscores the importance of extending studies evaluating the collection of PBPC to investigate the entire production process including possible post processing effects.

Collection of Large-scale Expanded Lymphocyte Cultures for Adoptive Immunotherapy Using a COBE Spectra Apheresis Machine

Adoptive cell transfer represents an important mode of cancer immunotherapy and posttransplant associated viral infections. This technique involves massive volume reduction, as the procedure starts with large-scale ex vivo expansion of lymphocyte cultures (volume up to 60 L), which are harvested at the end of the in vitro process and terminates in a small volume to be infused into the patient. Toward this end, we develop a novel efficient process based on the COBE Spectra apheresis machine usually used for apheresis process. As the COBE Spectra cell separator is easy to use and often available at medical centers, this novel technique is applicable to many transplant and cell processing centers. Our results show a high recovery yield (98%+/-15%) and viability (ranged 79% to 99%) of the large-scale expanded lymphocytes. It preserves sterility of the product and is therefore suitable for immunotherapy treatments.

Establishment of a national on-line registry for apheresis in Korea

National apheresis registries can be used to evaluate changes in technology, clinical indications, and applications over the years. Since the establishment of the Korean Society of Apheresis (KSFA) in 1999, basic data on the status of apheresis have been collected using letters and e-mails on a biennial basis. In February 2006, a KSFA homepage and an on-line apheresis registry were constructed ( http://www.apheresis.or.kr/). The registry consists of two sub-registries, one addressing overall aspects, e.g., the numbers and types of apheresis machines, total numbers of apheresis procedures, and the other addressing therapeutic plasmapheresis, e.g., diagnoses, modes of treatment, instrument used, replacement fluids, volumes processed, vascular access, anticoagulants, complications, and clinical responses. Data registered on-line is presumed to represent about 95% of total apheresis procedures performed in Korea. In this report, we introduce our on-line registry system and compared the data obtained by on-line registry with the previous ones.

Platelet-released supernatants enhance hematopoietic stem cell proliferation in vitro

Peripheral blood stem cell transplantation (PBSCT) is used to reconstitute normal hematopoiesis after myeloablative chemotherapy. The hematopoietic stem cells are collected from the blood by apheresis machines using density gradient centrifugation. Because of density similarities the grafts contain high levels of leukocytes and platelets that release various mediators into the grafts. The collected hematopoietic stem cells are therefore exposed to platelet released mediators including platelet-derived growth factor, transforming growth factor-β, vascular endothelial growth factor and platelet factor-4. To investigate whether platelet activation and secretion can affect hematopoietic stem cells during PBSCT, we cultured (i) normal cord blood stem cells and (ii) mobilized peripheral blood stem cells from autografts together with the total secretion product of thrombin activated platelets (i.e. platelet released supernatants). Platelet released supernatants enhanced the cell proliferation of both peripheral blood stem cell (PBSC) autograft and normal cord blood CD34+ cells. Our study shows that platelet secretion in PBSCT autografts affect the hematopoietic stem cell function and possibly thereby the hematopoietic reconstitution after PBSCT.

Leukoreduction System Chambers as a Source of Viable Human Peripheral Blood Mononuclear Cells.

Many blood banks are using apheresis machines to collect blood components such as platelets (PLTs), RBCs, or plasma. Especially, leukoreduced plateletpheresis using apheresis instrument (Trima Accel, Gambro BCT, Lakewood, CO) provided subsidiary cell products retained in leukoreduction system (LRS) chamber that was originally discarded. The LRS chamber is a conical-shaped chamber that uses saturated, fluidized, particle bed filtration technology to remove WBCs from PLTs. In the current study, a total of 24 LRS chambers from different donors were investigated to determine it would be a valuable source of viable human peripheral blood mononuclear cells (MNCs). The proportions of CD3+, CD19+, CD16+/CD56+, CD14+, CD45+ cells, and absolute CD34+ cell count within the LRS chambers were determined by flow cytometry. Dendritic cells (DCs) were generated from the immunomagnetically purified CD14+ cells from LRS chamber and characterized by phenotypic surface marker and stimulatory capacity in an allogeneic mixed lymphocyte reaction. In the LRS chamber, the total number of WBC count was 1.1 × 109 ± 0.3 × 109 and the mean percentage of MNCs was 80.6 ± 13.1%. The mean proportion of T cells, B cells, NK cells, CD14+ monocytes among CD45+ cells was 54.3 ± 11.5%, 6.4 ± 3.1%, 14.6 ± 3.9%, 12.9 ± 7.5%, respectively. Total absolute CD34+ cell count in LRS chamber was 0.95 × 106 ± 0.65 × 106. Also, we could demonstrate CD14+ cells isolated from LRS chamber was capable of differentiating into functionally mature DCs in vitro. LRS chambers are a valuable and convenient source of viable human peripheral blood mononuclear cell population and could replace standard buffy coat preparations for research applications.

Automated programs for collection of mononuclear cells and progenitor cells by two separators for peripheral blood progenitor cell transplantation: comparison by a randomized crossover study

Although automated programs have been increasingly used to collect peripheral blood (PB) progenitor cells (PBPCs), differences among them remain unclear. The automated programs of Amicus (Baxter Healthcare) and Spectra (software Version 6.1, Gambro BCT) apheresis machines were compared in a crossover study. The patients for autologous and donors for allogeneic PBPC transplantation mobilized with granulocyte-colony-stimulating factor were randomly assigned into two groups. PBPCs were collected by the Amicus on the first day and the Spectra on the second of 2 consecutive days in Group I, and the reverse order was used in Group II. Of 39 patients or donors enrolled, 17 reached their collection goal with only one procedure and did not participate in the paired study. Thus, 44 paired procedures of the remaining 22 subjects were evaluated. The product yields of white blood cells (WBCs; p < 0.005), mononuclear cells (MNCs; p < 0.02), and CD34+ PBPCs (p < 0.0002) from patients or donors were higher in the Amicus collections than those in the Spectra collections. The collection efficiencies of WBCs (p < 0.03), MNCs (p < 0.02), and CD34+ PBPCs (p < 0.03) were higher in the Amicus collections. The numbers of contaminating platelets (PLTs) in the Amicus collections were lower than those in the Spectra collections (p < 0.05) with a greater decrease in PB PLT counts after apheresis with the Spectra (p < 0.01). The Amicus had a longer running time than the Spectra for processing similar volumes (p < 0.005). The automated program of the Amicus may be better than that of the Spectra for collecting MNCs and CD34+ PBPCs and avoiding apheresis-induced thrombocytopenia.

Procedural Apheresis Instrumentation Algorithm Minimizes Platelets Loss during Peripheral Blood Stem Cells Collection.

Introduction:Peripheral blood hematopoietic progenitor cell collection is a more popular source of stem cells for transplantation than bone marrow harvest. A number of automated cell separators exist which can be used to perform mononuclear cell collections. These separators collect varying amounts of other cells during the collection process, including them in the mononuclear cell product. Because of this, collection of mononuclear cells can result in significant reductions in platelet count and loss of red blood cells during the procedure. In order to minimize platelet transfusion support, we developed an algorithm to optimize mononuclear cell collections while minimizing platelet losses using the Gambro COBE Spectra and the Baxter AmicusMethods:Previously, patients were assigned randomly to any available apheresis machine. Starting August 2nd 2002, patients with a WBC count higher than 35×10 (9)/L were preferably assigned to Amicus for 5 hour collection with processing 1000 ml/cycle or as second choice Spectra for 5 hours run with maximum draw rate 65 ml/Min., for both instruments. If the WBC was lower than 35×10 (9)/L, the preferred machine would be Amicus for 5 hours run at 1400 ml/cycle with maximum draw rate 90ml/Min. or Spectra for 5 hours run with maximum draw 100 ml/Min. We reviewed the difference of pre and post procedure platelet counts of non Hodgkin's Lymphoma patients undergoing stem cells collection for 6 months before and after the implementation of the above protocol from February 2002 till February 2003. All CBC were performed on the same Coulter analyzer.Results:14 patients (2 on Amicus and 12 on Spectra) underwent stem cells collection before August 2nd, 2002. 13 patients (8 on Amicus and 5 on Spectra) were collected after this date. The Fisher's exact test was used for this study. The median and mean differences in the first group were 141.5 ×10(9)/L and 135 ×10 (9)/L respectively (95% CI, p 0.0183). The second group had a median and mean of 45 ×10 (9)/L and 51 × 10(9)/L (95% I, p 0.0183). The minimum and maximum differences were 36 × 10(9)/L and 200 × 10(9)/L respectively in the first group and −19 ×10(9)/L and 121×10(9)/L for the second group. There was no difference in the numbers of the collections days in both groups in regard to the type of automated cell collector.Discussion:The implemented algorithm showed a net advantage. Even though none of the patients required blood transfusions, there was lesser drop of platelets counts with the new settings.

Proteomics and transfusion medicine: Future perspectives

Limited number of important discoveries have greatly contributed to the progresses achieved in the blood transfusion; ABO histo-blood groups, citrate as anticoagulant, fractionation of plasma proteins, plastic bags and apheresis machines. Three major types of blood products are transfused to patients: red cell concentrates, platelet concentrates and fresh frozen plasma. Several parameters of these products change during storage process and they have been well studied over the years. However, several aspects have completely been ignored; in particular those related to peptide and protein changes. This review presents what has been done using proteomic tools and the potentials of proteomics for transfusion medicine.

Viability and function of 8‐day‐stored apheresis platelets

Methods of bacterial detection and pathogen inactivation of platelets (PLTs) may allow extended storage of PLTs as long as PLT quality is maintained. Twenty normal volunteers had their PLTs collected with an apheresis machine (Haemonetics Corp.). A variety of in vitro PLT function and metabolic assays were performed both on Day 0 and after 8 days of storage. On Day 8, a small blood sample was drawn from each donor to obtain fresh PLTs. The fresh and stored autologous PLTs were labeled with either (51)Cr or (111)In, and the radiolabeled PLTs were transfused. Posttransfusion serial blood samples were drawn to determine the relative posttransfusion recoveries and survivals of the fresh versus the stored PLTs. Although the in vitro assays showed some differences between the two trial sites, the results were generally within the ranges expected for fresh and stored PLTs. Overall, PLT recoveries averaged 66 +/- 16 percent versus 53 +/- 20 percent and survivals averaged 8.5 +/- 1.6 days versus 5.6 +/- 1.6 days, respectively, for fresh compared to 8-day-stored PLTs. There were no significant differences in the in vivo PLT data between the trial sites or based on the radiolabel used for the measurements. After 8 days of storage, the in vivo posttransfusion recovery and survival of autologous Haemonetics apheresis PLTs meet the proposed standards for poststorage PLT quality.

P02 Inherent Variation in Donor Platelet Reactivity Contributes to the Quality of Apheresis Platelets

Introduction Provision of platelets is a major commitment for Blood Services. Iterative cycles of improvements in platelet procurement and storage have lead to a better quality of concentrates, but even the latest generation of apheresis machines may produce activated platelets. Less attention has been paid in determining the contribution of an individual donor's inherent platelet reactivity on the activation state of apheresis platelets. We investigated this donor related variable using a panel of donors from the BLOODOMICS project whose platelet responses to activation through the ADP and collagen pathways were known to represent the widest range of the normal responses. For the current study three groups of donors with responses that were characterised as high (n = 16), low (n = 15) or in the mid‐range (n = 16), were recalled and the activation state of their circulating platelets and donated apheresis platelets were measured.Method To assess the activation state of platelets in the circulation, prior to donation samples were taken using a 21G butterfly needle, without a tourniquet. Aliquots of platelets from the apheresis donation were taken immediately at the end of the procedure. The level of platelet‐bound fibrinogen, a sensitive marker for early‐stage activation was measured using a whole‐blood flow cytometric assay.Results Prior to donation resting bound fibrinogen levels in all subjects ranged from 1.6–11.1% (mean 3.6%), and there was a significant association between this index of baseline platelet activation and the donor's responder status (P = 0.009). The percentage of platelets with bound fibrinogen in the apheresis concentrates ranged from 0.6–84.3% (mean 14.7%) and were generally higher than resting levels. Increased apheresis‐induced activation was associated with the responder status of the donor (P = 0.005). In particular, the 4 platelet concentrates with the highest levels of bound fibrinogen (&gt;50%) were all from high responder donors.Conclusion Overall it is not solely the process of donation that affects platelet quality. Platelets that show higher responses to agonists are particularly susceptible to activation during collection by apheresis. We postulate that the responses to agonists are largely genetically controlled, and are attempting to identify the relationship between variation in platelet‐gene sequence and platelet function.

Leucodepletion and blood products

Background: Leucoreduction of blood products is increasingly being employed to produce blood products with residual WBCs < 5 × 10 6 per unit (99.9 percent or a log 3 leucoreduction). Clinical data suggests that non-haemolytic febrile transfusion reactions can be prevented by leucodepletion. The procedure also prevents alloimmunisation to HLA antigens in patients who will repeatedly require transfusion of blood/blood products. Method: Of the methods available to reduce the number of WBC in blood products washing of red cells, freezing and deglycerolisation are effective and yield a product with only a 24 hour shelf life. Other methods such as leucodepletion filters are relatively inexpensive, simple and the final product has a normal shelf life. Modern generation of leucoreduction filters and apheresis machines can provide greater than 4 log reduction of WBC. Results: After the introduction of leucodepletion of blood for Thalassemics at our center in 2003, the incidence of non haemolytic febrile transfusion reactions (NHFTR) fell from 4% in 2002 to 1% in 2003. Conclusion: In patients undergoing long-term blood transfusion therapy e.g. Thalassemics, alloimmunisation against the HLA antigens on donor white cells is prevented by leucodepletion and prevents NHFTRs.