Apheresis Machine Research Articles

Donor Parameters and Platelet Yield during Plateletpheresis: A Cross-sectional Prospective Study

Abstract Background: Platelet transfusion can be life-saving in bleeding patients with thrombocytopenia or reduced platelet function. Single donor platelets (SDP) unit use is preferred due to the various advantages like reduction in transfusion-transmitted diseases and transfusion reactions. The quality of SDP is determined by platelet yield. Therefore, we conducted this study to assess the donor parameters affecting platelet yield during plateletpheresis. Materials and Methods: This cross-sectional prospective study included 160 single-donor platelet apheresis procedures done for 1 year. The pre-donation platelet count of the donor was set to 250 × 109/L to get double-dose platelet. Plateletpheresis was performed using Trima Accel single-needle separator apheresis machine. The demographic and hematologic parameters of donors were correlated with their platelet yield. Data obtained were tabulated using version 20 of the Statistical Package for the Social Sciences (SPSS). A relationship between pre-donation donor variables and platelet yield was studied using the Pearson correlation coefficient (r). P < 0.05 was considered statistically significant. Results: There was a significant positive correlation between platelet yield and body mass index (BMI) (r = 1710 and P = 0.0304), total leukocyte count (TLC) (r = 0.2220 and P = 0.0048), and platelet count (r = 0.8880 and P < 0.0001). The mean platelet volume (MPV) showed a negative correlation with platelet yield (r = −0.1910 and P = 0.0156). Age, hemoglobin, hematocrit, and platelet distribution width showed no significant correlation with the platelet yield. Conclusion: Donor parameters such as pre-donation platelet count, BMI, TLC, and MPV need to be considered while recruiting the donors for the SDP procedure for better yield of platelets.

Analysis of changes in serum calcium and magnesium levels during plateletpheresis on different apheresis machines in healthy donors: A cross-sectional study

Abstract: BACKGROUND: The most common observed complication of plateletpheresis procedure is hypocalcemia due to citrate’s chelation of free calcium. Magnesium is also affected by citrate infusion. We have evaluated the impact of plateletpheresis on the total serum calcium (Ca++) and magnesium (Mg++) levels of the donor. MATERIALS AND METHODS: One hundred and thirty-seven healthy plateletpheresis donors were included in the study. Samples were collected from the donor at 0 min (baseline), 30 min, and 60 min, at the end of the procedure and 30 min after completion of the procedure. The pattern of changes in serum Ca++ and serum Mg++ levels at different time points for different apheresis machines (Fenwal Amicus, Fresenius COM.TEC, Spectra Optia, and Hemonetics MCS+) was studied. RESULTS: A significant decline in serum Ca++ and serum Mg++ levels from baseline to the end of the procedure was observed. This decline was observed maximum for Hemonetics MCS+. The baseline values were regained 30 min after completion of the procedure. Difference from baseline values 30 min after the procedure was lowest in amicus in the case of serum Ca++ and COM.TEC in case of serum Mg++. Twenty donors (14.60%) experienced adverse donor reactions. CONCLUSION: Serum calcium and serum magnesium levels decreased transiently during the procedure and regained normal values after 30 min of the completion of the plateletpheresis procedure on all four apheresis machines (whether based on continuous or intermittent centrifugation). Hence, it is concluded from our study that plateletpheresis is a well-tolerated and safe procedure.

Repeated apheresis donations cause important iron deficiency in male Japanese donors.

In Japan, apheresis donation of plasma is allowed to a maximum of 24 times a year, and plateletpheresis are counted as two plasmapheresis donations. Diversion of the initial blood flow is conducted for all donations, and additionally, blood remaining in apheresis machine circuit is lost. Here, we aimed to investigate on the health impact of frequent apheresis donations, as measured by the serum ferritin (sFer). A total of 538 male apheresis donors and 538 age-matched whole blood (WB) donors, who gave informed consent to join the study, were enrolled. sFer were compared, according to age. Another group of 19 apheresis donors were followed during four consecutive donations. About half (48%) of repeat male apheresis donors had iron deficiency (sFer < 26 ng/mL), compared with lower rates (13.9%) among male WB donors. It was evident in all age groups, except for teenagers, possibly because of the lower number of donations. Follow-up of the 19 donors for 4 months revealed a progressive decrease in sFer. Blood remaining in the apheresis machine circuit and diversion of the initial blood flow have been implicated in iron deficiency for many years. Taking the present results, the manufacturer of apheresis equipment was requested to improve it to allow rinseback of the remaining blood, which was achieved only for plateletpheresis. Until further improvement, plasmapheresis frequency was reduced to 12 times a year. Additional measures, such as oral supplementation of iron, need to be considered.

Study on leukapheresis of hyperleukocytic acute myeloid leukemia through in vitro centrifugation

Respiratory failure, intracranial hemorrhage and infection were more common in hyperleukocytic acute myeloid leukemia patients than in non-hyperleukocytic leukemia patients. Compared with non-apheresis treatment, the white blood cells decreased significantly and the infection rate decreased after apheresis treatment. However, the treatment time of leukapheresis in patients with hyperleukocytic leukemia is very long, while it is more damaging to cells. In this study, which conducted a retrospective analysis on patients with hyperleukocytic acute myeloid leukemia, the process of centrifugation of normal cells and patients’ cells by apheresis machine was simulated in vitro. Through selecting 5 healthy persons and 11 patients with hyperleukocytic acute myeloid leukemia, extracting their blood samples and performing in vitro centrifugation at different speeds or duration, we observed the changes of the numbers and morphology of peripheral blood cells in healthy people and patients, so as to explore the optimal centrifugation parameters during leukapheresis. The cells obtained by the optimal centrifugation parameters were cryopreserved and two groups of mice (10 mice in each group) were used to establish leukemia animal models. Through the research, it is found that when the centrifugal speed is below 6000 rpm, the damage to blood cells in healthy people and in patients with hyperleukocytic leukemia is not obvious. When the centrifugal speed is above 6000 rpm, the platelets will be damaged significantly. The cells obtained under the optimal centrifugation parameters can be successfully cryopreserved and used to establish leukemia animal models. This study is of great significance for improving the efficiency and reducing the side effects of leukapheresis, and is helpful to improve the treatment of white blood cells reduction.

The role of therapeutic plasma exchange in plasma cell disorders.

Therapeutic plasma exchange (TPE) is an extracorporeal technique where patient's plasma containing pathogenic substances is separated and removed from the whole blood, while the cellular component is returned to the patient mixed with replacement solution via an apheresis machine. Due to its ability to remove pathogenic substances from plasma including immunoglobulins, TPE has proven efficacious in the management of various disorders across different medical disciplines, including plasma cell dyscrasias, which are characterized by the abundant secretion of non-functional immunoglobulins produced by an abnormally proliferating plasma cell clone. This review summarizes the current indications of TPE in plasma cell-related disorders and discusses its application, safety, and therapeutic effects.

Manual red cell exchange (RBCXm) in acute sickle cell crisis: A feasible modality in resource limited settings

This short communication highlights the significance of manual red blood cell exchange (RBCXm) procedure which is an emergency procedure for patients of sickle cell disease (SCD) in sickle cell crisis . To the best of our knowledge there is no standardised technique for performing RBCXm meanwhile, an automated method using an apheresis machine is either unavailable or is unaffordable. As a result, patients end up receiving top up red cell transfusions further associated with risk of iron overload, hyper viscosity and sometimes volume overload overshadowing the benefits of red cell exchange. Therefore, we developed a protocol for manual red cell exchange (RBCXm) and performed it in a patient with painful sickle cell crisis who had cost constraints for automated red cell exchange (RBCXa) procedure. RBCXm provided symptomatic relief to our patient with adequate sickle cell reduction. This RBCXm protocol may be useful in low income (LIC) and low middle income countries (LMIC) where patients have recurrent episodes of sickle cell crisis and there is unavailability or unaffordability for RBCXa using an apheresis equipment.

Recent advances in microfluidic cell separation to enable centrifugation-free, low extracorporeal volume leukapheresis in pediatric patients.

Leukapheresis is a common extracorporeal procedure for leukodepletion and cellular collection. During the procedure, a patient's blood is passed through an apheresis machine to separate white blood cells (WBCs) from red blood cells (RBCs) and platelets (PLTs), which are then returned to the patient. Although it is well-tolerated by adults and older children, leukapheresis poses a significant risk to neonates and low-weight infants because the extracorporeal volume (ECV) of a typical leukapheresis circuit represents a particularly large fraction of their total blood volume. The reliance of existing apheresis technology on centrifugation for separating blood cells limits the degree to which the circuit ECV could be miniaturized. The rapidly advancing field of microfluidic cell separation holds excellent promise for devices with competitive separation performance and void volumes that are orders of magnitude smaller than their centrifugation-based counterparts. This review discusses recent advancements in the field, focusing on passive separation methods that could potentially be adapted to perform leukapheresis. We first outline the performance requirements that any separation method must meet to replace centrifugation-based methods successfully. We then provide an overview of the passive separation methods that can remove WBCs from whole blood, focusing on the technological advancements made in the last decade. We describe and compare standard performance metrics, including blood dilution requirements, WBC separation efficiency, RBC and PLT loss, and processing throughput, and discuss the potential of each separation method for future use as a high-throughput microfluidic leukapheresis platform. Finally, we outline the primary common challenges that must still be overcome for these novel microfluidic technologies to enable centrifugation-free, low-ECV leukapheresis in the pediatric setting.

Adverse Events Among Plateletpheresis Donors in a Tertiary Care Hospital at Dhaka, Bangladesh

Introduction: The rising demand for platelet transfusions among patients has increased the usage of automated blood collections. Many of the same reactions and injuries are found with pooled platelets received from whole blood donation, although notable differences exist. Objective: To study the adverse events (AEs) during plateletpheresis procedures in a tertiary care hospital and plateletpheresis procedure session profiles. Materials and Methods: This retrospective study was conducted from January 2021 to December 2021 by analyzing records of two-hundred and thirteen (213) plateletpheresis procedures done in transfusion medicine department. All the donors were male. All adverse effects were recorded and noted in the registrar. Results: A total of 13 (Thirteen) AEs were noted, of which 08 (61.53%) events were associated with donors, 03 (23.07 %) were owed to a fault in the kit/equipment, and 02 (15.38 %) were due to technical faults. Donor-related AEs included hematoma (23.07%), vasovagal (23.07%), and perioral tingling sensation (15.38%). Technique-related AEs were 23.07%, and faulty kit/equipment-related AEs were 15.38%. Conclusion: Apheresis donations performed on apheresis machines are safe. Careful donor selection, well-trained expert technical personnel, and supervision of experienced transfusion medicine specialists will make the donor’s experience more pleasant. Sir Salimullah Med Coll J 2023; 31: 67-72

Therapeutic Plasma Exchange (TPE) in pregnancy: A case report

Background: Therapeutic Plasma Exchange (TPE) is a therapeutic procedure that uses an apheresis machine to remove the patient's plasma. The main goal of TPE is to eliminate pathological mediators in plasma, such as autoantibodies, immune complexes, cryoglobulins, toxins and lipids that can cause several clinical effects in patients ranging from mild symptoms such as weakness shortness of breath to paralysis and respiratory failure. This case study aims to evaluate the effect of TPE in pregnancy with a history of Myasthenia Gravis (MG). Case Presentation: A female patient, 26 years old, 16 weeks of pregnancy, with a history of MG for 3 years and regularly consumes Mestinon. The patient’s general condition is weak, with blood pressure of 100/65 mmHg, pulse rate of 110 times/minute, body temperature of 36.5oC, and breathing with the help of a ventilator. Diagnosis of 16 weeks G2P1001 with myasthenic crisis. The clinical condition improved after undergoing TPE procedures 3 times, and the patient could breathe spontaneously. Conclusion: TPE in Myasthenia gravis crisis is highly recommended and is often used as the first choice of therapy. Various physiological changes may occur during pregnancy and may affect the effectiveness and increase the side effects of TPE. Therefore, it is necessary to do some special preparation and treatment.

Collection efficiency in apheresis

Significant advances in procedural information displayed by current apheresis machines have been made, but analyses of cell collection efficiency (CE) still rely on calculations done by apheresis professionals. Accordingly, understanding CE equations can support the optimization of apheresis techniques and identification of incidents that could impact the procedure’s effectiveness. This report summarizes classical and novel CE analyses applied to apheresis exemplified by an actual case of hematopoietic progenitor cell collection. In addition to the apheresis yield and most common CE1 and CE2 formulas, we present the instantaneous and corrected CE, fold enrichment, collection throughput, collection rate and its variants, average inlet rate, classical and adjusted captured cells, recruitment pool, recruitment factor, recruitment coefficient, blood component loss, predictive apheresis yield, and performance ratio calculations. Moreover, the mathematical relationship between these CE equations is also shown, which can be helpful in many apheresis procedures.

Review on Car-T Cell Therapy for Cancer Treatment

A set of illnesses known as cancer involve abnormal cell proliferation and have the ability to invade or spread to different bodily regions. These stand in contrast to benign tumours, which remain stationary. A lump, unusual bleeding, a persistent cough, unexplained weight loss, and a change in bowel habits are all potential warning signs and symptoms. Chimeric antigen receptors (CARs), often referred to as chimeric immunoreceptors or artificial T cell receptors, are receptor proteins that have been modified so that T cells now have the ability to target a particular antigen. Because they integrate antigen-binding and T cell activation functions into a single receptor, the receptors are chimeric. CAR T cell treatment is a form of treatment in which the patient's immune cells, called T cells, are altered in a lab so that they will adhere to and kill cancer cells. An apheresis machine receives blood from a vein in the patient's arm through a tube, filters out all white blood cells—including T cells—and returns the remaining blood back to the patient. The T cells are then genetically modified in the lab to contain the gene for a unique receptor known as a chimeric antigen receptor (CAR). The CAR T cells are multiplied in a lab before being infused into the patient in large numbers. In order to destroy cancer cells, the CAR T cells can connect to an antigen on the cancer cells.

Primed for change: The effect of a blood prime on peripheral blood stem cell collection and accuracy of a prediction tool in pediatric patients.

Pediatric apheresis collection of peripheral blood stem cells for autologous transplantation often requires use of a blood prime. We evaluated the relationship between pre-apheresis blood CD34+ counts and final CD34+ yield with use of a blood prime. Forty patients underwent apheresis stem cell collection in a 5 year period in our hospital, of which 27 required blood priming of the apheresis machine. Despite the blood prime group having significantly higher pre-apheresis CD34+ cell counts, this group processed a relatively higher volume of blood due to a higher dilutional effect and collected significantly less than predicted CD34+ cell yield. Use of weight-specific collection efficiencies and dilution-adjusted pre-apheresis CD34+ counts will help in accurately estimating the whole blood volume to process for PBSC collection and therefore increase efficiency and decrease the overall cost of collection.

Investigation on the feasibility of large-volume autologous red blood cells donation: A pilot trial in a small cohort of Chinese.

Preoperative autologous blood donation (PAD) is used for elective surgical procedures with a predictable blood loss. But a downward trend in PAD is due to the fact that patients with preoperative whole blood donation or two-unit red cell apheresis cannot avoid receiving allogenic blood during intensive surgery. To improve the clinical application of PAD, this study explores the feasibility of large-volume autologous red blood cells (RBCs) donation by a pilot trial in a small cohort of Chinese. This was a single-center, prospective study and 16 male volunteers were enrolled from May to October in 2020. Each volunteer donated 627.25 ± 109.74 mL (mean ± SD) RBC with apheresis machine or manually, and received 800 mg of intravenous iron in four divided doses. Blood pressure, oxygen saturation (SpO2 ), respiratory rate and heart rate were monitored throughout the procedure. The RBC count, hemoglobin (Hb) concentration, hematocrit (Hct), reticulocyte count, erythropoietin (Epo), serum iron, total iron binding capacity (TIBC), transferrin saturation, transferrin, and ferritin were dynamically detected and analyzed before and 8 weeks after blood donation. There was no differences in SpO2 , systolic and diastolic blood pressure before and after blood collection (P ≥ .05). The heart rate and respiratory rate after donation were slightly lower than those before (P < .05). The level of RBC, Hb concentration and Hct fell to a nadir on Day 3 (pre-donation vs post-donation on Day 3: RBC 4.81 ± 0.36*1012 /L vs 3.65 ± 0.31, P < .05; Hb 148.59 ± 11.92 g/L vs 113.19 ± 10.43 g/L, P < .05; Hct 44.08 ± 3.06% vs 33.38 ± 2.57%, P < .05) and recovered to the pre-donation levels at the eighth week post donation (pre-donation vs post-donation at the eighth week: RBC 4.81 ± 0.36*1012 /L vs 4.84 ± 0.34*1012 /L, P ≥ .05; Hb 148.59 ± 11.92 g/L vs 150.91 ± 11.75 g/L, P ≥ .05; Hct 44.08% ± 3.06% vs 43.86 ± 3.06%, P ≥ .05). Epo and the reticulocyte count reached the peak values on Days 1 and 7, respectively (Epo: D0 15.30 ± 7.47 mlU/ML vs D1 43.26 ± 10.52 mlU/ML, P < .05; reticulocyte count: D0 0.07 ± 0.02*109 /L vs D7 0.17 ± 0.04*109 /L, P < .05). The red cell net profits on Day 7, the second, fourth and eighth week postdonation were 160.39 ± 144.33 mL, 387.59 ± 128.74 mL, 530.95 ± 120.37 mL, and 614.18 ± 120.10mL, and accounted for 27.47% ± 24.70%, 63.75% ± 24.91%, 86.20% ± 22.99%, and 99.20% ± 19.19% of RBC donation, respectively. The levels of serum iron, serum ferritin, and transferrin saturation increased during the first week because of the supplement of intravenous iron, and then gradually decreased and declined to the baseline at the end of the study period at the eighth week. The large-volume autologous RBCs donation of 600 mL is proved safe in our study. Combination support of normal saline to maintain blood volume and intravenous iron supplementation may ensure the safety and effectiveness of large-volume RBC apheresis.

A novel predictive algorithm to personalize autologous T-cell harvest for chimeric antigen receptor T-cell manufacture

Background aimsThe most widely accepted starting materials for chimeric antigen receptor T-cell manufacture are autologous CD3+ T cells obtained via the process of leukapheresis, also known as T-cell harvest. As this treatment modality gains momentum and apheresis units struggle to meet demand for harvest slots, strategies to streamline this critical step are warranted. MethodsThis retrospective review of 262 T-cell harvests, with a control cohort of healthy donors, analyzed the parameters impacting CD3+ T-cell yield in adults with B-cell malignancies. The overall aim was to design a novel predictive algorithm to guide the required processed blood volume (PBV) (L) on the apheresis machine to achieve a specific CD3+ target yield. ResultsFactors associated with CD3+ T-cell yield on multivariate analysis included peripheral blood CD3+ count (natural log, ×109/L), hematocrit (HCT) and PBV with coefficients of 0.86 (95% confidence interval [CI], 0.80–0.92, P < 0.001), 1.30 (95% CI, 0.51–2.08, P = 0.001) and 0.09 (95% CI, 0.07–0.11, P < 0.001), respectively. The authors’ model, incorporating CD3+ cell count, HCT and PBV (L), with an adjusted R2 of 0.87 and root-mean-square error of 0.26 in the training dataset, was highly predictive of CD3+ cell yield in the testing dataset. An online application to estimate PBV using this algorithm can be accessed at https://cd3yield.shinyapps.io/cd3yield/. ConclusionsThe authors propose a transferrable model that incorporates clinical and laboratory variables accessible pre-harvest for use across the field of T-cell therapy. Pending further validation, such a model may be used to generate an individual leukapheresis plan and streamline the process of cell harvest, a well-recognized bottleneck in the industry.

Altered Cellular Sedimentation during Apheresis Impacts Outcomes of Peripheral Blood Stem Cell Collection Efficiency in Patients with Sickle Cell Disease

Recent reports have demonstrated the potential for gene therapy as a therapeutic option to achieve a durable cure in patients with sickle cell disease (SCD). However, for these emerging cell therapies, relatively large numbers of peripheral blood hematopoietic stem cells (PB HSCs) are required to generate a therapeutic dose. Outcomes of stem cell collections in patients with SCD are highly variable, at times yielding far fewer numbers of HSCs in the product than predicted by the number of PB CD34+ cells. While the CXCR4 antagonist plerixafor has emerged as a safe and reliable drug to mobilize CD34+ cells in patients with SCD, collection failures continue to occur requiring additional cycles or failure to generate a gene therapy product. We sought to understand the mechanics affecting stem cell sedimentation in real time and posited that SCD disease associated changes to red cells results in altered HSC sedimentation during apheresis, negatively impacting collection. Methods Autologous PB stem cell collections were performed in patients with SCD following mobilization with 240ug/kg plerixafor. To uncover the mechanisms impacting apheresis efficiency for collecting PB HSCs, we devised a method to interrogate the sedimentation of cells in peripheral blood in real time, by interrupting the return collection circuit line. Cellular composition analyses of the collecting interfaces were performed including CD34+ enumeration by flow cytometry, CBC and differential, reticulocyte counts, and surface CD47 expression of red blood cells (RBCs). Results Patients were mobilized with 240ug/kg of plerixafor up to 6 hours before apheresis collection. We collected fewer cells than predicted (3.78 million cells/kg) in these patients with an overall average apheresis collection efficiency of 38%, and a strikingly wide range of 2%-107%. We determined that the lower collection efficiency outcomes were primarily derived when using standard apheresis interface settings. The pre-apheresis PB CD34+ counts were less predictive of total CD34+ cells collected (p=0.012) in patients with SCD (r2=0.2557, p=0.0023) when compared to historical control patients without SCD (r2=0.7638, p<0.0001). Real time measurement of cell counts at standard (Hematocrit 3%, S) and deep (Hematocrit 5%, D) collecting interfaces of the apheresis machine showed a significant decrease in lymphocytes (p=0.0146), increase in monocytes (p=0.0496), and increase enrichment in CD34+ cells at the D interface (Panel A). Enrichment of CD34+ cells correlated with monocyte enrichment and (n=21, r2=0.6706, p<0.0001) and an increased fold change in CD34+ cells between the S and D interfaces correlated with higher PB reticulocyte percentage (r2=0.5295, p=0.0111). Further analysis of the individual collection interfaces revealed that most RBCs were HbS containing despite a PB HbS concentration <30%, consistent with an enrichment for shorter lived sickle red cells. CD47 expression has been previously reported in higher concentrations on the surface of younger RBCs during erythropoiesis. Surface expression of CD47 was found to be significantly higher at both the S and D interfaces compared to the PB of patients, indicating that the accumulation of a younger population of RBCs at the collecting interfaces. As microcytic RBCs have been associated with poor collection efficiencies, the SCD red cell hemoglobin concentration in the PB was used as a marker for size and a significant correlation was determined (r2=0.6086, p=0.0001). Patients with SCD can mobilize PB HSC in response to plerixafor but demonstrate specific characteristics that impede the collection of stem cells. During apheresis, CD34+ stem cells sediment at a deeper hematocrit interface in the buffy coat as a result of displacement by the younger patient-derived population of RBCs. The relative shift in erythrocyte sedimentation requires a corresponding alteration in collection strategies to improve the collection efficiency. In addition to red cell age, other factors that affect red cell buoyancy including iron status or additional globin gene mutations negatively impact apheresis stem cell collections. Full assessment of red cell parameters can identify patients that are at risk for poor stem cell collection outcomes. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Analysis of first apheresis services in Ghana-Greater Accra Regional Hospital

BackgroundAt the combined American Society for Apheresis (ASFA) annual meeting and World Apheresis Association (WAA) Congress in 2014, it was observed that there were significant disparities with regard to the access of apheresis services within and across developing countries, with only few of such facilities available in Africa; notably South Africa and Nigeria. In 2019, Bone Marrow Transplantation (BMT) Unit-Ghana, acquired an apheresis machine. By the collaboration between BMT-Ghana, the Greater Accra Regional Hospital (GARH) and the Ministry of Health (Ghana), apheresis services is now available in Ghana. The aim of this paper is to present an analysis of apheresis services so far in Ghana. MethodA 12-month period from 2019 to 2021 was examined (less the period of the COVID-19 outbreak when the Unit was virtually at a standstill). The electronic database and hard copies of documented activities were analysed. Basic information on demographics and procedure types and counts was used. ResultsThe retrospective study encompassed data of 43 patients. Two (2) patients came from the West Africa sub-region (Nigeria and Cameroon) with the rest from 6 out of the 14 regions of Ghana (Greater Accra, Western, Central, Eastern, Ashanti, Volta). The essential nature of the apheresis services being the first in Ghana, brought patients as far as 315 km from the hinterlands to the Unit. Ages ranged from 2-52 years with a mean of 16.3 ± 15.3 years. Slightly more females (n = 23, 53%) received services than males (n = 20, 47%). Eighty-six percent (n = 37, 86%) of the patients were sickle cell patients referred to the Unit. Red Blood Cell exchange (RBCx) accounted for 87% (n = 40), of the 46 procedure counts followed by Continuous Mononuclear Cell Collection (CMNC) (n = 4, 9%) and lastly, Therapeutic Plasma Exchange (TPE) (n = 2, 4%). ConclusionGhana can now be counted among African countries offering apheresis services and the GARH is acknowledged as the only hospital in the country with this facility, thus improving patient care significantly.

Capturing ctDNA from Unaltered Stationary and Flowing Plasma with dCas9.

Many studies have established that blood-based liquid biopsies can be used to detect cancer in its early stages. However, the limiting factor for early cancer detection is the volume of blood required to capture the small amount of circulating tumor DNA (ctDNA). An apheresis machine is a device that can draw whole blood, separate the blood components, and infuse the blood components back into the individual. This device provides the opportunity to screen large volumes of plasma without extracting it from the body. However, current DNA capture technologies require the plasma to be altered before the ctDNA can be captured. Our goal was to develop the first technology that can capture ctDNA from flowing unaltered plasma. To simulate cancer patient plasma, we spiked BRAF T1799A (BRAFMut) DNA into plasma from healthy individuals. We used catalytically dead Cas9 (dCas9), guide RNA, and allele-specific quantitative polymerase chain reaction (qPCR) to capture and measure the number of captured BRAFMut DNA copies. We found that dCas9 captured BRAFMut alleles with equal efficiency at room temperature (25 °C) and body temperature (37 °C). Next, we showed that, in stationary unaltered plasma, dCas9 was as efficient in capturing BRAFMut as a commercial cell-free DNA (cfDNA) capture kit. However, in contrast to the cfDNA capture kit, dCas9 enriched BRAFMut by 1.8-3.3-fold. We then characterized the dCas9 capture system in laminar and turbulent flowing plasma. We showed that the capture rate using turbulent flow was greater than that in laminar flow and stationary plasma. With turbulent flow, the number of captured BRAFMut copies doubles with time (slope = -1.035 Ct) and is highly linear (R2 = 0.874). While we showed that the dCas9 capture system can capture ctDNA from unaltered flowing plasma, further optimization and validation of this technology is required before its clinical utility can be determined.

The Influencing Factors for Stem Cell Apheresis in Pediatric Cancer Patients

Objective: Pediatric cancer patients comprise a fragile patient group regarding age and intensive therapy. It is known that factors like apheresis machine, characteristics of patients, primary disease, and cellular parameters before the process impact the efficacy of stem cell apheresis. In this study, we aim to evaluate the characteristic features of stem cell apheresis and the influencing factors of the process. Patients and Methods: This study involves 42 patients who received a total of 88 aphereses, between August 2012-March 2021in our pediatric stem cell transplantation unit. All of the patients received chemotherapy and GCSF for mobilization. The patients received plerixafor in case of unsuccessful mobilization. Results: For most of the patients (n= 23, 55%), targeted cell numbers could be reached on the second day of apheresis. Especially the patients with neuroblastoma and lymphoma need to have more than one apheresis. Our results indicate that median MNC and CD 34 + cell counts before the apheresis were significantly associated with successful apheresis (p&lt; 0.01 and p= 0.03 respectively). Regarding the influence of primary disease, we showed that successful apheresis was less in neuroblastoma and lymphoma compared to other pediatric cancers (p= 0.01). We reported successful apheresis with plerixafor for six patients who had unsuccessful apheresis before. Conclusion: In this study, it is shown that median MNC counts before apheresis, median CD 34 + cell counts before apheresis, and primary disease are influencing factors for successful apheresis. This study indicates that plerixafor may enhance the apheresis efficacy even in unsuccessful apheresis attempts with standard mobilization protocol. Identifying the influencing factors on apheresis for such a fragile patient population may help the procedure to be more efficient and safe for the children.

Comparison of Acidity Degree (pH) on Thrombocyte Concentrate Products: Apheresis Method and Pooling Method

One indicator of the decreasing quality of thrombocyte concentrate (TC) during storage is the pH value. Thrombocyte making can use pooling and apheresis methods. The pooling method is carried out by combining 4-6 bags of single thrombocytes with sterile connecting device, while apheresis method is done automatically using apheresis machine. Quality Control Inspection of TC product is conducted to ensure the quality of the product in accordance with applicable specifications. This study aims to find out the difference in acidity degree value (pH) in thrombocyte concentrate apheresis and pooling methods. This type of research is descriptive comparative with the design of cross sectional section study. The population of research was all the results of pH value examination on thrombocyte apheresis and pooling in UDD PMI Semarang city in 2020, with the number of 48 bags each. The sampling technique used is total sampling. Analysis of research data was conducted univariate and bivariate with the help of SPSS version 25. The average pH value in thrombocyte apheresis 7,145 and in thrombocyte pooling 7,417. Bivariate analysis of thrombocyte apheresis and pooling using Independent Sample T-Test has a significance value of 0.000. From the results of the analysis of research data, there is a significant difference between the pH value in thrombocytes apheresis and pooling method. Because there are differences between the two pH values in thrombocyte products, there needs to be an improvement in the evaluation and monitoring of each product.

Recovery of platelet-rich red blood cells and acquisition of convalescent plasma with a novel gravity-driven blood separation device.

ObjectivesOur objectives were to determine the separation characteristics and blood product quality of a gravity‐driven microfiltration blood separation system (HemoClear, The Netherlands).BackgroundA range of centrifugal blood separation devices, including intraoperative cell salvage devices (cell savers) and apheresis machines, are available to assist in preparing both allogenic and autologous blood products. These devices are expensive to operate and require extensive training.Methods and MaterialsNine whole blood units were collected under standard conditions and analysed for haematological parameters, thromboelastographic properties, platelet morphology and activation, and red blood cell (RBC) deformability and morphology. Three whole blood units were separated by means of the HemoClear device, into a liquid and cellular component. The cellular component was diluted with SAGM and cold stored for 14 days. To simulate cell salvage six whole blood units were diluted with isotonic saline, followed by multiple HemoClear separation rounds.ResultsThe recovery of both RBCs (100 ± 1.6%) and white blood cells (99 ± 4.5%) after undiluted filtration were very high, while platelet recovery was high (83 ± 3.0%). During the filtration, and cold storage after filtration storage both the non‐deformable RBC fraction and the RBC maximum elongation remained stable. Parameters of thromboelastography indicated that platelets remain functional after filtration and after 7 days of cold storage. In the cell salvage simulation the total protein load in the cellular fraction was reduced by 65 ± 4.1% after one washing round and 84 ± 1.9% after two consecutive washing rounds.ConclusionThe novel blood filter studied effectively separates whole blood into diluted plasma and platelet‐rich RBCs. Moreover, the device effectively washed diluted whole blood, driving over 80% of proteins to the liquid component.