Rainer Moog

Management strategies for poor peripheral blood stem cell mobilization

Peripheral blood stem cells (PBSC) have nearly replaced bone marrow (BM) as the preferred source of hematopoietic rescue for patients undergoing high-dose chemotherapy. However, some patients fail to mobilize sufficient numbers of PBSC into the peripheral blood thereby putting high-dose chemotherapy at risk. The present article reviews mobilization of PBSC with a special focus on poor mobilizers. Under steady-state conditions less than 0.05% of the white blood cells (WBC) are CD34+ cells. Chemotherapy results in a 5-15-fold increase of PBSC. Combining chemotherapy and growth factors increases CD34+ cells up to 6% of WBC. Several factors affect the mobilization of PBSC: age, gender, type of growth factor, dose of the growth factor and in the autologous setting patients diagnosis, chemotherapy regimen and number of previous chemotherapy cycles or radiation. Poor mobilizers are defined as patients with less than 10 CD34+ cells/mul in the peripheral blood during mobilization. Promising approaches for those patients rely on remobilization, use of high doses of granulocyte-colony stimulating factor (G-CSF), or the combination of G-CSF and granulocyte macrophage (GM)-CSF, which successfully mobilized the majority of poor mobilizing patients. New agents such as long lasting variants of G-CSF and CXCR4 antagonists are at the horizon and studied in clinical trials as mobilizing agents. Muscle and bone pain are frequent adverse events in stem cell mobilization but are usually tolerated under the use of analgesics. Large volume apheresis (LVL) with a processed volume of more than 4-fold patients blood volume is an approach to increase the CD34+ yield in patients with low CD34+ pre-counts resulting in higher yields of CD34+ cells for transplantation. Processing of more blood in LVL is achieved by an increase of the blood flow rate and an altered anticoagulation regimen with the occurrence of more citrate reactions.

Evaluation of a concurrent multicomponent collection system for the collection and storage of WBC‐reduced RBC apheresis concentrates

BACKGROUND: Multicomponent apheresis procedures offer the possibility of collecting blood components that are standardized, as compared to those available with whole‐blood donations. A new separator program for the concurrent collection of RBCs, platelets, and plasma (Amicus, Baxter Healthcare) was evaluated.

Collection of platelets and peripheral progenitor cells with the Fresenius AS.TEC 204 blood cell separator

The aim of the present study was to clinically evaluate the blood cell separator AS. TEC 204. One hundred fifteen platelet collections were carried out with the dual or single needle procedure. Platelet yield was 3.21 ± 0.80 × 1011 (mean ± standard deviation) and 59.1% of the collections showed platelet counts >3.0 × 1011. Leukocyte contamination was 1.77 ± 2.81 × 106 and 89.0% of the platelet concentrates had a white blood cell content <5 × 106. Using a dual needle technique with an alternating interface adjustment, all of the products were contaminated with less than 1 × 106 leukocytes.

Periodic alternating interface positioning to lower WBC contamination of apheresis platelet concentrates: a multicenter evaluation.

BACKGROUND: A new software version of a cell separator (AS TEC 204, Fresenius) providing WBC‐reduced single‐donor plateletpheresis concentrates was tested.

Donor safety in triple plateletpheresis: results from the German and Austrian Plateletpheresis Study Group multicenter trial

BACKGROUND: The objective was to investigate potential risks for apheresis donors associated with a triple‐plateletpheresis (TP) program.

Peripheral blood stem cell collection in children: Management, techniques and safety

Peripheral blood stem cell (PBSC) collection as a source of haematopoietic stem cells is steadily increasing. The collection procedure in children is more difficult than in adults because of the low blood volume and the poor venous access. Special apheresis equipment has been developed for paediatric PBSC collections to reduce the extracorporeal volume thereby avoiding circulatory side effects. Priming of the disposable with red blood cells and/or human albumin is recommended for children weighing less than 30kg. Poor venous access usually requires a special paediatric catheter to allow for a blood flow that results in the formation of a cell layer for the collection of PBSC. An optimal time point with a maximum peak of CD34+ cells should be chosen for the harvesting of PBSC to reduce the duration of the apheresis and possible side effects.

Reducing costs in flow-cytometric counting of residual white blood cells in blood products: utilization of a single-platform bead-free flow-rate calibration method.

BACKGROUND: Commercial flow‐cytometric methods for counting residual white blood cells (rWBCs) in leukoreduced blood products use calibration beads for estimation of the measured sample volume. A bead‐free flow‐rate calibration method is developed and validated.

Evaluation of a new microbeads assay for granulocyte antibody detection

To reduce the risk of transfusion‐associated acute lung injury (TRALI), a high number of plasma donors were tested for human leukocyte antigen (HLA) and human neutrophil antigen (HNA) antibodies. For HNA antibody detection, the gold standard is a combination of the granulocyte immunofluorescence test (GIFT) and the granulocyte agglutination test (GAT). However, these tests are not suitable for a high‐throughput of samples.

Collection of red blood cell units by apheresis.

Two units of red blood cells (RBC) can be collected by modern apheresis devices. A short description of the collection process is given in the present review. Apheresis RBCs show improved functionality compared to RBCs collected by manual whole blood donation. Provided that double RBC donor eligibility criteria are respected, collection of 2-units RBC is safe and feasible.

Quality control in neutrophil granulocyte (PMN) concentrates by flow cytometry

Abstract Background: In peripheral blood, chemotaxis, phagocytosis, and oxidative burst of polymorphonuclear cells (PMNs) can be assessed by flow cytometry, whereas function tests, i.e., quality control in PMN concentrates designed for neutropenia therapy, are lacking. Methods: PMN concentrates (n=6) harvested from healthy donors who had been premedicated with granulocyte colony-stimulating factor (G-CSF) and dexamethasone were stored undiluted (control, C; n=6) and diluted 1:4 (D; n=6) with autologous plasma for 72h. Commercial flow cytometry function tests were performed to quantify changes in chemotaxis, phagocytosis, and oxidative burst of PMNs over time. Results: Median levels of phagocytosis and oxidative burst levelled at 86% (82–94) and 98% (83–100) in C on the day of apheresis, respectively, but deteriorated to 15% (0–24) and 0% within 72h; in D these parameters remained close to 90%. Median levels of chemotaxis were comparable in C (69%, 65–74) and D (74%, 70–84) at baseline. No migration was detected in C after 72h; however, D retained approximately 63% (13–76) migration capacity. Conclusion: Quality control in PMN concentrates is practical using flow cytometry and commercial test kits. While phagocytosis and oxidative burst may be maintained for 72h in vitro, chemotaxis of apheresed PMNs is already reduced on the day of apheresis.