Feasibility of peripheral blood stem cell collection from sickle cell trait donors with an intensified G-CSF regimen.

OBJECTIVES: Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment for SCD and bone marrow from an HLA-matched sibling is currently the standard of care. Haploidentical HSCT from a family donor with a TCR αß/CD19 depleted graft (T-haplo) is an increasingly successful alternative, which requires the generation of G-CSF stimulated peripheral stem cell (PBSC) from haploidentical relatives. These sickle cell trait (SCT) donors reported to develop SCD-related complications in conditions of severe stress. METHODS: In this retrospective analysis, we compared the safety and efficacy of PBSC mobilization with a G-CSF intensified mobilization regimen in SCT donors with a conventional G-CSF mobilization regimen in healthy donors. RESULTS: The reported adverse events were similar during intensified G-CSF mobilization, apheresis, and shortly after stem cell apheresis in SCT and control donors. In SCT and control donors, we were able to mobilize high yields of CD34+ stem cells and the harvested CD34+ cell count was comparable with control donors. CONCLUSIONS: Peripheral stem cell mobilization using an intensified G-CSF regimen is safe, and well tolerated among SCT donors. SCT donors are a valid alternative for collection of peripheral CD34+ stem cells for T-cell-depleted haploidentical stem cell transplantation.

Impact of hydroxyethyl starch and modified fluid gelatin on granulocyte phenotype and function.

BACKGROUND: Patients with neutropenia or granulocyte dysfunction may require granulocyte transfusions for adequate immune restoration. High-molecular-weight hydroxyethyl starch (HES) is the most commonly used sedimentation agent to enhance granulocyte collection efficiency. However, authorities recently restricted the use of HES due to its unfavorable risk-benefit profile. As modified fluid gelatin (MFG) is already used as an alternative sedimentation agent, we tested the hypothesis that MFG is not inferior to HES in terms of the functionality and viability of granulocytes. STUDY DESIGN AND METHODS: Granulocytes from ten healthy donors were isolated, aliquoted and incubated in parallel for 2 hours with either 0% (control), 7.5%, 15%, or 30% MFG (Gelafundin) or HES (Hespan), respectively, and granulocyte migration, chemotaxis, reactive oxygen species (ROS) production, neutrophil extracellular trap formation (NETosis), antigen expression, and viability were subsequently investigated in vitro. RESULTS: Relative to the controls, all three concentrations of HES compared to only 15% and 30% MFG lowered migration distances, and the 15% and 30% concentrations of both sedimentation agents reduced track straightness. HES resulted in lower CD11b expression and higher CD62L expression compared to MFG and the controls, whereas the differences for CD66b did not reach statistical significance. No significant differences in the timing of ROS production or NETosis, or in neutrophil viability or respiratory burst were observed. CONCLUSION: These results indicate that MFG is not inferior to HES in terms of granulocyte function in vitro when used at equal concentrations, and that potential impairment of granulocyte function can occur with HES.

Granulocytapheresis with modified fluid gelatin versus high-molecular-weight hydroxyethyl starch: a matched-pair analysis.

BACKGROUND: Granulocyte apheresis requires a sedimentation agent. Usually, hydroxyethyl starch (HES) is administered to donors for this purpose and, as granulocyte concentrate (GC) ingredient, also to patients. Authorities recently recommended suspending market authorizations for starch-containing products due to side effects. Therefore, we tested the efficacy of modified fluid gelatin (MFG, Gelafundin 4%) versus hetastarch (Hespan) for GC apheresis. STUDY DESIGN AND METHODS: This retrospective matched-pair analysis compared MFG- and hetastarch-derived GCs. Each group consisted of 15 unrelated male donors mobilized with dexamethasone and granulocyte-colony-stimulating factor for apheresis on 1 or 2 days with the COBE Spectra's PMN program. RESULTS: In each group, 24 GCs were collected from 15 male donors and analyzed. None of the HES-derived products, but two of the MFG-derived products (8.3%), had aggregates and could not be used. The HES-derived products had significantly higher neutrophil counts on the first day (7.7 × 1010 /unit vs. 4.0 × 1010 /unit; p = 0.00005) as well as second day of apheresis (4.0 × 1010 /unit vs. 1.1 × 1010 /unit; p = 0.0002). Median white blood cell collection efficacies were lower with MFG than with HES on Day 1 (24% vs. 43%) and Day 2 (15% vs. 37%). Twenty-one percent of the MFG-derived products had less than 1 × 1010 granulocytes. CONCLUSION: These results indicate that granulocyte apheresis is feasible with MFG as well as with hetastarch and that the latter is superior for GC production, if used in the same dosage. In addition, aggregates in GC from the COBE Spectra were observed in the MFG group but not in the hetastarch group.

Multistep screening and selection of COVID-19 convalescent plasma donors at the early stage of the SARS-CoV-2 pandemic: A retrospective analysis.

Background and Aims: The COVID-19 pandemic reached Bavaria in February 2020. Almost simultaneously, Chinese physicians published reports on the first successful treatments with plasma from COVID-19 convalescent donors. With these silver linings on the horizon, we decided to establish the manufacturing of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody-containing plasma from COVID-19 convalescent donors at our site. Here we describe our donor selection process, built from the ground up, which enabled us to cope with the immense resonance after our social media call for donors. Methods: As a first step, we created a specific questionnaire for telephone interviews applied by trained students to filter the wave of callers interested in plasma donation. Afterward, the medical staff evaluated the hotline questionnaires and chose eligible donors to be invited for on-site donor evaluation. Data documentation was performed with MS Excel, and statistical analyses were calculated with GraphPad Prism 8. A quantitative in-house ELISA was used to detect anti-SARS-CoV-2 antibodies and determine specific titers. Results: Out of 1465 calls from potential plasma donors, we could register 420 persons with a completed questionnaire. Evaluation of questionnaires identified 222 of 420 persons as eligible for donation, and 55 were directly asked for on-site donor qualification. Subsequently, as anti-SARS-CoV-2 antibody titers ≥1:800 were required, we invited 89 of 222 potential donors for an antibody screening. This procedure resulted in another 28 potential donors for an on-site evaluation. Finally, 12 donors qualified with a titer of 1:400 and 24 with ≥1:800. Conclusion: Identifying suitable COVID-19 convalescent plasma donors was expected to be highly time-consuming. Implementing a screening procedure with our hotline questionnaire helped us streamline the donor selection process and reduce the workload for the staff. We propose combining the described selection process with the later introduced on-site antibody screening as an effective strategy.