Steady-state versus chemotherapy-based hematopoietic cell mobilization after anti-CD38-based induction therapy in newly diagnosed multiple myeloma.

BACKGROUND: The incorporation of anti-CD38 monoclonal antibodies (mAb) in induction regimens of newly diagnosed transplant-eligible multiple myeloma (MM) patients has been established as a new standard. However, the optimal strategy of stem cell mobilization in this context is not yet clear. STUDY DESIGN AND METHODS: From May 2020 till September 2022, we retrospectively reviewed patients receiving anti-CD38 mAb-based induction therapy followed by stem cell mobilization either in a steady-state protocol (SSM) using 10 µg/kg granulocyte colony-stimulating factor (G-CSF) for 5 days or in a chemotherapy-based protocol (CM) using 1-4 g/m2 cyclophosphamide and G-CSF. RESULTS: Overall, 85 patients (median age 61 years) were included in the analysis. In total, 90 mobilization attempts were performed, 42 with SSM and 48 with CM. There was no significant difference in the median concentration of CD34+ cells in peripheral blood (PB) prior to apheresis between SSM and CM (61/µL vs. 55.4/µL; p = .60). Cumulative CD34+ yields did not differ between the groups with median of 6.68 and 6.75 × 106 /kg body weight, respectively (p = .35). The target yield (≥4 × 106 CD34+ cells/kg body weight) was reached in 88% (CM) and 86% (SSM), with a high proportion even after a single apheresis session (76% vs. 75%). Plerixafor was found to be more frequently used in SSM (52%) than in CM (23%; p < .01). A total of 83 patients underwent autologous transplantation and all were engrafted. CONCLUSIONS: Stem cell collection in patients undergoing anti-CD38-based induction therapy is feasible with either CM or SSM, although SSM more frequently requires plerixafor.

Salvage treatment with plerixafor in poor mobilizing allogeneic stem cell donors: results of a prospective phase II-trial.

We conducted a prospective clinical trial to investigate the safety and efficacy of plerixafor (P) in allogeneic peripheral blood stem cells (PBSC) donors with poor mobilization response to standard-dose granulocyte colony-stimulating factor (G-CSF), defined by <2 × 106 CD34 + cells/kg recipient body-weight (CD34+/kg RBW) after 1st apheresis. A single dose of 240 µg/kg P was injected subcutaneously at 10 p.m. on the day of the 1st apheresis. Thirty-seven allogeneic PBSC donors underwent study treatment. The median CD34+ count in peripheral blood was 15/µl on Day 1 after G-CSF alone, versus 44/µl on Day 2 after G-CSF plus P (p < 0.001). The median yield of CD34+ cells was 1.1 × 108 on Day 1 and 2.8 × 108 on Day 2. In contrast to a median yield of only 1.31 × 106 CD CD34+/kg RBW on Day 1, triggering study inclusion, a median of 3.74 × 106 CD CD34+/kg RBW were collected with G-CSF plus P on Day 2. Of 37 donors, 21 reached the target cell count of >4.5 × 106 CD34+/kg RBW (57%, 95%CI 40-73%). No donor experienced a severe adverse event requiring treatment. In conclusion, P might be considered on a case-by-case basis for healthy allogeneic donors with very poor stem cell mobilization success after G-CSF.

Automated Clinical Grade Expansion of Regulatory T Cells in a Fully Closed System.

Adoptive transfer of T regulatory cells (Treg) has been successfully exploited in the context of graft-versus-host disease, transplantation, and autoimmune disease. For the majority of applications, clinical administration of Treg requires laborious ex vivo expansion and typically involves open handling for culture feeds and repetitive sampling. Here we show results from our approach to translate manual Treg manufacturing to the fully closed automated CliniMACS Prodigy® system reducing contamination risk, hands-on time, and quality variation from human intervention. Polyclonal Treg were isolated from total nucleated cells obtained through leukapheresis of healthy donors by CD8+ cell depletion and subsequent CD25high enrichment. Treg were expanded with the CliniMACS Prodigy® device using clinical-grade cell culture medium, rapamycin, IL-2, and αCD3/αCD28 beads for 13-14 days. We successfully integrated expansion bead removal and final formulation into the automated procedure, finalizing the process with a ready to use product for bedside transfusion. Automated Treg expansion was conducted in parallel to an established manual manufacturing process using G-Rex cell culture flasks. We could prove similar expansion kinetics leading to a cell yield of up to 2.12 × 109 cells with the CliniMACS Prodigy® and comparable product phenotype of >90% CD4+CD25highCD127lowFOXP3+ cells that had similar in vitro immunosuppressive function. Efficiency of expansion bead depletion was comparable to the CliniMACS® Plus system and the final ready-to-infuse product had phenotype stability and high vitality after overnight storage. We anticipate this newly developed closed system expansion approach to be a starting point for the development of enhanced throughput clinical scale Treg manufacture, and for safe automated generation of antigen-specific Treg grafted with a chimeric antigen receptor (CAR Treg).

Differences in Cellular Composition of Peripheral Blood Stem Cell Grafts from Healthy Stem Cell Donors Mobilized with Either Granulocyte Colony-Stimulating Factor (G-CSF) Alone or G-CSF and Plerixafor.

This study was conducted to characterize and compare peripheral blood stem cell grafts from healthy donors who underwent granulocyte colony-stimulating factor (G-CSF) mobilization and subsequently received 1 dose of plerixafor after insufficient stem cell yields were achieved at the first apheresis. Aliquots from 35 donors were collected from the first apheresis after mobilization with G-CSF alone and from the second apheresis after additional plerixafor administration. Samples were freshly analyzed for cellular subsets by 8-color flow cytometry. Leukapheresis samples mobilized with additional plerixafor showed a significant increase of total nucleated cells, including B cells, CD4+ and CD8+ T cells, and CD34+ hematopoietic stem and progenitor cells. Absolute numbers of plasmacytoid dendritic cells were also significantly increased, whereas no changes were detected for myeloid dendritic cells. Furthermore, absolute numbers of regulatory T cells increased, with naive CD45RA+ regulatory T cells showing the highest rise. Finally, strikingly higher numbers of myeloid-derived suppressor cells were detected in the plerixafor and G-CSF-mobilized graft. The mobilization of peripheral stem cells in healthy donors with G-CSF and plerixafor led to a significant difference in cellular graft composition compared with G-CSF alone. The clinical impact of the different cell composition for the graft recipient warrants further clinical investigation.

[Effect of autologous platelet concentrates on the anatomical and functional outcome of late stage macular hole surgery: A retrospective analysis]. / Wirkung von autologem Thrombozytenkonzentrat auf den anatomischen und funktionellen Erfolg bei der Chirurgie des Makulaforamens im Spätstadium : Eine retrospektive Analyse.

BACKGROUND: The macular hole (MH) is a disorder of the visual center of the retina in humans. An untreated MH leads to loss of central visual acuity and reading ability. Surgery for early-stage macular holes has been very successful for many years and leads to very good anatomical and functional results. Despite continuous improvement of surgical procedures, the outcome for the later stages of MH is still unsatisfactory. METHOD: In a retrospective analysis, we investigated the effect of autologous platelet concentrates in patients presenting later stages of MHs (stage III-IV) with respect to anatomic success (hole closure) and recovery of vision. The application of platelets was performed during retinal surgery (pars plana vitrectomy, ppV). In addition, selected platelet concentrates were qualitatively analysed for growth factors and platelet adhesion. RESULTS: In the first group, 74% of the patients showed a good anatomical macular hole closure. The analyses of the platelet concentrates indicated a possible wound-healing effect due to growth factors (e.g. the platelet-derived growth factor, PDGF) and lesser to the ability of the platelets to adhere after ristocetin administration. Further optimization of the production process of platelet concentrates and of the surgical procedure in the second group of patients showed an increase of the anatomical success (92%) and a very rapid increase of visual acuity within six weeks. DISCUSSION: In the past, the primary goal of MH surgery was to optimize the surgical procedures. Only few concepts focused on wound healing. Based on our data, we postulate the use of autologous platelet concentrates in MH surgery as a healing concept, which helps to increase the functional success of late-stage macular hole surgery.

Suitability Criteria for Adult Related Donors: A Consensus Statement from the Worldwide Network for Blood and Marrow Transplantation Standing Committee on Donor Issues.

The number of allogeneic hematopoietic stem cell (HSC) transplants performed globally each year continues to increase. Advances in HLA typing, better supportive care, and administration of reduced-intensity conditioning regimens allow treatment of older patients with older sibling donors. Pretransplant donor assessment and testing are very important processes affecting the quality and safety of donation. For unrelated HSC donors detailed recommendations for health assessment have been published, allowing donation only if they are unrestrictedly healthy. Eligibility criteria for related donors are less strict and vary significantly between centers. In situations where a family donor does not meet the suitability criteria for unrelated donors, involved physicians often struggle with the decision whether the matched relative is suitable for donation or not. On behalf of the Worldwide Network for Blood and Marrow Transplantation Standing Committee on Donor Issues, we intended to develop a consensus document with recommendations for donor workup and final clearance of family donors who would not be able to serve as unrelated donors because of their age or pre-existing diseases. This article covers different topics intending to support decision-making, with the goal of minimizing medical risk to the donor and protection of the recipient from transmissible diseases.

Prediction of hematopoietic stem cell yield after mobilization with granulocyte-colony-stimulating factor in healthy unrelated donors.

BACKGROUND: The collection of hematopoietic stem cells from the peripheral blood of healthy donors has been established as a highly efficient method. Nevertheless, some donors have a moderate or poor chance of harvest success with standard mobilization regimens. STUDY DESIGN AND METHODS: We retrospectively reviewed data from 7216 unrelated healthy donors, who underwent granulocyte-colony-stimulating factor mobilization and consecutive leukapheresis for allogeneic stem cell transplantation. We tested different donor variables of potential influence and established a statistical model for prediction of upfront mobilization capacity and harvest success. In addition, we calculated the likelihood of a successful harvest dependent on predicted preapheresis CD34+ count and recipient weight. RESULTS: Female sex, older age, smoking, elevated lactate dehydrogenase, higher relative lymphocyte count, and higher large unstained cell count at baseline were negatively correlated with the CD34+ cell count on Day +5 (p < 0.0001). In contrast, higher platelet count, higher body mass index, higher absolute lymphocyte count, and higher relative monocyte count at baseline showed a positive correlation with the CD34+ count on Day +5 (p < 0.0001). Using a model built on these factors, we could significantly improve the prediction of harvest success compared to a basic model. CONCLUSION: The model allows the identification of female donors who eventually have a significant risk of harvest failure if requested to donate for recipients with a high body weight.

G-CSF in Healthy Allogeneic Stem Cell Donors.

Mobilization of peripheral blood stem cells (PBSC) in healthy volunteers with granulocyte colony-stimulating factor (G-CSF) is currently carried out at many institutions worldwide. This report presents the experience of the Dresden center regarding donor evaluation and mobilization schedule. Data regarding efficacy, short- and long-term safety of G-CSF treatment gained from 8290 PBSC collections in healthy donors are outlined. These results are discussed against the background of the available evidence from the literature. Although established as a standard procedure, G-CSF application to allogeneic donors will always be a very delicate procedure and requires the utmost commitment of all staff involved to ensure maximum donor safety.

Efficacy and side effects of granulocyte collection in healthy donors.

BACKGROUND: We report on the efficacy and side effects of granulocyte collection, which is comparatively infrequently performed in Germany. METHODS: Data from 378 healthy donors who underwent 914 granulocyte collections between 1999 and 2007 were retrospectively analyzed. Donors received G-CSF (lenograstim) at a median dose of 5.58 (3.25-7.36) µg/kg body weight with (n = 243) or without (n = 57) 4 mg dexamethasone. Side effects were recorded by donor monitoring and interview (questionnaire). RESULTS: The median granulocyte yield in apheresis products was 8.47 × 10(10) (3.07-14.92 × 10(10)). Granulocyte yields correlated significantly with gender, baseline WBC, PMN and PLT counts, and nicotine consumption. Dexamethasone and lenograstim administration was more effective than lenograstim administration alone (p < 0.001). Side effects of granulocyte mobilization were generally mild: bone pain in 31.4%, headache in 19.6%, and fatigue in 15.7% of donors. During follow-up (4 weeks), pruritus and/or exanthema were reported in 17.6% of donors. CONCLUSIONS: Granulocyte mobilization with lenograstim with or without dexamethasone was a safe and effective regimen for granulocyte mobilization. Side effects were tolerable and milder than those seen in peripheral blood stem cell donors. Long-term monitoring of granulocyte donors is important to establish optimal standards for the procedure.

Sex and body mass index but not CXCL12 801 G/A polymorphism determine the efficacy of hematopoietic cell mobilization: a study in healthy volunteer donors.

Analyses of healthy donors of granulocyte colony-stimulating factor (G-CSF) mobilized hematopoietic stem and progenitor cells (HSPCs) and of patients undergoing autologous stem cell transplantation have suggested that individuals harboring the CXCL12-A allele mobilize a higher number of CD34 + HSPCs after G-CSF administration. We typed 463 healthy unrelated donors (376 men and 87 women) who had received daily subcutaneous injections at a mean dose of 7.36 ± 1.71 µg/kg G-CSF for 5 days for CXCL12 801 G/A using a real-time PCR assay. Interestingly, the median concentration of mobilized CD34 + cells on day 5 was almost identical in donors with the A-allele (79/µL; range, 11 to 249/µL) and the G/G-group (82/µL; range, 15 to 268/µL). In addition, the allelic distribution was not different in donors (n = 11) who mobilized less than 20/µL CD34 + cells. No difference in the overall yield of CD34 + cells in the apheresis product and in the number of CD34 + cells/kg recipient could be detected between both groups. In a multivariate regression model for the endpoint CD34 + cells/µL at day 5, only male sex (regression coefficient, 11.5; 95% confidence interval, 1.7 to 21.2, P = .021) and body mass index as continuous variables (regression coefficient, 3.5; 95% confidence interval, 2.5 to 4.5, P = .0001) but not age, smoking status, or CXCL12 allelic status represented independent variables. Our data derived from a large well-controlled cohort contradict previous analyses suggesting an association between CXCL12 allelic status and the yield of CD34 + HSPC after G-CSF mobilization. Concentration of CD34 + cells in the peripheral blood, the most objective parameter, could not be predicted by CXCL12 genotype.

Leukocyte Depletion by Therapeutic Leukocytapheresis in Patients with Leukemia.

Hyperleukocytosis is a complication of various leukemias and can result in life-threatening leukostasis. Critical white blood cell (WBC) counts are conventionally defined as higher than 100 × 10(9)/l in acute myeloid leukemia and > 300 × 10(9)/l in acute lymphatic leukemia and other leukemic disorders (e. g. chronic myeloid leukemia). Leukocytapheresis is a therapeutic tool to reduce leukocyte counts in patients with symptomatic or threatening leukostasis until induction chemotherapy works. In patients with temporary contraindications against cytotoxic drugs, e.g. during pregnancy, leukocytapheresis can be used as a bridging therapy until conventional chemotherapy can be started. Therapeutic leukocytapheresis should be performed in specialized centers by experienced, well-trained staff. Thorough monitoring of the patients is extremely relevant. During a single procedure, WBC count can be reduced by 10-70%. Treatment should be repeated daily and can be discontinued when the symptoms of leukostasis have been resolved and/or leukocyte counts have fallen below the critical thresholds. There are no prospective studies evaluating the clinical efficacy of therapeutic leukocytapheresis in patients with hyperleukocytosis. It can be concluded from retrospective studies that leukocytapheresis might have some beneficial effect in early morbidity and mortality of patients with newly diagnosed AML but has no influence on overall long-term survival. Induction chemotherapy is the most important treatment in these patients and must never be postponed.

Peripheral blood stem cell collection in allogeneic donors: impact of venous access.

BACKGROUND: Peripheral blood stem cell (PBSC) collection is accepted as a routine procedure in related and unrelated healthy donors worldwide. Venous access can be accomplished by peripheral veins or a central venous catheter (CVC). STUDY DESING AND METHODS: We compared efficacy and tolerability of 40 PBSC collections via CVC with 6267 PBSC collections via peripheral veins in healthy allogeneic donors. Results of the leukapheresis procedures and side effects in the donors were evaluated. RESULTS: The median CD34+ cell counts on Day 5 and the results of the stem cell collection were not significantly different between the two groups of allogeneic donors. Pain or problems at the site of puncture or catheter insertion occurred in 58.6% of the donors with a CVC versus 37.8% of the donors with peripheral venous access (p = 0.03). The incidence and severity of paresthesia during the leukapheresis was not significantly different in both groups of donors (p = 0.09). During follow-up no major adverse events related to CVC were reported. CONCLUSION: Central femoral lines proved to be safe and tolerable in healthy allogeneic donors but peripheral venous access should be preferred, whenever possible.

The clinical, quality of life, and economic consequences of chronic anemia and transfusion support in patients with myelodysplastic syndromes.

Most patients with myelodysplastic syndromes (MDS) require transfusions due to chronic anemia. Apart from the acute risks associated with transfusions, chronic anemia and red blood cell (RBC) transfusion dependence impact negatively on survival and quality of life (QoL), and are associated with iron overload, potentially leading to organ damage. QoL studies demonstrate that regular transfusions do not correct the impact of chronic anemia. Furthermore, chronic transfusion support requires substantial resources. Therefore, major goals are to prevent or effectively treat anemia. Indeed, innovative drugs have been shown to be effective in achieving transfusion independence by altering the natural course of MDS.

Differential effect of platelet-rich plasma and fetal calf serum on bone marrow-derived human mesenchymal stromal cells expanded in vitro.

Mesenchymal stromal cells (MSCs) derived from various sources have great potential for use in cell-based therapies. Since the proportion of primary MSCs contained in bone marrow or adipose tissue is low, plastic adherence and in vitro expansion are necessary to expand MSCs prior to clinical application. Human platelet-rich plasma has been introduced as an alternative serum source but functional differences have so far not been described. Here we cultured MSCs derived from human bone marrow in medium supplemented with either 10% fetal calf serum (FCS) or 5% and 10% platelet-rich plasma (PRP) until the first or second passage. Parameters under investigation were cell yield, clonogenicity, phenotype as well as migratory and differentiation potential. In addition, the secretion of SDF-1α and the induced migration of CD34(+) haematopoietic stem cells (HSCs) were investigated with regard to the different serum source. The use of PRP resulted in a significantly higher expansion rate and yield at passages 0 and 1. In addition, the level of secreted SDF-1α was significantly increased in the supernatant of MSCs cultured with FCS instead of human PRP. Consistent with this, the migration capacity of MSCs cultured with 10% FCS as well as their capability to induce the migration of CD34(+) haematopoietic progenitors in a transwell assay was higher. Our results demonstrate that human PRP can be seen as an alternative serum source to FCS for MSC cultivation. However, the requirements of the specific clinical application must be carefully considered before the respective serum source is selected.

Prophylactic transfer of BCR-ABL-, PR1-, and WT1-reactive donor T cells after T cell-depleted allogeneic hematopoietic cell transplantation in patients with chronic myeloid leukemia.

Donor lymphocyte infusions have been effective in patients with chronic myeloid leukemia (CML) relapsing after allogeneic stem cell transplantation, but their use is associated with the risk of graft-versus-host disease. We investigated the effects of prophylactic infusion of in vitro-generated donor T cells reactive against peptides derived from CML-associated antigens. Fourteen CML patients received conditioning therapy followed by CD34(+)-selected peripheral blood stem cells from matched siblings (n = 7) or unrelated (n = 7) donors. Donor-derived mature dendritic cells generated in vitro from CD14(+) monocytes were loaded with human leukocyte Ag-restricted peptides derived from PR1, WT1, and/or B-cell receptor-ABL and used to repetitively stimulate donor CD8(+) T cells in the presence of IL-2 and IL-7. Stimulated T cells were infused 28, 56, and 112 days after transplantation. Thirteen patients are alive and 7 remain in molecular remission (median follow-up, 45 months). Interestingly, all 4 patients receiving CD8(+) T cells displaying marked cytotoxic activity in vitro and detectable peptide-reactive CD8(+) T cells during follow-up have not experienced graft-versus-host disease or relapse. Our study reveals that prophylactic infusion of allogeneic CD8(+) T cells reactive against peptides derived from CML-associated antigens is a safe and promising therapeutic strategy. This trial was registered at www.clinicaltrials.gov as #NCT00460629.

Safety and efficacy of hematopoietic stem cell collection from mobilized peripheral blood in unrelated volunteers: 12 years of single-center experience in 3928 donors.

We present results of peripheral blood stem cell (PBSC) mobilization, collection, and follow-up from 3928 consecutive unrelated stem cell donors. Assessments were performed prospectively at baseline, leukapheresis, 1 month, 6 months, and annually after PBSC donation. During follow-up, side effects were recorded by return post questionnaires. The median CD34+ cell counts on day 5 were 67.5/microL in male and 51/microL in female donors. Bone pain and headache were the most common side effects of recombinant human granulocyte-colony stimulating factor. Central venous access was required for 23 donations (0.6%). Throughout the follow-up, the absolute neutrophil counts were slightly below the initial baseline values but remained within the normal range. The majority of the donors reported good or very good health. Malignancies occurred in 12 donors (0.3%), among whom were 1 case of acute myeloid leukemia, 1 case of chronic lymphatic leukemia, and 2 cases of Hodgkin disease. Only the incidence of Hodgkin lymphoma differed significantly from an age-adjusted population. In conclusion, 7.5 microg/kg per day lenograstim proved to be safe and effective for mobilizing hematopoietic stem cells for allogeneic transplantation. Long-term monitoring of healthy PBSC donors remains important to guarantee the safety standards of PBSC mobilization and collection.