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Abstract Background Exudative retinal detachment in patients with multiple myeloma is exceedingly rare. Only two Cases are known to us. We successfully identified light-chain proteins in subretinal fluid, allowing for a more precise understanding of the pathogenesis of this complication. Case presentation A 68-year-old patient presented with bilateral exudative retinal detachment. The visual impairment was reported one day after stem cell mobilization by granulocyte-colony stimulating factor (G-CSF) and the additional administration of Plerixafor. The symptoms began during stem cell apheresis. The patient underwent surgical treatment for both eyes through vitrectomy and silicone oil tamponade. Light-chain proteins were detected in the collected subretinal fluid through electrophoresis in one eye. Conclusions We successfully identified light-chain proteins in subretinal fluid, allowing for a more precise understanding of the pathogenesis of this complication. The pathomechanism likely involves damage to the outer blood-retina barrier due to the deposition of light-chain proteins. Whether mobilization of bone marrow cells with Plerixafor led to a breakdown of the outer blood-retina barrier in these patients is a topic for discussion and has to be considered in the use of Plerixafor.

The treatment of patients diagnosed with hematologic malignancies typically includes hematopoietic stem cell transplantation (HSCT) as part of a therapeutic standard of care. The primary graft source of hematopoietic stem and progenitor cells (HSPCs) for HSCT is mobilized from the bone marrow into the peripheral blood of allogeneic donors or patients. More recently, these mobilized HSPCs have also been the source for gene editing strategies to treat diseases such as sickle-cell anemia. For a HSCT to be successful, it requires the infusion of a sufficient number of HSPCs that are capable of adequate homing to the bone marrow niche and the subsequent regeneration of stable trilineage hematopoiesis in a timely manner. Granulocyte-colony-stimulating factor (G-CSF) is currently the most frequently used agent for HSPC mobilization. However, it requires five or more daily infusions to produce an adequate number of HSPCs and the use of G-CSF alone often results in suboptimal stem cell yields in a significant number of patients. Furthermore, there are several undesirable side effects associated with G-CSF, and it is contraindicated for use in sickle-cell anemia patients, where it has been linked to serious vaso-occlusive and thrombotic events. The chemokine receptor CXCR4 and the cell surface integrin α4β1 (very late antigen 4 (VLA4)) are both involved in the homing and retention of HSPCs within the bone marrow microenvironment. Preclinical and/or clinical studies have shown that targeted disruption of the interaction of the CXCR4 or VLA4 receptors with their endogenous ligands within the bone marrow niche results in the rapid and reversible mobilization of HSPCs into the peripheral circulation and is synergistic when combined with G-CSF. In this review, we discuss the roles CXCR4 and VLA4 play in bone marrow homing and retention and will summarize more recent development of small-molecule CXCR4 and VLA4 inhibitors that, when combined, can synergistically improve the magnitude, quality and convenience of HSPC mobilization for stem cell transplantation and ex vivo gene therapy after the administration of just a single dose. This optimized regimen has the potential to afford a superior alternative to G-CSF for HSPC mobilization. [ABSTRACT FROM AUTHOR]

Background: Nivestym, a biosimilar granulocyte colony‐stimulating factor (G‐CSF) to the originator filgrastim (Neupogen), is now being used for the mobilization of peripheral blood stem cells (PBSC) in allogeneic hematopoietic stem cell transplantation (allo‐HSCT). We aim to compare the efficacy of Nivestym and Neupogen for PBSC mobilization in healthy allogeneic donors. Methods: We conducted a retrospective single‐center study including 541 adult allo‐HSCT donors receiving Nivestym (January 2013–July 2020), or Neupogen (July 2020–June 2023) for donor PBSC mobilization. Bivariate analysis was conducted using SPSS version 28. Statistical significance was determined at a p‐value <.05. Results: Our study included 541 allo‐HSCT donors who received Neupogen (n = 345, 64%) or Nivestym (n = 196, 36%) for PBSC mobilization. The median age was 47 years (range 17–76). The median donor weight was 86 kg (95% confidence interval [CI]: 87–91). Donors receiving Neupogen had similar pre‐G‐CSF white blood cell count, CD34+ percentages, and circulating CD34+ count compared with donors receiving Nivestym. The Neupogen group had similar median PBSC product total neutrophil count, CD34+ percentage, absolute CD34+ count, and infused CD34+ dose compared with the Nivestym group. For donors aged 35 years or younger, the median CD34+ dose was higher in donors who received Neupogen compared with Nivestym (6.9 vs. 6.3 million cells/kg, p =.044). Conclusions: Nivestym demonstrated similar efficacy for PBSC mobilization compared with Neupogen among allo‐HSCT donors. In donors aged 35 years or younger, a slightly lower PBSC product CD34+ count was noted with Nivestym compared with Neupogen. [ABSTRACT FROM AUTHOR]

Background: Autologous stem cell transplantation (ASCT) is a potentially curative strategy for relapse or refractory(r/r) aggressive lymphoma. However, a proportion of lymphoma patients who are at high risk of mobilization failure fail to mobilize stem cells and cannot proceed to ASCT. The aim of this study is to explore the efficacy and safety of Etoposide combined with Cytarabine (EA) plus G-CSF mobilization in poor mobilizers (PMs) with r/r aggressive lymphoma. Methods: This retrospective study analyzed the outcomes of chemomobilization based on EA (Etoposide 0.1 g/m2, qd d1~3; AraC 0.5 g/m2, q12h d1~3) in 98 patients with r/r aggressive lymphoma. Of these, 39 patients met the criteria for predicted PMs as proposed by the Gruppo Italiano Trapianto di Midollo Osseo working group. Results: Of the 39 PMs, 38(97.4%) patents harvested adequate mobilization (=2×106 CD34+ cells/kg), while 31(79.5%) patients achieved optimal mobilization (=5×106 CD34+ cells/kg). Overall, the mean number of CD34+ cells/kg collected was 17.99(range: 1.08~83.07) ×106 with an average of 1.4 apheresis sessions, and the number was 15.86(range: 0.37~83.07) ×106 for the first apheresis, respectively. A single apheresis procedure was sufficient to reach the target yield of adequate mobilization in 35(89.7%) PMs, while 76.9% of PMs achieved optimal collection within two apheresis sessions. We observed acceptable hematological toxicity and antibiotic usage exposure in 26 patients with a mean duration of 3.6 days. No grade 4 infection or mobilization-related mortality was recorded. Most patients underwent ASCT and achieved successful hematopoietic recovery with prompt engraftment duration, except for one NK/T-cell lymphoma patient who succumbed to severe septicemia after receiving conditioning chemotherapy. Conclusion: Our findings indicate that EA plus G-CSF is an effective and tolerable CD34+ stem cell mobilization strategy for patients with r/r lymphoma, including those predicted to be PMs. This regimen could be an option for patients with r/r lymphoma, particularly those undergoing mobilization for salvage ASCT therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Autologous hematopoietic cell transplantation (auto-HCT) can be used to salvage at least a proportion of plasma cell myeloma patients who relapse after a previous auto-HCT. It may, however, occur that there is either no or an insufficient stem cell dose in storage to proceed to transplantation. Remobilization to procure new cells is then required. There are very limited data in the literature concerning the efficacy of stem cell remobilization after previous auto-HCT. In our previous report, we showed that remobilization with cytarabine was associated with a lower risk of remobilization failure in comparison to etoposide or cyclophosphamide. In the current study, we analyze the efficacy and safety of different doses of cytarabine (800, 1600, and 2400 mg/m2), showing that all doses are efficacious but that the dose of 2400 mg/m2 is associated with the most toxicity. Therefore, lower doses of cytarabine seem to be preferable, with plerixafor rescue when needed. Salvage autologous hematopoietic cell transplantation (auto-HCT) may be used to treat relapse of plasma cell myeloma occurring after previous auto-HCT. When an insufficient number of hematopoietic stem cells have been stored from the initial harvest, remobilization is necessary. Here, we aimed to analyze the efficacy and safety of different doses of cytarabine (total 800 vs. 1600 vs. 2400 mg/m2) for remobilization. Sixty-five patients, 55% male, with a median age at remobilization 63 years, were included. Remobilization was performed with cytarabine_800 in 7, cytarabine_1600 in 36, and cytarabine_2400 in 22 patients. Plerixafor rescue was used in 25% of patients receiving cytarabine_1600 and 27% of those receiving cytarabine_2400. Patients administered cytarabine_800 were not rescued with plerixafor. Remobilization was successful in 80% of patients (57% cytarabine_800; 86% cytarabine_1600; 77% cytarabine_2400; p = 0.199). The yield of collected CD34+ cells did not differ between the different cytarabine doses (p = 0.495). Patients receiving cytarabine_2400 were at the highest risk of developing severe cytopenias, requiring blood product support, or having blood-stream infections. One patient died of septic shock after cytarabine_2400. In summary, remobilization with cytarabine is feasible in most patients. All doses of cytarabine allow for successful remobilization. Cytarabine_2400 is associated with higher toxicity; therefore, lower doses (800 or 1600 mg/m2) seem to be preferable. [ABSTRACT FROM AUTHOR]

Gemtuzumab ozogamicin (GO), a CD33-targeting antibody drug conjugate, previously showed longer relapse-free survival when combined with induction chemotherapy in patients with favorable-risk acute myeloid leukemia (AML). In this patient population, characterized by lower relapse risk as compared to other ELN risk groups, autologous stem cell transplantation (ASCT) can be used as consolidation strategy. However, there are limited data on the impact of GO on the peripheral blood stem cell (PBSC) mobilization potential. We therefore retrospectively analyzed data from 54 AML patients with favorable-risk AML treated with (n = 17) or without (n = 37) GO during induction treatment. We observed no significant differences in the PBSC mobilization rate between patients treated with vs. without GO. The mobilization success in a first attempt directly following cycle 2 was 65% vs. 70% (p = 0.92); and the mobilization success in a subsequent second attempt after hematologic recovery and repeated stimulation procedure was 24% vs. 19% (p = 0.56). No significant impact on treatment outcome in terms of EFS (p = 0.31) or OS (p = 0.99) was observed. Thus, our results suggest that the addition of GO to induction regimens does not negatively impact PBSC mobilization in favorable-risk AML patients. To our best knowledge, this is the first study comparing the stem cell mobilization potential in favorable-risk AML patients treated with vs. without GO. [ABSTRACT FROM AUTHOR]

Objective: The combination of high-dose cyclophosphamide (HD-Cy) (3g/m²) plus granulocyte colony-stimulating factor (G-CSF) and on-demand plerixafor (PXF) has been considered an effective mobilization regimen of patients with multiple myeloma(MM). However, the daily multi-injection regimen of G-CSF poses challenges. This study delves into the efficiency and cost implications of a novel approach, using HD-Cy alongside pegylated G-CSF (PEG G-CSF) and ondemand PXF. Unlike G-CSF, which necessitates daily injections, the half-life of PEG G-CSF extended allows for a single injection. Methods: A retrospective analysis was conducted on 350 MM patients, which were categorized based on their mobilization regimens: Cy+PEG G-CSF+/-PXF (n=66), Cy+PEG G-CSF (n=91), Cy+ G-CSF (n=169), and G-CSF+PXF (n=24). Results: Mobilization with Cy+PEG G-CSF+/-PXF(8.79)yielded a notably higher median CD34+ cell count compared to the other regimens: Cy+PEG G-CSF(4.96), Cy+G-CSF (4.65), and G-CSF+PXF (2.99) (P<0.001). The percentage of patients who achieved >6×106 /kg CD34+ cells was significantly higher in the Cy+PEG GCSF+/-PXF group (77.3%) than in the other mobilization regimens: Cy+PEG G-CSF (41.8%), Cy+ G-CSF (37.3%), and G-CSF+PXF (8.3%) (P<0.001). From a cost perspective, the Cy+PEG G-CSF+/-PXF approach was more economical than the G-CSF+PXF strategy but was marginally costlier than the other two methods. A multivariate assessment highlighted that the combination of Cy+PEG G-CSF with on-demand PXF had a superior potential to achieve the desired harvest (6×106 /kg) compared to the Cy+PEG G-CSF protocol without PXF. The incremental costeffectiveness ratio for each 1% increase in the probability of achieving a successful optimal harvest was $ 97.02 per patient. The incidence of neutropenic fever was 3.0% in the Cy+PEG G-CSF+/-PXF group. Conclusion: The combination of on-demand PXF with HD-Cy and PEG G-CSF offers a cost-effective approach with a high mobilization success rate, manageable side effects, and the convenience of fewer injections. It stands as a promising mobilization strategy for MM patients. [ABSTRACT FROM AUTHOR]

This study aimed to clarify the effectiveness and safety of two different infusion durations of cyclophosphamide (CTX) plus granulocyte colony-stimulating factor (G-CSF) for peripheral blood stem cell mobilization in patients with newly diagnosed multiple myeloma (NDMM). One hundred and fifty-six consecutive NDMM patients receiving CTX plus G-CSF mobilization and autologous stem cell transplantation during the period of September 2008 to May 2020 were selected for retrospective analysis. According to differences in prolonged infusion time of CTX, they were divided into a 24-h group (24-h continuous infusion) and a control group (4-6 h of infusion). Mobilization and safety of infusion were analyzed. Flow cytometry was used to detect the peripheral blood CD34+ cell count. Multivariate analysis was performed to determine the factors influencing the number of CD34+ cells. The mean CD34+ cell counts collected in 24-h and control groups were 6.78 (interquartile range [IQR] 3.59-11.69) and 4.48 (IQR 2.39-6.30) ×106/kg, respectively (p < 0.001). Meanwhile, the target number of CD34+ cells/kg (defined as ≥4 × 106/kg) was collected from 51 (75%) of cases in 24-h group vs. 45 (51%) in the control group (p = 0.002). Multivariate analysis identified the independence of CTX infusion time as a factor influencing the target number of CD34+ cells/kg [odds ratio OR, 4.045; 95% CI: 1.630-10.038, p = 0.003]. The post-transplantation time to neutrophil engraftment was 10 (IQR 9-11) in 24-h group and 11 (IQR 10-12) in control group (p < 0.001). Finally, no statistical differences were identified between groups in terms of hematologic and non-hematologic toxicities. For patients with NDMM, 24-h continuous infusion of CTX plus G-CSF contributes to improved mobilization efficiency and equivalent toxicity as a stem cell mobilization regimen. [ABSTRACT FROM AUTHOR]

A single injection of 12 mg pegfilgrastim was used to mobilize peripheral blood progenitor cells (PBPCs) from healthy donors in some studies. The purpose of this study was to determine if 6 mg of pegfilgrastim was effective and safe for mobilizing CD34+ cells in donors for allogeneic hematopoietic stem cell transplantation. We conducted a retrospective case-matched design. A single dosage of 6 mg pegfilgrastim was used to mobilize PBPCs from 60 healthy donors. Granulocyte colony-stimulating factor (G-CSF, 10 μg/kg) was administered daily to the matched donors. Leukapheresis was scheduled to commence on day 4 of the mobilization regimen. The median yielded CD34+ cell in the pegfilgrastim group was higher than those in the G-CSF group, at 5.06 × 106/kg recipient weight. The 73.3% of donors mobilized with pegfilgrastim yielded >4 × 106 cells/kg CD34+ cells in a single apheresis procedure when compared to the 33.3% of donors mobilized with G-CSF (P < 0.001). The myeloid-derived suppressor cells (MDSC) proportion in the pegfilgrastim group was significantly higher than that in the G-CSF group (P < 0.001). The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was higher in the G-CSF group than that in the pegfilgrastim group (26.7% vs. 11.7%), without statistical difference. In comparison to the G-CSF group, the pegfilgrastim group had a reduced median pain intensity numerical rating scale score (1 vs. 2). A single 6 mg dosage of pegfilgrastim is effective and safe for allogeneic PBPCs collection from healthy donors. Pegfilgrastim may decrease the incidence of aGVHD by boosting MDSCs, which need further investigation. [ABSTRACT FROM AUTHOR]

Background: Adequate stem cell collection is essential for successful stem cell transplantation. Heparin enhances stem cell mobilization by competing with heparin sulfate proteoglycans. Heparin is also used as an anticoagulant before leukapheresis. Here, we evaluated the effects of heparin on stem cell mobilization in patients who underwent autologous stem cell transplantation (ASCT). Methods: We evaluated patients who underwent ASCT. Patients were divided into two groups: those who received heparin plus citrate (heparinized patients) and those who received citrate only (nonheparinized patients) for anticoagulation. Univariate and multivariate analyses were also performed. The collection efficiency 2 (CE2) for CD34+ cells was calculated and compared between heparinized and nonheparinized patients. Results: This study included 1017 patients. There were 478 (47%) heparinized and 539 (53%) nonheparinized patients. The number of collected CD34+ cells was significantly higher in heparinized patients (P <.00001). The multivariate analyses showed that using heparin was an independent positive factor for collected CD34+ cells (adj‐R2 = 0.744; F = 369.331, P <.00001). CE2 was significantly higher in heparinized patients than in nonheparinized patients (66.8% vs 52.1%; P <.00001). The rate of collecting at least 2 × 106/kg CD34+ cells was 3.3 times higher for heparinized patients in poor mobilizers (P <.00001). Heparinized patients had significantly higher total nucleated and mononuclear cell counts (P <.00001 and <.00001, respectively). Conclusion: Heparin enhances stem cell collection and increases CE2. The use of heparin may reduce the need for other strategies to increase stem cell mobilization. [ABSTRACT FROM AUTHOR]

Not applicable.

Abstract Background While quadruplet induction therapies deepen responses in newly diagnosed multiple myeloma patients, their impact on peripheral blood stem cell (PBSC) collection remains incompletely understood. This analysis aims to evaluate the effects of prolonged lenalidomide induction and isatuximab- or elotuzumab-containing quadruplet induction therapies on PBSC mobilization and collection. Methods A total of 179 transplant-eligible patients with newly diagnosed MM treated at a single academic center were included. The patients were evaluated based on PBSC mobilization and collection parameters, including overall collection results, CD34+ cell levels in peripheral blood, leukapheresis (LP) delays, overall number of LP sessions, and the rate of rescue mobilization with plerixafor. The patients underwent four different induction regimens: Lenalidomide, bortezomib, and dexamethasone (RVd, six 21-day cycles, n = 44), isatuximab-RVd (six 21-day cycles, n = 35), RVd (four 21-day cycles, n = 51), or elotuzumab-RVd (four 21-day cycles, n = 49). Results The patients' characteristics were well balanced across the different groups. Collection failures, defined as the inability to collect three sufficient PBSC transplants, were rare (n = 3, 2%), with no occurrences in the isatuximab-RVd and elotuzumab-RVd groups. Intensified induction with six 21-day cycles of RVd did not negatively impact the overall number of collected PBSCs (9.7 × 106/kg bw versus 10.5 × 106/kg bw, p = 0.331) compared to four 21-day cycles of RVd. Plerixafor usage was more common after six cycles of RVd compared to four cycles (16% versus 8%). Addition of elotuzumab to RVd did not adversely affect overall PBSC collection (10.9 × 106/kg bw versus 10.5 × 106/kg bw, p = 0.915). Patients treated with isatuximab-RVd (six cycles) had lower numbers of collected stem cells compared to those receiving RVd (six cycles) induction (8.8 × 106/kg bw versus 9.7 × 106/kg bw, p = 0.801), without experiencing significant delays in LP or increased numbers of LP sessions in a multivariable logistic regression analysis. Plerixafor usage was more common after isatuximab plus RVd compared to RVd alone (34% versus 16%). Conclusions This study demonstrates that stem cell collection is feasible after prolonged induction with isatuximab-RVd without collection failures and might be further explored as induction therapy. Trial registration Patients were treated within the randomized phase III clinical trials GMMG-HD6 (NCT02495922, 24/06/2015) and GMMG-HD7 (NCT03617731, 24/07/2018). However, during stem cell mobilization and -collection, no study-specific therapeutic intervention was performed.

The treatment of patients diagnosed with hematologic malignancies typically includes hematopoietic stem cell transplantation (HSCT) as part of a therapeutic standard of care. The primary graft source of hematopoietic stem and progenitor cells (HSPCs) for HSCT is mobilized from the bone marrow into the peripheral blood of allogeneic donors or patients. More recently, these mobilized HSPCs have also been the source for gene editing strategies to treat diseases such as sickle-cell anemia. For a HSCT to be successful, it requires the infusion of a sufficient number of HSPCs that are capable of adequate homing to the bone marrow niche and the subsequent regeneration of stable trilineage hematopoiesis in a timely manner. Granulocyte-colony-stimulating factor (G-CSF) is currently the most frequently used agent for HSPC mobilization. However, it requires five or more daily infusions to produce an adequate number of HSPCs and the use of G-CSF alone often results in suboptimal stem cell yields in a significant number of patients. Furthermore, there are several undesirable side effects associated with G-CSF, and it is contraindicated for use in sickle-cell anemia patients, where it has been linked to serious vaso-occlusive and thrombotic events. The chemokine receptor CXCR4 and the cell surface integrin α4β1 (very late antigen 4 (VLA4)) are both involved in the homing and retention of HSPCs within the bone marrow microenvironment. Preclinical and/or clinical studies have shown that targeted disruption of the interaction of the CXCR4 or VLA4 receptors with their endogenous ligands within the bone marrow niche results in the rapid and reversible mobilization of HSPCs into the peripheral circulation and is synergistic when combined with G-CSF. In this review, we discuss the roles CXCR4 and VLA4 play in bone marrow homing and retention and will summarize more recent development of small-molecule CXCR4 and VLA4 inhibitors that, when combined, can synergistically improve the magnitude, quality and convenience of HSPC mobilization for stem cell transplantation and ex vivo gene therapy after the administration of just a single dose. This optimized regimen has the potential to afford a superior alternative to G-CSF for HSPC mobilization.

Gemtuzumab ozogamicin (GO), a CD33-targeting antibody drug conjugate, previously showed longer relapse-free survival when combined with induction chemotherapy in patients with favorable-risk acute myeloid leukemia (AML). In this patient population, characterized by lower relapse risk as compared to other ELN risk groups, autologous stem cell transplantation (ASCT) can be used as consolidation strategy. However, there are limited data on the impact of GO on the peripheral blood stem cell (PBSC) mobilization potential. We therefore retrospectively analyzed data from 54 AML patients with favorable-risk AML treated with (n = 17) or without (n = 37) GO during induction treatment. We observed no significant differences in the PBSC mobilization rate between patients treated with vs. without GO. The mobilization success in a first attempt directly following cycle 2 was 65% vs. 70% (p = 0.92); and the mobilization success in a subsequent second attempt after hematologic recovery and repeated stimulation procedure was 24% vs. 19% (p = 0.56). No significant impact on treatment outcome in terms of EFS (p = 0.31) or OS (p = 0.99) was observed. Thus, our results suggest that the addition of GO to induction regimens does not negatively impact PBSC mobilization in favorable-risk AML patients. To our best knowledge, this is the first study comparing the stem cell mobilization potential in favorable-risk AML patients treated with vs. without GO.

ObjectiveThe combination of high-dose cyclophosphamide (HD-Cy) (3g/m2) plus granulocyte colony-stimulating factor (G-CSF) and on-demand plerixafor (PXF) has been considered an effective mobilization regimen of patients with multiple myeloma(MM). However, the daily multi-injection regimen of G-CSF poses challenges. This study delves into the efficiency and cost implications of a novel approach, using HD-Cy alongside pegylated G-CSF (PEG G-CSF) and on-demand PXF. Unlike G-CSF, which necessitates daily injections, the half-life of PEG G-CSF extended allows for a single injection.MethodsA retrospective analysis was conducted on 350 MM patients, which were categorized based on their mobilization regimens: Cy+PEG G-CSF+/-PXF (n=66), Cy+PEG G-CSF (n=91), Cy+ G-CSF (n=169), and G-CSF+PXF (n=24).ResultsMobilization with Cy+PEG G-CSF+/-PXF(8.79)yielded a notably higher median CD34+ cell count compared to the other regimens: Cy+PEG G-CSF(4.96), Cy+G-CSF (4.65), and G-CSF+PXF (2.99) (P6×106/kg CD34+ cells was significantly higher in the Cy+PEG G-CSF+/-PXF group (77.3%) than in the other mobilization regimens: Cy+PEG G-CSF (41.8%), Cy+ G-CSF (37.3%), and G-CSF+PXF (8.3%) (P

AbstractObjectives This study aimed to clarify the effectiveness and safety of two different infusion durations of cyclophosphamide (CTX) plus granulocyte colony-stimulating factor (G-CSF) for peripheral blood stem cell mobilization in patients with newly diagnosed multiple myeloma (NDMM).Methods One hundred and fifty-six consecutive NDMM patients receiving CTX plus G-CSF mobilization and autologous stem cell transplantation during the period of September 2008 to May 2020 were selected for retrospective analysis. According to differences in prolonged infusion time of CTX, they were divided into a 24-h group (24-h continuous infusion) and a control group (4-6 h of infusion). Mobilization and safety of infusion were analyzed. Flow cytometry was used to detect the peripheral blood CD34+ cell count. Multivariate analysis was performed to determine the factors influencing the number of CD34+ cells.Results The mean CD34+ cell counts collected in 24-h and control groups were 6.78 (interquartile range [IQR] 3.59-11.69) and 4.48 (IQR 2.39-6.30) ×106/kg, respectively (p

Background: While quadruplet induction therapies deepen responses in newly diagnosed multiple myeloma patients, their impact on peripheral blood stem cell (PBSC) collection remains incompletely understood. This analysis aims to evaluate the effects of prolonged lenalidomide induction and isatuximab- or elotuzumab-containing quadruplet induction therapies on PBSC mobilization and collection. Methods: A total of 179 transplant-eligible patients with newly diagnosed MM treated at a single academic center were included. The patients were evaluated based on PBSC mobilization and collection parameters, including overall collection results, CD34+ cell levels in peripheral blood, leukapheresis (LP) delays, overall number of LP sessions, and the rate of rescue mobilization with plerixafor. The patients underwent four different induction regimens: Lenalidomide, bortezomib, and dexamethasone (RVd, six 21-day cycles, n = 44), isatuximab-RVd (six 21-day cycles, n = 35), RVd (four 21-day cycles, n = 51), or elotuzumab-RVd (four 21-day cycles, n = 49). Results: The patients' characteristics were well balanced across the different groups. Collection failures, defined as the inability to collect three sufficient PBSC transplants, were rare (n = 3, 2%), with no occurrences in the isatuximab-RVd and elotuzumab-RVd groups. Intensified induction with six 21-day cycles of RVd did not negatively impact the overall number of collected PBSCs (9.7 × 106/kg bw versus 10.5 × 106/kg bw, p = 0.331) compared to four 21-day cycles of RVd. Plerixafor usage was more common after six cycles of RVd compared to four cycles (16% versus 8%). Addition of elotuzumab to RVd did not adversely affect overall PBSC collection (10.9 × 106/kg bw versus 10.5 × 106/kg bw, p = 0.915). Patients treated with isatuximab-RVd (six cycles) had lower numbers of collected stem cells compared to those receiving RVd (six cycles) induction (8.8 × 106/kg bw versus 9.7 × 106/kg bw, p = 0.801), without experiencing significant delays in LP or increased numbers of LP sessions in a multivariable logistic regression analysis. Plerixafor usage was more common after isatuximab plus RVd compared to RVd alone (34% versus 16%). Conclusions: This study demonstrates that stem cell collection is feasible after prolonged induction with isatuximab-RVd without collection failures and might be further explored as induction therapy. Trial registration: Patients were treated within the randomized phase III clinical trials GMMG-HD6 (NCT02495922, 24/06/2015) and GMMG-HD7 (NCT03617731, 24/07/2018). However, during stem cell mobilization and -collection, no study-specific therapeutic intervention was performed. [ABSTRACT FROM AUTHOR]

Adequate mobilization of hematopoietic stem cells (HSCs), especially CD34+ cells, is necessary for stem cell transplantation in patients with hematological malignancies or autoimmune diseases. Burixafor is an inhibitor of the C‐X‐C Chemokine Receptor 4 that disrupts the C‐X‐C motif chemokine 12 (CXCL12)/CXCR4 axis in the bone marrow, releasing HSCs into circulation. In mice, a single intravenous dose of burixafor was rapidly absorbed (time to maximum concentration, 5 minutes) and increased peripheral white blood cell counts within 30 minutes. Additionally, burixafor was administered to 64 healthy subjects in a randomized, double‐blind, placebo‐controlled, single‐ascending‐dose study to evaluate safety, pharmacokinetics, and pharmacodynamics. Subjects received burixafor intravenous doses ranging from 0.10 to 4.40 mg/kg in 8 cohorts. Single doses were generally safe and well tolerated. Gastrointestinal events were reported at doses of 2.24 mg/kg or greater. Exposure (maximum concentration and area under the concentration–time curve) increased in an approximately dose‐proportional manner. Time to maximum concentration occurred with a median of 0.26–0.30 hours that was not dose proportional. As expected, white blood cell, CD133+ cell, and CD34+ cell concentrations generally increased with the increases in burixafor dose from 0.10 to 3.14 mg/kg. At maximal levels, the CD34+ cell counts increased 3‐ to 14‐fold from baseline levels. These results provide support for continued clinical development of burixafor. [ABSTRACT FROM AUTHOR]

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 aß/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. [ABSTRACT FROM AUTHOR]

Introduction: High-dose chemotherapy (HDCT) followed by autologous blood stem-cell transplantation (ABSCT) remains the standard consolidation therapy for newly diagnosed eligible multiple myeloma (MM) patients. As a prerequisite, peripheral blood stem cells (PBSCs) must be mobilized and collected by leukapheresis (LP). Many factors can hamper PBSC mobilization/collection. Here, we provide a comprehensive multiparametric assessment of PBSC mobilization/collection outcome parameters in a large cohort. Methods: In total, 790 MM patients (471 [60%] male, 319 [40%] female) who underwent PBSC mobilization/collection during first-line treatment were included. Evaluated PBSC mobilization/collection outcome parameters included the prolongation of PBSC mobilization, plerixafor administration, number of LP sessions, and overall PBSC collection goal/result. Results: 741 (94%) patients received cyclophosphamide/adriamycin/dexamethasone (CAD) and granulocyte-colony-stimulating factor (G-CSF) mobilization. Plerixafor was administered in 80 (10%) patients. 489 (62%) patients started LP without delay. 530 (67%) patients reached the PBSC collection goal at the first LP session. The mean overall PBSC collection result was 10.3 (standard deviation [SD] 4.4) × 106 CD34+ cells/kg. In a multiparametric analysis, variables negatively associated with PBSC mobilization/collection outcomes were female gender, age >60 years, an advanced ISS stage, and local radiation pre-/during induction, but not remission status postinduction. Notably, the identified risk factors contributed differently to each PBSC mobilization/collection outcome parameter. In this context, compared to all other induction regimens, lenalidomide-based induction with/without antibodies negatively affected only the number of LP sessions required to reach the collection goal, but no other PBSC mobilization/collection outcome parameters. In contrast, the probability of reaching a high collection goal of ≥6 × 106 CD34+ cells/kg body weight was higher after lenalidomide-based induction compared to VCD/PAD or VAD – taking into account – that a higher G-SCF dosage was given in approximately one-third of patients receiving lenalidomide-based induction with/without antibodies. Conclusion: Considering the identified risk factors in the clinical setting can contribute to optimized PBSC mobilization/collection. Moreover, our study demonstrates the necessity for a differentiated evaluation of PBSC mobilization/collection outcome parameters. [ABSTRACT FROM AUTHOR]

Keywords: autologous stem cell transplantation (ASCT); long-term safety; multiple myeloma; plerixafor; stem cell mobilization EN autologous stem cell transplantation (ASCT) long-term safety multiple myeloma plerixafor stem cell mobilization 583 586 4 08/11/23 20230801 NES 230801 DATA AVAILABILITY STATEMENT The data that support the findings of this study are available on request from the corresponding author. Myeloma patients received G-CSF and a non-myelosuppressive mobilization chemotherapy with either vinorelbine or, in patients with preexisting neuropathy, gemcitabine.[[1], [8], [10]] In few patients, only G-CSF was used (Table S1). Consequently, we compared myeloma patients who received at least one dose of plerixafor for peripheral stem cell mobilization to a cohort of myeloma patients not in need of (rescue) plerixafor administration. Long-term safety of the stem cell releasing compound plerixafor for peripheral stem cell collection in myeloma patients. [Extracted from the article]

INTRODUCTION: Autologous stem cell transplantation (ASCT) is a well-established consolidation treatment for many hematologic cancers which delivers prolonged survival. A subset of patients’ adequate stem cell harvest is not achievable with a solitary use of granulocyte colony-stimulating agents (G-CSF). Generally, chemomobilization is employed for patients failing G-CSF and its most feared complication febrile neutropenia (FN). MATERIALS AND METHODS: Here, we aimed to investigate the impact of the FN in chemomobilization on apheresis outcomes and engraftment. One hundred and eighty-three patients with the diagnosis of lymphoma or myeloma who underwent chemomobilization between 2015 and 2020 were included in the study. RESULTS: Forty-three patients experienced FN. All patients received G-CSF. All myeloma patients were mobilized with 4 g/m2 cyclophosphamide, but it was heterogeneous for lymphoma patients. The precollection blood counts, harvested CD34+ hematopoietic stem cells (HSCs)/kg, apheresis count, and engraftment durations were recorded. Preapheresis leukocyte and platelet were lower in the FN group (P = 0,004 and P = 0,001). Peripheral CD34 HSCs and total harvested CD34 HSCs were similar among groups (P = 0.25 and P = 0.9). More apheresis was needed in the FN group, but it was not significant (P = 0.07). Undergoing ASCT was similar (P = 0.7); however, platelet and neutrophil engraftment durations were slower in the FN group (P = 0.05 and P = 0.001). CONCLUSION: Harvesting sufficient CD34+ HSCs from patients with FN is still feasible; however, FN treatment should begin promptly, and further apheresis sessions may be required.

Among hematological malignancies, multiple myeloma (MM) represents the leading indication of autologous hematopoietic stem cell transplantation (auto-HCT). Auto-HCT is predominantly performed with peripheral blood stem cells (PBSCs), and the mobilization and collection of PBSCs are essential steps for auto-HCT. Despite the improved success of conventional methods with the incorporation of novel agents for PBSC mobilization in MM, mobilization failure is still a concern. The current review comprehensively summarizes various mobilization strategies for mobilizing PBSCs in MM patients and the evolution of these strategies over time. Moreover, existing evidence substantiates that the mobilization regimen used may be an important determinant of graft content. However, limited data are available on the effects of graft characteristics in patient outcomes other than hematopoietic engraftment. In this review, we discussed the effect of graft characteristics on clinical outcomes, mobilization failure, factors predictive of poor mobilization, and potential mobilization regimens for such patients. [ABSTRACT FROM AUTHOR]

In a previous pilot study of HLA-matched sibling donor hematopoietic cell transplantation (HCT), the authors determined the feasibility of day 4 versus day 5 granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cell (PBSC) collection compared with a historical cohort. Given identified differences in the PBSC product (day 4 cohort with significantly lower infused total nucleated, mononuclear and CD3 cells compared with other collection cohorts), the authors performed a follow-up study to determine long-term post-HCT outcomes, including detailed characterization of chronic graft-versus-host disease (GVHD). This was a prospective observational study, and the authors collected data on chronic GVHD, staging, sites of involvement and treatments. Performance status, incidence of relapse, overall survival and duration of immunosuppressive therapy (IST) were also evaluated. Data were examined retrospectively. To account for differences in length of follow-up among cohorts, the authors also determined performance status and chronic GVHD staging, sites and treatment at 2 years post-HCT. At 2 years post-HCT, the overall survival rate was 71.7% in the day 4 cohort compared with 61.5%, 52% and 56% in the day 5, 2-day and historical cohorts, respectively (P = 0.283). The cumulative incidence of chronic GVHD was 65.2% in the day 4 cohort versus 46.4% in the day 5 cohort, 51.1% in the 2-day cohort and 65% in the historical cohort (P = 0.26). There was no significant difference in the maximum overall stage of chronic GVHD (P = 0.513), median number of sites involved (P = 0.401) or cumulative incidence of discontinuation of IST (P = 0.32). Death from chronic GVHD was less common in the day 4 and day 5 cohorts compared with the 2-day and historical cohorts, though this did not reach statistical significance. The authors' preliminary results demonstrated that collection of allogeneic matched sibling donor PBSCs on day 4 of G-CSF was feasible, reduced donor exposure to growth factor and was associated with an initial cost savings. Importantly, the authors now demonstrate that transplantation of day 4 mobilized PBSCs is not associated with any adverse outcomes post-HCT, including late effects such as chronic GVHD. Further investigation of donor G-CSF collection algorithms is merited in other HCT settings, including unrelated and mismatched related donors. [ABSTRACT FROM AUTHOR]

Stem cell mobilization by cytokines and peptide drugs contributes to wound healing in injured tissues. Owing to the short half-life of cytokines and short peptides in vivo, precisely predicting the in vivo therapeutic efficacy of stem cell mobilizers is difficult using current in vitro models. To address this problem, we developed a multichannel microfluidic device with diffusion barriers to recapitulate drug gradients in an in vivo-like environment. We investigated the effects of Substance P (SP), a stem cell mobilizer, on the migration of human bone marrow-derived mesenchymal stem cells (BM-MSCs) in the microfluidic chip, which replicated in vivo drug gradients. Simulations of SP concentration indicated that our microfluidic chip established SP gradients in migration channels, unlike the existing scratch model for cell migration assays. The scratch model did not distinguish the effects of SP with a short half-life and PEGylated SP with an extended half-life on BM-MSC migration, whereas the microfluidic system demonstrated that PEG-SP affected BM-MSC migration more than SP. Furthermore, the microfluidic chip allowed accurate quantification of the distance and direction of BM-MSC migration. Our microfluidic system could be useful for the precise evaluation of drugs associated with cell migration and mobilization. [ABSTRACT FROM AUTHOR]

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Simple Summary: High-dose chemotherapy (HDCT) followed by autologous stem cell transplantation (ASCT) is the standard consolidation strategy for patients with newly diagnosed multiple myeloma (MM), as well as for a subset of patients with relapsed/refractory disease. ASCT reduces the duration of myelosuppression induced by HDCT. Chemotherapy agents combined with granulocyte-colony stimulating factors (G-CSF), as well as plerixafor, are key components of currently used stem cell mobilization regimens. However, chemotherapy mobilizing agents are associated with risk of infectious complications and peripheral neuropathy, which is as well a common toxicity of many drugs used in MM treatment. Ixazomib is an oral proteasome inhibitor and has lower neurotoxic potential. We for the first time combined ixazomib with G-CSF (filgrastim) for stem cell mobilization in patients with MM undergoing HDCT and ASCT, and assessed safety and efficacy of this mobilization strategy. Ixazomib was globally well tolerated and no new toxicities have been observed. The combination of ixazomib and G-CSF showed promising stem cell mobilizing activity and led to successful stem cell mobilization in 17 out of 19 (89%) patients. However, 9 (47%) patients required the addition of plerixafor to ensure optimal stem cell collection. Future larger studies might further investigate the role of ixazomib in stem cell mobilization regimens for MM. (1) Background: High-dose chemotherapy (HDCT) followed by autologous stem cell transplantation (ASCT) is the standard consolidation strategy for patients with newly diagnosed multiple myeloma (MM) and for a subset of patients with relapsed/refractory disease. For stem cell mobilization, G-CSF alone or in combination with chemotherapy mobilizing agents and/or plerixafor are commonly used. Ixazomib is an oral proteasome inhibitor with less neurotoxic potential, which previously showed the ability to mobilize stem cells in preclinical studies. (2) Methods: Prospective single-center phase 1 study assessing the efficacy and safety of stem cell mobilization with ixazomib and G-CSF in patients with newly diagnosed or relapsed/refractory MM undergoing HDCT and ASCT. Primary endpoint was percentage of patients achieving a yield of at least 6.0 × 106/kg CD34+ cells within the first apheresis. G-CSF (filgrastim) 10 μg/kg/day was administered subcutaneously (s.c.) from day 1 to day 5 (planned apheresis) and ixazomib 4 mg orally at day 4. Plerixafor 24 mg s.c. was administered if the stem cell mobilization with ixazomib and G-CSF was not sufficient. (3) Results: 19 patients were treated within the study between 06/2020 and 02/2021. The primary endpoint was reached in 17 (89%) patients, with a median of 7.1 × 106/kg CD34+ cells collected within the first apheresis, comparable to previously published results, and only 2 (11%) patients required a second apheresis. Median number of circulating CD34+ cells was 14.0 × 106/L (2.0–95.2) before the administration of ixazomib, and 33.0 × 106/L (4.2–177.0) pre-apheresis. However, 9 (47%) patients required the addition of plerixafor to ensure optimal stem cell collection. (4) Conclusions: The combination of ixazomib and G-CSF showed promising stem cell mobilizing activity in patients with MM prior to HDCT and ASCT. Future larger studies might further investigate the role of ixazomib in stem cell mobilization regimens for MM. [ABSTRACT FROM AUTHOR]

Introduction: Autologous hematopoietic stem cell transplantation (ASCT) is a well-established treatment for patients with multiple myeloma (MM), and adequate stem cell collection must be assured before ASCT. However, prediction of poor mobilizers (PMs) is still difficult despite several risk factors for mobilization failure having been identified. Methods: We retrospectively analyzed MM patients at Taipei Veterans General Hospital in Taiwan who underwent stem cell collection between October 2006 and August 2020. A CD34+ cell collection of <1 × 106 cells/kg was defined as a mobilization failure. The primary endpoint was mobilization failure. The secondary endpoint was overall survival (OS). Odds ratios (ORs) and 95% confidence intervals (CIs) for mobilization failure were calculated using a logistic regression model. The cumulative incidence of mortality was estimated using the Kaplan-Meier method. Results: In the multivariate analysis, absolute monocyte count <500/µL (adjusted OR 10.75, 95% CI: 1.82–63.57, p = 0.009), platelet count <150,000/µL (adjusted OR 12.49, 95% CI: 2.65–58.89, p = 0.001) before mobilization, and time interval from diagnosis to stem cell harvest ≥180 days (adjusted OR 7.69, 95% CI: 1.61–36.87, p = 0.011) were risk factors for PMs. PM patients had poorer OS compared to patients with successful stem cell collection in the univariate analysis (log-rank test p = 0.027). The predicted probability of PMs was estimated by the multiple logistic regression model with a sensitivity of 84.6% and a specificity of 84.0%. Conclusion: Absolute monocyte count <500/µL, platelet count <150,000/µL, and treatment duration more than 180 days before stem cell mobilization are risk factors for unsuccessful stem cell collection. Our prediction models have high sensitivity and specificity for mobilization failure prediction and allow for early interventions for possible PMs. [ABSTRACT FROM AUTHOR]

Salvage immunochemotherapy and transplant consolidation is the standard treatment for relapsed or refractory (R/R) diffuse large B‐cell lymphoma (DLBCL). We tested a combination of Obinutuzumab and DHAP for treating R/R DLBCL. The primary end point was the rate of complete metabolic response (CMR). Secondary end points were stem cell mobilization, stem cell engraftment, overall survival, and feasibility. In this prospective, phase‐2, single‐arm trial (EudraCT 2014‐004014‐17) patients received the standard three doses of Obinutuzumab for the first cycle, and then one dose. Patients with CMR were consolidated with an autologous stem cell transplantation (ASCT). An interim analysis was provided after the first 29 patients to confirm the initial null hypothesis that at least 10/29 patients would achieve CMR. Among the 29 patients evaluated for the first stage only six patients (6/29, 21%) achieved CMR, thus, study enrollment was stopped. Nine patients exhibited extra‐hematologic toxicities ≥ grade 3. Among the 19 patients that started stem cell mobilization, one failed (5%) and 18 achieved mobilization (95%). Of these 18 patients, nine were reinfused. Mobilization was observed in 16 patients (89%) after one or two apheresis rounds. The mean number of CD34 + cells mobilized was 5.8 × 106/Kg (median: 5.5, IQR: 5–6.75). The mean number of reinfused CD34 + cells in the nine patients was 4.1 × 106/Kg (median: 4.1, IQR: 3.5–5). Obinutuzumab combined with DHAP did not compromise stem cell mobilization or engraftment after ASCT in patients with DLBCL. However, Obinutuzumab + DHAP provided a lower CMR rate than expected. [ABSTRACT FROM AUTHOR]

Inflammation and stem cell mobilization or homing play pivotal roles in tissue repair and regeneration. This review explores their intricate interplay, elucidating their collaborative role in maintaining tissue homeostasis and responding to injury or disease. While examining the fundamentals of stem cells, we detail the mechanisms underlying inflammation, including immune cell recruitment and inflammatory mediator release, highlighting their self-renewal and differentiation capabilities. Central to our exploration is the modulation of hematopoietic stem cell behavior by inflammatory cues, driving their mobilization from the bone marrow niche into circulation. Key cytokines, chemokines, growth factors, and autophagy, an intracellular catabolic mechanism involved in this process, are discussed alongside their clinical relevance. Furthermore, mesenchymal stem cell homing in response to inflammation contributes to tissue repair processes. In addition, we discuss stem cell resilience in the face of inflammatory challenges. Moreover, we examine the reciprocal influence of stem cells on the inflammatory milieu, shaping immune responses and tissue repair. We underscore the potential of targeting inflammation-induced stem cell mobilization for regenerative therapies through extensive literature analysis and clinical insights. By unraveling the complex interplay between inflammation and stem cells, this review advances our understanding of tissue repair mechanisms and offers promising avenues for clinical translation in regenerative medicine., Competing Interests: Dr. Hsin-Hou Chang, an editorial board member at the Tzu Chi Medical Journal, had no role in the peer review process or the decision to publish this article. The other authors declared no conflicts of interest in writing this article., (Copyright: © 2024 Tzu Chi Medical Journal.)

There is wide interindividual variation in the efficacy of CD34 + cell mobilization and collection in healthy allogenic hematopoietic stem cell donors. Donor characteristics, blood cell counts, and various factors related to mobilization and collection have been associated with blood CD34 + cell count and CD34 + cell yield after granulocyte colony-stimulating factor (G-CSF) mobilization and collection. Given the heterogenous nature of the literature reporting these associations, in this scoping review we clarify the determinants of CD34 + count and yield. Studies published between 2000 and 2023 reporting allogeneic donors undergoing G-CSF mobilization and peripheral blood stem cell (PBSC) collection were evaluated. Eligible studies were those that assessed blood CD34 + cell count or CD34 + cell yield in the first PBSC collection after mobilization with 4 or 5 days of G-CSF treatment. Associations were recorded between these outcomes and donor factors (age, sex, weight, ethnicity), mobilization factors (G-CSF scheduling or dose), collection factors (venous access, processed blood volume [PBV]) or laboratory factors (blood cell counts at baseline or after mobilization). The 52 studies evaluated between 15 and 20,884 donors. Forty-three studies were retrospective, 33 assessed blood CD34 + cell counts, and 39 assessed CD34 + cell yield from PBSCs. Blood CD34 + cell counts consistently predicted CD34 + cell yield. Younger donors usually had higher blood CD34 + cell counts and CD34 + cell yield. Most studies that investigated the effect of donor ancestry found that donors of non-European ancestry had higher blood CD34 + cell counts after mobilization and higher CD34 + cell yields from collection. The poor consensus about the best predictors of blood CD34 + cell count and yield necessitates further prospective studies, particularly of the role of donor ancestry. The current focus on donor sex as a major predictor requires re-evaluation., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background: Ewing sarcoma is one of the most frequent soft-tissue tumors in pediatric patients. The current treatment protocols recommend stem cell apheresis (SCA) after completion of the second course of induction therapy with vincristine, ifosfamide, doxorubicine, and etoposide (VIDE). The feasibility of SCA and graft compositions in adult patients with Ewing sarcoma have not been previously analyzed.Methods and Materials: The authors analyzed 29 stem cell collections of 19 adult patients (9 male, 10 female) at a median age of 27 (range 19-53) years mobilized after VIDE (n = 17), cyclophosphamide/topotecan (n = 1) or vincristine, dactinomycin and ifosfamide (n = 1) chemotherapy. All patients were mobilized with filgrastim 5 μg/kg twice daily from day +7 of chemotherapy. The collections were performed if CD34+ cell count in peripheral blood was >10/μL. The target yields were ≥4×106 CD34+ cells/kg body weight.Results: Median CD34+ cells/μL in peripheral blood before SCA were 45.8 (range 6.7-614.4)/μL. The median cumulative yields were 10.6 (range 1.5-38.8) CD34+ cells/kg body weight and ≥2×106 in all but two patients (89%). CD34, CD3, and CD56 yields in collections after the third VIDE and after later courses did not differ. Four patients underwent high-dose therapy with autologous transplantation, and all were engrafted.Discussion: Stem cell mobilization is feasible in most Ewing sarcoma patients. Additionally, the present study's data suggest that it is safe to postpone stem cell collection to a later VIDE chemotherapy cycle if medically indicated. [ABSTRACT FROM AUTHOR]

Introduction. Our previous research demonstrated P2X purinergic receptors as important extracellular adenosine triphosphate (eATP) sensing receptors promoting the trafficking of hematopoietic stem progenitor cells (HSPCs). Accordingly, mice deficient in expression of P2X4 and P2X7 receptors turned out to mobilize poorly HSPCs. Similarly, defective expression of these receptors on transplanted HSPCs or in the bone marrow (BM) microenvironment of graft recipient mice led to defective homing, engraftment, and delayed hematopoietic reconstitution. This correlated with decreased activation of intracellular pattern recognition receptor Nlrp3 inflammasome. The P2X receptor family consists of seven purinergic receptors (P2X1-7) and we noticed that in addition to P2X4 and P2X7, HSPCs also highly express rapidly signaling the P2X1 receptor. Therefore, we asked if P2X1 receptor is also involved in HSPCs trafficking. Material and methods. We employed in vitro and in vivo murine models to study the role of P2X1 receptor blocked on HSPCs or bone marrow microenvironment cells by specific small molecular inhibitor NF499. First, we performed in vitro cell migration assays of bone marrow mononuclear cells (BMMNCs) isolated from normal mice that were exposed to NF499 and compared them to unexposed control cells. Next, in experiments in vivo we mobilized mice exposed to NF499 with G-CSF or AMD3100 and compared mobilization to control unexposed animals. Flow cytometry was employed to identify cell populations and clonogenic assays to enumerate the number of mobilized clonogenic progenitors. Similarly, in homing and engraftment experiments BMMNCs or recipient mice were exposed to NF499 and we evaluated homing and engraftment of transplanted cells by enumerating the number of cells labeled with fluorochromes in recipient mice BM and by evaluating the number of clonogenic progenitors in BM and spleen 24 hours and 12 days after transplantation. We also evaluated the potential involvement of Nlrp3 inflammasome in P2X1 receptor-mediated HSPCs trafficking. Results. We report that the functional P2X1 receptor is highly expressed on murine and human HSPCs. We could demonstrate that the P2X1 receptor promotes the trafficking of murine cells in Nlrp3 inflammasome-dependent manner. Mice after exposure to P2X1 receptor inhibitor poorly mobilized HSPCs from the bone marrow into the peripheral blood. Mice transplanted with BMNNCs exposed to NF499 or recipient mice pretreated with this inhibitor demonstrated defective homing and engraftment as compared to control animals transplanted with cells not exposed to P2X1 inhibitor. Similar effects were noticed for control recipient mice that were not exposed to NF499. Conclusions. This study demonstrates for the first time the novel role of the P2X1 receptor in HSPCs trafficking in the mouse. Furthermore, it supports an important role of purinergic signaling engaging its downstream target Nlrp3 inflammasome in the mobilization, homing and engraftment of HSPCs. (Folia Histochemica et Cytobiologica 2022, Vol. 60, No. 3, 280-290). [ABSTRACT FROM AUTHOR]

Background and Objectives: Implementation of the technique of immunomagnetic selection requires the procurement of a large number of CD34+ cells from haploidentical donors within a single apheresis procedure. The release of stem cells with granulocyte colony‐stimulating factor (G‐CSF) alone is unsatisfactory in a number of donors, and plerixafor, a CXCR4 chemokine receptor antagonist, could be used as an additional mobilization agent. The aim of our study was to examine whether a lower dose of plerixafor (0.12 mg/kg) can provide sufficient increase in CD34+ cells in the peripheral blood of allogeneic healthy donors in comparison with a historical control group. In addition, we assessed the risk of inability to provide the recipient with a transplant containing the optimal dose of 8–10 × 106 CD34+ cells/kg body weight of the recipient. Materials and Methods: In a prospective, single‐arm study, we examined the results of 105 mobilizations in healthy adult haploidentical donors with G‐CSF and plerixafor at a dose of 0.12 mg/kg. The historical control group consisted of 106 mobilizations with G‐CSF and plerixafor at 0.24 mg/kg. Results: The median increase in the number of CD34+ cells from day 4 to day 5 of mobilization was 69 cells/μl (range, 28–240) versus 77 cells/μl (24–217) in the groups of 0.12 and 0.24 mg/kg of plerixafor, respectively (p‐value 0.255). The apheresis products contained a median of 14.4 × 106/kg recipient body weight CD34+ cells versus 12.9 × 106/kg in the groups that received 0.12 and 0.24 mg/kg of plerixafor, respectively (p‐value 0.118). The obtained differences were not significant, which means the application of a decreased dose of plerixafor did not affect the results of mobilization. Conclusion: The obtained differences in collection were not significant, and thus the application of a decreased dose of plerixafor did not affect the results of mobilization. [ABSTRACT FROM AUTHOR]

In April 2014, the Japan Society for Hematopoietic Cell Transplantation started a prospective observational study entitled "A short-term follow-up investigation of related hematopoietic stem cell donors receiving biosimilar G-CSF to mobilize peripheral blood stem cells." A total of 106 donors were registered from 25 transplant facilities through the end of March 2017. The study cohort consisted of 47 men and 58 women, and their median age was 38.5 years (range 15–65 years). The mean total count of collected CD34-positive cells/recipient body weight for all 106 donors was 4.40 ± 2.38 × 10 6/kg. The yield of CD34-positive cells was weakly correlated with donor age was observed. However, gender, WBC count on day 4, G-CSF dose reduction, type of apheresis device, collection speed, and treated blood volume had no significant impact on the collection efficacy of CD34-positive cells. The safety profile of biosimilar G-CSF was also acceptable: 126 adverse events in 73 donors were reported, but none was serious. The most common adverse events were low back pain, headache, and bone pain. This prospective study confirmed that biosimilar G-CSF had comparable efficacy and safety to reference G-CSF for CD34-positive cell mobilization in healthy related donors. [ABSTRACT FROM AUTHOR]

Objective: Autologous stem cell transplantation (ASCT) is a significant and potentially curative treatment modality for patients with relapsed/refractory lymphoma. Insufficient mobilization and harvest of peripheral stem cells can be a major obstacle for performing ASCT. The aim of this study was to evaluate the factors which might influence mobilization failure in patients with lymphoma. Materials and Methods: Eighty-seven patients with diagnosed non-Hodgkin and Hodgkin lymphoma who underwent stem cell mobilization after at Hacettepe University Medical School, Bone Marrow Transplantation Center, Turkey, between the years of 2000 and 2018 were evaluated. Results: A total of 87 patients were included in this study. In 66 of 87 patients (75.9%) first mobilization trial was successful. Adequate (≥2 × 106/kg) CD34+ cells were collected at first apheresis in 66 patients (9.5+-8.1). In 21 of 87 (24.1%) first mobilization trial was unsuccessful. Therefore, a second mobilization trial was made to these patients with plerixafor (5.5+-3.3). The number of CD34+ cell was significantly higher in patients who were successful in the first mobilization (p=0.002). Conclusion: The success rate of the first mobilization trial was found to be higher in patients with high platelet counts before mobilization and patients who received chemotherapy-based mobilization protocols. In the patients who had mobilization failure in the first trial, plerixafor was used in a later mobilization, and those patients had an adequate amount of stem cells for ASCT. Parameters predicting mobilization failure would allow for preemptive, more cost-effective use of such agents during the first mobilization attempt; however, risk factors for mobilization failure are still not clear.

Yavuz M Bilgin Department of Internal Medicine/Hematology, Admiraal de Ruijter Hospital, Goes, the NetherlandsCorrespondence: Yavuz M BilginDepartment of Internal Medicine/Hematology, Admiraal de Ruijter Hospital, PO Box 15, Goes, 4460 AA, the NetherlandsTel +31-88-1250000Email y.bilgin@adrz.nlAbstract: Mobilization failure is an important issue in stem cell transplantations. Stem cells are yielded from the peripheral blood via apheresis. Granulocyte colony-stimulating factor (G-CSF) is the most commonly used mobilization agent among patients and donors. G-CSF is administered subcutaneously for multiple days. However, patients with mobilization failure cannot receive autologous stem cell transplantation and, therefore, cannot be treated adequately. The incidence rate of mobilization failure among patients is about 6– 23%. Plerixafor is a molecule that inhibits the binding of chemokine receptor-4 with stromal-cell-derived factor-1, thereby resulting in the release of CD34+ cells in the peripheral blood. Currently, plerixafor is used in patients with mobilization failure with G-CSF and is administered subcutaneously. Several studies conducted on different clinical settings have shown that plerixafor is effective and well tolerated by patients. However, more studies should be conducted to explore the optimal approach for plerixafor in patients with mobilization failure. The incidence of mobilization failure among donors is lower. However, plerixafor is not approved among donors with mobilization failure. Moreover, several clinical studies in donors have shown a beneficial effect of plerixafor. In addition, the adverse events of plerixafor are mild and transient, which can overcome the adverse events due to G-CSF. This review assessed the current role and effects of plerixafor in stem cell mobilization for autologous and allogeneic stem cell transplantations.Keywords: stem cell mobilization, apheresis, autologous stem cell transplantation, allogeneic stem cell transplantation

This research is to investigate the parameters which may affect the mobilization of stem cells in patients receiving autologous hematopoietic peripheral blood stem cell transplantation (PBSCT). A retrospective study was carried out using the data derived from the medical files of 242 patients who received PBSCT. Descriptive, clinical, and laboratory parameters were compared between patients with successful and unsuccessful stem cell mobilization. Successful stem cell mobilization ratio was 4.463 times higher when preemptive plerixafor was administrated; 1.032 times higher when CD34+ cell count increased 1 unit at the beginning of mobilization. The white blood cell count was inversely correlated with the success of mobilization. An increase of 1 unit in WBC count was associated with a 1.027 times decrease in the success rate. The data indicated that the administration of preemptive plerixafor and CD34+ cell count at the beginning of mobilization were directly related to the success of mobilization after PBSCT. On contrary, WBC count was inversely associated with the success rate.

Bilgin YM. J Blood Med. 2021;12:403–412. The author wishes to advise of an error in the units of measurement for CD34 concentrations which were shown as 109/L but should have been 106/L throughout the paper. The author apologizes for any inconvenience and advises it does not affect the results of the paper.

Background: Efficient mobilization of CD34+ hematopoietic stem cells plays a vital role in successful autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM), especially in cases with high-risk cytogenetic recommended for tandem ASCT. However, the optimal mobilization strategy remains a matter of debate in the era of lenalidomide. The combination of etoposide with Cytarabine plus G-CSF as a novel mobilization regimen in MM has not been reported previously. Methods: This research retrospectively studied mobilization efficacy and safety using etoposide combined with Cytarabine (etoposide 50–100 mg/m2, qd d1–3; AraC 0.5 g/m2, q12h d1~3) plus G-CSF (5 µg/kg/day, from d5 until the day of apheresis) in 128 patients with MM. 70(54.7%) patients received lenalidomide-based induction regimens treatment Results: A median of 27.75×106 CD34+ cells/kg was collected in the first apheresis, and 28.23×106 CD34+ cells/kg were collected overall. Of the 128 patients, all achieved adequate collection (≥2×106 CD34+ cells/kg), 121(94.5%) achieved optimal collection for single ASCT (≥5×106 CD34+ cells/kg), and 114(89.1%) harvested optimal collection for tandem ASCT (≥10×106 CD34+ cells/kg). In particular, the target yield of optimal collection for tandem ASCT was reached in 82.8% (106/128) by a single apheresis procedure. 14 patients obtained deeper response post mobilization. In multivariate analysis, cycles of prior chemotherapy independently affected the optimal achievement of CD34+ cells (p =0.004, OR 0.695, 95% CI 0.544~0.888). Previous lenalidomide exposure did not significantly impair CD34+ cells collection. Although 68% episodes of antibiotic usage were observed, no severe infection or treatment-related mortality occurred. Conclusion: Stem cell mobilization with Etoposide + Cytarabine plus G-CSF was highly efficient and safe in patients with MM, which could be considered in high-risk MM patients who were referred for tandem ASCT. [ABSTRACT FROM AUTHOR]

Acute exercise enhances circulating stem and precursor cells (CPCs) in the peripheral blood. The responsible mechanisms and molecular pathways, however, have not been fully identified. The aim of the present study was to investigate a pathway related to elevated levels of apoptotic peripheral blood mononuclear cells (MNCs) and their secretome. An increased uptake of miRNA126 in MNCs was suggested to lead to reduced levels of RGS16 mRNA and, in turn, an enhanced translation and secretion of CXCL12. Eighteen healthy, young men underwent two identical incremental cycling exercises of which the first served as control while the second was preceded by a 7-day-long antioxidative supplementation. Blood samples were collected at baseline (−10min) and several time points after exercise (0, 30, 90, 180, and 270min). Relative concentrations of miRNA126 in MNCs and CXCL12 levels in plasma were determined at all time points while RGS16 mRNA was assessed in MNCs at baseline and 30min after exercise. CXCL12 increased after exercise and strongly correlated with CPC numbers. MiRNA126 increased 30min and, to a lesser extent, also 180 and 270min after exercise but only with supplementation. RGS16 mRNA decreased 30min after exercise independent of the intervention. The amount of RGS16 mRNA inversely correlated with levels of miRNA126, but not with plasma CXCL12. In conclusion, even though plasma CXCL12 correlated with CPC numbers, the increase in CXCL12 cannot be explained by the increased concentration of miRNA126 and lower RGS16 mRNA in MNCs that would have allowed for an enhanced translation of CXCL12. Clinical Trial Registration: ClinicalTrials.gov, NCT03747913. Registered 20 November 2018, https://clinicaltrials.gov/ct2/show/NCT03747913. [ABSTRACT FROM AUTHOR]

Based on positive results from small single center studies, granulocyte-colony stimulating factor (G-CSF) is being widely used for the treatment of patients with acute-on-chronic liver failure (ACLF). Herein, we aimed to evaluate the safety and efficacy of G-CSF in patients with ACLF. In this multicenter, prospective, controlled, open-label phase II study, 176 patients with ACLF (EASL-CLIF criteria) were randomized to receive G-CSF (5 μg/kg daily for the first 5 days and every third day thereafter until day 26) plus standard medical therapy (SMT) (n = 88) or SMT alone. The primary efficacy endpoint was 90-day transplant-free survival analyzed by Cox regression modeling. The key secondary endpoints were overall and transplant-free survival after 360 days, the development of ACLF-related complications, and the course of liver function scores during the entire observation period. Patients treated with G-CSF had a 90-day transplant-free survival rate of 34.1% compared to 37.5% in the SMT group (hazard ratio [HR] 1.05; 95% CI 0.711–1.551; p = 0.805). Transplant-free and overall survival at 360 days did not differ between the 2 arms (HR 0.998; 95% CI 0.697–1.430; p = 0.992 and HR 1.058; 95% CI 0.727–1.548; p = 0.768, respectively). G-CSF did not improve liver function scores, the occurrence of infections, or survival in subgroups of patients without infections, with alcohol-related ACLF, or with ACLF defined by the APASL criteria. Sixty-one serious adverse events were reported in the G-CSF+SMT group and 57 were reported in the SMT group. In total, 7 drug-related serious adverse reactions occurred in the G-CSF group. The study was prematurely terminated due to futility after conditional power calculation. In contrast to previous findings, G-CSF had no significant beneficial effect on patients with ACLF in this multicenter controlled trial, which suggests that it should not be used as a standard treatment for ACLF. NCT02669680 Granulocyte-colony stimulating factor was considered as a novel treatment for acute-on-chronic liver failure (ACLF). We performed the first randomized, multicenter, controlled phase II trial, which showed that G-CSF did not improve survival or other clinical endpoints in patients with ACLF. Therefore, G-CSF should not be used to treat liver disease outside clinical studies. [Display omitted] • G-CSF was expected to be a novel therapy for acute-on-chronic liver failure. • In this first multicenter, randomized phase II trial, G-CSF did not improve patient survival. • G-CSF was unable to reduce the rate of complications and did not improve organ function. [ABSTRACT FROM AUTHOR]

Abstract Introduction Biosimilars of granulocyte colony-stimulating factors (G-CSF) have shown similar efficacy to originator filgrastim (Neupogen® [NEU]; Amgen Inc.) as prophylaxis in neutropenia and in the mobilization of stem cells in patients receiving combination chemotherapy with G-CSF. Methods This was a retrospective study in which the characteristics of stem cell mobilization treated with a G-CSF alone were compared in 216 patients and 56 donors. The two G-CSF compared were NEU and the biosimilar filgrastim Zarzio® (Sandoz GmbH) (referred to hereafter as BIO). Primary objectives were mobilization rate (minimum of 10 × 103/ml CD34+ on day 4 of treatment [day +4]) and use of the immunostimulant plerixafor (PLEX) in each group. Results The general characteristics of the patients receiving NEU (n = 138) and those receiving BIO (n = 78) did not differ significantly. PLEX was used in 24% of BIO patients and in 25.7% of NEU patients. The median CD34+ cell count on day +4 was significantly lower in BIO patients who needed PLEX than in those who did not (2.4 vs. 4.8 × 103/ml; p = 0.002), as was the final CD34+ cell count (2.5 vs. 3.3 × 106/kg; p 0.03). Mobilization failure rate was higher in the BIO group than in the NEU group (20 vs. 0%; p = 0.01). With respect to donors, more than one apheresis was needed in three BIO donors, one of them with PLEX. The use of BIO was the only risk factor for mobilization failure in patients who needed PLEX (hazard ratio 10.3; 95% confidence interval 1.3–77.8). Conclusion The study revealed that BIO had a lower efficacy for stem cell mobilization when the only treatment was G-CSF, especially in poor mobilizers needing PLEX.

BackgroundEfficient mobilization of CD34+ hematopoietic stem cells plays a vital role in successful autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM), especially in cases with high-risk cytogenetic recommended for tandem ASCT. However, the optimal mobilization strategy remains a matter of debate in the era of lenalidomide. The combination of etoposide with Cytarabine plus G-CSF as a novel mobilization regimen in MM has not been reported previously.MethodsThis research retrospectively studied mobilization efficacy and safety using etoposide combined with Cytarabine (etoposide 50–100 mg/m2, qd d1–3; AraC 0.5 g/m2, q12h d1~3) plus G-CSF (5 µg/kg/day, from d5 until the day of apheresis) in 128 patients with MM. 70(54.7%) patients received lenalidomide-based induction regimens treatmentResultsA median of 27.75×106 CD34+ cells/kg was collected in the first apheresis, and 28.23×106 CD34+ cells/kg were collected overall. Of the 128 patients, all achieved adequate collection (≥2×106 CD34+ cells/kg), 121(94.5%) achieved optimal collection for single ASCT (≥5×106 CD34+ cells/kg), and 114(89.1%) harvested optimal collection for tandem ASCT (≥10×106 CD34+ cells/kg). In particular, the target yield of optimal collection for tandem ASCT was reached in 82.8% (106/128) by a single apheresis procedure. 14 patients obtained deeper response post mobilization. In multivariate analysis, cycles of prior chemotherapy independently affected the optimal achievement of CD34+ cells (p=0.004, OR 0.695, 95% CI 0.544~0.888). Previous lenalidomide exposure did not significantly impair CD34+ cells collection. Although 68% episodes of antibiotic usage were observed, no severe infection or treatment-related mortality occurred.ConclusionStem cell mobilization with Etoposide + Cytarabine plus G-CSF was highly efficient and safe in patients with MM, which could be considered in high-risk MM patients who were referred for tandem ASCT.

Acute exercise enhances circulating stem and precursor cells (CPCs) in the peripheral blood. The responsible mechanisms and molecular pathways, however, have not been fully identified. The aim of the present study was to investigate a pathway related to elevated levels of apoptotic peripheral blood mononuclear cells (MNCs) and their secretome. An increased uptake of miRNA126 in MNCs was suggested to lead to reduced levels of RGS16 mRNA and, in turn, an enhanced translation and secretion of CXCL12. Eighteen healthy, young men underwent two identical incremental cycling exercises of which the first served as control while the second was preceded by a 7-day-long antioxidative supplementation. Blood samples were collected at baseline (−10min) and several time points after exercise (0, 30, 90, 180, and 270min). Relative concentrations of miRNA126 in MNCs and CXCL12 levels in plasma were determined at all time points while RGS16 mRNA was assessed in MNCs at baseline and 30min after exercise. CXCL12 increased after exercise and strongly correlated with CPC numbers. MiRNA126 increased 30min and, to a lesser extent, also 180 and 270min after exercise but only with supplementation. RGS16 mRNA decreased 30min after exercise independent of the intervention. The amount of RGS16 mRNA inversely correlated with levels of miRNA126, but not with plasma CXCL12. In conclusion, even though plasma CXCL12 correlated with CPC numbers, the increase in CXCL12 cannot be explained by the increased concentration of miRNA126 and lower RGS16 mRNA in MNCs that would have allowed for an enhanced translation of CXCL12.Clinical Trial Registration: ClinicalTrials.gov, NCT03747913. Registered 20 November 2018, https://clinicaltrials.gov/ct2/show/NCT03747913.