Peripheral Blood Progenitor Cells Research Articles

Association between polymorphism in the MTHFR gene and encephaloduroarteriosynangiosis-induced collateral circulation formation.

This study aimed to investigate whether high homocysteine (Hcy) levels associated with the MTHFR gene influence the formation of the collateral vascular network in patients with moyamoya disease (MMD) after encephaloduroarteriosynangiosis (EDAS) by influencing the number of endothelial progenitor cells (EPCs) in peripheral blood. A total of 118 Chinese patients with bilateral primary MMD were prospectively included. Blood samples were collected from the anterior cubital vein before surgery, and MTHFR rs9651118 was genotyped using high-throughput mass spectrometry to determine the genotype of the test specimen. Serum Hcy and EPC levels were measured, the latter with flow cytometry. Digital subtraction angiography was performed 6 months after EDAS, and the formation of collateral circulation was evaluated using the Matsushima grade system. The correlations between MTHFR rs9651118 genotype, Hcy and EPC levels, and Matsushima grade were compared. Among the 118 patients, 53 had the TT genotype (wild type) of MTHFR rs9651118, 33 TC genotype (heterozygous mutation), and 32 CC genotype (homozygous mutation). The mean ± SD Hcy level was 13.4 ± 9.5 μmol/L in TT patients, 9.8 ± 3.2 μmol/L in TC patients, and 8.9 ± 2.9 μmol/L in CC patients (p < 0.001). The level of EPCs in the venous blood of TT patients was 0.039% ± 0.016%, that of TC patients 0.088% ± 0.061%, and that of CC patients 0.103% ± 0.062% (p < 0.001). When the rs9651118 gene locus was mutated, Matsushima grade was better (p < 0.001) but there was no difference between heterozygous and homozygous mutations. The results suggest that the MTHFR rs9651118 polymorphism is a good biomarker for collateral vascular network formation after EDAS in MMD patients.

Evaluation of blood cell count using an automatic hematology analyzer to optimize collection of peripheral blood progenitor cells by leukapheresis

BackgroundAutologous stem cell transplantation is a treatment modality for several diseases. Prediction of successful mobilization may be useful to optimize hematopoietic stem cell collection. Study design and methodsThis was a retrospective study with data from transplantation candidates between September 2015 and December 2021 being analyzed. The medical record of each patient was reviewed to mine mobilization information. The laboratory data analyzed were CD34+ cell enumeration and pre-collection peripheral blood cell count. The primary outcome, good mobilization, was defined as a CD34+ cell count ≥20/μL. ResultsThis study included 807 patients. Increased patient weight, low mean corpuscular volume, high nucleated red blood cells, peripheral blood mononuclear cell and immature granulocyte counts were significantly associated with good mobilization. In addition, patients diagnosed with multiple myeloma were two times more likely to be good mobilizers than patients with lymphoma. The model was applied to a validation set to identify patients who underwent apheresis (CD34+ cell count ≥10 µL), resulting in a sensitivity of 69 %, a specificity of 95 %, positive predictive value of 98 %, and a negative predictive value of 50 %. ConclusionSuccess in mobilization was greater in patients who underwent the first mobilization cycle and who had a diagnosis of multiple myeloma. Furthermore, greater body weight, and nucleated red blood cells, immature granulocytes and mononuclear cell counts, as well as low mean corpuscular volumes, were associated with successful mobilization.

Long Term Remission of Capillary Leak Syndrome Associated with Monoclonal Gammopathy with Progression to Multiple Myeloma After Autologous Stem Cell Transplantation: a Case Report and Review of the Literature.

Clarkson's disease is a very rare entity characterised by acute episodes of systemic oedema and severe hypotension associated with paraproteinaemia. Its classical treatment relies on methylxanthine combined with terbutaline. Although this prophylactic therapy reduces the mortality rate, relapses are frequent. Eighty percent of patients with Clarkson's disease present with monoclonal gammopathy of unknown significance (MGUS). The risk of progression to multiple myeloma is 1% per year. Here, we present a 49-year-old woman who suffered multiple such episodes requiring treatment in the intensive care unit. Treatment with terbutaline and theophylline was ineffective. She was diagnosed with multiple myeloma (MM) 8 years after the first of these acute episodes. Antimyeloma treatment with bortezomib and dexamethasone was started, followed by autologous haemopoietic transplantation, with no further acute episodes since then. Our case is, to our knowledge, unique because eradication of MM was followed by complete disappearance of acute episodes of capillary leakage. Our case report is also the first to support the use of bortezomib and dexamethasone in this setting. Furthermore, autologous peripheral blood progenitor cell transplantation consolidated the MM stringent complete remission achieving a very long progression-free survival (> 11 years) of both MM and Clarkson's disease.

Detection and Prevention of ADAR1p150-Induced Hematopoietic Stem and Progenitor Cell Aging

Introduction: Over the last decade, ADAR1p150 has been linked by our research team and others to malignant progenitor reprogramming and therapeutic resistance in a broad array of malignancies. However, ADAR1p150's role in accelerated hematopoietic stem and progenitor cell (HSPC) aging in response to inflammatory cytokines had not been clearly elucidated. Here, we investigate ADAR1 splice isoform switching and the ADAR1p150 inhibitory effects of Rebecsinib on human HSPC function in normal humanized aged normal bone marrow (aNBM) HSPC mouse models. Methods: Whole transcriptome RNA sequencing (RNA-seq) was utilized with splice isoform and editome analysis to detect ADAR1 splice isoform switching and adenosine to inosine RNA editing. Rebecsinib (17S-FD-895), a pre-IND drug candidate, has shown promising potential as an inhibitor of ADAR1p150-mediated RNA editing ( Crews, Ma...Jamieson. Cell Stem Cell 2023), which is an important therapeutic target in patients with myelofibrosis or acute myeloid leukemia that overexpress ADAR1p150 compared with ADAR1p110. Human CD34 + cells, isolated from aged normal bone marrow (aNBM) from patients undergoing elective hip replacement surgery, were transduced with a lentiviral ADAR1-nano-luciferase reporter and transplanted into NSG-SGM3 adult mice that secrete human SCF, IL-3, and GM-CSF cytokines that support normal hematopoiesis. After engraftment confirmation peripheral blood human CD45 flow cytometric assessment and IVIS 200 system imaging of ADAR1-nano-luc-GFP reporter expressing HSPC engraftment, the mice were randomly divided into vehicle-treated and Rebecsinib-treated groups (15mg/kg, twice a week for two weeks). Peripheral blood, bone marrow, and spleen were collected upon treatment completion for analysis. Results: By HSPC RNA-seq, we detected an imbalance between ADAR1p150 and ADAR1p110 expression together with increased RNA editing and splicing alterations using whole transcriptome RNA sequencing (RNA-seq) of aged compared with young bone marrow hematopoietic stem and progenitor cells (HSPCs). However, the functional relevance of ADAR1 splice isoform switching had not been evaluated in human-aged normal bone marrow HSPC xenograft (PDX) mouse models nor had this cytokine-induced HSPC aging been reversed. Flow cytometric analysis and immunohistochemistry staining revealed that Rebecsinib treatment at a dose of 10mg/kg, twice a week for two weeks, effectively spared normal human immune cells (CD3+, CD14+, and CD19+ cells). Remarkably, Rebecsinib treatment not only preserved Hematopoietic Stem (CD34+CD38-) cells and Progenitor (CD34+CD38+) cells in peripheral blood, bone marrow, and spleen but also promoted their expansion. These findings demonstrate the potential of Rebecsinib to enhance the retention of HSPC populations in the bone marrow niche. Conclusions: Our pre-clinical experiments utilizing RNA-seq, a novel ADAR1-nano-luciferase-GFP reporter, and aNBM PDX mouse models provide compelling evidence supporting the potential of Rebecsinib to restore the balance of ADAR1p150:p110 ratios and engraftment in humanized aNBM HSPC mouse models. These findings highlight Rebecsinib as a promising therapeutic candidate for targeting leukemia and myelofibrosis while preserving essential HSPC populations.

Effectiveness of single-dose 6 mg pegfilgrastim in mobilizing peripheral blood stem cells in allogeneic hematopoietic cell transplantation donors.

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.

Tibial cortex transverse transport potentiates diabetic wound healing via activation of SDF-1/CXCR4 signaling.

The current treatments for diabetic foot ulcers have disadvantages of slow action and numerous complications. Tibial cortex transverse transport (TTT) surgery is an extension of the Ilizarov technique used to treat diabetic foot ulcers, and can shorten the repair time of diabetic foot ulcers. This study assessed the TTT technique for its effectiveness in healing diabetic foot ulcer skin lesions and its related molecular mechanisms. Diabetic rat models were established by injecting healthy Sprague-Dawley rats with streptozotocin (STZ). The effects of TTT surgery on the model rats were assessed by recording changes in body weight, analyzing skin wound pictures, and performing H&E staining to assess the recovery of wounded skin. The numbers of endothelial progenitor cells (EPCs) in peripheral blood were analyzed by flow cytometry, and levels of CXCR4 and SDF-1 expression were qualitatively analyzed by immunofluorescence, immunohistochemistry, qRT-PCR, and western blotting. Both the histological results and foot wound pictures indicated that TTT promoted diabetic wound healing. Flow cytometry results showed that TTT increased the numbers of EPCs in peripheral blood as determined by CD34 and CD133 expression. In addition, activation of the SDF-1/CXCR4 signaling pathway and an accumulation of EPCs were observed in skin ulcers sites after TTT surgery. Finally, the levels of SDF-1 and CXCR4 mRNA and protein expression in the TTT group were higher than those in a blank or fixator group. TTT promoted skin wound healing in diabetic foot ulcers possibly by activating the SDF-1/CXCR4 signaling pathway.

Post-Transplant Cyclophosphamide for the Prevention of Graft-vs.-Host Disease in Allogeneic Hematopoietic Cell Transplantation: A Guide to Management for the Advanced Practitioner.

Cyclophosphamide remains a critical component to haploidentical transplant conditioning regimens. Post-transplant cyclophosphamide (PTCy) emerged as an effective component of graft-vs.-host disease (GVHD) prophylaxis in the nonmyeloablative haploidentical bone marrow transplant setting. The relative ease of administration compared with ex vivo manipulations and efficacy in reducing GVHD has led to increasing PTCy use in transplant centers around the world. The role of PTCy has expanded to haploidentical transplantation with myeloablative conditioning regimens and peripheral blood progenitor cells as the donor source. Moreover, encouraging results in GVHD management have been shown with the use of PTCy alone or in combination with other immunosuppressives in the human leukocyte antigen-matched donor setting. The toxicity profile of cyclophosphamide varies extensively depending on dose, duration, overall drug exposure, and, potentially, pharmacogenetics. This review highlights the pharmacology, pharmacokinetics, and toxic effects of cyclophosphamide and offers practical guidance for clinical application in the post-transplant setting. We summarize data on the management of high-dose cyclophosphamide toxicities and provide insights into the pharmacogenetic implications on drug efficacy and safety data.

Adverse events related to central venous catheters (CVC) and the influence of CVC characteristics on peripheral blood hematopoietic progenitor cell collection in children.

The use of peripheral blood progenitor cells (PBPCs) as a source for hematopoietic stem cell transplantation (HSCT) in pediatric healthy donors is still under debate. The risk of a central venous catheter (CVC) placement and catheter-related complications continue to be the main arguments to discourage its use. we present a retrospective analysis of 140 PBPC collections in pediatric patients and donors, describing adverse events (AE) related to CVCs as well as the influence of catheterrelated variables on the efficiency of the leukapheresis. 14 CVC-related AEs were recorded (10%). The most common was fever in 5 patients, 4 of which had a catheter-related bacteriemia. Thrombotic events were only observed in 3 patients with active malignancy. A healthy donor presented a moderate bleeding after catheter withdrawal that resolved with local measures, and none of the rest presented any AE. Regarding variables related to the development of AEs, the subject group (patient or donor) was the only one significantly associated (p < 0.0001). Of interest, efficiency was also related to catheter location, being worse in those located in the femoral vein than in into the jugular or the subclavian veins (p < 0.05). In a multivariate analysis, the only variable significantly associated was catheter size (beta 0.238, p < 0.01). Placing a CVC for PBPC collection in pediatric subjects is overall safe; CVC-related complications in pediatric healthy donors are very rare. Furthermore, we should try to place catheters of the largest caliber possible, since the efficiency of the collection is related to this variable.

Clonal hematopoiesis in patients with stem cell mobilization failure: a nested case-control study.

Inadequate mobilization of peripheral blood progenitor cells (PBPCs) is a limiting factor to proceeding with autologous hematopoietic cell transplantation (auto-HCT). To assess the impact of clonal hematopoiesis (CH) on mobilization failure of PBPC for auto-HCT, we investigated the characteristics of poor mobilizers (with a total PBPC collection <2× 106 CD34+ cells per kg) in a consecutive single-center cohort of 776 patients. Targeted error-corrected next-generation sequencing of 28 genes was performed in a nested case-control cohort of 90 poor mobilizers and 89 matched controls. CH was detected in 48 out of 179 patients (27%), with most patients carrying a single mutation. The presence of CH (detected at variant allele frequency [VAF] ≥ 1%) did not associate with poor mobilization potential (31% vs 22% in controls, odds ratio, 1.55; 95% confidence interval, 0.76-3.23; P= .238). PPM1D mutations were detected more often in poor mobilizers (P= .005). In addition, TP53 mutations in this cohort were detected exclusively in patients with poor mobilization potential (P= .06). The incidence of therapy-related myeloid neoplasms (t-MN) was higher among patients with mobilization failure (P= .014). Although poor mobilizers experienced worse overall survival (P= .019), this was not affected by the presence of CH. We conclude that CH at low VAF (1%-10%) is common at the time of stem cell mobilization. TP53 mutations and PPM1D mutations are associated with poor mobilization potential and their role in subsequent development of t-MN in these individuals should be established.

Umbilical Cord Blood Transplantation: Connecting Its Origin to Its Future.

Transplantation of umbilical cord blood (UCB) is an attractive alternative source of hematopoietic stem cells (HSCs). The unique properties of cord blood and its distinct immune tolerance and engraftment kinetics compared to bone marrow (BM) and peripheral blood progenitor cells, permit a wider disparity in human leukocyte antigen levels between a cord blood donor and recipient after an unrelated umbilical cord blood transplant (UCBT). In addition, it is readily available and has a lowered risk of graft-versus-host disease (GvHD), with similar long-term clinical outcomes, compared to BM transplants. However, the relatively low number of cells administered by UCB units, as well as the associated delayed engraftment and immune reconstitution, pose limitations to the wide application of UCBT. Research into several aspects of UCBT has been evaluated, including the ex vivo expansion of cord blood HSCs and the process of fucosylation to enhance engraftment. Additionally, UCB has also been used in the treatment of several neurodegenerative and cardiovascular disorders with varying degrees of success. In this article, we will discuss the biology, clinical indications, and benefits of UCBT in pediatric and adult populations. We will also discuss future directions for the use of cord blood.

233 - Impact of the COVID-19 Pandemic on Unrelated Allogeneic Hematopoietic Peripheral Blood Progenitor Cell Collections in Canada

233 - Impact of the COVID-19 Pandemic on Unrelated Allogeneic Hematopoietic Peripheral Blood Progenitor Cell Collections in Canada

Comparison between peripheral blood progenitor cell collection on the 4th or 5th day of granulocyte colony-stimulating factor treatment in allogeneic stem cell donors: implications for hematopoietic progenitor cell apheresis guidelines.

Comparison between peripheral blood progenitor cell collection on the 4th or 5th day of granulocyte colony-stimulating factor treatment in allogeneic stem cell donors: implications for hematopoietic progenitor cell apheresis guidelines.

RGI-2001 Infusion for Prevention of Acute Gvhd after Allogeneic Hematopoietic Cell Transplantation

Background Acute graft-versus-host disease (aGvHD) is a major cause of early morbidity after allogeneic hematopoietic cell transplantation (alloHCT). Despite the use of prophylactic immunosuppressive therapy, aGvHD occurs in 40% -60% of matched related and unrelated alloHCT and severe cases contribute to non-relapse mortality. RGI-2001 is a liposomal glycolipid that binds CD1d receptor of antigen-presenting cells (APC) resulting in activation of invariant natural killer (iNKT) cells. This interaction results in a cytokine-dependent Treg proliferation with subsequent modulation of the GvHD pathogenic cascade. RGI-2001 is being evaluated for the potential to reduce or prevent aGvHD after alloHCT. Earlier studies had shown that a single dose of RGI-2001 given on the day of hematopoietic cell transplantation was safe and potentially contributed to aGvHD prevention. Methods: RGI-2001-003 (NCT04014790) is an open-label, multi-center phase 2b study to evaluate the potential efficacy and safety of RGI-2001 when added to calcineurin inhibitor with methotrexate or mycophenolate mofetil (without T-cell depletion) for the prevention of aGvHD in subjects following myeloablative alloHCT. RGI-2001 was administered in a 30-minute infusion at a dose of 100 ug/kg IV infusion weekly x 6 doses, starting on the day of transplant (Days 0, 7, 14, 21, 28, 35). The primary endpoint of the phase 2b study was grade II-IV acute GVHD by Day 100. Results: A total of 53 subjects were screened and 49 treated at 7 U.S. transplant centers. Median age was 52 (range 21-65). The most common underlying indications for alloHCT were AML(n=27, 55%), ALL (n=11, 22%), and MDS (n=7, 14%). Donors were HLA-matched related (n=15), match unrelated (n=28) or mismatched unrelated (n=6, 5 HLA DQ and 1 HLA-A). Graft source was peripheral blood progenitor cells (n=40) or bone marrow (n=9). Common myeloablative conditioning regimens included Fludarabine/ Busulfan (81.6%), Cyclophosphamide/TBI (12.2%), and Cytarabine/Cyclophosphamide/TBI (4%). All subjects received tacrolimus/methotrexate for GvHD prophylaxis. Preliminary results are reported herein with all 49 subjects having completed study day 100. There were no reported serious infusion reactions and one subject received 5 of 6 doses due to a treatment related AE (increased ALT, grade 3). Treatment-emergent AE (TEAE) related to RGI-2001 (> 5%) were diarrhea (12%), nausea (12%), abdominal pain (8%), increased ALT (6%), increased alkaline phosphatase (6%), and rash (6%). Grade 3/4 related TEAE (>1 subject) were decreased neutrophil count (6%), decreased platelet count (4%), anemia (4%), stomatitis (4%) and decreased appetite (4%). Serious adverse events reported were sepsis, upper respiratory tract infection, diarrhea, headache, VOD, pelvic pain and DVT; none were deemed related to RGI-2001. There were no cases of engraftment failure. All 49 patients had at least 100 days of follow-up (FU), and 39 of 49 had complete FU to day 180. The median FU of survivors was 310 days (range, 111-365). Through day 100, there were 10 cases of grades II-IV aGvHD [20.4% (95% confidence interval 10.2-34.3%)], two of which were grades III-IV aGvHD [(4.1% (0.5-14.0%)]. One subject died from aGvHD due to GI bleed. There have been 3 relapses, 3 deaths, and 7 cases of moderate (0 severe cases) chronic GVHD (cGVHD) by last contact. Day-180 estimates of overall survival (OS), grades II-IV aGvHD-free survival (GFS), and relapse were 93.6% (81.6-97.9%), 75.2% (60.5-85.1%), and 4.1% (0.7-12.6%), respectively. Figure 1 summarizes the probability of OS and GFS as a function of time. Conclusions: Intravenous administration of RGI-2001 added to standard-of-care tacrolimus / methotrexate showed promising efficacy in the prevention of clinically significant aGVHD with a favorable safety profile. A phase 3 study is planned. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Radiation Therapy Can Be Safely Incorporated into Pretransplantation Treatment Regimens for Patients with Multiple Myeloma

Primary treatment of multiple myeloma (MM) often involves systemic induction therapy (SIT) followed by autologous stem cell transplantation (ASCT). Radiation therapy (RT) is sometimes used for palliation; however, many practitioners avoid RT out of concern that future peripheral blood progenitor cell (PBPC) collection required for ASCT may be compromised. In this study, we retrospectively examined the possible effect of RT on PBPC collection. We reviewed the charts of 732 patients with MM treated with RT at our institution from 1999 to 2017, including patients who received RT prior to PBPC collection for planned ASCT. RT plans (both MM and non-MM RT) were reviewed to estimate the percentage of bone marrow (BM) treated using published estimates of skeletal BM distribution. Statistics were performed using Pearson correlation and the t-test. The 732 MM patients included 485 planned for ASCT; of these, 223 received RT prior to PBPC collection and were included in the final cohort. The median age at PBPC collection was 59 years (range, 33 to 80 years). For SIT, patients received combination regimens including the following agents: bortezomib (142 patients; 64%), lenalidomide (111 patients; 50%), and alkylators (46 patients; 21%). Nine patients (4%) received dexamethasone alone. The median cumulative %BM treated per patient was 6.7 (range .0 to 47.4). The median RT dose was 24 Gy (range, 10.0 to 75.6 Gy). Mobilization was performed using granulocyte-colony stimulating factor (G-CSF) alone (189 patients; 85%), G-CSF with plerixafor (15 patients; 7%), or chemotherapy (19 patients; 9%). A median of 7.8×106 CD34+/kg PBPCs (range, .5 to 54.8× 106 CD34+/kg) were collected in a median of 3 (range, 1 to 9) apheresis procedures. One hundred ninety-six patients (99%) collected ≥2.0×106 CD34+/kg PBPCs, and 166 (83%) collected >5.0×106 CD34+/kg PBPCs. The number of PBPCs collected was not associated with %BM treated (P=.15) or RT dose (P=.56). The number of apheresis procedures performed was not associated with %BM treated (P=.54) or RT dose (P=.85). The amount of PBPCs collected did not differ significantly between patients receiving RT to the pelvis/sacrum (P=.20) and those receiving RT to the spine (P=.13). The time to platelet engraftment was longer for patients with higher %BM treated (P=.02). Eleven patients did not undergo a confirmed ASCT, owing to patient preference (3 patients), trial therapy (1 patient), comorbidities (1 patient), election for hospice (1 patient), inadequate collection (4 patients), or inadequate follow-up (1 patient). In our study cohort, RT prior to ASCT did not impair successful ASCT. RT must be carefully planned and delivered to ensure safe incorporation into pre-ASCT treatment regimens.

BML-260 promotes the growth of cord blood and mobilized peripheral blood hematopoietic stem and progenitor cells with improved reconstitution ability.

Hematopoietic stem cells (HSCs), which are multipotent and have the ability to self-renew, are frequently used in the treatment of hematological diseases and cancer. Small molecules that target HSC quiescence regulators could be used for ex vivo expansion of both mobilized peripheral blood (mPB) and umbilical cord blood (UCB) hematopoietic stem and progenitor cells (HSPC). We identified and investigated 35 small molecules that target HSC quiescence factors. We looked at how they affected HSC activity, such as expansion, quiescence, multilineage capacity, cycling ability, metabolism, cytotoxicity, and genotoxicity. A transplantation study was carried out on immunocompromised mice to assess the expanded cells' repopulation and engraftment abilities. 4-[(5Z)-5-benzylidene-4-oxo-2-sulfanylidene-1,3-thiazolidin-3-yl]benzoic acid (BML)-260 and tosyl-l-arginine methyl ester (TAME) significantly increased both mPB and UCB-HSPC content and activated HSC re-entry into the cell cycle. The improved multilineage capacity was confirmed by the colony forming unit (CFU) assay. Furthermore, gene expression analysis revealed that BML-260 and TAME molecules aided HSC expansion by modulating cell cycle kinetics, such as p27, SKP2, and CDH1. In addition to these in vitro findings, we discovered that BML-260-expanded HSCs had a high hematopoietic reconstitution capacity with increased immune cell content after xenotransplantation into immunocompromised mice. In addition to the BML-260 molecule, a comparison study of serum-containing and serum-free chemically defined media, including various supplements, was performed. These in vitro and xenotransplantation results show that BML-260 molecules can be used for human HSC expansion and regulation of function. Furthermore, the medium composition discovered may be a novel platform for human HSPC expansion that could be used in clinical trials.

P1338: INFUSION OF DIMETHYL SULFOXIDE (DMSO) - DEPLETED AUTOLOGOUS PERIPHERAL BLOOD PROGENITOR CELLS REDUCES POST-AUTOGRAFTING SEVERE GASTRIC TOXICITIES AND HOSPITALIZATION LENGTH

Background: High-dose chemotherapy (HD CHT) and autologous blood stem cell transplantation (ABSCT) are the cornerstone in the treatment of several hematologic malignancies. Cryopreservation of stem cells needs the use of DMSO as cryoprotectant. Unfortunately, DMSO may induce some severe adverse effects during and after autograft infusion, justifying the attempts to deplete DMSO. Despite several studies have demonstrated that DMSO depletion did not affect engraftment of peripheral blood progenitor cell (PBPC), there is still few and inconclusive data on its impact on post-infusion toxicities. Aims: Since from March 2021 we started to remove DMSO, we are comparing infusion and post-infusion outcome in 55 patients consecutively autografted with DMSO depleted (25 pts; group1) or undepleted (30 pts; group 2) at the hematology unit of the S.M. Goretti Hospital of Latina (Italy) from January 2019 and December 2021, aiming to evaluate whether post-infusion toxicities and clinical outcome may differ between the two groups. Methods: The DMSO was removed by rinsing the units with the Sepax S-100 (Biosafe S.A. Eysins, Switzerland) cellular centrifugation instrument that automatically processes blood or haematic components in a closed and sterile environment followed by the PBSC washing, using the dedicated CS-600 kit. The clinical characteristics, biological parameters of autografted PBPC and post-infusion outcome of the 55 patients entered this study are reported in Table 1. In group 1, 12 patients had a diagnosis of multiple myeloma (MM) and 13 of non Hodgkin’s lymphoma (NHL), whereas in group 2, 17 patients were affected by MM, 6 by Hodgkin’s lymphoma (HL) and 7 by NHL. Results: As reported in Table 1, the amount of harvested and infused CD34+ cells were similar in the two groups. To evaluate viability in group 1 we used a different ISHAGE protocol with lower thresholds. This consideration explains the lower viability rates observed in group 1 respect to those of group 2. No differences between the two groups were observed in the average time to neutrophil (N≥0.5 x 109/L) and platelet (PLTs ≥20x 109/L) recovery (10.4 vs 10 days and 12.5 vs 11.7 days, respectively), as well as in the number of transfused RBCs and PLTs units. No grade 3-4 infusion reactions were observed in any case. By contrast, as concern the post-infusion adverse events, in group 2 we observed a significant higher incidence of grade 3 mucositis (37% in group 2 vs 4% in group 1, p=0.003) and of episodes of nausea associated with vomiting (40% in group 2 vs 8% in group 1, p=0.007). Occurrence of febrile neutropenia, sepsis and other documented infections were similar between the two groups. Overall, the average hospitalization length after the infusion was 17 days (median=16) for group 2 and 14 days (median=13) for group 1 (p=0.059). Image:Summary/Conclusion: Present findings for the first time show a significant lower incidence of severe post infusional gastrointestinal adverse effect in patients receiving depleted DMSO autograft that may result in a reduced hospitalization length. As reported in animal model, this finding may suggest a direct gastrotoxicity of DMSO, that can potentiate that of chemotherapy. Whether these data may be confirmed in future larger studies they further suggest the usefulness of DMSO depletion from PBPC autografts.

Ramipril Improves Endothelial Function and Increases the Number of Endothelial Progenitor Cells in Patients With Systemic Lupus Erythematosus.

Endothelial dysfunction and reduced number of endothelial progenitor cells (EPCs) in peripheral blood are contributing factors to cardiovascular disease in systemic lupus erythematosus (SLE) patients. Endothelial progenitor cell proliferation is regulated by vascular endothelial growth factor (VEGF). Angiotensin-converting enzyme inhibitors reduce cardiovascular mortality in patients with coronary heart disease. This was a randomized trial including 37 female SLE patients without cardiovascular risk factors allocated into 2 groups: 19 patients received ramipril 10 mg/d for 12 weeks (IG) and 18 patients maintained without ramipril (CG). Endothelial function was assessed by brachial artery ultrasound measuring flow-mediated dilation, and EPCs were quantified by flow cytometry and cell culture, at baseline and after 12 weeks. Serum VEGF levels were measured by enzyme-linked immunosorbent assay. Statistical analysis was intention to treat. p < 0.05 was considered significant. After 12 weeks, higher flow-mediated dilation (6.17% vs. 11.14%, p < 0.001) was observed in IG, without change in CG (5.37% vs. 5.02%, p = 0.630). Higher number of EPC colony-forming units was also observed in IG (21.3 ± 10.4 vs. 31.6 ± 8.5, p < 0.001), without difference in CG ( p = 0.714). No difference was found in EPCs evaluated by flow cytometry. Vascular endothelial growth factor level increased after 12 weeks in IG ( p = 0.048), with no difference in CG ( p = 0.661). Ramipril improved endothelial function and increased the numbers of EPCs evaluated by cell culture and VEGF levels in SLE patients without cardiovascular risk factors. These data suggest that angiotensin-converting enzyme inhibitor bring an extra benefit beyond the hypotensive action and should be considered as a preferred antihypertensive drug in SLE patients.

The Impact of Pre-Apheresis Health Related Quality of Life on Peripheral Blood Progenitor Cell Yield and Donor's Health and Outcome: Secondary Analysis of Patient-Reported Outcome Data from the RDSafe and BMT CTN 0201 Clinical Trials

There is a lack of evidence about how health-related quality of life (HRQoL), including psychosocial factors, might affect donation-related experiences and clinical markers in the context of hematopoietic stem cell donation. The broader literature suggests that psychological factors, including anxiety and depression, are associated with higher levels of inflammatory burden leading to poorer postprocedural outcomes including longer hospital stays and increased pain perception. In this study, we aimed to evaluate whether predonation HRQoL markers predict toxicity profile and stem cell yield after peripheral blood stem cell (PBSC) donation in healthy donors. The study population comprised adult granulocyte colony-stimulating factor mobilized PBSC-related donors (RD) (n=157) and unrelated donors (URD) (n=179) enrolled in the related donor safety study (RDSafe) and Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0201 clinical trials. Pre-donation HRQoL was assessed using the Short-Form-12 (SF-12) in RDSafe and SF-8 questionnaire in BMT CTN 0201 (higher score is better). The aims of this study were to (a) determine the impact of pre-donation HRQoL on peri-collection pain and acute toxicities experienced and (b) to investigate the pre-procedural HRQoL indicators on stem cells yield. URDs were younger than RDs (median age 35 versus 63). A higher proportion of RDs were female (50% versus 40%) and obese (41% versus 35%). A higher proportion of RD PBSC donations required 2 days or more of apheresis (44% versus 21%). More RD collections were lower volume procedures (<18L, 16% versus 28%), and required a central line (28% versus 11%). RDs were more likely to report pre-donation grade 1-2 pain (27% versus 8%) and other toxicities (16% versus 6%). Among RDs, a lower pre-donation physical component summary (PCS) score was associated with significantly more grade 2-4 pain at 1 month (P=.004) and at 1-year after donation (P=.0099) in univariable analyses. In multivariable analysis, pre-donation PCS remained significantly associated with grade 2-4 pain 1 month after donation (P=.0098). More specifically, RDs with predonation PCS scores in the highest quartile were less likely to report pain compared with donors with PCS scores in the lowest quartile (odds ratio 0.1; 95% confidence interval 0.01-0.83; P=.005). There was also a trend toward higher grade 2-4 pain at 1-year post-donation among RDs with lower predonation PCS score (P=.018). Among URDs, neither PCS nor mental component summary (MCS) scores were associated with pain or toxicities at any time point after donation based on the univariable analysis. Because of low rates of postdonation grade 2-4 pain and toxicities, multivariable analysis was not performed in the URD setting. Moreover, there was no correlation between preapheresis HRQoL score (PCS or MCS) and PBSC collection yield in either the RD or URD setting. Our study demonstrates that pre-donation HRQoL scores are significantly associated with the toxicity profile after PBSC donation in the RD setting, with adult RDs with lower predonation physical HRQoL experiencing higher levels of pain at 1 month and persisting up to 12 months after a PBSC collection procedure. There were no such associations found in URD. Our findings can help clinicians identify donors at higher risk of pain with donation, and lead to personalized information and interventions for specific donors. Lack of correlation between predonation HRQoL and stem cell yield may be due to a small sample size and warrants further evaluation.

Albumin-Based Nanoparticles Loaded with miR-503 Antagonist Facilitate Neovascularization in the Ischemic Area of Myocardial Infarction

Albumin is successfully applied as a nanocarrier in the clinical nanomedicine and the abnormal miR-503 expression is related to the development of myocardial infarction (MI). This study aimed to explore the efficacy of albumin nanoparticles (NPs)-based delivery of miR-503 antagonist for MI therapy. After establishment of an animal model of MI, mice were administered albumin NPs loaded with miR-503 agonist or antagonist, normal saline (model group), CCNE1 agonist, or CCNE1 inhibitor (n = 10) with 10 mice sham-operated. Murine peripheral blood was collected to measure endothelial progenitor cells (EPCs) in peripheral blood along with analysis of miR-503, CCNE1 and SDF-1α expression by RT-qPCR, formation of new blood vessels and EPCs viability. Albumin NPs loaded with miR-503 antagonist increased EPCs number and new blood vessels formation, accompanied with down-regulation of miR-503 and up-regulation of SDF-1α and CCNE1. The NPs carrying miR-503 agonist exerted an opposite activity with less EPCs and new blood vessels than sham-operated group without significant difference between agonist group and model group. Besides, miR-503 antagonist promoted EPCs viability. Furthermore, inhibition of CCNE1 suppressed blood vessel formation and miR-503 targeted CCNE1. In conclusion, albumin-based NPs loaded with miR-503 antagonist decrease miR-503 expression and increase CCNE1 and SDF-1α expression to promotes EPCs viability and enhance the formation of new blood vessels, thereby improving MI.

Eosinophil Progenitors in Patients With Non-Asthmatic Eosinophilic Bronchitis, Eosinophilic Asthma, and Normal Controls.

ObjectiveThis study aims to explore the potential of in situ airway differentiation of eosinophil progenitors (EoPs) and hematopoietic progenitor cells (HPCs) in sputum and peripheral blood from patients with non-asthmatic eosinophilic bronchitis (NAEB), eosinophilic asthma (EA), and healthy controls (HC).MethodsUsing flow cytometry, we enumerated sputum and blood HPCs and EoPs in patients with NAEB (n=15), EA (n=15), and HC (n=14) at baseline. Patients with NAEB and EA were then treated for 1 month with budesonide (200 μg, bid) or budesonide and formoterol (200/6 μg, bid), respectively. HPCs and EoPs in both compartments were re-evaluated.ResultsAt baseline, NAEB and EA both had significantly greater numbers of sputum but not blood HPCs and EoPs (p<0.05) compared to HC. There were no differences between NAEB and EA. After 1 month of inhaled corticosteroid (ICS) treatment, NAEB patients showed a significant improvement in cough symptoms, but the attenuation of sputum HPC and EoP levels was not significant.ConclusionsNAEB patients have increased airway levels of HPCs and EoPs. One-month treatment with ICS did not fully suppress the level of EoPs in NAEB. Controlling in situ airway differentiation of EoPs may control airway eosinophilia and provide long-term resolution of symptoms in NAEB.