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Allogeneic hematopoeitic cell transplantation (allo-HCT) is the only curative treatment for myelofibrosis (MF). We evaluate the impact of various factors on survival outcomes post-transplant in MF. Data of 89 consecutive MF patients (primary 47%) who underwent allo-HCT between 2005 and 2018 was evaluated. Fifty-four percent patients had received JAK1/2 inhibitors (JAKi) pre-HCT. The median CD34 count was 7.1x106 cells/kg. Graft failure was seen in 10% of the patients. Grade 3-4 acute GVHD (aGVHD) and moderate/severe chronic graft versus host disease (cGVHD) occurred in 24% and 40% patients, respectively. Two-year overall survival (OS) and relapse free survival (RFS) were 51% and 43%, respectively. Cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) at 2 years were 11% and 46%, respectively. Higher CD34 cell dose (≤5 × 106 cells/kg vs 5-9 or ≥9 × 106 cells/kg) and lower pre-HCT ferritin (

Plerixafor was introduced to Japan in 2017 as a stem cell mobilization enhancement reagent, but the threshold for its use remains unclear. In this study, we assessed 57 patients treated with plerixafor (33 patients with multiple myeloma (MM) and 24 with malignant lymphoma (ML) and 152 patients without plerixafor administration. When CD34+ cell pre-counts were between 5.5 and 20 cells/μL in MM or 6 and 21 cells/μL in ML, the CD34+ cell count increased significantly, attaining the highest yield in response to plerixafor (achievement rate by one leukapheresis is 93.3% and 91.7% in MM and ML, at P < .001 and P = .012, respectively). In case the CD34+ cell pre-count was less than 5.5 cells/μL, an increase of at least 7 cells/μL from baseline by plerixafor was the necessary condition to achieve successful collection through a two-time leukapheresis. Monitoring CD34+ cell numbers might improve the collection efficiency and reduce the cost.

For patients with angiitis‐induced critical limb ischemia (AICLI), cell transplantation, such as purified CD34+ cells (PCCs) and peripheral blood mononuclear cells (PBMNCs), is gradually being used as a promising treatment. This was the first randomized single‐blinded noninferiority trial (number: {"type":"clinical-trial","attrs":{"text":"NCT 02089828","term_id":"NCT02089828"}}NCT 02089828) specifically designed to evaluate the therapeutic efficacies of the transplantation of PCCs vs those of PBMNCs for the treatment of AICLI. We aimed to compare the mid‐term safety and efficacy between the two groups and determine their respective advantages. From April 2014 to September 2019, 50 patients with AICLI were equally allocated to the two groups, except for 1 lost patient, 1 amputee, and 1 patient who died of heart disease. The other 47 patients completed the 36‐month follow‐up. The endpoints were as follows: major amputation‐free survival and total amputation‐free survival at 6 months, which were 96.0% and 84.0% in the PBMNCs group and 96.0% and 72.0% in the PCCs group, respectively. These rates remained stable at 12, 24, and 36 months. The PCCs group had a significant higher probability of rest pain relief than the PBMNCs group, whereas earlier significant improvements in the Rutherford classification were observed in the PBMNCs group. Accordingly, PCCs would be preferred for patients with significant pain, whereas PBMNCs may be a good option for patients with two or more critically ischemic limbs. Concerning cost‐effectiveness, PCCs are not more cost‐effective than PBMNCs. These outcomes require verification from long‐term trials involving larger numbers of patients.

Background: Hematopoietic progenitor cells (HPCs) cryopreservation have applications, especially in the autologous setting, allowing therapeutic use several years after collection. Cryopreservation...

Background Intra bone marrow (IBM) injection has been proposed as a strategy to bypass homing inefficiencies associated with intravenous (IV) hematopoietic progenitor stem cell (HSPC) transplantation and thus increases the number of HSPC that engraft. Despite physical delivery into the bone marrow cavity, many donor cells are rapidly redistributed by vascular perfusion. Thus, the objective of our study was to evaluate the ability of human platelet lysates (hPL) to improve HSPC retention into the bone marrow and consequently to improve engraftment. Study design and methods HSPC were isolated from human umbilical cord blood. HSPC were seeded in the wells of a 24-well microplate and exposed to increasing concentrations of hPL with or without cytokines for 24 hours. Following priming, HSPC cells chemotaxis to rhSDF-1 was determined in vitro and engraftment in NSG mice was evaluated. Results Priming of cord blood CD34+ cells to a combination of hPL and cytokines resulted in a significant increase (up to 3-fold) in the expression of the CD34 antigen on HSPC. This effect was closely correlated to a significantly increased (up to 7-fold) migration toward a rhSDF-1 concentration gradient. In addition, IBM injection of CD34+ cells previously primed with hPL+cytokines into NSG mice showed significantly increased engraftment as measured by human platelet numbers, human CD45 and human CD34+ cells for unprimed and primed cells, respectively. Conclusion The use of hPL + cytokines as a short-term priming treatment for UCB could be an advantageous strategy to improve clinical outcomes following IBM injection.

The CD34 cell surface antigen is widely expressed in tissues on cells with progenitor-like properties and on mature vascular endothelia. In adult human bone marrow, CD34 marks hematopoietic stem and progenitor cells (HSPCs) starting from the bulk of hematopoietic stem cells with long-term repopulating potential (LT-HSCs) throughout expansion and differentiation of oligopotent and unipotent progenitors. CD34 protein surface expression is typically lost as cells mature into terminal effectors. Because of this expression pattern of HSPCs, CD34 has had a central role in the evaluation or selection of donor graft tissue in HSC transplant (HSCT). Given its clinical importance, it is surprising that the biological functions of CD34 are still poorly understood. This enigma is due, in part, to CD34's context-specific role as both a pro-adhesive and anti-adhesive molecule and its potential functional redundancy with other sialomucins. Moreover, there are also critical differences in the regulation of CD34 expression on HSPCs in humans and experimental mice. In this review, we highlight some of the more well-defined functions of CD34 in HSPCs with a focus on proposed functions most relevant to HSCT biology.

To elucidate the impact of infused CD34+ cell doses on transplant outcome, we retrospectively analyzed 851 adult patients who received peripheral blood stem cell transplantation (PBSCT) from human leukocyte antigen (HLA)-matched related donors. The patients were divided into high- and low-CD34 groups at the cutoff value of 4.5 × 106/kg. Overall, the high CD34 group showed early neutrophil and platelet recovery. Stratification of disease risks demonstrated that among the patients with low-risk diseases, the high-CD34 group showed better disease-free survival (DFS) (64.9% vs. 55.5%, P = 0.0415) than did the low-CD34 group, without any increase in graft-versus-host disease (GVHD). Meanwhile, a higher CD34+ cell dose had no impacts on the outcomes of patients with high-risk diseases. Multivariate analyses for the patients with low-risk diseases revealed that a high CD34+ cell dose (hazard ratio [HR] 0.72, P = 0.048) and development of grade III-to-IV acute GVHD (HR 1.64, P = 0.018) were significantly associated with DFS. An excessive dose of CD34+ cells (>8.0 × 106/kg) led to an increase in acute GVHD. By stratification of disease risk, a CD34+ cell dose between 4.5 and 8.0 × 106/kg can be suggested for patients with low-risk diseases who undergo PBSCT from HLA-matched related donors.

Induced pluripotent stem cell (iPS) technology may be advantageous for the study of genetic aberrations in terms of recapitulating the full manifestation of pathological features in vitro, identifying underlying pathways, and developing personalized therapeutics rather than procuring somatic cells from patients. Here, we derived an iPSC line from a patient with reciprocal chromosome translocation, t(1;5)(p31.1;35.1), as a novel alternative model to identify clinical phenotypes induced by genetic instability. The resulting iPSC line generated from somatic cells with an existing instability showed representative characteristics of PSCs, and might serve as an unparalleled cellular resource for the development of a custom remedy.

BackgroundAcute myeloid leukemia (AML) is a fatal hematopoietic malignancy which has a prognosis that varies with genetic heterogeneity of its hematopoietic stem/progenitor cells(HSCPs). Intensive induction chemotherapy with cytarabine and anthracycline has been the standard of care for newly diagnosed AML, but about 30% of patients have no response to this regimen. The resistance mechanisms require deeper understanding. Methods In our study, using 10× Genomics, a high-throughput single cell RNA sequencing (scRNA-seq) platform, we analyzed the cellular heterogeneity of bone marrow CD34+ cells from newly diagnosed AML patients who were then divided into sensitive and resistant groups according to their responses to induction chemotherapy with cytarabine and anthracycline. ScRNA-seq data for healthy controls were obtained from the GEO database. We verified our findings by the TCGA database, GEO datasets and the multiparameter flow cytometry.ResultsFrom the integrative analysis of 60,402 cells, we established a landscape for single-cell CD34+ cells in AML patients and identified the hematopoietic stem/progenitor cell types based on the lineage signature genes. Interestingly, through recognizing the malignant-like clusters and comparing “resistant group” with “sensitive group”, we found a cell population with specific gene signatures (CRIP1highLGALS1highS100Ashigh) showing features of granulocyte-monocyte progenitors (GMP) was associated with poor prognosis of AML. And two cell populations of AML CD34+ cells marked by CD52+ or CD74+DAP12+ were related to good response of patients to induction therapy, showing characteristics of hematopoietic stem cell (HSC). ConclusionOur study indicates the heterogeneity of AML CD34+ cells confers for outcomes of AML and provides possible biomarkers to predict the response of AML patients to induction chemotherapy.

Objectives: Immune aplastic anemia (AA) is a hematological disease characterized by pancytopenia and bone marrow (BM) hypocellularity. It is caused by an immune attack against hematopoietic stem and progenitor cells (HSPC). Its treatment is based on allogeneic BM transplantation and immunosuppressive therapy. More recently, the addition of eltrombopag showed that the expansion of hematopoietic precursors is a therapeutic alternative. Fares et al. demonstrated that the small molecule UM171 is capable of expanding the most primitive CD34+ cell compartment of umbilical cord blood (UCB) ex vivo. Our research group showed that UM171 is also capable of effectively expanding immature subpopulations of CD34+ cells from patients with immune AA. The aim of this study was to evaluate the engraftment capacity of CD34+ cells from patients with AA expanded with UM171 in a murine xenotransplantation model. Methods: CD34+ cells were purified from either bone marrow of one patient or one UCB unit using immunomagnetic labeling with human CD34 MicroBeads, MS columns, and a magnetic separator. Cells were cultured for seven days in medium supplemented with cytokines and 35 nM UM171 or 0.1% DMSO (control) and then transplanted via retro-orbital injection into pre-conditioned 8-to-12-week-old female NSG-SGM3 (NSGS) mice. The progeny of 3×104UCB CD34+ cells or 8.250 AA patient CD34+ cells was transplanted per mouse (four mice per experimental condition). The conditioning regimen consisted of two intraperitoneal injections of 12.5 mg/kg busulfan administered 48 and 24 hours before transplantation. Human hematopoietic cells were monitored in the murine BM by flow cytometry at week 20 post-transplantation. BM cells were collected from the two femurs and the two tibias of each animal and treated twice with red cell lysis, labeled with APC-Cy7 anti-mouse and PerCP-Cy5.5 anti-human CD45 antibodies, then analyzed on a flow cytometer using the FlowJo V.10 software. Results: We found that both progenies of UCB and AA BM CD34+ cells cultured with UM171 showed an improved reconstitution potential in mice BM 20 weeks after transplant compared to DMSO, which was demonstrated by the detection of higher percentages of human CD45+ cells in the mice BM (UCB: UM171 = 10,07% ±2,29 vs DMSO = 3,73% ±1,99; AA BM: UM171 = 0,095% ±0,075 vs DMSO = 0,042% ±0,002; data represent mean ±Standard Error). Differences were not significant. Discussion: We wondered whether the UM171 treatment would impact the engraftment capacity of the in vitro expanded CD34+ cells. The enhanced engraftment capacity enabled by UM171 could allow for immune AA patients to be treated with a novel strategy, autologous transplantation of their own CD34+ expanded cells. The present study indicates that UM171 could be a promising candidate drug for treating patients with immune AA. More replicates (patients and controls) are required to firmly establish the benefit of UM171 in conferring repopulation potential to ex vivo expanded CD34+ cells from AA patients. Conclusion: In initial experiments, in vitro treatment with UM171 appears to increase the engraftment of CD34+ cells isolated from UCB and from the BM of immune AA patients. These results need to be confirmed in additional experiments.

Rationale: Endothelial cells play a critical role in multiple cardiovascular diseases. Circulating CD34 + cells are believed to be endothelial progenitors that have been used to treat cardiovascular diseases. However, the exact identity and the role of CD34 + cells in vascular regeneration remains unclear. Objective: We aimed to investigate the exact identity and the role of CD34 + cells in vascular regeneration. Methods and Results: Compared with healthy arteries, CD34 expression percentage was significantly increased in diseased femoral arteries from patients. Using a guidewire-induced endothelial denudation model, we reported the transcriptional profiling of over 30 000 cells by single-cell RNA sequencing analysis and provided a cell atlas of normal and lesioned arteries in mouse, in which a heterogeneous population of CD34 + cells was revealed. Combining the inducible lineage tracing Cd34 -CreER T2 ;R26-tdTomato mouse model and bone marrow transplantation experiments, we showed that nonbone marrow CD34 + mesenchymal cells acquired endothelial cell fate in the injured femoral artery rather than preexiting endothelial cells, while bone marrow-derived CD34 + cells differentiated into immune cells locally after vessel injury. Depletion of nonbone marrow CD34 + cells using diphtheria toxin-induced cell ablation models exacerbate neointimal lesions of the injured vessel. Furthermore, isolated vascular adventitia CD34 + cells displayed endothelial differentiation, in which microRNA-21-Smad7-pSmad2/3 pathway regulated endothelial gene expression and function during differentiation. Conclusions: Our study provides a transcriptional and cellular landscape of vessels after endothelial denudation. Our findings suggest heterogeneous CD34 + cells serve as a contributor not only to endothelial regeneration but also an inflammatory response that may provide therapeutic insights into vascular diseases.

Visual Abstract, Highlights • Patients with CAD and renal insufficiency (eGFR, Summary Patients with coronary artery disease and renal insufficiency (RI) (estimated glomerular filtration rate median) were at a similar risk as those without RI.

Objectives Haploidentical hematopoietic stem cell transplant (haplo-SCT) has been associated with higher rates of graft rejection, and a higher dose of CD34+ cell dose is frequently requested. We aim to explore the impact of CD34+ cell dose in peripheral blood stem cell (PBSC) grafts using reduced intensity conditioning (RIC) in haplo-SCT. Methods Sixty-eight consecutive haplo-SCT in adult patients were included. Graft-vs-host disease (GVHD) prophylaxis consisted on ATG, PTCy, and CsA. The cohort was divided in two groups using CD34+ dose of ≥ 9 × 106 CD34+/Kg as cutoff point. Median follow-up was 8.9 months. Results Median cell dose infused was 9.32 × 106 CD34+/Kg. Forty (58.8%) recipients received grafts with CD34+ cells ≥9 × 106 /kg. The infusion ≥ 9 × 106 CD34+/Kg cell dose had a negative impact in overall survival (P = .03) after adjusting for age at transplant. The cumulative incidence of acute GVHD and graft failure were not significantly influenced per CD34+ cell dose. Only four recipients had grade III aGVHD, and all of them received grafts with a CD34+ cell dose ≥ 9 × 106 . Conclusion In RIC haplo-SCT, recipients may not benefit from PBSC grafts with a CD34+/kg cell dose higher than 9 × 106 cells/kg, as it can have an adverse impact in post-transplant outcome.

Haploidntical hematopoietic stem cell transplantation has been increasingly used in recent years for patients without a matched donor. The αβTCR+/CD19+ depletion technique provide a graft that is enriched with CD34 cells, γδ-T-cells and natural killer. The current experience with αβTCR+/CD19+ depleted grafts in pediatric patients with malignant and non-malignant disorders, demonstrated rapid engraftment, improved immune reconstitution and low risk of GVHD. Future studies will need to define the optimal conditioning regimen in order to improve transplant outcome.

In 1997, the seminal manuscript by Asahara, Murohara, Isner et al outlined the evidence for the existence of circulating, bone marrow-derived cells capable of stimulating and contributing to the formation of new blood vessels. Consistent with the paradigm shift that this work represented, it triggered much scientific debate and controversy, some of which persists 2 decades later. In contrast, the clinical application of autologous CD34 cell therapy has been marked by a track record of consistent safety and clinical benefit in multiple ischemic conditions. In this review, we summarize the preclinical and clinical evidence from over 700 patients in clinical trials of CD34 cell therapy.

Ventricular arrhythmias (VA) are of major concern in the field of cell therapy, potentially limiting its safety and efficacy. We sought to investigate the effects of CD34+ cell therapy on VA burden in patients with chronic heart failure (CHF). We performed registry data analysis of patients with CHF and implanted ICD/CRT devices treated with transendocardial CD 34+ cell therapy. Demographic, echocardiographic, and biochemical parameters were analyzed. Device records were reviewed and the number and type of VA 1 year prior to and 1 year after cell therapy were analyzed. All patients underwent electroanatomical mapping, and myocardial scar was defined as unipolar voltage (UV) + cell therapy does not appear to increase the risk of VA in chronic heart failure patients.

CD34+ cell dose is critical for cord blood (CB) engraftment. However, the CD34+ content of the CB inventory in the United States is unknown. We examined the CD34+ cell content of 126 341 red blood cell–depleted US units banked from January 2007 to September 2017 with a total nucleated cell (TNC) count of ≥90 × 107 and a cryovolume of 24-55 mL. Median pre-cryopreservation TNC content was 127 × 107 (interquartile range [IQR], 108-156 × 107); CD34+ cell content was 44 × 105 (IQR, 29 to 67 × 105). The median CD34+:TNC ratio was 0.34%. TNC and CD34+ cell content correlation was weak (r = 0.24). Of 7125 units with TNCs of ≥210 × 107, only 47% had CD34+ content of ≥100 × 105. However, some units had high CD34+ content for a given TNC count. Only 4% of CB units were acceptable as single-unit grafts (TNCs, ≥2.5 × 107/kg; CD34+ cells, ≥1.5 × 105/kg) for 70-kg patients; 22% of units were adequate for 70-kg patients using lower dose criteria (TNCs, ≥1.5 × 107/kg; CD34+ cells, ≥1.0 × 105/kg) suitable for a double-unit graft. These findings highlight that units with the highest TNC dose may not have the highest CD34+ dose, units with unexpectedly high CD34+ content (a ratio of >1.0%) should be verified, and the US CB inventory of adequately sized single units for larger patients is small. They also support the ongoing use of double-unit grafts, a focus on banking high-dose units, and development of expansion technologies.

Background Cord blood banks have to determine the regenerative potential of cord blood units (CBUs) on a representative sample of the cryopreserved product before release to the transplant center. Potency can be measured by using a colony-forming unit (CFU) method, which delays the release of CBU by 7 to 14 days. To accelerate CBU qualification, we have developed a rapid method to assess the response of CD34 cells to interleukin (IL)-3. Flow cytometry was used to measure IL-3-induced STAT5 phosphorylation within CD34-cells. This IL-3 test was compared to the CFU method, as well as the aldehyde dehydrogenase (ALDH) enzyme-based assay. Study design and methods Ten cryopreserved CBUs were analyzed for their contents in CD34 and CD45 viable cells, total CFUs, ADLHbright cells, and IL-3-responsive CD34+ cells. Extreme and mild warming event scenarios were simulated on CBUs and used as poor-quality samples. Segments, tubes, and bags from five CBUs were compared for their potency using IL-3 and CFU methods. Results The IL-3 test was accurate in identifying the samples handled following standard operating procedures and those subjected to extreme warming events. Based on these results, a threshold of 55% of IL-3-responsive CD34 cells was established to identify good-quality samples. The IL-3 test was also the most sensitive to detect samples subjected to milder warming events. Conclusions Our new method for determining CBU functionality is rapid, unbiased, and robust. The IL-3 test described herein fulfills the requirements for validation, and we intend to implement this method in our cord blood bank facility.

We studied DNA methylation profiles in four different cell populations from a unique constellation of monozygotic triplets in whom two had developed Hodgkin Lymphoma (HL). We detected shared differences in DNA methylation signatures when comparing the two HL-affected triplets with the non-affected triplet. The differences were observed in naïve B-cells and marginal zone-like B-cells. DNA methylation differences were also detected when comparing each of the HL-affected triplets against each other. Even though we cannot determine whether treatment and/or disease triggered the observed differences, we believe our data are important on behalf of forthcoming studies, and that it might provide important clues for a better understanding of HL pathogenesis.

Early evidence from COVID-19 patients and autopsy series indicates that moderate to severe cases are accompanied by damage to the pulmonary endothelium and microcirculation. These data indicate that SARS-CoV-2 infection is particularly avid for lung microvascular endothelium, reflecting endothelial cell infection, inflammation, and focal thrombi occluding the pulmonary circulation leading to progressive fibrosis reminiscent of endothelial-mesenchymal transition. This appears to be a potential mechanism by which COVID-19 causes progressive fibrotic changes, impairment in the pulmonary vasculature, and loss of lung function that persists after acute recovery. Early data from the SARS-CoV-1 epidemic indicated that CD34+ cells in the lung could also be a target of infection and that destruction of lung CD34+ progenitors could account for persistence of pulmonary manifestations. Preclinical studies reveal that restoration of microvasculature in the lung can trigger and sustain regeneration of lung tissue. The microvascular repair function of CD34+ has been documented in preclinical models and multiple human trials in ischemic tissue repair. Accordingly, we designed a clinical trial to evaluate autologous CD34+ cells (CLBS119) for amelioration/repair of COVID-19 lung damage. Subjects must be hospitalized for COVID-19 and have ongoing pulmonary involvement based on room air hypoxia. The study will include approximately 50% of subjects who cannot be liberated from ventilatory support. CD34+ cells will be mobilized with plerixafor and selected from the mononuclear fraction following apheresis. Doses up to 500 x 10 6 cells will be administered IV. Subjects will receive a single administration of cells. Key measures will include assessment of oxygenation, need for supplemental oxygen, pulmonary function assessments, radiographic assessments, and biomarkers. Subjects will be followed for 6 months following administration. Interim findings will be presented.

Introduction: Right ventricular (RV) dysfunction is an important predictor of adverse prognosis in patients with heart failure with preserved ejection fraction (HFpEF). Hypothesis: We sought to investigate the effects of transendocardial CD34 + cell therapy on RV function in HFpEF patients. Methods: We enrolled 30 patients with HFpEF who underwent transendocardial CD34 + cell transplantation. At baseline, all patients received granulocyte-colony stimulating factor; cells were collected by apheresis and immunomagnetic selection and injected transendocardialy in the left ventricle targeting the areas of local diastolic dysfunction. Patients were followed for 6 months and changes in RV function were assessed by tricuspid annular plane systolic excursion (TAPSE), peak systolic velocity of tricuspid annulus (St), and fractional area change (FAC). Impaired RV function was defined as TAPSE Results: At baseline, RV function was impaired in 11 (37%, Group A), and preserved in 19 (63%, Group B) of patients. The groups did not differ in age (64±6 years in Group A vs. 61±11 years in Group B, P=0.37), gender (male: 82% vs. 74%, P=0.61), or left ventricular E/e' (17.7±2.3 vs. 17.3±3.4, P=0.74). Patients in Group A had lower LVEF (55.6±5.1% vs. 61.3±6.5% in Group B, P=0.02), and higher NTproBNP levels (1750±1139 pg/ml vs. 1038±658 pg/ml, P=0.05). At 6 months after cell transplantation we found an overall improvement in all parameters of RV function (TAPSE: +0.21±0.37 cm, P=0.01; St: +0.7±2.1 cm/s, P=0.03; FAC: +8.5±1.9%, P=0.02). However, RV function improvement was significant in Group A (TAPSE: +0.43±0.37 cm, P=0.004; St: +1.4±2.3 cm/s; P=0.01; FAC: +9.8±2.0%, P=0.01), but not in Group B (TAPSE: +0.04±0.27 cm, P=0.65; St: +0.4±1.3 cm/s, P=0.32; FAC: +7.1±3.7%, P=0.08). In both groups we found comparable changes in E/e' (-5.1±3.0 in Group A vs. -5.9±3.2 in Group B, P=0.53), LVEF (1.2±5.7% vs. 1.9±6.5%, P=0.45) and NTproBNP (-462±410 pg/ml vs. -390±398 pg/ml, P=0.64) at 6 months after cell transplantation. Conclusions: Transendocardial CD34 + cell therapy appears to be associated with improvement of right ventricular dysfunction in patients with HFpEF.

Introduction: The evidence supporting the impact of electroanatomic guidance in defining the targets for transendocardial cell injections in chronic heart failure (CHF) remains inconclusive. Hypothesis: We evaluated a correlation between electroanatomic properties of the myocardium at the cell injection sites and clinical response to CD34 + cell therapy in CHF patients. Methods: We enrolled 131 consecutive patients with CHF and LVEF+ cell therapy at a single study site. All patients received bone-marrow stimulation with filgrastim for 5 days; CD34 + cells were collected by apheresis and injected transendocardialy (80x10 6 cells per patient). Target injection sites were defined by electroanatomical mapping as myocardial areas with unipolar voltage >8.3mV and local linear shortening Results: Of 131 patients 69 (53%) displayed a favorable clinical response (Group A) and 62 (47%) patients failed to respond to cell therapy (Group B). At baseline, the groups did not differ in gender (male: 89% in Group A vs. 84% in Group B, P=0.45), age (53±12 years vs. 55±11 years, P=0.25), CHF etiology (ischemic: 22% vs. 32%, P=0.17), LVEF (29±6% vs. 32±7%, P=0.06), or LVEDD (6.3±1.2 cm vs. 6.7±1.0 cm, P=0.10). Patients in Group A had lower baseline creatinine (81±20 μmol/L vs. 92±24 μmol/L in Group B, P=0.005), and lower levels of NT-proBNP (931±1078 pg/mL vs. 2716±2716, P=0.001). The number of cell injections in Groups A and B was comparable (17.3±2.6 injections vs. 17.6±3.5 injections, P=0.60). When analyzing the electroanatomical properties at cell injection sites, we found significantly higher unipolar voltage in Group A (11.2±3.7 mV vs. 9.5±2.6 mV in Group B, P=0.005). However, we found no differences in injection site local linear shortening between the groups (2.7±3.9% in Group A vs. 3.4±3.4 in group B, P=0.56). Conclusions: In CHF patients, higher unipolar voltage at the cell injection sites appears to correlate with better clinical response to transendocardial CD34 + cell therapy. Thus, cell injections guided by measurements of myocardial viability may offer an advantage over blind cell injection strategies in this patient population.

Mind–body interventions (MBIs) have many health benefits, such as reducing stress, modulating blood pressure, and improving sleep and life quality. The long-term practice of Tai chi, an MBI, also increases the number of CD34+ cells, which are surface markers of hematopoietic stem cells, so prolonged Tai chi practice may have antiaging effects. We developed the day easy exercise (DEE), an innovative MBI, that is easy to learn and requires only a small exercise area and a short practice time. The aim of this study was to explore whether DEE, like Tai chi, has antiaging effects after short-term practice. Total 44 individuals (25 to 62 years old) with or without 3-month DEE practice were divided into young- and middle-aged groups (≤30 and >30 years old) and peripheral blood was collected at 0, 1, 2, and 3 months for analysis of CD34+ cells. The number of CD34+ cells in peripheral blood remained unchanged in control young- and middle-aged groups. After DEE, the number of CD34+ cells in peripheral blood was increased over time in both young- and middle-aged groups. For young-aged adults, the cell number was markedly increased by threefold at 3 months after DEE, and for middle-aged adults, the increase was significant from the first month. DEE practice indeed increased the number of CD34+ cells in peripheral blood and the increase was more significant for older people in a shorter time. This is the first study to provide evidence that the DEE may have antiaging effects and could be beneficial for older people.

OBJECTIVE: We assessed the predictive potential of XN-HPC for CD34+ cell count as obtained through Sysmex automated hematology analyzers (XN-1000). METHODS: This study was conducted at the National Institute of Blood Diseases and Bone Marrow Transplantation in 84 donors between December 2012 and December 2017 in the first phase and later validated in 112 donors between December 2017 and December 2018. Sysmex XN-1000 and BD FACS Calibur estimated XN-HPC and CD34+ cells of peripheral blood apheresis product, respectively. Spearman's correlation was assessed between XN-HPC and CD34+ cell count followed by receiver operating characteristic curve calculation to determine the XN-HPC cutoff for a CD34+ count of ≥2 million cells/kg of recipient's body weight RESULTS: There is a moderately positive correlation (P value = .003) between XN-HPC and CD34+ count. Receiver operating characteristic curve analyses demonstrated that a cutoff value for XN-HPC of ≥1·845×106cells/kg of recipient's body weight has a specificity and sensitivity of 100% and 78·2%, respectively, for predicting the CD34+ count of ≥2 million cells/kg of recipient's body weight. This cutoff value of XN-HPC was prospectively validated in 112 donors. The positive predictive value was found to be 100%, while negative predictive value was 17%. CONCLUSION: XN-HPC has a highly promising potential to serve as a cost-effective and time-saving surrogate for CD34+ cell count.

BACKGROUND: The achievement of optimal number of CD34(+) umbilical cord stem cells is essential for successful umbilical cord stem cell transplantation. So the aim of this study was to assess the potential effect of both maternal and neonatal factors on the umbilical cord blood CD34(+) cell count. METHODS: The study was done on umbilical cord blood samples obtained from 20 mothers during labor. Their ages ranged from 22 to 34 years and were subjected to history taking, physical examination of the baby and assessment of the CD34(+) cells count in umbilical cord blood. RESULTS: Number of previous live births and weight of the baby had a significant effect on CD34(+) cells count while the sex of the baby, delivery route, maternal age and gestation period had no significant effect on CD34(+) cells count. CONCLUSIONS: Umbilical cord blood-derived CD34(+) cell count is better with good weight and first babies and decreased with subsequent babies.

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and their associated CRISPR-associated nucleases (Cas) are among the most promising technologies for the treatment of hemoglobinopathies including Sickle Cell Disease (SCD). We are only beginning to identify the molecular variables that influence the specificity and the efficiency of CRISPR- directed gene editing, including the position of the cleavage site and the inherent variability among patient samples selected for CRISPR-directed gene editing. Here, we target the beta globin gene in human CD34+ cells to assess the impact of these two variables and find that both contribute to the global diversity of genetic outcomes. Our study demonstrates a unique genetic profile of indels that is generated based on where along the beta globin gene attempts are made to correct the SCD single base mutation. Interestingly, even within the same patient sample, the location of where along the beta globin gene the DNA is cut, HDR activity varies widely. Our data establish a framework upon which realistic protocols inform strategies for gene editing for SCD overcoming the practical hurdles that often impede clinical success.

Diagnosis of myelodysplastic syndromes (MDS) is not straightforward when objective data, such as blast excess and abnormal cytogenetics, are lacking. Expert laboratories use flow cytometry (FCM) to help diagnose MDS. However, most of FCM protocols for MDS are complex, requiring a high level of expertise and high cost. We have reported a FCM mini-panel consisting of four FCM parameters (so-called Ogata score), which is simple to conduct and inexpensive. In this paper, to refine this mini-panel, we have introduced a new FCM parameter, which quantifies CD33 expression on CD34+ cells (called Granulocyte/CD34 cell CD33 ratio). Bone marrow cells from MDS without blast excess (low-grade MDS) and controls were stained with CD34, CD45, and CD33 and analyzed for five parameters ("Granulocyte/CD34 cell CD33 ratio" plus four parameters in the Ogata score). By a multivariate logistic regression model, only three parameters, including "Granulocyte/CD34 cell CD33 ratio" had statistically significant power for diagnosing low-grade MDS. Based on the results, we constructed a new scoring system, which showed approximately 50% sensitivity and more than 95% specificity in diagnosing low-grade MDS. Our revised mini-panel is suitable for screening samples suspected for MDS and provides a basis for further improvement in diagnostic FCM protocols for MDS.

Noncompaction cardiomyopathy is a rare congenital heart disorder characterized by an arrest of the myocardial compaction process. This results in the altered formation of coronary microvessels with a resulting decrease in myocardial perfusion. Transendocardial CD34+ cell transplantation has been shown to increase myocardial perfusion and function in patients with non-ischemic heart failure. In our first-in-man case study, we investigated the feasibility, safety and clinical effect of transendocardial CD34+ cell therapy in a patient with noncompaction cardiomyopathy.