Generation of human ILC3 from allogeneic and autologous CD34+ hematopoietic progenitors toward adoptive transfer.

Type 3 innate lymphoid cells (ILC3) are important in tissue homeostasis. In the gut, ILC3 repair damaged epithelium and suppress inflammation. In allogeneic hematopoietic cell transplantation (HCT), ILC3 protect against graft-versus-host disease (GvHD), most likely by restoring tissue damage and preventing inflammation. We hypothesize that supplementing HCT grafts with interleukin-22 (IL-22)-producing ILC3 may prevent acute GvHD. We therefore explored ex vivo generation of human IL-22-producing ILC3 from hematopoietic stem and progenitor cells (HSPC) obtained from adult, neonatal and fetal sources. We established a stroma-free system culturing human cord blood-derived CD34+ HSPC with successive cytokine mixes for 5 weeks. We analyzed the presence of phenotypically defined ILC, their viability, proliferation and IL-22 production (after stimulation) by flow cytometry and enzyme-linked immunosorbent assay (ELISA). We found that the addition of recombinant human IL-15 and the enhancer of zeste homolog 1/2 inhibitor UNC1999 promoted ILC3 generation. Similar results were demonstrated when UNC1999 was added to CD34+ HSPC derived from healthy adult granulocyte colony-stimulating factor mobilized peripheral blood and bone marrow, but not fetal liver. UNC1999 did not negatively impact IL-22 production in any of the HSPC sources. Finally, we observed that autologous HSPC mobilized from the blood of adults with hematological malignancies also developed into ILC3, albeit with a significantly lower capacity. Together, we developed a stroma-free protocol to generate large quantities of IL-22-producing ILC3 from healthy adult human HSPC that can be applied for adoptive transfer to prevent GvHD after allogeneic HCT.

Label-Free CD34+ Cell Identification Using Deep Learning and Lens-Free Shadow Imaging Technology.

Accurate and efficient classification and quantification of CD34+ cells are essential for the diagnosis and monitoring of leukemia. Current methods, such as flow cytometry, are complex, time-consuming, and require specialized expertise and equipment. This study proposes a novel approach for the label-free identification of CD34+ cells using a deep learning model and lens-free shadow imaging technology (LSIT). LSIT is a portable and user-friendly technique that eliminates the need for cell staining, enhances accessibility to nonexperts, and reduces the risk of sample degradation. The study involved three phases: sample preparation, dataset generation, and data analysis. Bone marrow and peripheral blood samples were collected from leukemia patients, and mononuclear cells were isolated using Ficoll density gradient centrifugation. The samples were then injected into a cell chip and analyzed using a proprietary LSIT-based device (Cellytics). A robust dataset was generated, and a custom AlexNet deep learning model was meticulously trained to distinguish CD34+ from non-CD34+ cells using the dataset. The model achieved a high accuracy in identifying CD34+ cells from 1929 bone marrow cell images, with training and validation accuracies of 97.3% and 96.2%, respectively. The customized AlexNet model outperformed the Vgg16 and ResNet50 models. It also demonstrated a strong correlation with the standard fluorescence-activated cell sorting (FACS) technique for quantifying CD34+ cells across 13 patient samples, yielding a coefficient of determination of 0.81. Bland-Altman analysis confirmed the model's reliability, with a mean bias of -2.29 and 95% limits of agreement between 18.49 and -23.07. This deep-learning-powered LSIT offers a groundbreaking approach to detecting CD34+ cells without the need for cell staining, facilitating rapid CD34+ cell classification, even by individuals without prior expertise.

Use of subgroup-specific hematopoietic stem cell collection efficiencies to improve truncation calculations for large-volume leukapheresis procedures.

PURPOSE: A critical component of optimizing peripheral blood (PB) hematopoietic stem cell (HSC) collections is accurately determining the processed blood volume required to collect the targeted number of HSCs. Fundamental to most truncation equations employed to determine this volume is the procedure's estimated collection efficiency (CE), which is typically applied uniformly across all HSC collections. Few studies have explored the utility of using different CEs in subpopulations of donors that have substantially different CEs than the institutional average. METHODS: Initial procedures from 343 autologous and 179 allogeneic HSC collections performed from 2018 to 2021 were retrospectively analyzed. Predictive equations were developed to determine theoretical truncation rates in various donor subgroups. RESULTS: Quantitative variables (pre-procedure cell counts) and qualitative variables (relatedness to recipient, gender, method of venous access, and mobilization strategy) were found to significantly impact CE. However, much of the variability in CE between donors could not be explained by the variables assessed. Analyses of procedures with high pre-collection PB cell counts identified lower CE values for these donors' truncation equations which still allow truncation but minimize risk of collecting less CD34+ cells than requested. CONCLUSIONS: Individualized CE does not substantially improve truncation volume calculations over use of a fixed CE and adds complexity to these calculations. The optimal fixed CE varies between autologous and allogeneic donors, and donors with high pre-collection PB cell counts in either of these groups. This model will be clinically validated and continuously refined through analysis of future HSC collections.

Stem cell mobilizating effect of heparin in patients undergoing autologous stem cell transplantation.

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.

Determination of the relationship between CD34+ stem cell amount and DMSO in hematopoetic stem cell transplantation.

It is important to calculate the CD34+ stem cell (SC) count at the right time in patients with hematological malignancies who will undergo Hematopoietic Stem Cell Transplantation (HSCT). The amount of SC infused into the patient affects the engraftment time and healing process of the patient. In this study, we aimed to compare which of the DMSO-not removed and DMSO-removed samples showed the CD34 + SC amount more accurately as the SC amount determination method after the SC was dissolved after cryopreservation in patients who will undergo HSCT. A total of 22 patients were included in the study. All 22 patients were transplanted from frozen samples using DMSO. After the SC products were dissolved in a 37 °C water bath, they were washed 2 times and the amount of CD34+ SC was studied from the samples taken by removing DMSO and without removing DMSO. In the findings, the amounts of CD34+ SC studied with both methods were compared. The increase in the number and percentage of CD34+ SC after DMSO-removed was found to be statistically significant both in terms of difference and proportionally, and the calculated effect sizes also showed that the increase was clinically significant (Cohen's d is between 0.43 and 0.677). After thawing the frozen SCs of the patients who will undergo HSCT, the analysis of CD34+ SCs from which DMSO is removed provides a more accurate calculation of the CD34+ SC amount in the AP.

Single-cell dissection of human hematopoietic reconstitution after allogeneic hematopoietic stem cell transplantation.

Hematopoietic stem cell transplantation is an effective regenerative therapy for many malignant, inherited, or autoimmune diseases. However, our understanding of reconstituted hematopoiesis in transplant patients remains limited. Here, we uncover the reconstitution dynamics of human allogeneic hematopoietic stem and progenitor cells (HSPCs) at single-cell resolution after transplantation. Transplanted HSPCs underwent rapid and measurable changes during the first 30 days after transplantation, characterized by a strong proliferative response on the first day. Transcriptomic analysis of HSPCs enabled us to observe that immunoregulatory neutrophil progenitors expressing high levels of the S100A gene family were enriched in granulocyte colony-stimulating factor-mobilized peripheral blood stem cells. Transplant recipients who developed acute graft-versus-host disease (aGVHD) infused fewer S100Ahigh immunoregulatory neutrophil progenitors, immunophenotyped as Lin-CD34+CD66b+CD177+, than those who did not develop aGVHD. Therefore, our study provides insights into the regenerative process of transplanted HSPCs in human patients and identifies a potential criterion for identifying patients at high risk for developing aGVHD early after transplant.

Prediction of mobilized hematopoietic stem cell yield in patients with multiple myeloma: Usefulness of whole-body MRI-derived indices.

INTRODUCTION: High-dose chemotherapy followed by autologous stem cell transplant is the mainstay of treatment for multiple myeloma (MM). The purpose of this study was to evaluate the ability of MRI-derived indices to predict mobilized hematopoietic stem cell yield. MATERIALS AND METHODS: In this exploratory pilot work, we retrospectively analyzed 38 mobilization procedures for MM. Successful mobilization procedure was defined as a total yield of >4.0×106 CD34+ cells/kg. Univariate and multivariate analyses were performed to identify factors with a significant effect on successful mobilization from among clinical characteristics including number of prior lines of therapy, period from diagnosis to harvest, type of monoclonal protein (M protein); and radiological characteristics including total diffusion volume (tDV), median apparent diffusion coefficient (ADC) of tDV, and mean fat fraction of bone marrow calculated by MRI. RESULTS: Univariate analyses showed that relatively poor mobilization was significantly associated with M protein of Bence-Jones type and with median ADC of tDV (P = 0.02 and P = 0.004, respectively). Multivariate analyses using these two indices showed that median ADC of tDV was a significant predictive factor for adequate mobilization (P = 0.01), with an area under the curve of 0.784 (cutoff value, 1.18×10-3 mm2/s; sensitivity, 72.7%; specificity, 87.5%). CONCLUSION: The present data indicate that median ADC of tDV is a predictive factor for relatively poor mobilization of hematopoietic stem cells in MM patients undergoing autologous stem cell transplant.

Effect of Autograft CD34+ Dose on Outcome in Pediatric Patients Undergoing Autologous Hematopoietic Stem Cell Transplant for Central Nervous System Tumors.

Consolidation with autologous hematopoietic stem cell transplantation (HSCT) has improved survival for patients with central nervous system tumors (CNSTs). The impact of the autologous graft CD34+ dose on patient outcomes is unknown. We wanted to analyze the relationship between CD34+ dose, total nucleated cell (TNC) dose, and clinical outcomes, including overall survival (OS), progression-free survival (PFS), relapse, non-relapse mortality (NRM), endothelial-injury complications (EIC), and time to neutrophil engraftment in children undergoing autologous HSCT for CNSTs. A retrospective analysis of the CIBMTR database was performed. Children aged <10 years who underwent autologous HSCT between 2008 to 2018 for an indication of CNST were included. An optimal cut point was identified for patient age, CD34+ cell dose, and TNC, using the maximum likelihood method and PFS as an endpoint. Univariable analysis for PFS, OS, and relapse was described using the Kaplan-Meier estimator. Cox models were fitted for PFS and OS outcomes. Cause-specific hazards models were fitted for relapse and NRM. One hundred fifteen patients met the inclusion criteria. A statistically significant association was identified between autograft CD34+ content and clinical outcomes. Children receiving >3.6×106/kg CD34+ cells experienced superior PFS (p = .04) and OS (p = .04) compared to children receiving ≤3.6 × 106/kg. Relapse rates were lower in patients receiving >3.6 × 106/kg CD34+ cells (p = .05). Higher CD34+ doses were not associated with increased NRM (p = .59). Stratification of CD34+ dose by quartile did not reveal any statistically significant differences between quartiles for 3-year PFS (p = .66), OS (p = .29), risk of relapse (p = .57), or EIC (p = .87). There were no significant differences in patient outcomes based on TNC, and those receiving a TNC >4.4 × 108/kg did not experience superior PFS (p = .26), superior OS (p = .14), reduced risk of relapse (p = .37), or reduced NRM (p = .25). Children with medulloblastoma had superior PFS (p < .001), OS (p = .01), and relapse rates (p = .001) compared to those with other CNS tumor types. Median time to neutrophil engraftment was 10 days versus 12 days in the highest and lowest infused CD34+ quartiles, respectively. For children undergoing autologous HSCT for CNSTs, increasing CD34+ cell dose was associated with significantly improved OS and PFS, and lower relapse rates, without increased NRM or EICs.

Association of CD34+ Cell Dose with Progression-free Survival after Allogeneic Peripheral Blood Hematopoietic Cell Transplantation in Children with Hematologic Malignancies.

BACKGROUND: A higher CD34+ cell dose is associated with improved engraftment but may also be associated with an increased risk of complications after allogeneic hematopoietic stem cell transplantation, including graft-versus-host disease (GVHD). METHODS: We retrospectively analyze the impact of CD34+ cell dose on OS, PFS, neutrophil engraftment, platelet engraftment, treatment-related mortality, and GVHD grading. RESULTS: For analyses, CD34+ cell dose was stratified into low (< 8.5 × 106/kg) and high (> 8.5 × 106/kg). A subgroup analysis of higher CD34+ cell dose leads to prolonged OS and PFS, but statistical significance was achieved only for PFS (OR 0.36; 95%CI 0.14-0.95; P = 0.04). CONCLUSIONS: This study reinforced that CD34+ cell dose at the time of allo-HSCT retained a positive impact on PFS.

Manufacturing of CD34 + HPC-enriched, high-purity mononuclear cell products from umbilical cord blood.

The purpose of this study was to explore methods of selectively enriching CD34 + haematopoietic progenitor cells (HPC) in mononuclear cell (MNC) preparations, and to outline a procedure for cryopreservation and thawing of manufactured material. Density gradient centrifugation of umbilical cord blood was achieved using Ficoll-Paque™ media at 1.077 g/mL and 1.065 g/mL densities and Leucosep preparation tubes. Post-process samples were analysed for CD34 + and MNC content. Finally, MNCs were frozen down at a concentration of 8.5 × 106 cells/mL in CryoStor CS10 using an Asymptote VIAFreeze controlled rate freezer at a rate of - 2 °C per minute, then thawed and analysed for viability and recovery. Processing with 1.065 g/mL media selectively depleted non-HPC cell types, producing an approximately fourfold increase in CD34 + frequency (M ± 1SD = 1.4 ± 1.3%, P < 0.01) relative to the pre-process sample (M ± 1SD = 0.4 ± 0.3%), whereas 1.077 g/mL media produced only a twofold enrichment (0.7 ± 0.6, P < 0.01). This was not accompanied by any significant forfeit of CD34 + recovery (79 ± 32% vs. 78 ± 32% respectively; P = 0.87). The MNCs generated by the 1.065 g/mL procedure were of greater purity (96 ± 2%) than in the 1.077 g/mL procedure (80 ± 7%, P < 0.01). Post-thaw, MNC viability was 95 ± 1% and CD34 + viability was 98 ± 1%. Ultra-pure MNCs rich in CD34 + HPCs can be generated with a simple, inexpensive modification to Ficoll-Paque™ media. These products can be easily cryopreserved using a simple controlled rate freezing procedure.

Stemness-related genes revealed by single-cell profiling of naïve and stimulated human CD34+ cells from CB and mPB.

BACKGROUND: Hematopoietic stem cells (HSCs) from different sources show varied repopulating capacity, and HSCs lose their stemness after long-time ex vivo culture. A deep understanding of these phenomena may provide helpful insights for HSCs. METHODS: Here, we applied single-cell RNA-seq (scRNA-seq) to analyse the naïve and stimulated human CD34+ cells from cord blood (CB) and mobilised peripheral blood (mPB). RESULTS: We collected over 16 000 high-quality single-cell data to construct a comprehensive inference map and characterised the HSCs under a quiescent state on the hierarchy top. Then, we compared HSCs in CB with those in mPB and HSCs of naïve samples to those of cultured samples, and identified stemness-related genes (SRGs) associated with cell source (CS-SRGs) and culture time (CT-SRGs), respectively. Interestingly, CS-SRGs and CT-SRGs share genes enriched in the signalling pathways such as mRNA catabolic process, translational initiation, ribonucleoprotein complex biogenesis and cotranslational protein targeting to membrane, suggesting dynamic protein translation and processing may be a common requirement for stemness maintenance. Meanwhile, CT-SRGs are enriched in pathways involved in glucocorticoid and corticosteroid response that affect HSCs homing and engraftment. In contrast, CS-SRGs specifically contain genes related to purine and ATP metabolic process, which is crucial for HSC homeostasis in the stress settings. Particularly, when CT-SRGs are used as reference genes for the construction of the development trajectory of CD34+ cells, lymphoid and myeloid lineages are clearly separated after HSCs/MPPs. Finally, we presented an application through a small-scale drug screening using Connectivity Map (CMap) against CT-SRGs. A small molecule, cucurbitacin I, was found to efficiently expand HSCs ex vivo while maintaining its stemness. CONCLUSIONS: Our findings provide new perspectives for understanding HSCs, and the strategy to identify candidate molecules through SRGs may be applicable to study other stem cells.

Validation of a rapid potency assay for cord blood stem cells using phospho flow cytometry: The IL-3-pSTAT5 assay.

INTRODUCTION: Public cord blood banks (CBBs) are required to measure cord blood units (CBUs) potency before their release, allowing for the identification of units that may be unsuitable for haematopoietic transplantation. We have developed a rapid flow cytometry assay based on the measurement of STAT-5 phosphorylation of CD34+ stem cells in response to IL-3 stimulation. METHOD: To adapt the assay from a research setting to its implementation within our CBB regulated operations, we proceded with a full method validation and a correlation comparison of the IL-3-pSTAT5 assay results with the colony-forming unit assay (CFU) results. A total of 60 CBUs cryopreserved in vials were analysed by flow cytometry to determine the sensitivity, specificity, intra-assay precision, robustness, reproducibility, and inter-laboratory agreement of the assay. The CFU assay was also done on the same samples for comparison purposes. RESULTS: The assay threshold was established at 50% CD34+CD45+pSTAT5+, which provides a 100% sensitivity and a 98.3% specificity. An average intra-assay CV of 7.3% was determined. All results met our qualitative results acceptance criteria regarding the inter-user and inter-laboratory agreements, IL-3 stimulation time, post-thaw incubation delay and staining time. The IL-3-pSTAT5 assay results correlated well with the total CFU determined using the CFU assay (r2  = 0.82, n = 56). CONCLUSION: This study shows that our rapid flow cytometry assay can be successfully validated and that the potency data obtained display good sensitivity, specificity and robustness. These results demonstrate the feasibility of implementing this assay within CBB operations, as a validated potency assay.

CD34 negative HLA-DR negative acute myeloid leukaemia: A higher association with NPM1 and FLT3-ITD mutations.

INTRODUCTION: CD34 and HLA-DR negativity is often used as a characteristic immunophenotypic feature of acute promyelocytic leukaemia (APL) that differentiates APL from other subtypes of acute myeloid leukaemia (AML). However, other subtypes of AML, without expression of CD34 and HLA-DR antigens, have also been reported. METHODS: We analysed the HLA-DR negative de novo non-APL AML cases by dividing HLA-DR negative non-APL group into 2 sub-groups based on CD34 expression and compared the characteristics of CD34 negative HLA-DR negative with CD34 positive HLA-DR negative non-APL AML cases with respect to morphologic, immunophenotypic, molecular and clinical parameters. RESULTS: There were 70 cases (8.54%) which were CD34 negative HLA-DR negative and 52 cases (6.34%) were CD34 positive HLA-DR negative. The median age at diagnosis was higher in CD34 negative HLA-DR negative AML than in CD34 positive HLA-DR negative AML group (38 years vs. 12 years, p < 0.001). DIC rate was higher in CD34 negative HLA-DR negative group than the other group (p < 0.001). Median total leucocyte count was higher with higher blast count in peripheral blood and bone marrow in CD34 negative HLA-DR negative AML cases than the other group (p < 0.05). CD34 negative HLA-DR negative AML was more associated with normal karyotype (96.2% vs. 38.5%; p < 0.001), NPM1 mutation (67.8% vs. 8.3%; p < 0.001) and FLT-ITD mutation (37.3% vs. 13.9%; p < 0.05). In CD34 negative HLA-DR negative group, 16 cases had co-occurrence of NPM1 and FLT3-ITD mutations, whereas no case of CD34 positive HLA-DR negative group had such dual mutation positivity. There was poor median overall survival [3.8 months (95%CI: 2.3-7.8 months) vs. 20.4 months (95% CI: 12.8-25.7 months); p = 0.0148] in CD34 positive HLA-DR negative AML than CD34 negative HLA-DR negative AML cases. CONCLUSION: We found that the CD34 negative HLADR negative non APL AML is highly associated with NPM1 and FLT3-ITD mutation, older age at diagnosis, DIC, higher total leucocyte count, higher blast counts and normal karyotype in comparison to CD34 positive HLA-DR negative AML group. Co-occurrence of NPM1 and FLT3-ITD mutation was also exclusively seen in CD34 negative HLA-DR negative group. There was poor overall survival in CD34 positive HLA-DR negative AML than CD34 negative HLA-DR negative AML cases.

Durable Engraftment and Excellent Overall Survival After CD34-Selected Peripheral Blood Stem Cell Boost in Pediatric Patients With Poor Graft Function Following Allogeneic Stem Cell Transplantation.

Poor graft function (PGF) is a life-threatening complication after allogeneic stem cell transplantation (alloSCT). Historically, outcomes of patients with PGF have been very poor, and there are no standardized approaches to treatment. Furthermore, few outcomes after CD34-selected stem cell boost (CD34+SCB) for PGF in pediatric alloSCT recipients have been reported. Here we report on a single center experience with CD34+SCB for PGF after alloSCT in patients treated on the Pediatric Transplant and Cellular Therapy Service at MSK Kids, Memorial Sloan Kettering Cancer Center. A retrospective analysis of patients transplanted for malignant and nonmalignant disorders who received a CD34+SCB between 2008 to 2020 for treatment of PGF defined as the need for granulocyte colony-stimulating factor (G-CSF) and/or packed red blood cell or platelet transfusion support with bone marrow donor chimerism ≥85%. Peripheral blood stem cells from the original donor were the source for CD34+SCB. Durable complete recovery (durable CR) was defined as recovery of peripheral blood counts without recurrent need for G-CSF or transfusion support. The main outcomes of interest were recovery of hematopoiesis and overall survival. Development of graft versus host disease (GVHD) was an additional outcome of interest. Fourteen patients with PGF received a boost. Six patients had no known infection, while 8 patients had PGF associated with an infection. The probability of CR at 60 days was 79% (95% confidence interval [CI], 57%-100%). The overall survival at both 2 and 5 years was 78% (95% CI, 56%-100%). One patient developed GVHD, which was fatal. No other CD34+SCB-related toxicities were observed. While including patients with PGF as recently defined by the American Society for Transplantation and Cellular Therapy, as well as PGF in patients with concomitant infections, we demonstrate that CD34+SCB is safe and can provide for durable trilineage hematopoietic recovery and long-term survival in pediatric patients after alloSCT.

Frequency Of CD34 Expression In Acute Lymphoblastic Leukaemia And Its Correlation With Clinicopathological Characteristics: A Single Centre Experience From Pakistan.

Background: This study was carried out to determine the frequency of CD34 positivity in acute lymphoblastic leukaemia (B-ALL) in our population and to report its association with the clinicopathological profile at the time of diagnosis. Methods: The cross-sectional study was conducted at National Institute of Blood Diseases and Bone Marrow Transplantation, Karachi, Pakistan, from March 2020 till December 2020.Newly diagnosed patients were selected, from both genders and all age groups. Relevant history and findings of physical examination were recorded. Immunohistochemistry was done on trephine biopsy and molecular studies were carried on bone marrow aspirates or peripheral blood samples. Results: Out of 105 patients enrolled, 67 (63.8%) were males, with a male to female ratio (M: F) 1.8:1. Of the total patients, 62 (59.04%) were above 15 years of age. CD34 was expressed in 73 (69.5%) cases. Lymphadenopathy, splenomegaly, and hepatomegaly were separately noted in context to CD 34 expression in 22 (66.6%), 24 (64.8%), and 14 (58.3%) patients, respectively. CNS disease was seen in a total of 3(2.75%) subjects, in which 2 (66.6%) of the patients had CD34 expression. Total 81 patients in our study fall into the high-risk group out of which CD 34 expression was seen in 58(71.6%) subjects. Cytogenetic analysis, BCR-ABL p190, and MLL gene rearrangement were investigated in all participants. Cytogenetic analysis revealed an abnormality in 20 (19%) cases out of which 13 (17.8%) cases were from CD34 positive group. Conclusion: Our study reported CD34 expression in more than two-thirds of cases. High-risk disease was significantly associated with CD34 expression.

Immunohistochemical expression of renin and GATA3 help distinguish juxtaglomerular cell tumors from renal glomus tumors.

Juxtaglomerular cell tumors and glomus tumors both arise from perivascular mesenchymal cells. Juxtaglomerular cells are specialized renin-secreting myoendocrine cells in the afferent arterioles adjacent to glomeruli, and juxtaglomerular tumors derived from these cells are therefore unique to the kidney. In contrast, glomus tumors have been described at numerous anatomic sites and may show significant morphologic and immunophenotypic overlap with juxtaglomerular tumors when occurring in the kidney. Although ultrastructural studies and immunohistochemistry for renin may distinguish these entities, these diagnostic modalities are often unavailable in routine clinical practice. Herein, we studied the clinicopathologic features of a large series of juxtaglomerular tumors (n = 15) and glomus tumors of the kidney (n = 9) to identify features helpful in their separation, including immunohistochemistry for smooth muscle actin (SMA), CD34, collagen IV, CD117, GATA3, synaptophysin, and renin. Markers such as SMA (juxtaglomerular tumors: 12/13, 92%; glomus tumors: 9/9, 100%), CD34 (juxtaglomerular tumors: 14/14, 100%; glomus tumors: 7/9, 78%), and collagen IV (juxtaglomerular tumors: 5/6, 83%; glomus tumors: 3/3, 100%) were not helpful in separating these entities. In contrast to prior reports, all juxtaglomerular tumors were CD117 negative (0/12, 0%), as were glomus tumors (0/5, 0%). Our results show that juxtaglomerular tumors have a younger age at presentation (median age: 27 years), female predilection, and frequently exhibit diffuse positivity for renin (10/10, 100%) and GATA3 (7/9, 78%), in contrast to glomus tumors (median age: 51 years; renin: 0/6, 0%; GATA3: 0/6, 0%). These findings may be helpful in distinguishing these tumors when they exhibit significant morphologic overlap.

Leukocytapheresis variables and transit time for allogeneic cryopreserved hpc: better safe than sorry.

Cryopreservation was recommended to ensure continuity in allogeneic hematopoietic progenitor cells (HPC) transplantation during the COVID-19 pandemic. Several groups have shown no impact on clinical outcomes for patients who underwent HPC transplantation with cryopreserved products during the first months of this pandemic. However, concerns about quality control attributes after cryopreservation have been raised. We investigated, in 155 allogeneic peripheral blood cryopreserved HPC, leukocytapheresis characteristics influencing viable CD34+ and CD3+ cells, and CFU-GM recoveries after thawing. Collection characteristics such as volume, nucleated cells (NC)/mL and hematocrit correlated with viable CD34+ and CD3+ cells recoveries after thawing in univariate analysis but only CD3+ cells remained statistically significant in multivariate analysis (r2 = 0.376; P = < 0.001). Additionally, transit time also showed correlation with viable CD34+ (r2 = 0.186), CD3+ (r2 = 0.376) and CFU-GM recoveries (r2 = 0.212) in multivariate analysis. Thus, diluting leukocytapheresis below 200 × 106 NC/mL, avoiding red cells contamination above 2%, cryopreserving below 250 × 106 NC/mL and minimizing transit time below 36 h, prevented poor viable CD34+ and CD3+ cells, and CFU-GM recoveries. In summary, optimizing leukocytapheresis practices and minimizing transportation time may better preserve the quality attributes of HPC when cryopreservation is indicated.

Mobilization with high-dose granulocyte colony-stimulating factor alone at 12 µg/kg twice a day in high-risk pediatric patients: A retrospective analysis of the experience in a single center.

INTRODUCTION: Mobilization regimes in pediatric patients at high risk for poor mobilization are not standardized across different institutions. We present a retrospective analysis of our experience with a high-dose granulocyte colony-stimulating factor (G-CSF) regime of 12 µg/Kg per body weight (BW) twice a day for 4 days used in high-risk patients. MATERIAL AND METHODS: We report the results of all pediatric patients mobilized with high-dose G-CSF between January 1999 and February 2021 in our center. A successful mobilization was defined as a peripheral blood (PB) CD34+ cell count of ≥10 CD34+ cells/µl on the fifth day of mobilization immediately before leukapheresis. A minimum cell yield of ≥2 × 106 CD34+ cells/Kg of BW was required for a successful collection. RESULTS: Of the 262 patients included in the analysis, mobilization failure was found in 27 (10.3%). In a univariate analysis, this was associated with age, weight, baseline diagnosis, and having undergone a previous mobilization cycle, the latter being the only factor that remained significantly associated in a multivariate analysis (P = 0.03). The 54 patients (20.6%) did not reach the minimum required CD34+ cell yield. 50.4% of the patients reported adverse events (AEs) during the mobilization period, and 23 (9.1%) reported 3 or more concomitant AEs. However, all of them were mild and did not affect the mobilization schedule. CONCLUSIONS: Although most high-risk pediatric patients are successfully mobilized with the high-dose G-CSF regime, this approach does not salvage all of them and significantly increases the presence of AEs in comparison to standard-dose regimes.

Telocytes in the esophageal wall of chickens: a tale of subepithelial telocytes.

The esophagus is a tubular organ which act as a passage for food from oral cavity to stomach. Telocytes (TCs) are a unique type of interstitial cell whose existence in many organs of various species still remains unknown. In the present study, we used transmission electron microscopy (TEM) and immunohistochemistry (CD34, Vimentin, PDGFR-α) to identify subepithelial TCs in the esophageal wall of chickens. TEM micrographs confirmed the presence of TCs in the lamina propria, tunica submucosa, and tunica muscularis muscular layer of the esophageal wall. A large population of TCs were observed just beneath the epithelial layer of the esophageal wall, and the TCs demonstrated structural heterogenicity, featuring various cell body shapes of cell bodies and telopodes (Tps) with podoms, podomeres, and dichotomous branching. Furthermore, a large number of extracellular vesicles were found to be associated with TCs/Tps. Cellular extensions from TCs were observed in close proximity to blood vessels, immune cells, and mucosal glands. In the submucosa, Tps and immune cells were in very close contact. Immunohistochemical results showed that there were CD34+ cells, vimentin+ cells, and PDGFR-α+ cells in the subepithelium, lamina propria, and mucosal glands of the chicken esophageal wall, which was consistent with the TEM results. Overall, our data confirmed the existence of TCs in the chicken esophagus and suggested that TCs might contribute to epithelial regeneration and tissue homeostasis.