The ISHAGE guidelines for CD34+ cell determination by flow cytometry. International Society of Hematotherapy and Graft Engineering

Orchestration of Chemomobilization and G-CSF Administration for Successful Hematopoietic Stem Cell Collection

Successful collection of peripheral blood stem cells (PBSCs) depends on the optimal orchestration of mobilization chemotherapy, granulocyte colony stimulating factor (G-CSF) application, and CD34⁺ cell number assessment in the peripheral blood (PB). However, determining the optimal timing in accordance to the applied chemomobilization regimen can be challenging. Although most centers apply their own local timing schedules, a reliable timetable including the currently most often used mobilization regimens is lacking. We present a comprehensive analysis of the timing modalities for 11 of the most commonly used chemomobilization regimens. A retrospective analysis was performed on the clinical and PBSC collection parameters (including duration of G-CSF application, time point of CD34⁺ assessment, PB CD34⁺ cell count, number of leukapheresis [LP] sessions, processed blood volume, and CD34⁺ collection results) of 91 representatively selected patients who had undergone stem cell mobilization at 2 collection centers. Six to 10 patients were analyzed per regimen with a variety of diagnoses, including multiple myeloma, malignant lymphoma, and sarcoma. No collection failures (<2 × 10⁶ CD34⁺ cells/kg body weight) were observed. All analyzed patients successfully reached their individual collection goal in adherence to the given schedule of chemotherapy, application of G-CSF, measurement of CD34⁺ cells, and subsequent LP. The presented data on the timing of chemomobilization, G-CSF application, and stem cell collection may be helpful in clinical decision making and contribute to a more transparent and predictable treatment process.

Pegylated Filgrastim Versus Filgrastim for Stem Cell Mobilization in Multiple Myeloma After Novel Agent Induction

BACKGROUND

The current standard of care for transplant-eligible myeloma patients is novel agent-based induction, followed by high-dose chemotherapy and autologous stem cell rescue. Chemo-mobilization of peripheral blood CD34⁺ stem cells (PBSCs) with pegylated filgrastim (pegfilgrastim), a sustained-duration formulation of filgrastim, has been used as an alternative to filgrastim in several studies involving heterogeneous cohorts of lymphoma and multiple myeloma (MM) patients and shown to be equivalent in PBSC yield and cost-effectiveness. The present study focused on the efficacy of pegfilgrastim in PBSC mobilization compared with filgrastim exclusively after novel agent-based induction in a homogeneous group of MM patients.

PATIENTS AND METHODS

We analyzed the data from 89 patients with MM treated at 2 transplant centers in Singapore who had received novel agent-based induction chemotherapy, PBSC mobilization with vinorelbine/cyclophosphamide, high-dose melphalan conditioning, and autologous stem cell rescue. Of the 89 patients, 61 were included in the pegfilgrastim group and 28 in the filgrastim group, with a similar median age and disease characteristics. PBSC harvesting was performed at a similar median time of 9.51 ± 0.84 days for both, and the peak peripheral blood CD34⁺ stem cell count was 19.90 × 10⁶/kg for pegfilgrastim and 32.50 × 10⁶/kg for filgrastim (95% confidence interval, -4.36 to 0.70 × 10⁶/kg).

RESULTS

No significant difference was found in the median PBSC collection between the 2 groups (pegfilgrastim, 7.90 × 10⁶/kg vs. filgrastim, 10.10 × 10⁶/kg; P = .16).

CONCLUSION

The present study has demonstrated that a single dose of pegfilgrastim is comparable to filgrastim in terms of the timing and efficacy of PBSC harvest and could potentially spare the patient 6 days of filgrastim injections. In addition, ours is the first study to compare these growth factors using vinorelbine/cyclophosphamide as mobilization chemotherapy.

Outcome of 51 autologous peripheral blood stem cell transplants after uncontrolled-rate freezing ("dump freezing") using -80°C mechanical freezer

BACKGROUND AND OBJECTIVE:

Controlled-rate freezing is a complicated, expensive, and time-consuming procedure. Therefore, there is a growing interest in uncontrolled-rate freezing (UCF) with −80°C mechanical freezers for cryopreservation of hematopoietic stem cells. This is a retrospective analysis of efficiency of UCF and outcome of autologous peripheral hematopoietic stem cell (PBSC) transplants at our center from December 2011 to June 2016.

MATERIALS AND METHODS:

Cryoprotectant solutions used included 5% dimethyl sulfoxide and 5% albumin with 2% hydroxyethyl starch and stored at −80°C mechanical freezer till transplant. Evaluation of cryopreservation was studied by analyzing the variation in cellularity, viability, and CD34+ stem cell dose recovery as well as clinical follow-up with engraftment.

RESULTS:

A total of 51 patients (23 females and 28 males) underwent autologous PBSC transplantations with a median age of 31 years (range: 3–60 years) for both hematological and nonhematological indications. Mean recovery post by UCF at −80°C mechanical was 92.9% ± 15.5% for nucleated cells, 86.6% ± 15.5% for viability, and 80% ± 21.5% in CD34+ dose. The median day to neutrophil engraftment was 10 (range 5–14 days) and platelets engraftment was 15 (range 8–45 days). The cryopreserved products were stored at −80°C for median 7 days (range 2-41 day) before transplant.

DISCUSSION/CONCLUSION:

Our analysis shows that PBSC can be successfully cryopreserved with mechanical uncontrolled rate freezing. This is a cheap and simple method to freeze the stem cells for a short period in resource-constrained setting.

Possible mechanism underlying the association between height and vascular remodeling in elderly Japanese men

Height is reported to be inversely associated with cardiovascular disease. And platelets play an important role in vascular remodeling by supporting CD34-positive cells. To clarify the association between height and platelet, we conducted a cross-sectional study of 219 elderly Japanese men. Since hemoglobin concentration is influenced by vascular remodeling activity, an analysis stratified by hemoglobin level was performed. An inverse association was seen between height and platelet count in subjects with a high hemoglobin concentration (≥ 14.5 g/dL), but not in subjects with a low hemoglobin concentration (< 14.5 g/dL). The standardized parameter estimates (β) were β = -0.22, p = 0.019 for subjects with high hemoglobin, and β = -0.01, p = 0.931 for subjects with low hemoglobin. We also found a positive association between platelets and carotid intima media thickness (CIMT) and circulating CD34-positive cells in subjects with high hemoglobin (partial correlation coefficient (r) = 0.21, p = 0.037 and r = 0.40, p =< 0.001), but not in subjects with low hemoglobin (r = 0.04, p = 0.710 and r = 0.06, p = 0.544). In subjects with a high hemoglobin concentration, platelets were inversely associated with height, and positively associated with CIMT and circulating CD34-positive cells. These results indicate that subjects with a short stature activate vascular remodeling to a much greater extent than subjects with a tall stature.

Impact of Single-Dose Plerixafor as an Adjunct to Granulocyte Colony-Stimulating Factor-Based Peripheral Blood Stem Cell Mobilization on the Graft Composition and Outcome for T Cell-Replete Haploidentical Peripheral Blood Stem Cell Transplantation with Post-Transplantation Cyclophosphamide: A Comparative Study

We conducted a prospective study on T and natural killer (NK) cell subset composition of graft and transplant outcomes in T cell-replete haploidentical transplantation with a single dose of subcutaneous plerixafor (Px) added to granulocyte colony-stimulating factor (G-CSF)-based mobilization in allogeneic donors to collect 10 × 10⁶/kg CD34⁺ hematopoietic stem cells (HSCs) at single apheresis. Twnety-six donors received G-CSF + Px and 25 G-CSF alone for mobilization. Despite significantly lower peripheral blood (PB) CD34⁺ HSCs on day 4 in the G-CSF + Px group (33 [range, 6-47] cells/µL versus 81 [range, 50-168] cells/µL in the G-CSF group; P = .0001), PB CD34⁺ HSC count (median 136 versus 139 cells/µL) on day 5 as well as that in the graft (2.7 versus 2.3 × 10⁶/mL, P = .1) were comparable between the 2 groups. The total nucleated cell count was higher (3.4 versus 3.1 × 10⁸/mL, P = .05), but CD4⁺ T cells (2.3 versus 2.7 × 10⁷/mL, P = .09) were lower in the G-CSF group with mobilization of regulatory T cells being similar. NK cells were skewed toward the CD56⁺/16^- subset in both groups, varying significantly from the steady-state NK subset ratio in PB. The time to engraftment, incidences of acute and chronic graft-versus-host disease, nonrelapse mortality, and overall survival were also similar. Addition of single-dose Px to G-CSF mobilization improves CD34 recovery and does not significantly alter the T and NK cell composition of the graft, including regulatory T cells, with no adverse impact on transplant outcomes.

Two versus three day upfront use of granulocyte-colony stimulating factor in healthy bone marrow donors for pediatric bone marrow transplantation

In order to decrease donors' exposure to granulocyte-colony stimulating factor (G-CSF), we compared the effect of two versus three days of G-CSF priming on CD34+ yield in bone marrow (BM) harvest. Although the number of BM-CD34+ cells was higher in 3day G-CSF priming, we achieved the same number of CD34+ cells per recipient's weight in 2day G-CSF priming group, too. In addition, the number of total nucleated cells (TNC) harvested from BM were similar with two or three day regimen. But mononuclear cells (MNC) of the BM graft was higher in the 3day G-CSF priming group. Similar to CD34+ cell numbers, BM harvest yielded similar TNC, and MNC numbers per kilogram of the recipient. We also found that, young donors (≤10year) had more peripheral blood MNC, bone marrow MNC and CD34+ cell numbers. Another interesting finding of this study was obtaining adequate number of peripheral blood stem cells for leukapheresis with three day G-CSF administration. Since engrafment times were also similar in two groups, we concluded that 2-days G-CSF priming was resulted in sufficient mobilization of BM stem cells.

Triglycerides and blood pressure in relation to circulating CD34-positive cell levels among community-dwelling elderly Japanese men: a cross-sectional study

Background

Triglycerides are reported to be positively associated with blood pressure (both systolic and diastolic). However, in a previous study, we reported a significant positive association between triglycerides and circulating CD34-positive cells (endothelial repair) among non-hypertensive, but not hypertensive, participants. Since hypertension and endothelial dysfunction have a bi-directional association (vicious cycle), the status of circulating CD34-positive cells may influence the association between triglycerides and hypertension.

Methods

Since antihypertensive medication use may influence results of the present study, we conducted a cross-sectional study of 327 community dwelling elderly (aged 60–69 years) Japanese participants who were not taking anti-hypertensive medication and who had participated in a general health check-up in 2013–2015.

Results

Participants were classified into two groups based on median values of circulating CD34-positive cells (0.93 cells/μL). For participants with lower circulating CD34-positive cells (n = 165), a significant positive association was seen between triglycerides and blood pressure, but not for participants with higher circulating CD34-positive cells (n = 162). The multivariable standardized parameter estimates (β) and p values of systolic blood pressure and diastolic blood pressure were 0.23 (p = 0.007) and 0.18 (p = 0.036) for participants with lower circulating CD34-positive cells and 0.08 (p = 0.409) and 0.03 (p = 0.786) for those with higher circulating CD34-positive cells.

Conclusion

A significant positive association between triglycerides and blood pressure exists among those with lower, but not higher, circulating CD34-positive cells. The level of circulating CD34-positive cells acts as a determinant factor for the association between triglycerides and blood pressure.

Comparison of human umbilical cord blood processing with or without hydroxyethyl starch

BACKGROUND

Umbilical cord blood (UCB) processing with hydroxyethyl starch (HES) is the most common protocol in the cord blood banks. The quality of UCB volume reduction was guaranteed by minimum manipulation of cord blood samples in the closed system. This study aimed to analyze and compare cell recovery and viability of UCB processed using the Sepax automated system in the presence and absence of HES.

STUDY DESIGN AND METHODS

Thirty UCB bags with a total nucleated cell (TNC) count of more than 2.5 × 109 were divided in two bags with equal volume. HES solution was added to one bag and another was intact. Both bags were processed with the Sepax. To determine cell recovery, viability, and potential of colony-forming cells (CFCs), preprocessing, postprocessing, and thawing samples were analyzed.

RESULTS

The mean TNC recovery after processing and after thaw was significantly better with the HES method (p < 0.01 for the postprocessing step and p < 0.05 for the postthaw step). There were no significant differences to mononucleated cells (MNCs) and CD34+ cell recovery between the two methods after processing and after thaw. TNC and MNC viability was significantly higher without HES after processing and after thaw (p < 0.01). The results of the CFC assay were similar for both methods after processing and after thaw.

CONCLUSION

These results showed that processing of UCB using the Sepax system with the without-HES protocol due to the lower manipulation of samples could be used as an eligible protocol to reduce the volume of UCB.

Alpha-2-macroglobulin as a Promising Biological Marker of Endothelial Function

Aims: Alpha-2-macroglobulin (α₂MG) is thought to be associated with inflammatory reactions and procoagulant properties that might cause ischemic stroke. Endothelial dysfunction plays an important role in atherosclerosis development and in the occurrence of cardiovascular events. In this study, we investigated whether serum α₂MG levels, endothelial function, and endothelial progenitor cell (EPC) number were associated in patients with chronic stroke or cardiovascular risk factors.

Methods: Patients with a history of stroke or any established cardiovascular risk factors were enrolled in this study (n = 102; 69 men, 70.1 ± 9.2 years). Endothelial function was assessed by flow-mediated dilation (FMD). EPC numbers (CD34+/CD133+) were measured using flow cytometry (n = 91). Serum α₂MG levels were measured by nephelometry.

Results: Patients in the highest tertile of serum α₂MG levels were older (P = 0.019) and more frequently exhibited dyslipidemia (P = 0.021). Univariate-regression analysis revealed that increased α₂MG levels were negatively associated with FMD values (r = −0.25; P = 0.010), whereas increased EPC numbers were positively associated (r = 0.21; P = 0.044). Multivariate-regression analysis adjusted for male gender, hypertension, and severe white-matter lesions showed that serum α₂MG levels were independently associated with FMD values (standardized partial regression coefficient [β] −0.185; P = 0.033), although not significantly associated with EPC numbers.

Conclusion: Serum α₂MG levels might reflect endothelial dysfunction evaluated by FMD in patients with chronic stroke or cardiovascular risk factors.

Role of circulating endothelial progenitor cells in the reparative mechanisms of stable ischemic myocardium

BACKGROUND

Mobilization of endothelial progenitor cells (EPCs) into circulation from bone marrow in patients with acute myocardial infarction has strong scientific evidence; less is known about EPC mobilization in patients with stable coronary artery disease (CAD). The aim of this study was to investigate the association of stable ischemic heart disease with EPC levels in tissue and blood.

METHODS

Fifty-five consecutive patients admitted to a single treatment center for valve or coronary artery bypass grafting (CABG) surgeries were included in the study. Blood samples were collected in the morning before surgery and analyzed by flow-cytometry to determine peripheral EPC levels (EPC/ml). Tissue EPC (CD34+VEGFR2+) levels were assessed on a right atrial appendage segment.

RESULTS

Mean age was 76±5years, 48% were men, and 53% had CAD The number of CD34+ VEGFR2+ cells in the tissue of patients with CAD was significantly higher (p<0.005) and circulating EPC showed a tendency to be reduced by approximately 20% in peripheral blood of patients with CAD when compared to those without CAD.

CONCLUSION

Patients with stable CAD had higher EPC density values (EPC/mm2) and were more likely to have lower EPC blood levels when compare with normal controls.

Biosimilar G-CSF versus filgrastim and lenograstim in healthy unrelated volunteer hematopoietic stem cell donors

The World Marrow Donor Organization recommends original granulocyte-colony stimulating factor (G-CSF) for the mobilization of stem cells in healthy unrelated hematopoietic stem cell donors. We report the comparison of a biosimilar G-CSF (Zarzio) with two original G-CSFs (filgrastim and lenograstim) in mobilization in unrelated donors. We included data of 313 consecutive donors who were mobilized during the period from October 2014 to March 2016 at the Medical University of Warsaw. The primary endpoints of this study were the efficiency of CD34+ cell mobilization to the circulation and results of the first apheresis. The mean daily dose of G-CSF was 9.1 μg/kg for lenograstim, 9.8 μg/kg for biosimilar filgrastim, and 9.3 μg/kg for filgrastim (p < 0.001). The mean CD34+ cell number per microliter in the blood before the first apheresis was 111 for lenograstim, 119 for biosimilar filgrastim, and 124 for filgrastim (p = 0.354); the mean difference was even less significant when comparing CD34+ number per dose of G-CSF per kilogram (p = 0.787). Target doses of CD34+ cells were reached with one apheresis in 87% donors mobilized with lenograstim and in 93% donors mobilized with original and biosimilar filgrastim (p = 0.005). The mobilized apheresis outcomes (mean number of CD34+ cells/kg of donor collected during the first apheresis) was similar with lenograstim, biosimilar filgrastim, and filgrastim: 6.2 × 10⁶, 7.6 × 10⁶, and 7.3 × 10⁶, respectively, p = 0.06. There was no mobilization failure in any of the donors. Biosimilar G-CSF is as effective in the mobilization of hematopoietic stem cells in unrelated donors as original G-CSFs. Small and clinically irrelevant differences seen in the study can be attributed to differences in G-CSF dose and collection-related factors. Active safety surveillance concurrent to clinical use and reporting to donor outcome registry (e.g., EBMT donor outcome registry or WMDA SEAR/SPEAR) might help to evaluate the possible short- and long-term complications of biosimilar G-CSF.

Increased levels of circulating CD34+ cells in neovascular age-related macular degeneration: relation with clinical and OCT features

PURPOSE

To investigate the levels of circulating CD34+ stem cells in patients with neovascular type age-related macular degeneration (AMD) and its relation with clinical and optical coherence tomography (OCT) findings.

METHODS

The study consisted of 55 patients: 28 patients (18 male and 10 female) with neovascular type AMD as a study group and 27 patients (12 male and 15 female) scheduled for cataract surgery as a control group. The level of CD34+ stem cells was measured by flow cytometry. Demographic and clinical data were recorded.

RESULTS

The mean ages of patients in the study and control groups were 71 ± 8 and 68 ± 6 years, respectively. There was no statistically significant difference in terms of age, sex, or systemic disease association between study and control groups. However, smoking status was significantly higher in the study group (67.9% vs 37.0%; p = 0.02). Stem cell levels were significantly higher in the study group (1.5 ± 0.9 vs 0.5 ± 0.3; p<0.001), but there was no relation between stem cell levels and clinical and OCT findings.

CONCLUSIONS

Increased circulating CD34+ stem cell levels were observed in patients with choroidal neovascular membrane associated with AMD, but no significant relation was found between cell levels and clinical and OCT findings.

[Absolute numbers of peripheral blood CD34+ hematopoietic stem cells prior to a leukapheresis procedure as a parameter predicting the efficiency of stem cell collection]

AIM

To identify a parameter predicting a collection of at least 2·106 CD34+ hematopoietic stem cells (HSC)/kg body weight per leukapheresis (LA) procedure.

SUBJECTS AND METHODS

The investigation included 189 patients with hematological malignancies and 3 HSC donors, who underwent mobilization of stem cells with their subsequent collection by LA. Absolute numbers of peripheral blood leukocytes and CD34+ cells before a LA procedure, as well as a number of CD34+ cells/kg body weight (BW) in the LA product stored on the same day were determined in each patient (donor).

RESULTS

There was no correlation between the number of leukocytes and that of stored CD34+ cells/kg BW. There was a close correlation between the count of peripheral blood CD34+ cells prior to LA and that of collected CD34+ cells calculated with reference to kg BW.

CONCLUSION

The optimal absolute blood CD34+ cell count was estimated to 20 per µl, at which a LA procedure makes it possible to collect 2·106 or more CD34+ cells/kg BW.

Predictors of Mononuclear Cell Yield in Patients Undergoing Autologous Mononuclear Stem Cell Therapy in Non-haemopoietic Degenerative Disorders

Cellular therapy outcomes are influenced by cellular composition of the product. We analyzed the cellular profiles (TNC, MNC and CD34+ cells) of patients receiving mononuclear cell therapy in terms of age, gender, BMI, pre-harvest haematological counts and clinical conditions. Cellular profiles of 262 patients were analyzed in terms of age (age < 40 year, age 41-60 year and age > 60 year), gender, BMI (BMI < 22 kg/m², BMI 22-25 kg/m² and BMI > 25 kg/m²), pre-harvest haematological profile and clinical conditions (chronic disorders, group A, acute vascular group B and traumatic events, group C). A steady decline was observed in TNC and MNC counts with increasing age and BMI. In clinical conditions, group C showed a highest cellular yield followed by group A and group B respectively. Amongst the three age groups, group I (age < 40 year) showed a better cellular profiles than group II (age 41-60 year) and group III (age > 60 year). Patients with Higher TLC (>7000/μl) and platelet count (>200 × 10³/μl) yielded better cellular profile in the harvest. Patient age, BMI, haematological counts and clinical condition significantly affect the bone marrow cellular profile.

Preclinical studies for a phase 1 clinical trial of autologous hematopoietic stem cell gene therapy for sickle cell disease

BACKGROUND AIMS

Gene therapy by autologous hematopoietic stem cell transplantation (HSCT) represents a new approach to treat sickle cell disease (SCD). Optimization of the manufacture, characterization and testing of the transduced hematopoietic stem cell final cell product (FCP), as well as an in depth in vivo toxicology study, are critical for advancing this approach to clinical trials.

METHODS

Data are shown to evaluate and establish the feasibility of isolating, transducing with the Lenti/β^AS3-FB vector and cryopreserving CD34⁺ cells from human bone marrow (BM) at clinical scale. In vitro and in vivo characterization of the FCP was performed, showing that all the release criteria were successfully met. In vivo toxicology studies were conducted to evaluate potential toxicity of the Lenti/β^AS3-FB LV in the context of a murine BM transplant.

RESULTS

Primary and secondary transplantation did not reveal any toxicity from the lentiviral vector. Additionally, vector integration site analysis of murine and human BM cells did not show any clonal skewing caused by insertion of the Lenti/β^AS3-FB vector in cells from primary and secondary transplanted mice.

CONCLUSIONS

We present here a complete protocol, thoroughly optimized to manufacture, characterize and establish safety of a FCP for gene therapy of SCD.

Study of stem cell homing & self-renewal marker gene profile of ex vivo expanded human CD34+ cells manipulated with a mixture of cytokines & stromal cell-derived factor 1

BACKGROUND & OBJECTIVES

Next generation transplantation medicine aims to develop stimulating cocktail for increased ex vivo expansion of primitive hematopoietic stem and progenitor cells (HSPC). The present study was done to evaluate the cocktail GF (Thrombopoietin + Stem Cell factor + Flt3-ligand) and homing-defining molecule Stromal cell-derived factor 1 (SDF1) for HSPC ex vivo expansion.

METHODS

Peripheral blood stem cell (n=74) harvests were analysed for CD34hiCD45lo HSPC. Immunomagnetically enriched HSPC were cultured for eight days and assessed for increase in HSPC, colony forming potential in vitro and in vivo engrafting potential by analyzing human CD45+ cells. Expression profile of genes for homing and stemness were studied using microarray analysis. Expression of adhesion/homing markers were validated by flow cytometry/ confocal microscopy.

RESULTS

CD34hiCD45lo HSPC expansion cultures with GF+SDF1 demonstrated increased nucleated cells (n=28, P+ cells (n=8, P=0.021) and increased colony forming units (cfu) compared to unstimulated and GF-stimulated HSPC. NOD-SCID mice transplanted with GF+SDF1-HSPC exhibited successful homing/engraftment (n=24, PInterpretation & conclusions: Cocktail of cytokines and SDF1 showed good potential to successfully expand HSPC which exhibited enhanced ability to generate multilineage cells in short-term and long-term repopulation assay. This cocktail-mediated stem cell expansion has potential to obviate the need for longer and large volume apheresis procedure making it convenient for donors.

The influence of temperature treatment before cryopreservation on the viability and potency of cryopreserved and thawed CD34+ and CD45+ cord blood cells

BACKGROUND

Hematopoietic stem cell (HSC) viability and potency is crucial for qualified cord blood (CB) transplants. This study analyzes time and temperature condition before cryopreservation for the viability of CD34⁺/CD45⁺ cells after cryopreservation.

METHODS

Cell viabilities were determined by antibody co-staining with 7-aminoactinomycin D detecting necrotic cells, and subsequent flow cytometric analysis. Additionally, Annexin V staining for determination of apoptotic cells and colony-forming unit (CFU) assays for testing functional potency of HSCs were performed.

RESULTS

For all cell types assessed (CD45⁺/CD34⁺ cells, lymphocytes and granulocytes), the highest viabilities were obtained for CB maintained at 4°C or room temperature (RT; 22 ± 4°C) and cryopreserved directly after collection. Starting material were CB units with an age of 24.7 ± 3.5 h after birth. Post-thaw CD34⁺ cell results were > 90% after temperature treatment of t = 24 h (48 h total age) and > 70% after t = 48 h (72 h total age) at 4°C (48 h, 91.4 ± 5.5%; 72 h, 75.0 ± 12.0%) and RT (48 h, 84.2 ± 9.7%; 72 h, 72.6 ± 0.6%). Viabilities for 30°C samples were < 80% after t = 24 h (48 h total age, 79.8 ± 3.1%) and < 50% after t = 48 h of treatment (72 h total age, 46.8 ± 14.3%). Regarding CFU recovery of pre-freeze (without volume reduction) and thawed CB, a trend toward the highest recoveries was observed at 4°C/RT. The difference between 4°C (77.5 ± 12.0%) and 30°C samples (53.9 ± 4.8%) was shown to be significant in post-thaw samples after t = 24 h treatment (48 h total age; P = 0.0341).

DISCUSSION

Delays between collection and cryopreservation should be minimized because increasing time reduces numbers of viable cells and CFUs before/after cryopreservation. CB units should be maintained at 4°C/RT to retain the highest possible potency of the cells after thawing.

Analysis of Factors that Influence Hematopoietic Recovery in Autologous Transplanted Patients with Hematopoietic Stem Cells from Peripheral Blood

BACKGROUND:

Successful hematopoietic stem cell transplantation (HSCT) requires a rapid and durable hematopoietic recovery.

AIM:

The aim of our study was to analyse factors that influence hematopoietic recovery after autologous HSCT.

MATERIALS AND METHODS:

Multiple regression analysis was used to analyse factors affecting neutrophil and platelet engraftment in 90 autologous transplanted patients – 30 with acute myeloid leukaemia (AML), 30 with lymphoma and 30 with multiple myeloma (MM) from 2008 till 2016.

RESULTS:

The neutrophil recovery in AML patients was significantly influenced by transfusion support with random-donor platelets, sex and number of transplanted mononuclear cells (MNC) and CD34+ cells; and in lymphoma patients, it was influenced by sex, age, mobilisation strategy and some transplanted MNC. The influence of investigated factors on neutrophil engraftment in MM patients was not statistically significant. The platelet recovery in AML patients was influenced by transfusion support with random-donor platelets; in lymphoma patients, it was influenced by sex, age, time from diagnosis to harvesting and time from diagnosis to HSCT; and in MM patients it was influenced by transfusion support with random-donor platelets.

CONCLUSION:

Additional studies are necessary to better understanding of engraftment kinetic to improve the safety of HSCT and to minimise potential complications and expenses related to HSCT.

Association between high-density lipoprotein-cholesterol and hypertension in relation to circulating CD34-positive cell levels

Background

Although high-density lipoprotein-cholesterol (HDL) level is inversely correlated with cardiovascular events, HDL is also reported to be positively associated with hypertension, which is a known endothelial impairment factor. Since HDL mediates important protective actions on the vascular endothelium by increasing the number of circulating endothelial progenitor cells (CD34-positive cells), the level of circulating CD34-positive cells should influence the association between HDL and hypertension.

Methods

To investigate the association between HDL and hypertension in relation to the level of circulating CD34-positive cells, we conducted a cross-sectional study of 477 elderly men aged 60–69 years who participated in general health checkup.

Results

HDL was found to be significantly positively associated with hypertension in subjects with a high level of circulating CD34-positive cells, while no significant association was observed for subjects with low circulating CD34-positive cells. Known cardiovascular risk factors adjusted odds (ORs) and 95% confidence intervals (CIs) of hypertension for increments of one standard deviation (SD) in HDL (13.8 mg/dL) were 1.44 (1.06, 1.96) for subjects with a high level of circulating CD34-positive cells and 0.87 (0.63, 1.19) for subjects with low circulating CD34-positive cells. We also revealed a significant association between HDL level and CD34-positive cell level on hypertension, with fully adjusted p values for the effect of this interaction on hypertension at 0.022.

Conclusions

Independent of known cardiovascular risk factors, HDL was found to be positively associated with hypertension in subjects with a high level of circulating CD34-positive cells but not for subjects with low circulating CD34-positive cells.

A theorem proving approach for automatically synthesizing visualizations of flow cytometry data

Background

Polychromatic flow cytometry is a popular technique that has wide usage in the medical sciences, especially for studying phenotypic properties of cells. The high-dimensionality of data generated by flow cytometry usually makes it difficult to visualize. The naive solution of simply plotting two-dimensional graphs for every combination of observables becomes impractical as the number of dimensions increases. A natural solution is to project the data from the original high dimensional space to a lower dimensional space while approximately preserving the overall relationship between the data points. The expert can then easily visualize and analyze this low-dimensional embedding of the original dataset.

Results

This paper describes a new method, SANJAY, for visualizing high-dimensional flow cytometry datasets. This technique uses a decision procedure to automatically synthesize two-dimensional and three-dimensional projections of the original high-dimensional data while trying to minimize distortion. We compare SANJAY to the popular multidimensional scaling (MDS) approach for visualization of small data sets drawn from a representative set of benchmarks, and our experiments show that SANJAY produces distortions that are 1.44 to 4.15 times smaller than those caused due to MDS. Our experimental results show that SANJAY also outperforms the Random Projections technique in terms of the distortions in the projections.

Conclusions

We describe a new algorithmic technique that uses a symbolic decision procedure to automatically synthesize low-dimensional projections of flow cytometry data that typically have a high number of dimensions. Our algorithm is the first application, to our knowledge, of using automated theorem proving for automatically generating highly-accurate, low-dimensional visualizations of high-dimensional data.

Possible mechanism underlying the association between higher hemoglobin level and hypertension in older Japanese men

AIM

Hemoglobin is reported to be positively associated with hypertension. However, the underlying mechanism of this association is unknown. Recently, bone marrow-derived CD34-positive cells have been reported to play an important role in endothelial repair in conjunction with platelets. As the association between hypertension and endothelial dysfunction is bidirectional, the influence of endothelial repair also might strongly influence the association between hemoglobin and hypertension.

METHODS

To clarify the clinical importance of the hematological parameter on endothelial maintenance in older men, we carried out a cross-sectional study of 222 Japanese men aged 60-69 years undergoing a general health checkup.

RESULTS

For participants with a lower platelet count (≤21.0/μL), hemoglobin was significantly positively associated with hypertension, but not for participants with a higher platelet count (>21.0/μL). The classical cardiovascular risk factor adjusted odds ratio of hypertension for 1-standard deviation increment of hemoglobin (1.0 g/dL) was 2.09 (95% CI: 1.26, 3.48) for participants with a lower platelet count, and 1.07 (95% CI: 0.68, 1.67) for participants with a higher platelet count. We also found that although there was no significant correlation between hemoglobin and circulating CD34-positive cells for participants with a lower platelet count (β = -0.06, P = 0.603), a significant positive correlation was seen for participants with a higher platelet count (β = 0.29, P = 0.004).

CONCLUSIONS

The positive association between hemoglobin and hypertension was limited to participants with a lower platelet count as a result of insufficient endothelial repair. These results represent an efficient tool for clarifying the mechanism of endothelial maintenance that correlates with hypertension. Geriatr Gerontol Int 2017; 17: 2586-2592.

Performance and safety of femoral central venous catheters in pediatric autologous peripheral blood stem cell collection

INTRODUCTION

Autologous peripheral blood hematopoietic progenitor cell collection (A-HPCC) in children typically requires placement of a central venous catheter (CVC) for venous access. There is scant published data regarding the performance and safety of femoral CVCs in pediatric A-HPCC.

METHODS

Seven-year, retrospective study of A-HPCC in pediatric patients collected between 2009 and January 2017. Inclusion criteria were an age ≤ 21 years and A-HPCC using a femoral CVC for venous access. Femoral CVC performance was examined by CD34 collection rate, inlet rate, collection efficiency (MNC-FE, CD34-FE), bleeding, flow-related adverse events (AE), CVC removal, and product sterility testing. Statistical analysis and graphing were performed with commercial software.

RESULTS

A total of 75/119 (63%) pediatric patients (median age 3 years) met study criteria. Only 16% of children required a CVC for ≥ 3 days. The CD34 collect rate and CD34-FE was stable over time whereas MNC-FE decreased after day 4 in 80% of patients. CD34-FE and MNC-FE showed inter- and intra-patient variability over time and appeared sensitive to plerixafor administration. Femoral CVC showed fewer flow-related AE compared to thoracic CVC, especially in pediatric patients (6.7% vs. 37%, P = 0.0005; OR = 0.12 (95%CI: 0.03-0.45). CVC removal was uneventful in 73/75 (97%) patients with hemostasis achieved after 20-30 min of pressure. In a 10-year period, there were no instances of product contamination associated with femoral CVC colonization.

CONCLUSION

Femoral CVC are safe and effective for A-HPCC in young pediatric patients. Femoral CVC performance was maintained over several days with few flow-related alarms when compared to thoracic CVCs.

Use of allogeneic apheresis stem cell products as an interlaboratory proficiency challenge

BACKGROUND

AABB Standards requires that laboratories participate in a proficiency test (PT) program for critical analytes. Institutions can purchase commercial PT materials; however, PT can also be performed through interlaboratory exchange. We investigated the utility of allogeneic hematopoietic progenitor cell apheresis (HPC-A) products as an interlaboratory PT challenge for total nucleated cell count (TNC) and CD34 assessment.

STUDY DESIGN AND METHODS

Three-year retrospective and comparative review of unrelated allogeneic HPC-A products received by the University of Michigan between January 2011 and December 2013. Internal TNC and CD34 count were compared to the external collecting facility by paired t test and linear regression. The absolute and percent difference between external and internal counts and 95% limits of agreeability (95% LA) were determined. Results were analyzed relative to donor center location (international, domestic), time zone (domestic), and calendar year.

RESULTS

There was a strong correlation between internal and external TNC, regardless of donor center location or year. For CD34, there was a good correlation between centers (R = 0.88-0.91; slope = 0.95-0.98x) with a median difference of -1% (95% LA, -50%, +47%). This was considerably better than commercial PT challenges, which showed a persistent negative bias for absolute CD34 and CD3 counts.

CONCLUSION

Allogeneic HPC-A products represent an interlaboratory PT exchange for all critical analytes, including TNC and CD34 count, cell viability, and sterility. Allogeneic HPC-A products, which are fresh and transported under validated conditions, are less subject to preanalytical variables that may impact commercial PT samples such as aliquoting and sample homogeneity, commercial additives, and sample stability during manufacturing and transport.

Granulocyte colony-stimulating factor improves survival of patients with decompensated cirrhosis: a randomized-controlled trial

BACKGROUND

Liver transplantation is the only curative option for patients with decompensated cirrhosis; however, many patients die while awaiting transplantation. Granulocyte colony-stimulating factor (GCSF) has shown promising results in improving outcomes in patients with advanced liver disease. We evaluated the efficacy of GCSF in patients with decompensated cirrhosis in an open-labeled randomized-controlled trial.

METHODS

Consecutive patients with decompensated cirrhosis were randomized to receive either GCSF 300 μg twice daily for 5 days plus standard medical therapy (SMT) (GCSF+SMT group) or SMT alone (SMT alone group). Outcomes were assessed at 6 months from randomization.

RESULTS

A total of 126 patients [median age: 53 (range: 31-76) years, 85% men] received GCSF+SMT and 127 patients received SMT alone. Baseline characteristics were similar in both the groups. The 5-day GCSF therapy did not lead to any significant adverse effects. At 6 months, in the GCSF+SMT group, 17 patients had died and nine were lost to follow-up, whereas in the SMT-alone group, 30 patients had died and 11 were lost to follow-up. By intention-to-treat analysis, cumulative survival was significantly higher in the GCSF+SMT group (79 vs. 68%; P=0.025). Also, significantly more patients (66%) showed improvement or stability in the Child-Turcotte-Pugh score at 6 months in the GCSF+SMT group compared with the SMT-alone group (51%, P=0.021).

CONCLUSION

GCSF therapy improves survival and clinical outcome in patients with decompensated cirrhosis. It may be useful in patients awaiting transplantation to prevent worsening during the waiting period. Further studies are needed to explore whether repeated periodic GCSF courses can further increase the survival and decrease the need for liver transplantation.Clinical trial registered at https://clinicaltrials.gov vide NCT02642003.

Poor stem cell harvest may not always be related to poor mobilization: lessons gained from a mobilization study in patients with β-thalassemia major

BACKGROUND

Hematopoietic stem cell mobilization and leukapheresis in adult patients with β-thalassemia have recently been optimized in the context of clinical trials for obtaining hematopoietic stem cells for thalassemia gene therapy. In some patients, however, the yield of cluster of differentiation 34-positive (CD34+) cells was poor despite successful mobilization, and a modification of apheresis settings was mandatory for harvest rescue.

STUDY DESIGN AND METHODS

Data were analyzed from 20 adult patients with β-thalassemia who were enrolled in a clinical trial of optimizing mobilization strategies for stem cell gene therapy. The aim of this post-hoc analysis was to assess how certain hematological and/or clinical parameters may correlate with low collection efficiency in the presence of adequate numbers of circulating stem cells after pharmacological mobilization and standard leukapheresis procedures.

RESULTS

Among 19 patients who achieved optimal mobilization with Plerixafor, four who underwent splenectomy demonstrated disproportionately poor CD34+ cell harvests, as determined by their circulating CD34+ cell counts after mobilization. All four patients who underwent splenectomy presented at baseline and before first apheresis with lymphocytosis resulting in lymphocyte/neutrophil ratios well above 1 and marked reticulocytosis compared with patients who achieved optimal mobilization/CD34+ cell harvest. Such unexpected expansion of specific cell populations disrupted the normal cell layer separation and necessitated modification of the apheresis settings to rescue the harvests.

CONCLUSIONS

By close examination of certain hematological and/or clinical parameters before leukapheresis, patients who, despite adequate mobilization, are at risk for poor CD34+ cell harvests may be identified, and harvest failure can be prevented by adjusting the apheresis settings.

Increased serum levels of fractalkine and mobilisation of CD34+CD45- endothelial progenitor cells in systemic sclerosis

Background

The disruption of endothelial homeostasis is a major determinant in the pathogenesis of systemic sclerosis (SSc) and is reflected by soluble and cellular markers of activation, injury and repair. We aimed to provide a combined assessment of endothelial markers to delineate specific profiles associated with SSc disease and its severity.

Methods

We conducted an observational, single-centre study comprising 45 patients with SSc and 41 healthy control subjects. Flow cytometry was used to quantify circulating endothelial microparticles (EMPs) and CD34⁺ progenitor cell subsets. Colony-forming unit-endothelial cells (CFU-ECs) were counted by culture assay. Circulating endothelial cells were enumerated using anti-CD146-based immunomagnetic separation. Blood levels of endothelin-1, vascular endothelial growth factor (VEGF) and soluble fractalkine (s-Fractalkine) were evaluated by enzyme-linked immunosorbent assay. Disease-associated markers were identified using univariate, correlation and multivariate analyses.

Results

Enhanced numbers of EMPs, CFU-ECs and non-haematopoietic CD34⁺CD45⁻ endothelial progenitor cells (EPCs) were observed in patients with SSc. Patients with SSc also displayed higher serum levels of VEGF, endothelin-1 and s-Fractalkine. s-Fractalkine levels positively correlated with CD34⁺CD45⁻ EPC numbers. EMPs, s-Fractalkine and endothelin-1 were independent factors associated with SSc. Patients with high CD34⁺CD45⁻ EPC numbers had lower forced vital capacity values. Elevated s-Fractalkine levels were associated with disease severity, a higher frequency of pulmonary fibrosis and altered carbon monoxide diffusion.

Conclusions

This study identifies the mobilisation of CD34⁺CD45⁻ EPCs and high levels of s-Fractalkine as specific features of SSc-associated vascular activation and disease severity. This signature may provide novel insights linking endothelial inflammation and defective repair processes in the pathogenesis of SSc.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1271-7) contains supplementary material, which is available to authorized users.

Standardized and flexible eight colour flow cytometry panels harmonized between different laboratories to study human NK cell phenotype and function

Advancements in multi-colour fluorescence activated cell sorting (FACS) panel warrant harmonized procedures to obtain comparable data between various laboratories. The intensifying clinical exploration of Natural Killer (NK) cell-based immunotherapy demands standardized and harmonized NK cell FACS panels and acquisition protocols. Eight colour FACS panels were designed to study human NK cell phenotype and function within peripheral blood mononuclear cells (PBMC). The panels were designed around fixed backbone markers and channels, covering antigens for non-NK lineage exclusion (CD3, TCRγδ, CD19, CD14, SYTOX^® Blue) and NK cell selection (CD45, CD56, CD16), complemented with variable drop-in markers/channels to study NK cell phenotype (NKG2A, NKG2C, NKG2D and KIR2D) or NK cell function and activation (CD25, NKp44 and CD107a). Harmonized FACS set-up and data analysis for three different flow cytometers has been established, leading to highly comparable and reproducible data sets using the same PBMC reference samples (n = 6). Further studies of NK cells in fresh or cryopreserved PBMC samples (n = 12) confirmed that freezing and thawing of PBMC samples did not significantly affect NK phenotype or function. In conclusion, our data demonstrate that cryopreserved PBMC samples analysed by standardized FACS panels and harmonized analysis protocols will generate highly reliable data sets for multi-center clinical trials under validated conditions.

GMP-conformant on-site manufacturing of a CD133+ stem cell product for cardiovascular regeneration

Background

CD133⁺ stem cells represent a promising subpopulation for innovative cell-based therapies in cardiovascular regeneration. Several clinical trials have shown remarkable beneficial effects following their intramyocardial transplantation. Yet, the purification of CD133⁺ stem cells is typically performed in centralized clean room facilities using semi-automatic manufacturing processes based on magnetic cell sorting (MACS®). However, this requires time-consuming and cost-intensive logistics.

Methods

CD133⁺ stem cells were purified from patient-derived sternal bone marrow using the recently developed automatic CliniMACS Prodigy® BM-133 System (Prodigy). The entire manufacturing process, as well as the subsequent quality control of the final cell product (CP), were realized on-site and in compliance with EU guidelines for Good Manufacturing Practice. The biological activity of automatically isolated CD133⁺ cells was evaluated and compared to manually isolated CD133⁺ cells via functional assays as well as immunofluorescence microscopy. In addition, the regenerative potential of purified stem cells was assessed 3 weeks after transplantation in immunodeficient mice which had been subjected to experimental myocardial infarction.

Results

We established for the first time an on-site manufacturing procedure for stem CPs intended for the treatment of ischemic heart diseases using an automatized system. On average, 0.88 × 10⁶ viable CD133⁺ cells with a mean log₁₀ depletion of 3.23 ± 0.19 of non-target cells were isolated. Furthermore, we demonstrated that these automatically isolated cells bear proliferation and differentiation capacities comparable to manually isolated cells in vitro. Moreover, the automatically generated CP shows equal cardiac regeneration potential in vivo.

Conclusions

Our results indicate that the Prodigy is a powerful system for automatic manufacturing of a CD133⁺ CP within few hours. Compared to conventional manufacturing processes, future clinical application of this system offers multiple benefits including stable CP quality and on-site purification under reduced clean room requirements. This will allow saving of time, reduced logistics and diminished costs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-016-0467-0) contains supplementary material, which is available to authorized users.

Beneficial Effects of Reconstituted High-Density Lipoprotein (rHDL) on Circulating CD34+ Cells in Patients after an Acute Coronary Syndrome

Background

High-density lipoproteins (HDL) favorably affect endothelial progenitor cells (EPC). Circulating progenitor cell level and function are impaired in patients with acute coronary syndrome (ACS). This study investigates the short-term effects of reconstituted HDL (rHDL) on circulating progenitor cells in patients with ACS.

Methods and Findings

The study population consisted of 33 patients with recent ACS: 20 patients from the ERASE trial (randomized to receive 4 weekly intravenous infusions of CSL-111 40 mg/kg or placebo) and 13 additional patients recruited as controls using the same enrolment criteria. Blood was collected from 16 rHDL (CSL-111)-treated patients and 17 controls at baseline and at 6–7 weeks (i.e. 2–3 weeks after the fourth infusion of CSL-111 in ERASE). CD34⁺ and CD34⁺/kinase insert domain receptor (KDR⁺) progenitor cell counts were analyzed by flow cytometry. We found preserved CD34⁺ cell counts in CSL-111-treated subjects at follow-up (change of 1.6%), while the number of CD34⁺ cells was reduced (-32.9%) in controls (p = 0.017 between groups). The level of circulating SDF-1 (stromal cell-derived factor-1), a chemokine involved in progenitor cell recruitment, increased significantly (change of 21.5%) in controls, while it remained unchanged in CSL-111-treated patients (p = 0.031 between groups). In vitro exposure to CSL-111 of early EPC isolated from healthy volunteers significantly increased CD34⁺ cells, reduced early EPC apoptosis and enhanced their migration capacity towards SDF-1.

Conclusions

The relative increase in circulating CD34⁺ cells and the low SDF-1 levels observed following rHDL infusions in ACS patients point towards a role of rHDL in cardiovascular repair mechanisms.

Human Umbilical Cord Blood CD34-Positive Cells as Predictors of the Incidence and Short-Term Outcome of Neonatal Hypoxic-Ischemic Encephalopathy: A Pilot Study

BACKGROUND AND PURPOSE

Neonatal hypoxic-ischemic encephalopathy (HIE) is one of the leading causes of neurological handicap in developing countries. Human umbilical cord blood (hUCB) CD34-positive (CD34⁺) stem cells exhibit the potential for neural repair. We tested the hypothesis that hUCB CD34⁺ stem cells and other cell types [leukocytes and nucleated red blood cells (NRBCs)] that are up-regulated during the acute stage of perinatal asphyxia (PA) could play a role in the early prediction of the occurrence, severity, and mortality of HIE.

METHODS

This case-control pilot study investigated consecutive neonates exposed to PA. The hUCB CD34⁺ cell count in mononuclear layers was assayed using a flow cytometer. Twenty full-term neonates with PA and 25 healthy neonates were enrolled in the study.

RESULTS

The absolute CD34⁺ cell count (p=0.02) and the relative CD34⁺ cell count (CD34⁺%) (p<0.001) in hUCB were higher in the HIE patients (n=20) than the healthy controls. The hUCB absolute CD34⁺ cell count (p=0.04), CD34⁺% (p<0.01), and Hobel risk scores (p=0.04) were higher in patients with moderate-to-severe HIE (n=9) than in those with mild HIE (n=11). The absolute CD34⁺ cell count was strongly correlated with CD34⁺% (p<0.001), Hobel risk score (p=0.04), total leukocyte count (TLC) (p<0.001), and NRBC count (p=0.01). CD34⁺% was correlated with TLC (p=0.02).

CONCLUSIONS

hUCB CD34⁺ cells can be used to predict the occurrence, severity, and mortality of neonatal HIE after PA.

Identification of cardiovascular risk factors associated with bone marrow cell subsets in patients with STEMI: a biorepository evaluation from the CCTRN TIME and LateTIME clinical trials

Autologous bone marrow mononuclear cell (BM-MNC) therapy for patients with ST-segment elevation myocardial infarction (STEMI) has produced inconsistent results, possibly due to BM-MNC product heterogeneity. Patient-specific cardiovascular risk factors (CRFs) may contribute to variations in BM-MNC composition. We sought to identify associations between BM-MNC subset frequencies and specific CRFs in STEMI patients. Bone marrow was collected from 191 STEMI patients enrolled in the CCTRN TIME and LateTIME trials. Relationships between BM-MNC subsets and CRFs were determined with multivariate analyses. An assessment of CRFs showed that hyperlipidemia and hypertension were associated with a higher frequency of CD11b+ cells (P = 0.045 and P = 0.016, respectively). In addition, we found that females had lower frequencies of CD11b+ (P = 0.018) and CD45+CD14+ (P = 0.028) cells than males, age was inversely associated with the frequency of CD45+CD31+ cells (P = 0.001), smoking was associated with a decreased frequency of CD45+CD31+ cells (P = 0.013), glucose level was positively associated with the frequency of CD45+CD3+ cells, and creatinine level (an indicator of renal function) was inversely associated with the frequency of CD45+CD3+ cells (P = 0.015). In conclusion, the frequencies of monocytic, lymphocytic, and angiogenic BM-MNCs varied in relation to patients' CRFs. These phenotypic variations may affect cell therapy outcomes and might be an important consideration when selecting patients for and reviewing results from autologous cell therapy trials.

Storage Duration of Autologous Stem Cell Preparations Has No Impact on Hematopoietic Recovery after Transplantation

Peripheral blood stem cells (PBSCs) are widely used for autologous blood stem cell transplantation (ABSCT). These cells must be stored for months or even years, usually at temperatures ≤-140°C, until their use. Although several in vitro studies on CD34⁺ viability and clonogenic assays of PBSCs after long-term storage have been reported, only a few publications have investigated the influence of long-term storage on in vivo hematopoietic reconstitution. In this study, we retrospectively analyzed hematopoietic recovery after storage of PBSCs via controlled-rate freezing (CRF) and cryostorage in 10% DMSO at ≤-140°C in 105 patients with multiple myeloma who received high-dose melphalan before ABSCT. Three groups of PBSC transplantation (n = 247) were delineated based on the storage period: short-term (≤12 months, n = 143), medium-term (>12 and ≤60 months, n = 75), and long-term storage (>60 months, n = 29). A neutrophil increase of ≥.5 × 10⁹/L in medium-term or long-term PBSC cryopreservation groups was observed at day 14 after ABSCT; this increase was comparable to patients who received briefly stored PBSCs (day 15). No negative effect of PBSC storage duration was observed on leucocyte or neutrophil reconstitution. Platelet reconstitutions of ≥20  × 10⁹/L and 50 × 10⁹/L were observed after median times of 10 to 11 and 13 to 14 days after ABSCT, respectively. No influence of PBSC storage duration on platelet recovery of ≥20  × 10⁹/L and ≥50 × 10⁹/L was observed in the 3 storage groups (P = .07, P = .32). The number of previous ABSCTs also had no significant impact upon hematopoietic reconstitution. In conclusion, these results indicate that long-term cryopreservation of PBSC products at vapor nitrogen temperature after CRF does not have a negative effect on hematopoietic recovery even after prolonged storage.

Mobilization of hematopoietic progenitor cells for autologous transportation: consensus recommendations

Selected patients with certain hematological malignancies and solid tumors have the potential to achieve long-term survival with autologous hematopoietic progenitor cell transplant. The collection of these cells in peripheral blood avoids multiple bone marrow aspirations, results in faster engraftment and allows treatment of patients with infection, fibrosis, or bone marrow hypocellularity. However, for the procedure to be successful, it is essential to mobilize a sufficient number of progenitor cells from the bone marrow into the blood circulation. Therefore, a group of Brazilian experts met in order to develop recommendations for mobilization strategies adapted to the reality of the Brazilian national health system, which could help minimize the risk of failure, reduce toxicity and improve the allocation of financial resources.