Number Of Viable CD34 Research Articles

Abstract 17 Umbilical Cord Blood Collection. How Do Different Factors Affect CD45 Cell Viability in Our Experience?

Abstract Introduction Umbilical cord blood (UCB) is an important source of hematopoietic stem cells for transplantation in some hematological diseases. One of the main factors influencing sample quality and transplantation success, in addition to histocompatibility, is the number of viable CD34+ cells. Over the years, different factors that could directly affect viability have been studied and evaluated. It is important to be able to define favorable ranges for obtaining high viabilities and optimal samples for their use. Objectives The aim of our study is to evaluate the incidence of three factors temperature during transport, volume and time between collection and process of UCB over cellular viability previous to cryopreservation. Methods We analyzed 10483 UCB samples collected between 2018 and 2022. Cell viability values were analyzed in total CD45 using flow cytometry with 7-AAD and Annexin V. We evaluated the relationship between cell viability with the three factors mentioned above. Results We observed a tendency for viability to decrease as the blood volume collected decreases, and as the temperature and elapsed hours increase. In concordance, we found that viability is dependent on the 3 factors analyzed (p <<0.001), observing that its variability can be explained in 4% by the variation of elapsed hours as well as the collection volume, while temperature explains this variation in 1%. Discussion With our samples we can assume that the variations in the ranges analyzed would not affect them to a great extent, since they are not determinant for obtaining an average viability lower than that established as acceptable in our bank (75%). On the other hand, we also conclude that viability cannot be explained from the variation of a single factor, so it would be important to analyze the interactions between them. For the time being, and in order to improve the quality of the samples, we consider it necessary to emphasize the collection of a good volume of blood and the rapid transport of the samples for processing.

Incidence of mucositis in patients undergoing autologous hematopoietic stem cell transplantation at a single center

Goal: The aim of this study was to describe the incidence of oral mucositis (OM) in patients undergoing autologous hematopoietic stem cell transplantation (auto-HSCT), relating it to the main clinical factors. Methodology: Descriptive analysis based on a randomized clinical study was conducted with patients undergoing HSCT at the University Hospital of Federal University of Juiz de Fora between January 2018 and June 2019. The World Health Organi­zation oral toxicity scale was used to assess the degree of oral mucositis and adverse events were graded according to the Common Terminology Criteria for Adverse Events (CTCAE) 4.0 version. Results: Thirty-eight patients were evaluated. The incidence of OM and severe oral mucositis (SOM) was 57.9% and 21.0%, respectively. The mean duration of OM was 7.2 ± 2.6 days and the lomustine, etoposide, cytarabine and cyclophosphamide protocol (LEAC) pre­sented the longest mean time 8.1 ± 3.1 days (p-value 0.02). The number of viable CD34+ cells and the onset day of neutropenia were predictors of SOM. Conclusion: The incidence of OM in patients undergoing HSCT was lower than reported in the literature, being more severe in patients who received less CD34+ cells and in patients with early onset of neutropenia.

Cryopreserved cord blood mononuclear cells in DMSO are healthy for at least 6 hours after thawing

PurposesWe investigated the impact of time, storage temperature, and dimethyl sulfoxide (DMSO) on the viability of HSCs, as well as on apoptotic changes in thawed CB. Materials & MethodsThirteen units of cryopreserved CB were thawed and half of each sample was stored at room temperature (RT) and the other half at 4℃, without removing or diluting DMSO. Flow cytometry was employed to enumerate total nucleated cells (TNCs), total/viable CD34+ cells, and early/late apoptotic cells using anti-CD45, anti-CD34, and annexin V(AnV), 7-amino actinomycin D(AAD) staining, respectively. ResultsIn CBs stored at 4℃ there were no significant changes in numbers of TNCs, total/viable CD34+ cells, or early/late apoptotic cell up to 48 h. However, the numbers of these cells declined significantly at RT. Total and viable CD34+ cell counts did not change for up to 6 h at RT but viable CD34+ cells decreased significantly after 24 h, and total CD34+ cell after 48 h. Early and late apoptosis tended to increase with time at RT, and numbers of viable CD34+ cells and early apoptotic cells differed significantly between RT and 4℃ after 48 h. ConclusionsThere are no significant changes of viability and apoptosis in CBs stored in DMSO at 4℃ until 48 h after thawing, while at RT, there are no significant changes of total/viable CD34+ cell counts or in the proportion of apoptotic cells for at least 6 h after thawing.

Flow cytometric analyses of CD34+ cells with inclusion of internal positive controls

Flow cytometric measurement of CD34+ events is used to ensure the quality of human progenitor cell grafts. This study was conducted to evaluate whether the spiking of routine samples from peripheral blood and apheresis products with CD34+ positive controls is feasible. A total of 42 samples from 32 patients and one healthy donor were stained in duplicate for CD34+ cells. Before flow cytometric analysis, one tube was spiked with stabilized CD34+ cells at a defined concentration. Median numbers of viable CD34+ cells/µL did not differ between unspiked and spiked tubes (median 37, range 0-714; and median 34, range 0-719, respectively). The 95% confidence interval (CI) of the mean showed a broad overlap between these samples (41.9-119.1 and 41.4-119.3, respectively). In addition, the 95% CI of the mean for CD45+ cells/µL overlapped broadly and median numbers did not differ. Median viability of all CD45+ cells was significantly lower in the spiked tubes (96.75, range 64-98.8 vs. 99.25, range 97.5-99.8) with no overlap of the 95% CI of the mean viability. The results of this study show that spiking of routine samples with internal positive controls does not affect CD34+ cell analyses, but does support the reliability of important clinical data. The inclusion of positive controls is expedient for laboratories that perform analyses with low CD34+ numbers and laboratories that use different flow cytometric analyzers and may also become a requirement to meet statutory regulations.

704 Cold-Agglutinin Hemolytic Anemia: A Harbinger of Recurrent Lymphoma

704 Cold-Agglutinin Hemolytic Anemia: A Harbinger of Recurrent Lymphoma

Aldehyde Dehydrogenase (ALDH) Vs CD34 for Predicting Engraftment After Autologous Hematopoietic Progenitor Cell (autoHPC) Transplant

AbstractAbstract 4441 Introduction:When the cell surface marker CD34 became available for enumerating HPC there was controversy as to whether it was useful for predicting time to engraftment after autologous peripheral blood HPC transplant (autoHPCT). It was demonstrated that a threshold dose of 2.0–2.5 × 106 CD34+ cells/kg in the product, measured before cryopreservation, predicted reliable engraftment within a reasonable period of time. CD34 is expressed on the surface of HPC ranging from primitive to committed progenitor cells. ALDH is highly expressed in primitive cells such as HPC, endothelial progenitor cells and mesenchymal stromal cells. ALDHbr cells are by definition viable, while measurement of viable CD34+ cells requires an additional assay. We tested the correlation of CD34 and ALDH activity in fresh HPC products and then examined the usefulness of these two assays for predicting time to WBC and platelet engraftment after autoHPCT. Materials and Methods:We identified 42 consecutive HPC apheresis products used for autoHPCT for which data on CD34+ numbers and viability as well as ALDHbr cell numbers were available. Data from 5 of these product were not used for predicting engraftment due to lack of engraftment data. Viability was assesed by flow cytometry on pre-cryopreservation (fresh) and post-thaw samples by looking at propidium iodide or 7-AAD uptake within the CD34+ population identified using the ISHAGE method. ALDH activity was measured by flow cytometry on pre-freeze samples using the manufacturers prescribed method. HPC were cryopreserved using a controlled rate freezer and 10% DMSO, then stored in liquid nitrogen. Data on time to WBC and platelet engraftment were determined by chart review. The patents received a median of 3.78 × 106 CD34+ cells/kg (range 2.43–8.59 × 106 CD34+ cells/kg) for autoHPCT. Regression analyses were performed to see if viable CD34 in the fresh product, and in the thawed product, correlated with ALDH and whether any of these measures correlate with time to WBC (ANC >500/mm3) or platelet engraftment (>20,000/mm3). Results:The correlation coefficients for ALDHbr vs viable CD34+ cells pre-cryopreservation (r=0.97; n=42) and for ALDHbr cells vs post-thaw CD34+ cells (r=0.96; n=42) were both significant. The percent of variation for ALDHbr cells to WBC engraftment (r2 = 2.2%; n=37) and for CD34+ cells both pre-freezing and post-thaw to WBC engraftment (r2 =1.9%; n=37) were not significant. The r2 for ALDHbr cells and platelet engraftment was 0.9%, the r2 for CD34+ cells and platelet engraftment was 1.1% pre-freeze (n=37) and was 0.9% post-thaw (n=37) were also not significant. Conclusion:Enumeration of HPC by ALDH correlates well with CD34, suggesting that the two assays are equivalent when analyzing autologous peripheral blood. Neither the number of ALDHbr cells or CD34+ cells in fresh products, nor the number of viable CD34+ cells in the thawed products, correlates with time to WBC and platelet engraftment. Since our patients received at least 2.4 × 106 CD34+ cells/kg, our observations support previous data showing no correlation between cell dose and time to engraftment if more than the HPC threshold dose for engraftment is given for transplant. Disclosures:No relevant conflicts of interest to declare.

Long‐term cryopreservation of autologous stem cell grafts: a clinical and experimental study of hematopoietic and immunocompetent cells

Autologous stem cell transplantation(ASCT) is used in the treatment of several malignancies.Harvesting sufficient peripheral blood progenitor cells (PBPCs) for a potential second autotransplantation at the time of relapse several years after diagnosis is becoming an increasingly common practice. Cryopreserved PBPCs were prepared with different concentrations of dimethyl sulfoxide (DMSO; 2, 4, 5, and 10%) and stored for at least 5 years before the recovery of CD34+ cells and various T- and natural killer (NK)-cell subsets were analyzed by flow cytometry. Furthermore,clinical variables for myeloma patients having a second autotransplantation with long-term-stored autografts were evaluated. The number of viable CD34+ cells in longterm-stored grafts was higher when autografts were cryopreserved with 4 or 5% than with 2 and 10%DMSO. The number of viable CD34+ cells was reduced by 13.9% after 5 years of cryostorage in 5% DMSO.Lymphocyte viability was also higher with 4 or 5%DMSO. However, the frequencies of several T-cell subsets showed DMSO-dependent differences,whereas NK-cell subsets did not. Furthermore, after a second autotransplantation with long-term-stored PBPC grafts at the time of myeloma relapse (median storage time, 42 months) all 17 patients reached neutrophil counts exceeding 0.5 x 10⁹/L and platelet counts exceeding 20 x 10⁹/L within 15 days. There was no difference in engraftment between patients receiving autografts preserved with 5 and 10% DMSO. PBPC autografts can safely be stored for at least 5 years in 5% DMSO and used for ASCT.

Similar Outcomes of Cryopreserved Allogeneic Peripheral Stem Cell Transplants (PBSCT) Compared to Fresh Allografts

The BMT program at Princess Margaret Hospital performed 105 transplants using cryopreserved peripheral blood stem cells (PBSC) from related allogeneic donors. The outcomes were compared with those of a historic control of 106 patients transplanted with freshly procured PBSC. The infusions were tolerated with limited toxicity related to nausea/vomiting or bradycardia, correlated with the total amount of DMSO infused. The average viability of the total nucleated cell (TNC) population after thawing was 71%. The survival of clonogenic progenitors amounted to 75% for colony-forming unit-granulocyte-macrophage (CFU-GM), 69% for burst-forming units erythroid (BFU-E), and 78% for colony-forming units granulocyte-erythrocyte-monocyte-megakaryocyte (CFU-GEMM). In contrast, colony-forming units megakaryocyte (CFU-MEG) was significantly more cryosensitive with recovery rates of 39%. The number of viable CD34 + cells transplanted was correlated with the number of transplanted viable CFU-GM ( P < .001), BFU-E ( P < .001), CFU-MEG ( P < .001), and CFU-GEMM ( P = .049), but not with the TNC dose. The number of transplanted CD34 + cells was correlated with engraftment of neutrophils ( P = .012) and platelets ( P = .013). The outcomes of cryopreseved or fresh PBSC transplants (PBSCT) with respect to engraftment of neutrophils ( P = .178) and platelets ( P = .785), lymphocyte recovery ( P = .926), acute ( P = .113), and chronic graft-versus-host disease ( P = .673), recurrence ( P = .295), nonrelapse mortality ( P = .340), and overall survival ( P = .668) were not significantly different. It is therefore reasonable to consider the option of cryopreserved allografts.

A novel high-yield volume-reduction method for the cryopreservation of UC blood units

For the application of umbilical cord blood (UCB) units as hematopoietic grafts, a dose of 3.7 x 10(7) nucleated cells (NC)/kg body weight is required. NC can be lost during volume-reduction processing and during thawing. A novel modification of the double-processing protocol with the aim of minimizing NC loss is described and evaluated. One-hundred and fifty UCB were collected. The volume was reduced by a centrifugation step following double-processing in the presence of 2% HES 200/0.5. Pre- and post-processing cell counts and platelet parameters were measured with an automatic counter. The number of viable CD34+ hemopoietic stem cells was measured by flow cytometry. In 25 of the samples, colony-forming units (CFU) were also determined. The same samples were thawed 6 months after cryopreservation and re-evaluated. The volume was reduced to 6 +/- 1.5 mL. The recovery of NC, MNC, CD34+ hemopoietic stem cells, RBC depletion and CFU following double-processing was 93.6 +/- 3.2%, 95.8 +/- 2.2%, 98.4 +/- 1.5%, 96.8 +/- 1.1% and 107.1 +/- 6.1% (for 25 samples), respectively. The post-thaw recoveries of NC, MNC, CD34+ hemopoietic stem cells and CFU (for 25 samples) were 78.6 +/- 5.4%, 90.8 +/- 4.4%, 96.4 +/- 2.5%, 89.1 +/- 4.1%, respectively. No post-thaw cell aggregation was observed. A significant (P<0.05) post-thaw loss of platelets and signs of platelet activation was observed. The protocol uses non-expensive equipment and clinically approved materials and results in samples that can be used in patients with a mean weight of 32.7 kg.

Does continuous flow apheresis influence viability in allogeneic hematopoietic stem cell harvest?

One of the important clinical variables determining the success of hematopoietic stem cell transplantation is the number of viable CD34 + stem cells transfused to the patient. G-CSF mobilized peripheral blood stem cells from 17 healthy donors were collected by continuous flow apheresis. The median (range) proportions of early apoptotic (Annexin V-FITC pos/7-AAD neg) and viable (Annexin V-FITC neg/7-AAD neg) CD45 dimCD34 + stem cells were 1.5 (0.9–3.7)% and 97.7 (82.8–100)% in the peripheral blood before apheresis and 2.6 (0.8–7.9)% and 97.3 (91.9–99)% in the apheresis products, respectively. Despite an increase in the number of apoptotic cells among all cell compartments, this was statistically significant only in CD34 + cells and granulocytes. The majority of the cells still retained their viability.

Evaluation of the Reactivity of Apoptosis Markers Before and After Cryopreservation in Cord Blood CD34+Cells

Umbilical cord blood (CB) CD34(+) cells, on the basis of flow cytometry analysis, are comprised of multiple populations. In in vitro assays, only CD34(regular) FSC(high) cells are functional and low percentages of nonfunctional CD34(regular) FSC(low) cells were determined to be present in liquid-stored CB. Liquid-stored CD34(regular) FSC(high) cells prior to cryopreservation were judged to be functional by the formation of erythroid and myeloid colonies and transmigration assays. We have further evaluated the occurrence of apoptosis in CB CD34(+) cells using various apoptotic markers to understand better the influence of storage conditions that could be utilized with transplantation of CB. Of the CD34(regular) FSC(low) cells shown in the present study, 20-45% were labeled with the apoptotic reagents annexin-V, fluorescent caspase peptide substrates, and the anti-mitochondrial antibody APO2.7, but these cells were minimally stained with 7-aminoactinomycin-D (7-AAD). These apoptotic reagents identify different cellular targets, indicating the initiation of the apoptotic cascade prior to cryopreservation/thawing. Following cryopreservation and thawing, the apoptotic markers SYTO-16, tetramethyl rhodamine ethyl ester (TMRE), and 7-AAD showed the presence of apoptotic cells. After cryopreservation/thawing, enumeration of CB CD34(+) cells was reduced 10-65% when excluding cells positive for apoptotic markers. We attempted to limit the progression of apoptosis observed after cryopreservation/thawing by the addition of anti-apoptotic reagents z-VAD-fmk (100 microM) and Q-VD-OPH (100 microM) (peptide inhibitors of caspases) without or with the inclusion of survival reagents for CD34(+) cells-stromal-derived factor-1 (SDF-1), stem cell factor (SCF), thrombopoietin, and diprotin A, an inhibitor of CD26 prior to cryopreservation. The expression of apoptosis markers was minimally affected even when using combinations of caspase inhibitors/ CD34(+) cell survival cytokines in an attempt to block apoptosis caused by cryopreservation/thawing. Decreases in apoptosis marker reactivity following cryopreservation were not observed except for a reduced expression of APO2.7 reactivity with z-VAD-fmk and Q-VD-OPH caspase inhibitors. The ability of the inhibitors of apoptosis of CD34(+) cells to generate CFU-GM, CFU-MK, or BFUE colonies was also unaffected except with z-VAD-fmk (100 microM) and Q-VD-OPH (100 microM). The occurrence of apoptosis, as measured by flow cytometry with selected apoptotic markers, suggests a reduction in the number of viable CD34(+) cells.

Immunophenotype of hematopoietic stem cells from placental/umbilical cord blood after culture

Identification and enumeration of human hematopoietic stem cells remain problematic, since in vitro and in vivo stem cell assays have different outcomes. We determined if the altered expression of adhesion molecules during stem cell expansion could be a reason for the discrepancy. CD34+CD38- and CD34+CD38+ cells from umbilical cord blood were analyzed before and after culture with thrombopoietin (TPO), FLT-3 ligand (FL) and kit ligand (KL; or stem cell factor) in different combinations: TPO + FL + KL, TPO + FL and TPO, at concentrations of 50 ng/mL each. Cells were immunophenotyped by four-color fluorescence using antibodies against CD11c, CD31, CD49e, CD61, CD62L, CD117, and HLA-DR. Low-density cord blood contained 1.4 +/- 0.9% CD34+ cells, 2.6 +/- 2.1% of which were CD38-negative. CD34+ cells were isolated using immuno-magnetic beads and cultured for up to 7 days. The TPO + FL + KL combination presented the best condition for maintenance of stem cells. The total cell number increased 4.3 +/- 1.8-fold, but the number of viable CD34+ cells decreased by 46 +/- 25%. On the other hand, the fraction of CD34+CD38- cells became 52.0 +/- 29% of all CD34+ cells. The absolute number of CD34+CD38- cells was expanded on average 15 +/- 12-fold when CD34+ cells were cultured with TPO + FL + KL for 7 days. The expression of CD62L, HLA-DR and CD117 was modulated after culture, particularly with TPO + FL + KL, explaining differences between the adhesion and engraftment of primary and cultured candidate stem cells. We conclude that culture of CD34+ cells with TPO + FL + KL results in a significant increase in the number of candidate stem cells with the CD34+CD38- phenotype.

Autologous transplantation: the viable transplanted CD34+ cell dose measured post-thaw does not predict engraftment kinetics better than the total CD34+ cell dose measured pre-freeze in patients that receive more than 2×106 CD34+ cells/kg

The aim of the study was to investigate whether the number of viable CD34+ cells in cryopreserved PBPC autografts is a better predictor of engraftment than the total CD34+ cell number determined before freezing. A total of 119 patients was treated with autotransplantation for various malignant disorders during the period 1996-2002. All patients were reinfused with at least 2x10(6)/kg total CD34 cells analyzed before programmed freezing in 10% DMSO. The total CD34 cell number determined before freezing was compared with the number of viable cells determined after cryopreservation for 51 of these patients. The number of viable cells was determined by a flow cytometric analysis including triple staining with anti-CD34, anti-CD45 and the viability marker 7-actinomycin D (7-AAD). Simple linear regression analyses showed that both the total transplanted CD34 cell dose measured before freezing and the viable CD34 cell dose determined after cryopreservation were significantly correlated with neutrophil and platelet engraftment. In a multiple regression model the prediction of engraftment was not improved when the transplanted viable CD34 cell dose was included as a variable in addition to the total CD34 cell dose measured immediately after collection. Routine estimation of viable CD34 cells after cryopreservation of PBPC autografts is not necessary as long as the total CD34 cell dose is determined before freezing and the patients are reinfused with at least 2x10(6) cells/kg body weight.

Better preservation of early hematopoietic progenitor cells when human peripheral blood progenitor cells are cryopreserved with 5 percent dimethylsulfoxide instead of 10 percent dimethylsulfoxide

Previous studies have demonstrated that cryopreservation of PBPCs in 5 percent DMSO is superior to 10 percent DMSO with regard to CD34+ cell viability and preservation of mature clonogenic cells. Nevertheless, preservation with 5 percent DMSO of primitive progenitors responsible for long-term post-transplant reconstitution must be characterized before this decreased concentration is further evaluated in clinical studies of autotransplantation in cancer patients. PBPCs from 15 patients with malignant diseases were cryopreserved in 5 and 10 percent DMSO and stored in liquid nitrogen for at least 14 months before the preservation of long-term culture-initiating cells (LTC-ICs) was evaluated. LTC-IC survival was significantly better after PBPC cryopreservation with 5 percent DMSO instead of 10 percent DMSO (median, 43 colonies vs. 7 colonies, p = 0.003) The frequency of 5-week LTC colony-forming cells showed a significant correlation with the percent-age and number of viable CD34+ cells but not to the number of mature colony-forming cells in cryopreserved PBPCs. Primitive progenitor cells in PBPC autografts from patients with malignant disorders can be cryopreserved with 5 percent DMSO, and the number of viable CD34+ cells can be used as a marker for the number of primitive progenitors in the graft.

Flow cytometric CD34+ determination in stem cell transplantation: before or after cryopreservation of grafts?

Various attempts have been made to standardize and improve the reproducibility of flow cytometric determination of CD34+ hematopoietic progenitor cells. It is still not clear, however, whether the quantification of CD34+ cells in a stem cell graft should be done before or after cryopreservation. To address this issue, we investigated 78 unselected and 32 immunomagnetically selected autologous and allogeneic leukapheresis products (LA) before and after cryopreservation using pilot vials. Cell numbers were quantified within a Neubauer chamber, and CD34+ content was determined by flow cytometry; propidium iodide staining was used to exclude dead cells from analysis. Before freezing, the mean viable CD34 cell content in the unselected samples was 1.22% and increased after thawing to a mean of 2.16% of viable cells. Taking into account cell loss and cell death, the overall recovery of viable cells was 64.5%; all CD34+ cells could be recovered. Mean purity in the CD34-selected cell fraction was 85% (48-97) before and 91.3% (67-99) after thawing. The number of viable cells was 86.8% before and 86.1% after freezing with a 93.9% recovery of total cells. This leads to a mean 93.7% (SD +/- 23.1) recovery of viable cells and 100% (SD +/- 22.3) recovery of viable CD34+ cells. There was no significant difference in tolerance to freeze/thaw stress between cells from heavily pretreated autologous patients and healthy allogeneic donors. Our data show that freezing significantly increases the percentage of CD34(+) cells in unmanipulated LA, probably due to the death of granulocytes and mononuclear cells (MNCs). Nevertheless, the overall number of viable CD34+ cells in unselected as well as selected samples remains unchanged. Thus, CD34 data from different laboratories, for example, within multicenter trials, should be comparable independent of the different time points of acquisition.

Effect of Human Immunodeficiency Virus Type 1 on CD34+ Cellsa

The effect of HIV-1 on the in vitro growth of enriched hematopoietic stem cells (CD34+ cells) obtained from normal peripheral blood samples was studied. In comparison to untreated controls, the number of viable CD34+ cells progressively and significantly decreased in liquid cultures containing interleukin-3 (IL-3, 100 U/ml) after inoculation with HIV-1. In inoculated samples there was a significant reduction of all the hematopoietic progenitors (CFU-GM, BFU-E, CFU-Meg) starting from the second day of culture, CFU-GM being the most affected. In spite of these findings, no evidence of viral replication was observed: the total amount of p24 in HIV-1-inoculated CD34+ cell cultures showed a plateau, slightly declining towards the end of the experimental observation period. Moreover, erythroid and granulomacrophage colonies harvested from inoculated CD34+ cell cultures were unable to infect susceptible cells.

Endotoxin-induced tumor necrosis factor formation in man and its reversal by pentoxifylline: [formula omitted] Forschungsinstitut Borstel, D-2061 Borstel, FRG and Hoechst Werk Albert, D-6000 Wiesbaden, FRG

The BMT program at Princess Margaret Hospital performed 105 transplants using cryopreserved peripheral blood stem cells (PBSC) from related allogeneic donors. The outcomes were compared with those of a historic control of 106 patients transplanted with freshly procured PBSC. The infusions were tolerated with limited toxicity related to nausea/vomiting or bradycardia, correlated with the total amount of DMSO infused. The average viability of the total nucleated cell (TNC) population after thawing was 71%. The survival of clonogenic progenitors amounted to 75% for colony-forming unit-granulocyte-macrophage (CFU-GM), 69% for burst-forming units erythroid (BFU-E), and 78% for colony-forming units granulocyte-erythrocyte-monocyte-megakaryocyte (CFU-GEMM). In contrast, colony-forming units megakaryocyte (CFU-MEG) was significantly more cryosensitive with recovery rates of 39%. The number of viable CD34+ cells transplanted was correlated with the number of transplanted viable CFU-GM (P < .001), BFU-E (P < .001), CFU-MEG (P < .001), and CFU-GEMM (P = .049), but not with the TNC dose. The number of transplanted CD34+ cells was correlated with engraftment of neutrophils (P = .012) and platelets (P = .013). The outcomes of cryopreseved or fresh PBSC transplants (PBSCT) with respect to engraftment of neutrophils (P = .178) and platelets (P = .785), lymphocyte recovery (P = .926), acute (P = .113), and chronic graft-versus-host disease (P = .673), recurrence (P = .295), nonrelapse mortality (P = .340), and overall survival (P = .668) were not significantly different. It is therefore reasonable to consider the option of cryopreserved allografts.