In vitro collection and posttransfusion engraftment characteristics of MNCs obtained by using a new separator for autologous PBPC transplantation

BACKGROUND: A clinical study was performed to evaluate the peripheral blood progenitor cell (PBPC) collection, transfusion, and engraftment characteristics associated with use of a blood cell separator (Amicus, Baxter Healthcare). STUDY DESIGN AND METHODS: Oncology patients (n = 31) scheduled for an autologous PBPC transplant following myeloablative therapy were studied. PBPCs were mobilized by a variety of chemotherapeutic regimens and the use of G-CSF. As no prior studies evaluated whether PBPCs collected on the Amicus separator would be viable after transfusion, to ensure patient safety, PBPCs were first collected on another cell separator (CS-3000 Plus, Baxter) and stored as backup. The day after the CS-3000 Plus collections were completed, PBPC collections intended for transfusion were performed using the Amicus instrument. For each transplant, >2.5 x 10(6) CD34+ PBPCs per kg of body weight were transfused. RESULTS: Clinical data collected on the donors immediately before and after PBPC collection with the Amicus device were comparable to donor data similarly obtained for the CS-3000 Plus collections. While the number of CD34+ cells and the RBC volume in the collected products were equivalent for the two devices, the platelet content of the Amicus collections was significantly lower than that of the CS-3000 Plus collections (4.35 x 10(10) platelets/bag vs. 6.61 x 10(10) platelets/bag, p<0.05). Collection efficiencies for CD34+ cells were 64 +/- 23 percent for the Amicus device and 43 +/- 14 percent for the CS-3000 Plus device (p<0.05). The mean time to engraftment for cells collected via the Amicus device was 8.7 +/- 0.7 days for >500 PMNs per microL and 9.7 +/- 1.5 days to attain a platelet count of >20,000 per microL-equivalent to data in the literature. No CS-3000 Plus backup cells were transfused and no serious adverse events attributable to the Amicus device were encountered. CONCLUSIONS: The mean Amicus CD34+ cell collection efficiency was better (p<0.05) than that of the CS-3000 Plus collection. Short-term engraftment was durable. The PBPCs collected with the Amicus separator are safe and effective for use for autologous transplant patients requiring PBPC rescue from high-dose myeloablative chemotherapy.     

The predictive value of white cell or CD34+ cell count in the peripheral blood for timing apheresis and maximizing yield

BACKGROUND: The collection of peripheral blood stem and progenitor cells (PBPCs) for transplantation can be time-consuming and expensive. Thus, the utility of counting CD34+ cells and white cells (WBCs) in the peripheral blood was evaluated as a predictor of CD34+ cell yield in the apheresis component. STUDY DESIGN AND METHODS: The WBC and CD34+ cell counts in the peripheral blood and the apheresis components from 216 collections were assessed. Sixty-three patients underwent mobilization with chemotherapy plus filgrastim, and 17 patients and 14 allogeneic PBPC donors did so with filgrastim alone. The relationship between the number of WBC and CD34+ cells in the peripheral blood and in the apheresis component was analyzed by using rank correlation and linear regression analysis. RESULTS: The correlation coefficient for CD34+ cells per liter of peripheral blood with CD34+ cell yield (x 10(6)/kg) was 0.87 (n = 216 collections). This correlation existed for many patient and collection variables. However, patients with acute myeloid leukemia had fewer CD34+ cells in the apheresis component at any level of peripheral blood CD34+ cell count. Components collected from patients with CD34+ cell counts below 10 x 10(6) per L in the peripheral blood contained a median of 0.75 x 10(6) CD34+ cells per kg. When the WBC count in the blood was below 5.0 x 10(9) per L, the median number of CD34+ cells in the peripheral blood was 5.6 x 10(6) per L (range, 1.0-15.5 x 10(6)/L). A very poor correlation was found between the WBC count in the blood and the CD34+ cell yield (p = 0.12, n = 158 collections). CONCLUSION: The number of CD34+ cells, but not WBCs, in the peripheral blood can be used as a predictor for timing of apheresis and estimating PBPC yield. This is a robust relationship not affected by a variety of patient and collection factors except the diagnosis of acute myeloid leukemia. Patients who undergo mobilization with chemotherapy and filgrastim also should undergo monitoring of peripheral blood CD34+ cell counts, beginning when the WBC count in the blood exceeds 1.0 to 5.0 x 10(9) per L.     

Immune reconstitution after autologous selected peripheral blood progenitor cell transplantation: comparison of two CD34+ cell-selection systems

BACKGROUND: Selection of CD34+ PBPCs has been applied as a method of reducing graft contamination from neoplastic cells. This procedure seems to delay lymphocyte recovery, while myeloid engraftment is no different from that with unselected PBPC transplants. STUDY DESIGN AND METHODS: Lymphocyte recovery was studied in two groups of patients who underwent autologous CD34+ PBPC transplant with two different technologies (Ceprate SC, Cellpro [n = 17]; CliniMACS, Miltenyi Biotech [n = 13]). The median number of CD34+ cells transfused was 3.88 x 10(6) per kg and 3.32 x 10(6) per kg, respectively. Residual CD3 cells x 10(6) per kg were 4.97 and 0.58, respectively (p = 0.041). Residual CD19 cells x 10(6) per kg were 1.33 and 0.73, respectively (NS). RESULTS: No differences were found between the two groups in total lymphocyte recovery to >0.5 x 10(9) per L, which achieved a stable count by Day 30. During the study period, the CD4+ cell count remained below 0.2 x 10(9) per L, and the B-cell subset showed a trend toward normalization. CD3/HLA-DR+ and CD16/56 increased markedly in both groups by Day 30. An increase in CMV (13%) and adenovirus (17.4%) infection was found in both groups. CONCLUSION: Both CD34+ cell selection technologies used here determined an excellent CD34+ cell purity and an optimal depletion of T cells. The high rate of viral complications is probably due to the inability of residual T cells left from the CD34+ cell selection to generate, immediately after transplant, an adequate number of virus-specific lymphocytes.     

Collection of MNCs with two cell separators for adoptive immunotherapy in patients with stage IV melanoma

BACKGROUND: MNCs for adoptive immunotherapy may be collected by leukocytapheresis with a cell separator. STUDY DESIGN AND METHODS: Six healthy cytapheresis donors donated two MNC concentrates on a cell separator (AS.TEC 204, Fresenius): one on the standard MNC program and one on a modified MNC program with reduced centrifuge velocity that leads to a lower platelet contamination. Seventeen patients with malignant melanoma donated 26 MNC concentrates: 5 on the AS.TEC 204 MNC program, 9 on the modified AS.TEC 204 MNC program, and 12 on another modified MNC program (Spectra, COBE). RESULTS: In the course of cultivation of MNCs to dendritic cells (DCs), the donor MNC concentrates with the lower platelet contamination (475 +/- 85 x 10(9)/L) had a significantly higher relative DC yield (low platelet contamination: 3.9 +/- 1.6% of the plated cells; high platelet contamination: 2.5 +/- 1.8% of the plated cells; p = 0.019) than the concentrates with the higher platelet contamination (2364 +/- 448 x 10(9)/L). No significant difference was found in the yields of MNCs and CD14+ cells in the three protocols used for the collection of MNCs from patients with melanoma. The components obtained by the standard AS.TEC 204 MNC program had a significantly higher platelet contamination (1768 +/- 994 x 10(9)/L) than the components obtained by the modified AS.TEC MNC program (360 +/- 98 x 10(9)/L; p<0.05) and the modified Spectra MNC program (636 +/- 266 x 10(9)/L); p<0.05). Because of the low number of investigated components, no significant difference in the DC yield of the three protocols could be detected (mean DC yield after cultivation: 746 +/- 429 x 10(6)). CONCLUSION: A high platelet contamination of MNC concentrates intended for adoptive immunotherapy can lead to a significant impairment of the DC yield after cultivation. Both the modified AS.TEC 204 and the modified Spectra MNC programs are well suited for collecting MNC concentrates with high MNC yields and low platelet contamination from patients with malignant melanoma.     

Comparison of intermittent- and continuous-flow cell separators for the collection of autologous peripheral blood progenitor cells in patients with hematologic malignancies

BACKGROUND: The transplantation of autologous peripheral blood progenitor cells (PBPCs) after high-dose chemotherapy is a valuable therapy for patients with hematologic and solid malignancies. Several methods are used for harvesting PBPCs. The efficiency of intermittent- and continuous-flow blood cell separators in collecting progenitor cells from the blood of patients undergoing myeloablative treatment for cancer was compared. STUDY DESIGN AND METHODS: PBPC components (n = 133) were obtained from 72 patients by leukapheresis with continuous-flow machines (Spectra, COBE; CS 3000 Plus, Baxter) and with an intermittent-flow machine (MCS 3P, Haemonetics). The data were analyzed retrospectively. Blood samples obtained from the patients before leukapheresis and samples of the leukapheresis components themselves were analyzed for their content of RBCs, WBCs, platelets, and CD34+ cells. RESULTS: The Spectra processed more than twice the blood volume in the shortest time (15 L in 178 min), whereas the Baxter CS 3000 Plus (10 L in 185 min) and the MCS 3P (4.8 L in 239 min) processed significantly smaller volumes in a longer time. The mean ACD consumption was 403 mL with the MCS 3P, 900 mL with the CS 3000 Plus, and 1000 mL with the Spectra. The product volumes were 50 mL (CS 3000 Plus), 69 mL (MCS 3P), and 166 mL (Spectra). In all groups, differences in the preapheresis hemograms were not significant, but the Spectra group had fewer CD34+ cells than the other groups. Despite this, the differences in the number of CD34+ cells in the leukapheresis components of all groups were without statistical significance. In the Spectra group, the collection of MNCs of 104 percent and CD34+ cells of 154 percent was significantly more efficient than that in the MCS 3P group (42.2% and 56%, respectively) or the CS 3000 Plus group (50.8% and 47.15%) as related to the patients' blood volume. CONCLUSION: PBPC collection can be performed successfully with continuous-flow and intermittent-flow blood cell separators. The Spectra had the best recovery of CD34+ cells within the shortest time. Leukapheresis with the MCS 3P is indicated if only a single venous access is available.     

Comparison of plateletpheresis concentrates produced with Spectra LRS version 5.1 and LRS Turbo version 7.0 cell separators

BACKGROUND: The importance of transfusing WBC-reduced blood components is widely recognized, as it reduces the risk of alloimmunization and transfusion-transmitted CMV infections. The latest generation of cell separators allows the collection of WBC-reduced apheresis platelet concentrates (APCs). MATERIALS AND METHODS: Consecutive APCs (n = 232) were retrospectively evaluated: 163 collected with the Spectra LRS [leukocyte-reduction system] Version 5.1 (Group A) and 69 with the LRS Turbo Version 7.0 (Group B) (both: COBE BCT). Donor peripheral blood count, procedure data, platelet yield, collection efficiency (CE), and residual WBC count in APCs were recorded. RESULTS: The platelet yield was higher in Group B than in Group A: 5.5 +/- 1.4 versus 4.4 +/- 1.1, p<0.0001; residual WBCs were <5 x 10(6) in 99.4 percent of Group A APCs and in 97.1 percent of Group B APCs. CE was higher in Group B than in Group A: 51.4 +/- 8.7 versus 43.6 +/- 6.3, p<0.0001. Moreover, a correlation between predonation platelet count and platelet yield was observed in both groups. A double product (platelet yield >6.0 x 10(11)) was obtained in 28.9 percent of Group B APCs and in 9.2 percent of Group A APCs. CONCLUSIONS: The Spectra LRS Turbo version 7.0 release showed a better CE and resulted in a higher platelet harvest than did the LRS version 5.1. High predonation platelet counts allow a higher platelet yield.     

Inverse relationship between patient peripheral blood CD34+ cell counts and collection efficiency for CD34+ cells in two automated leukapheresis systems

BACKGROUND: The purpose of this study was to analyze the CD34 cell collection efficiency (CE) of automated leukapheresis protocols of two blood cell separators (Spectra, COBE [AutoPBSC protocol] and AS104, Fresenius [PBSC-Lym, protocol]) for peripheral blood progenitor cell (PBPC) harvest in patients with malignant diseases. STUDY DESIGN AND METHODS: PBPCs were collected by the Spectra AutoPBSC protocol in 95 patients (123 collections) and the AS104 PBSC-Lym protocol in 87 patients (115 harvests). Patients underwent a median of one (range, 1-4) conventional-volume apheresis procedure of 10.8 L (9.0-13.9) to obtain a target cell dose of > or =2.5 x 10(6) CD34+ cells per kg. RESULTS: The median overall CD34 CE was significantly better on the AS104 than on the Spectra: 55.8 percent versus 42.4 percent (p = 0.000). This was also true below (59.2% vs. 50.1%; p = 0.022) and above (51.2% vs. 41.3%; p = 0.001) the preleukapheresis threshold of 40 CD34+ cells per microL needed to collect a single-apheresis autograft. However, at > or =40 circulating CD34+ cells per microL, both cell separators achieved the target of > or =2.5 x 10(6) CD34+ cells per kg. The CD34 CE dropped significantly, from 59.2 percent at <40 cells per microL to 51.2 percent at > or =40 cells per microL on the AS104 (p = 0.017) and from 50.1 percent to 41.3 percent on the Spectra (p = 0.033). CONCLUSION: Whereas the CD34 CE was significantly different with the AS104 and the Spectra, the CD34 CE of both machines correlated inversely with peripheral blood CD34+ cell counts, showing a significant decline with increasing numbers of circulating CD34+ cells. Nevertheless, at > or 40 preapheresis CD34+ cells per microL, sufficient hematopoietic autografts of > or =2.5 x 10(6) CD34+ cells per kg were harvested by a single conventional-volume (11 L) leukapheresis on both cell separators.     

Cytokines and vascular cell adhesion molecule-1 in the blood of patients undergoing HPC mobilization

BACKGROUND: The mechanism of HPC mobilization in humans is unclear. In this study, the relationship between PBPC mobilization and blood levels of G-CSF, endogenous cytokines (IL-8, SCF, thrombopoietin [TPO]), and the vascular cell adhesion molecule-1 (VCAM-1) was analyzed in patients with malignancy who were undergoing a PBPC mobilization regimen. STUDY DESIGN AND METHODS: Fifty-four patients with multiple myeloma (MM) and 29 with breast cancer (BC) underwent a mobilization regimen combining conventional chemotherapy and G-CSF up to the last day of PBPC collection. The CD34+ cell count was determined on each day when leukapheresis was scheduled. Venous blood samples (n = 117) were drawn before apheresis for CD34+ cell count (flow cytometry) and cytokine (G-CSF, IL-8, SCF, TPO) and VCAM-1 measurements (ELISA). RESULTS: In multiple regression analysis, SCF was a significant determinant of CD34+ cell levels in BC patients (R = 0.50, p = 0.03) and of VCAM-1 levels in MM patients (R = 0.32, p = 0.02). SCF was negatively correlated with CD34+ cell count in patients with BC. SCF and VCAM-1 blood levels were correlated in MM and BC patients. CONCLUSION: SCF and VCAM-1 could play a role in PBPC mobilization in patients and could be useful measures by which to study patients undergoing a mobilization regimen.     

The dose of granulocyte-colony-stimulating factor after chemopriming treatment does not influence apheresis yield of progenitor cells: a retrospective study of 91 cases

BACKGROUND: The optimal dose of post-chemotherapy granulocyte-colony-stimulating factor (G-CSF) administration before peripheral blood progenitor cell (PBPC) collection has not been determined as yet, although 5 microg per kg per day has been recommended as the standard dose. This study retrospectively analyzed the effect of G-CSF dose on peripheral blood CD34+ cell collection from 91 patients with hematologic malignancies. STUDY DESIGN AND METHODS: Various doses of G-CSF were administered after several chemotherapeutic PBPC mobilization regimens. According to the dose of G-CSF administered, patients were assigned to two groups. Group 1 included 46 patients who received a low dose of G-CSF (median, 3.6 [range, 2.8-4.6] microg/kg/day). Group 2 included 45 patients who received a standard G-CSF dose of 6.0 (5.5-8. 1) microg per kg per day. Patients in the two groups were matched for age, diagnosis, previous therapy, and chemotherapeutic PBPC mobilization regimens. RESULTS: No difference was observed in the median number of CD34+ cells harvested from each group.The number of leukapheresis procedures necessary to obtain a minimum of 3 x 10(6) CD34+ cells per kg was the same in both groups, and the percentage of patients who failed to achieve adequate PBPC collections was similar in the two groups. CONCLUSION: The administration of low-dose G-CSF after chemotherapy appears equivalent to administration of the standard dose in achieving satisfactory PBPC collection.This approach could allow significant savings in medical cost. A randomized and prospective study is necessary, however, to assess the validity of these conclusions.     

The timing of granulocyte–colony-stimulating factor administration after chemotherapy does not affect stem and progenitor cell apheresis yield: a retrospective study of 65 cases

BACKGROUND: The optimal time for postchemotherapy granulocyte-colony stimulating factor (G-CSF) administration before peripheral blood stem and progenitor cell (PBPC) collection is not well defined. The impact of G-CSF scheduling on the number of CD34+ cells collected by leukapheresis from 65 patients with malignant disease was studied retrospectively. STUDY DESIGN AND METHODS: Chemotherapy was performed on Days 1 and 2 and was followed by G-CSF to mobilize PBPCs. In Group 1, 30 patients received the first dose of G-CSF immediately after the end of chemotherapy, as commonly recommended. In Group 2, 35 patients received the first G-CSF dose after the end of chemotherapy (Days 7 or 8). RESULTS: No difference was observed between the two groups in white cell recovery and the median number of CD34+ cells harvested. The number of leukapheresis procedures necessary to obtain the minimal number of 3 x 10(6) CD34+ cells per kg was the same. The proportion of patients with a failure of PBPC collection was similar, and G-CSF consumption was reduced in Group 2 without increasing infectious risks. CONCLUSION: Early administration of G-CSF after chemotherapy appears not to be a prerequisite for satisfactory PBPC collection. This approach could allow significant savings in terms of medical cost. A randomized and prospective study would be necessary, however, to assess the validity of these conclusions.     

The dose of granulocyte–colony-stimulating factor after chemopriming treatment does not influence apheresis yield of progenitor cells: a retrospective study of 91 cases

BACKGROUND: The optimal dose of post-chemotherapy granulocyte–colony-stimulating factor (G–CSF) administration before peripheral blood progenitor cell (PBPC) collection has not been determined as yet, although 5 μg per kg per day has been recommended as the standard dose. This study retrospectively analyzed the effect of G–CSF dose on peripheral blood CD34+ cell collection from 91 patients with hematologic malignancies.
STUDY DESIGN AND METHODS: Various doses of G–CSF were administered after several chemotherapeutic PBPC mobilization regimens. According to the dose of G–CSF administered, patients were assigned to two groups. Group 1 included 46 patients who received a low dose of G–CSF (median, 3.6 [range, 2.8-4.6] μg/kg/day). Group 2 included 45 patients who received a standard G–CSF dose of 6.0 (5.5-8.1) μg per kg per day. Patients in the two groups were matched for age, diagnosis, previous therapy, and chemotherapeutic PBPC mobilization regimens.
RESULTS: No difference was observed in the median number of CD34+ cells harvested from each group. The number of leukapheresis procedures necessary to obtain a minimum of 3 × 10⁶ CD34+ cells per kg was the same in both groups, and the percentage of patients who failed to achieve adequate PBPC collections was similar in the two groups.
CONCLUSION: The administration of low-dose G–CSF after chemotherapy appears equivalent to administration of the standard dose in achieving satisfactory PBPC collection. This approach could allow significant savings in medical cost. A randomized and prospective study is necessary, however, to assess the validity of these conclusions.     

Immunomagnetic selection of CD34+ cells: factors influencing component purity and yield

BACKGROUND: In immunomagnetic selection of CD34+ cells from HPC transplants, not all factors that affect yield and purity of CD34+ cells are known. METHODS: Forty-three consecutive procedures of immunomagnetic selection of CD34+ cells from peripheral blood HPCs and bone marrow harvests (autologous harvests, n = 27; allogeneic harvests; n=16) were performed by use of a cell selection system (Isolex 300i, Baxter Immunotherapy). The composition of the starting component and the subsets of CD34+ cells were analyzed for correlation with the yield and purity of the final component. RESULTS: The mean purity of the final components was 84.3 percent (range, 27-99%), and the mean yield was 51.4 percent (range, 9.4-80. 4%). Partial regression analysis showed that, among the factors correlating with purity and/or yield, the RBC volume in the starting fraction had the highest predictive impact on the purity and yield of CD34+ cells, even after the exclusion of procedures using bone marrow harvests as an HPC source (beta coefficient, -0.704; p = 0. 001). CONCLUSION: The use of the Isolex 300i system allows efficient recovery of CD34+ cells in routine selection procedures. The volume of RBCs in the starting component should be minimized to ensure a high yield and purity of the final component.     

PBPC mobilization with paclitaxel, ifosfamide, and G-CSF with or without amifostine: results of a prospective randomized trial

BACKGROUND: The impact of amifostine on PBPC mobilization with paclitaxel and ifosfamide plus G-CSF was assessed. STUDY DESIGN AND METHODS: Forty patients with a median age of 34 years (range, 19-53) who had germ cell tumor were evaluated for high-dose chemotherapy. Patients were randomly assigned to receive either a single 500-mg dose of amifostine (Group A, n = 20) or no amifostine (Group B, n = 20) before mobilization chemotherapy with paclitaxel (175 mg/m(2)) given over 3 hours and ifosfamide (5 g/m(2)) given over 24 hours (TI) on Day 1. G-CSF at 10 microg per kg per day was given subsequent to TI with or without amifostine from Day 3 until the end of leukapheresis procedures. RESULTS: In 2 (10%) of 20 patients receiving amifostine and 3 (15%) of 20 patients not receiving it, no PBPC separation was performed because of mobilization failure. No significant differences were observed in the study arms with regard to the time from chemotherapy until first PBPC collection or the number of apheresis procedures needed to harvest more than 2.5 x 10(6) CD34+ cells per kg. Furthermore, leukapheresis procedures yielded comparable doses of CD34+ cells per kg (3.4 x 10(6) vs. 3.6 x 10(6); p = 0.82), MNCs per kg (2.7 x 10(8) vs. 2.6 x 10(8); p = 0.18), and CFU-GM per kg (15.9 x 10(4) vs. 19.3 x 10(4); p = 0.20). Patients in Group A had higher numbers of circulating CD34+ cells on Day 10 (103.0/microL vs. 46.8/microL; p = 0.10) and on Day 11 (63.0/microL vs.14.3/microL; p = 0.04) than did patients in Group B. CONCLUSION: Administration of a single dose of amifostine before chemotherapy with TI mobilized higher numbers of CD34 cells in the circulation, but did not enhance the overall collection efficiency in the present trial.     

Allogeneic blood progenitor cell collection in normal donors after mobilization with filgrastim: the M.D. Anderson Cancer Center experience

BACKGROUND: Information on the safety and efficacy of allogeneic peripheral blood progenitor cell (PBPC) collection in filgrastim-mobilized normal donors is still limited. STUDY DESIGN AND METHODS: The PBPC donor database from a 42-month period (12/94-5/98) was reviewed for apheresis and clinical data related to PBPC donation. Normal PBPC donors received filgrastim (6 microg/kg subcutaneously every 12 hours) for 3 to 4 days and subsequently underwent daily leukapheresis. The target collection was > or =4 x 10(6)CD34+ cells per kg of recipient's body weight. RESULTS: A total of 350 donors were found to be evaluable. Their median age was 41 years (range, 4-79). Their median preapheresis white cell count was 42.8 x 10(9) per L (range, 18.3-91.6). Of these donors, 17 (5%) had inadequate peripheral venous access. Leukapheresis could not be completed because of apheresis-related adverse events in 2 donors (0.5%). Of the 324 donors evaluable for apheresis yield data, 221 (68%) reached the collection target with one leukapheresis. The median CD34+ cell dose collected (first leukapheresis) was 462 x 10(6) (range, 29-1463).The main adverse events related to filgrastim administration in donors evaluable for toxicity (n = 341) were bone pain (84%), headache (54%), fatigue (31%), and nausea (13%). These events were rated as moderate to severe (grade 2-3) by 171 (50%) of the donors. In 2 donors (0.5%), they prompted the discontinuation of filgrastim administration. CONCLUSION: PBPC apheresis for allogeneic transplantation is safe and well tolerated. It allows the collection of an "acceptable" PBPC dose in most normal donors with one leukapheresis, with minimal need for invasive procedures.     

Successful mobilization of peripheral blood HPCs with G-CSF alone in patients failing to achieve sufficient numbers of CD34+ cells and/or CFU-GM with chemotherapy and G-CSF

BACKGROUND: Mobilization with chemotherapy and G-CSF may result in poor peripheral blood HPC collection, yielding <2 x 10(6) CD34+ cells per kg or <10 x 10(4) CFU-GM per kg in leukapheresis procedures. The best mobilization strategy for oncology patients remains unclear. STUDY DESIGN AND METHODS: In 27 patients who met either the CD34 (n = 3) or CFU-GM (n = 2) criteria or both (n = 22), the results obtained with two successive strategies-that is, chemotherapy and G-CSF at 10 microg per kg (Group 1, n = 7) and G-CSF at 10 microg per kg alone (Group 2, n = 20) used for a second mobilization course-were retrospectively analyzed. The patients had non-Hodgkin's lymphoma (5), Hodgkin's disease (3), multiple myeloma (5), chronic myeloid leukemia (1), acute myeloid leukemia (1), breast cancer (6), or other solid tumors (6). Previous therapy consisted of 10 (1-31) cycles of chemotherapy with additional chlorambucil (n = 3), interferon (n = 3), and radiotherapy (n = 7). RESULTS: The second collection was undertaken a median of 35 days after the first one. In Group 1, the results of the two mobilizations were identical. In Group 2, the number of CD34+ cells per kg per apheresis (0.17 [0.02-0.45] vs. 0.44 [0.11-0.45], p = 0. 00002), as well as the number of CFU-GM (0.88 [0.00-13.37] vs. 4.19 [0.96-21.61], p = 0.00003), BFU-E (0.83 [0.00-12.72] vs. 8.81 [1. 38-32.51], p = 0.00001), and CFU-MIX (0.10 [0.00-1.70] vs. 0.56 [0. 00-2.64], p = 0.001134) were significantly higher in the second peripheral blood HPC collection. However, yields per apheresis during the second collection did not significantly differ in the two groups. Six patients in Group 1 and 18 in Group 2 underwent transplantation, and all but one achieved engraftment, with a median of 15 versus 12 days to 1,000 neutrophils (NS), 22 versus 16 days to 1 percent reticulocytes (NS), and 26 versus 26 days to 20,000 platelets (NS), respectively. However, platelet engraftment was particularly delayed in many patients. CONCLUSION: G-CSF at 10 microg per kg alone may constitute a valid alternative to chemotherapy and G-CSF to obtain adequate numbers of peripheral blood HPCs in patients who previously failed to achieve mobilization with chemotherapy and G-CSF. This strategy should be tested in prospective randomized trials.     

Donor age-related differences in PBPC mobilization with rHuG-CSF

BACKGROUND: Data on the administration of rHuG-CSF to normal donors <18 years old are very limited. STUDY DESIGN AND METHODS: The results of rHuG-CSF administration to 61 donors <18 years old (Group A) were retrospectively evaluated and compared with results from 353 donors > or = 18 years old (Group B) who are included in the Spanish National Donor Registry. The mean age (range) in Group A and B was 14 (1-17) and 38 (18-71) years, respectively (p<0.001). The mean dose of rHuG-CSF was 10 microg per kg per day (range, 9-16) during a mean of 5 days (range, 4-6). Central venous access was placed more frequently in younger donors (25% vs. 6%; p<0.001). RESULTS: The mean number of CD34+ cells collected was 7.6 and 6.9 x 10(6) per kg of donor's body weight in Group A and B, respectively. Fifty-six percent of Group A donors needed only one apheresis to achieve > or = 4 x 10(6) CD34+ cells per kg versus 39 percent of Group B donors (p = 0.01). Side effects were more common in Group B (71% vs. 41%; p<0.001). CONCLUSION: The administration of rHuG-CSF to donors <18 years old leads to CD34+ cell mobilization in a pattern similar to that observed in adults. Greater age was associated with a more frequent requirement for more than one apheresis to achieve a similar number of CD34+ cells.     

Ex vivo evaluation of PBMNCs collected with a new cell separator

BACKGROUND: This study reports on an evaluation of the ability of a cell separator (Amicus, Baxter Healthcare) and the integral MNC computer software program to collect a variety of MNC subsets. The collection efficiency (CE) of the Amicus for these MNC subsets was compared to that of another cell separator (CS-3000 Plus, Baxter). The collected MNCs were also assayed ex vivo to determine if these cells remained functional. STUDY DESIGN AND METHODS: Healthy volunteer blood donors were recruited to provide PBMNCs for the isolation of CD3+, CD4+, CD8+, CD19+, NK, and gammadelta+ cells and monocytes. Cells were collected with an Amicus (test arm; n = 16) or a CS-3000 Plus (control arm; n = 11) cell separator. Cells were counted on a flow cytometer and CEs were calculated. For functional studies, the Amicus-collected MNC data were compared to CS-3000 Plus historical data. Functional studies performed included surface antigen expression assays (CD8+), proliferation assays (CD4+ and CD8+ cells), NK cytotoxicity assays for K562 and HUVE cells, and E-selectin induction on endothelial cells through NK+ contact dependency. Dendritic cells (DCs) were generated from CD34+ cells collected on the Amicus, positively selected by the use of antibody-bound, magnetic bead technology, and then cultured ex vivo with a combination of growth factors to generate the DCs. RESULTS: CEs were higher on the Amicus than on the CS-3000 Plus for CD3+ (68 vs. 54%), CD4+ (70 vs. 56%), CD8+ (68 vs. 52%), and CD19+ (60 vs. 48%) cells (p<0.05). For the two separators, CEs were equivalent for monocytes, NK+, and gammadelta+ cells. The Amicus separator collected significantly fewer platelets than did the CS-3000 Plus (p<0.00001). CD4+, CD8+, and NK cells proliferated normally. NK cells appropriately stimulated E-selectin expression on endothelial cells. Culture-generated DCs obtained by using Amicus-collected CD34+ cells expressed appropriate cell surface markers. CONCLUSION: The Amicus separator is acceptable for the collection of PBMNC subsets. The device collects CD3+, CD4+, CD8+, and CD19+ T- and B-cell subsets with greater efficiency and collects MNCs with significantly fewer contaminating platelets than does the CS-3000 Plus. Cells collected on the Amicus are suitable for use in a variety of research and clinical immunobiologic studies.     

Isolation of CD34+ progenitor cells from peripheral blood by use of an automated immunomagnetic selection system: factors affecting the results

BACKGROUND: The isolation of CD34+ cells from mobilized peripheral blood is being increasingly used in the setting of allogeneic or autologous hematopoietic cell transplantation. Investigation of variables that may influence the effectiveness of CD34+ cell selection is of interest. STUDY DESIGN AND METHODS: Fifty-one CD34+ cell selections from peripheral blood progenitor cells (PBPCs) (39 allogeneic and 12 autologous) were performed using a magnetic cell separator (Isolex 300i, Baxter), including version 2.0 software. The results obtained were analyzed for different processing variables. The feasibility of transplanting these isolated CD34+ cells was also analyzed. RESULTS: The isolated CD34+ cell fraction had a median purity of 88.9 percent (range, 47.8-98.3). The median recovery of CD34+ cells was 45.1 percent (13.8-76.2), and the median colony-forming unit- granulocyte-macrophage (CFU-GM) content was 17. 2 percent (0.8-58.6). Logarithms of T- and B-cell depletion had median values of 3.7 and 2.8, respectively. The version 2.0 software of the Isolex 300i gave a higher CD34+ cell recovery in the enriched cell fraction (median 57.8%) than did version 1.11 (39.4%) or 1.12 (44.4%) (p = 0.01). The use of recombinant human deoxyribonuclease I during cell processing yielded more CD34+ cells (53% vs. 41%, p = 0. 01) and higher purity (92.8% vs. 87%, p = 0.03). There was a correlation between the percentage of CD34+ cells labeled with the monoclonal antibody 8G12 clone and the percentage of CD34+ cells labeled with the monoclonal antibody used during the processing technique (9C5 clone) in the initial, enriched, and depleted CD34+ cell fractions (R(2) = 0.95; 0.92; 0.78, p< 0.005, respectively). Median times for recovering >0.5 x 10(9) per L of granulocytes and >20 x 10(9) per L of platelets were 13 and 16 days in the allograft patients and 13 and 14 days in the autograft patients. CONCLUSION: CD34+ cells can be highly and effectively isolated from allogeneic and autologous grafts by use of this automated technique, with a high grade of T- and B-cell depletion. These purified CD34+ cell components can engraft normally.     

Umbilical cord blood progeny cells that retain a CD34+ phenotype after ex vivo expansion have less engraftment potential than unexpanded CD34+ cells

BACKGROUND: Because of the limitation of cell numbers associated with cord blood harvests, there is a need to determine the efficacy of using ex vivo-expanded cord blood cells in a transplantation setting. In this study, limiting-dilution analysis was used in nonobese diabetic mice with severe combined immunodeficiency (NOD/SCID) to compare the engraftment potential of progeny cells expressing the CD34+ phenotype after expansion with that of uncultured CD34+ cells. STUDY DESIGN AND METHODS: Cord blood CD34+ cells were cultured in Iscove's modified Dulbecco medium supplemented with 10-percent fetal calf serum (FCS) and IL-6, SCF, megakaryocyte growth and development factor, and Flt3 ligand. The resulting ex vivo-expanded products were assessed for total numbers of nucleated cells, CD34+ cells, and CFUs and long-term culture-initiating cell activity. The engraftment potentials of cultured progeny CD34+ cells and uncultured CD34+ cells were determined by using NOD/SCID mice. RESULTS: After 14 days of culture, total nucleated cell counts increased over input values by 180 +/- 59-fold, CD34+ cell numbers by 44 +/- 13-fold, CFU activity by 23 +/- 5-fold, and long-term culture-initiating cell activity by 20 +/- 6-fold (mean +/- SD; n = 6). The frequency of SCID-repopulating cells (SRC) in mice transplanted with uncultured products was 1 per 20,000 CD34+ cells (95% CI, 1:10,000-1:38,000) and that in mice receiving ex vivo-expanded products was 1 per 418,000 progeny CD34+ cells (95% CI, 1:158,000-1:1,100,000). Taken together, these data indicated that, after 2 weeks of culture, there was a modest twofold increase in the total number of SRCs. However, the levels of human CD45 cell engraftment in NOD/SCID recipients of progeny CD34+ cells were significantly lower than those in mice receiving equivalent numbers of uncultured CD34+ cells (p<0.05). CONCLUSION: Umbilical cord blood progeny cells retaining a CD34+ phenotype after ex vivo expansion have less engraftment potential than do unexpanded CD34+ cells.     

Immunologic changes after transfusion of autologous or allogeneic buffy coat-poor versus white cell-reduced blood to patients undergoing arthroplasty. I. Proliferative T-cell responses and the balance of helper and suppressor T cells

BACKGROUND: Donor white cells (WBCs) contained in red cell (RBC) transfusions are thought to provoke down-regulation of T-cell-mediated immunity. This study investigated this topic in otherwise healthy patients receiving buffy coat-depleted or WBC-filtered RBCs and undergoing standardized perioperative management. STUDY DESIGN AND METHODS: Patients undergoing elective orthopedic surgery (primary hip and knee replacement surgery) were enrolled in a prospective study. Perioperative changes in T-cell proliferation (stimulation with phytohemagglutinin and mixed lymphocyte culture) and T-cell balance (T-lymphocytes, helper T cells, and suppressor T cells) were compared after random assignment to allogeneic buffy coat-depleted (Group 2, n = 8) or WBC-reduced RBC (Group 3, n = 11) transfusion regimens. Recipients of autologous buffy coat-depleted RBC transfusions (n = 15) served as controls (Group 1). RESULTS: Compared to that in autologous transfusion recipients, alloantigen-induced T-cell proliferation was significantly reduced in recipients of allogeneic WBC-reduced RBCs (Day 3, p = 0.0274). After the transfusion of allogeneic buffy coat-depleted RBCs, a weak trend toward decreased T-cell proliferation was observed (p = 0.0933) and the numbers of CD4+ T cells were also significantly lower (Day 7, p = 0.0389). On Day 10, alloantigen-induced T-cell proliferation remained significantly below baseline after transfusion of WBC-reduced RBCs (p = 0.05), the numbers of CD3+ cells decreased in allogeneic RBC recipients (Group 2, p = 0.078; Group 3, p = 0.05), and those of CD8+ cells decreased significantly after the transfusion of allogeneic buffy coat-depleted RBCs (p = 0.0234) concomitant with an increased CD4:CD8 ratio (p = 0.0391). CONCLUSION: Results of the present study confirm the hypothesis of impaired T-cell-mediated immunity after allogeneic transfusion.