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PubMed1982

Comparison of filtration leukapheresis and centrifugation leukapheresis in treatment of lymphosarcoma cell leukemia.

A patient with lymphosarcoma cell leukemia resistant to chemotherapy was treated with filtration leukapheresis and centrifugation leukapheresis. Filtration leukapheresis removed only 10(11) leukemia cells per 8.5 liters of blood processed, while centrifugation leukapheresis removed approximately six times as many leukemia cells from the same amount of blood. Lymph nodes and spleen diminished in size and the WBC count decreased after nine treatments. However, the patient remained markedly thrombocytopenic, and his bone marrow remained infiltrated with lymphosarcoma cells on repeat biopsy. This study shows that centrifugation leukapheresis is superior to filtration leukapheresis in removing significant numbers of circulating lymphosarcoma cells, though the clinical benefit of leukapheresis in this situation remains to be determined.

Blood↗
PubMedDate not supplied

Evaluation of gravity leukapheresis and comparison with intermittent centrifugation leukapheresis.

Fifteen normal donors underwent gravity leukapheresis using a prototype collection and reinfusion harness after receiving dexamethasone for leukocyte stimulation. A mean of 4.6 units of blood were processed, producing a mean granulocyte yield of 10.8 X 10(9), with an average donation time of 261 minutes. Granulocyte collection efficiency was 79.9 per cent, but yield was only 2.5 X 10(9) granulocytes/hour. Granulocytes obtained by gravity leukapheresis were normal morphologically and had normal bactericidal capacity. Serial determinations showed no changes before and after donation of coagulation profile and serum chemistries in the donors. Seven donors underwent leukapheresis using intermittent centrifugation the day following gravity leukapheresis without further leukocyte stimulation. Mean granulocyte yield (16.1 X 10(9)), and yield/hour (5.37 X 10(9)) of donation were significantly greater for the mechanical method (p less than 0.0005). Gravity leukapheresis required considerable blood bag handling and bag entries, even with the prototype harness. Considering the amount of blood handling, the expense of the sedimenting agent, the probable dose response phenomenon of granulocyte transfusions, and the low yield resulting from the limited volume of blood processed, this technique should not be made widely available, especially where regional centers can provide granulocytes obtained by more productive methods.

Blood Platelets↗
PubMed2005

Large-volume leukapheresis yields more viable CD34+ cells and colony-forming units than normal-volume leukapheresis, especially in patients who mobilize low numbers of CD34+ cells.

BACKGROUND: Large-volume leukapheresis (LVL) differs from normal-volume leukapheresis (NVL) by increased blood flow and altered anticoagulation regimen. LVL is now regarded as a safe procedure for collection of peripheral blood progenitor cells (PBPCs), but it is not known whether the procedure will alter CD34+ cell quality or will be useful for patients who mobilize few CD34+ cells into peripheral blood. STUDY DESIGN AND METHODS: The results from 82 LVL and 125 NVL (4.0-5.3 and 2.7-3.5 times the patients' blood volumes processed, respectively) were retrospectively analyzed in altogether 112 consecutive patients with malignant diseases. RESULTS: The LVL yielded significantly more CD34+ cells (4.2 x 10(6) vs. 3.1 x 10(6)/kg, p = 0.006, all patients; and 1.8 x 10(6) vs. 1.3 x 10(6)/kg, p = 0.004, bad mobilizers) and significantly higher colony-forming units (77 x 10(4) vs. 33 x 10(4)/kg; all patients and 33 x 10(4) vs. 20 x 10(4)/kg, p < 0.001, both groups). Significantly fewer leukapheresis procedures were required to obtain 2 x 10(6) CD34+ cells per kg (one vs. two, p = 0.001, all patients; and two vs. three, p = 0.009, bad mobilizers). No significant differences in CD34+ cell viability and time to hematologic recovery were observed between the patients who received PBPCs harvested by NVL and LVL. CONCLUSION: Although a median platelet loss of 36 percent can be expected, LVL can be recommended as the standard apheresis method for PBPC collections in patients with malignant diseases. LVL is particularly useful in patients who mobilize a low number of CD34+ cells into the peripheral blood.

Adolescent↗
PubMedDate not supplied

The acquisition of granylocytes by leukapheresis: a comparison of continuous flow centrifugation and filtration leukapheresis in normal and corticosteroid-stimulated donors.

Leukapheresis by continuous flow centrifugation (CFC) or filtration (FL) were compared in untreated and corticosteroid-treated donors. The administration of prednisone 60 mg orally 10 to 12 hours before leukapheresis increased significantly both the donor's prepheresis WBC counts and the total granulocyte yields by CFC or FL. Dexamethasone 6 mg iv at the start of FL did not increase granulocyte yields significantly. In untreated donors FL yielded 0.25 x 10(10) granulocytes per liter donor blood processed as compared with 0.05 x 10(10) per liter in CFC donors. Corticosteroid premedication has a greater relative effect in increasing yields by CFC than by FL. Donor reaction rates were between 4 and 6 per cent for both procedures.

Blood Donors↗
PubMed1981

Filtration versus gravity leukapheresis in febrile granulocytopenic patients: a randomized prospective trial.

Forty-eight patients with fever greater than 38.3 degrees C for at least 24 hr despite broad spectrum antibiotics and an absolute granulocyte count less than 1000/microliter were randomly allocated to 4 days of granulocyte transfusions obtained by leukapheresis using filtration (n = 27) or gravity (n = 21) techniques, the latter permitting simultaneous nonmechanical collection of granulocytes and platelets utilizing hydroxyethyl starch as a sedimenting agent. Patient characteristics and dose of granulocytes obtained from both techniques were similar. Complete response to granulocyte transfusions was established by a reduction in temperature to less than 37.2 degrees C sustained for at least 48 hr after the fourth transfusion with sterilization of cultures where previously positive and diminution of measurable infection when present. This occurred in 6/21 (29%) for gravity leukapheresis and 9/27 (33%) for filtration leukapheresis. An additional group had diminution in temperature and clinical improvement during transfusions (6/21 gravity leukapheresis versus 10/27 filtration leukapheresis). Eighty-six percent of patients transfused with gravity leukapheresis cells were alive at day 20 compared with 81% for filtration leukapheresis cells. Transfusion reactions were comparable. Thus, gravity leukapheresis appears to be as efficacious as filtration leukapheresis for treating granulocytopenic febrile patients, with the added advantages of availability to any blood bank without new equipment, of having platelets as by-products, and of not requiring donor heparinization.

Adolescent↗
PubMed1975

Effects on cancer patients of leukapheresis with the continuous-flow blood cell separator. I. Hematologic and immunologic parameters in vivo.

A study was undertaken to investigate the hematologic and in vivo immunologic effects of leukapheresis of from 2 X 10(9) to 1.6 X 10(10) peripheral blood lymphocytes from 9 cancer patients and 13 normal donors on the blood cell separator. The same parameters were measured in 10 individuals who did not undergo leukapheresis and 4 individuals who underwent sham leukapheresis. Studies were performed immediately prior to and following leukapheresis and at 4 hours, 1 day, 3 days, and 7 days following leukapheresis. There was a transient decline in blood lymphocyte pool (BLP) of the normal donors which returned to preleukapheresis values within 72 hours. Six of 13 normal donors and 2 of 9 cancer patients had a fall in blood lymphocyte count which was below the lower limit of the range of change in control donors immediately following leukapheresis, but all returned to control range within 24 hours. Five cancer patients had increases in lymphocyte count. DNCB reactivity and delayed cutaneous hypersensitivity reactions to common recall antigens were performed 2 weeks before, immediately before, and after leukapheresis, at 7 days and at 4 to 6 weeks following leukapheresis. There were no differences in skin test reactivity between groups. No clinical exacerbations of malignant disease occurred which might be construed to be due to leukapheresis.

Adult↗
PubMed2003

Changes in immunological and virological parameters in HIV-1 infected subjects following leukapheresis.

In order to assess immune responses during HIV-1 therapeutic immunization, a large number of blood mononuclear cells (PBMC) are needed. Clinical tolerance and safety, as well as changes in immunological and virological parameters, were assessed, following leukapheresis in HIV-1 infected subjects with CD4(+) cell count >200 x 10(6)/l. PBMC were collected using a Fenwal CS3000 cell separator in 29 subjects with mean CD4(+) cell counts of 503 x 10(6)/l (range 172-1,119) and viral load of 2.5 log(10) copies/ml (range <1.7-5.4). Twenty-four (83%) subjects were on antiretroviral therapy while 5 (17%) were untreated. The blood volume processed was 7 L over a period of 3 hours. A mean value (+/- standard error) of 82 +/- 26 x 10(9)/l lymphocytes was collected by a single apheresis in a mean volume of 200 +/- 1.8 ml, containing 9.0 +/- 1.3 x 10(9)/l CD4(+) and 10.2 +/- 1.3 x 10(9)/l CD8(+) cells. The leukapheresis procedures were well tolerated and no immediate or delayed side effects were observed within 90 days of follow-up. No changes from blood pre-leukapheresis values were detected for white blood cells, lymphocytes, monocytes, CD8(+), CD34(+), naive and memory CD4(+) cell counts immediately after, 1 h, 7 days, or within 90 days after leukapheresis. However, absolute CD4(+) cell counts and percentage significantly increased from pre-leukapheresis values after 1 h (530 +/- 43 vs. 700 +/- 75 cell x 10(6)/l; 32.6 +/- 1.6 vs. 36.9 +/- 1.9%; P < 0.001 for both paired t-tests) before returning to pre-leukapheresis levels on day 7. No significant changes in viral load from pre-leukapheresis levels in treated or untreated subjects were detected at any time points. We conclude that leukapheresis in HIV-1 infected subjects with CD4(+) cell counts >200 x 10(6)/l is safe and induces a transient increase in the absolute and percentage of CD4(+) cell count without enhancing viral replication.

Adult↗
PubMed1999

Timing of platelet recovery is associated with adequacy of leukapheresis product yield after cyclophosphamide and G-CSF in patients with lymphoma.

A subgroup of patients with refractory Hodgkin's (HD) or non-Hodgkin's (NHL) lymphoma may be cured with high-dose chemotherapy and peripheral blood progenitor cell rescue. To investigate the relationship of adequate leukapheresis yield and time course of platelet recovery after mobilization chemotherapy, we retrospectively analyzed the leukapheresis yields in seven patients with Hodgkin's disease and fifteen patients with non-Hodgkin's lymphoma undergoing high-dose chemotherapy. Our goal was to develop a rule to determine when to initiate leukapheresis and then to prospectively validate this rule. All patients were mobilized with cyclophosphamide and G-CSF (granulocyte-colony stimulating factor). A total of 144 leukaphereses were completed and analyzed. Based on the CD34 content in the initial harvest product, fifteen patients were defined as poor mobilizers (CD34 < 0.15 x 10(6)/kg) and seven were good mobilizers. The platelet count on the first day of harvesting was significantly associated with the poor mobilizers (P = .03). Age, sex, marrow involvement, disease (HD vs. NHL), prior radiation, time since last chemotherapy, and total number of cycles of prior chemotherapy were not predictive of poor mobilizers. By using a platelet count cut off of 35 x 10(9)/L, we retrospectively analyzed 144 individual leukapheresis products, to test whether CD34 yield was predicted by the peripheral blood platelet count on the day of leukapheresis. This rule had an excellent sensitivity, 91%, and a specificity of 67%. Subsequently, we validated this rule with the next twenty-four patients undergoing leukapheresis of which there were 143 leukaphereses. The prediction rule exhibited a sensitivity of 72% and a specificity of 68% in the validation set. There does appear to be utility in using the platelet count to guide the initiation of leukapheresis after chemotherapy and G-CSF mobilization.

Adult↗
PubMed2000

Impact of pre-induction therapy leukapheresis on treatment outcome in adult acute myelogenous leukemia presenting with hyperleukocytosis.

Acute myeloid leukemia (AML) presenting with hyperleukocytosis is generally of poor prognosis due to an increased early death rate and a lower response to initial chemotherapy. Between April 1985 and December 1995, all patients with newly diagnosed AML admitted to our institution with an initial white blood cell (WBC) count greater than 100 x 10(9)/l were scheduled to undergo leukapheresis. This represented 53 patients (median age 59 years, range 16-78 years) who underwent from 1 to 4 sets of leukapheresis (median 1). The median initial WBC count was 160 x 10(9)/l (range 100-480 x 10(9)/l). Morphologic subtypes, according to the French-American-British classification, showed 3 M0, 16 M1, 6 M2, 10 M4, 16 M5, and 2 unclassified cases of AML. In 21 patients (40%), leukapheresis did not reduce their WBC counts significantly, while 32 patients (60%) achieved a WBC count of less than 100 x 10(9)/l (median 71 x 10(9)/l) after leukapheresis. Analysis of cell cycle was performed on bone marrow (BM) and peripheral blood leukemic cells before and after leukapheresis in three cases. In two of those cases, a recruitment of BM leukemic cells in the S phase was observed after leukapheresis. The median WBC count at the time of starting chemotherapy was 85 x 10(9)/l (range 23-264 x 10(9)/l). Complete remission was achieved in 55% (95% confidence interval 40-68%). Early death occurred in two cases. Median disease-free survival was 10 months, while median overall survival was 8 months. In this study, early death rate is lower than data previously published in the literature and almost all patients could receive chemotherapy. This might suggest a benefit of initial leukapheresis in the treatment of AML presenting with hyperleukocytosis.

Adolescent↗
PubMed2002

A randomized trial of assessment of efficacy of leukapheresis volumes, 8 liters vs 12 liters.

It is logical to expect that large-volume leukapheresis may be able to collect adequate numbers of PBSC with fewer procedures. To date, there is no agreement on the optimal volume of leukapheresis. Therefore, in this study we compared 8 l volume with 12 l and assessed whether a 50% increase in the blood volume processed would decrease the number of leukaphereses each patient needed to collect > or =2.5 x 10(6) CD34(+) cells/kg in normal mobilizers. PBSC mobilization was done with cyclophosphamide etoposide followed by rhG-CSF in all patients. Forty patients were randomized to undergo 8 l leukaphereses (n = 20 patients) or 12 l leukaphereses (n = 20). The median numbers of leukaphereses required in order to collect > or =2.5 x 10(6) CD34(+) cells/kg in patients processed with 8 l and 12 l were 1 (range 1-5) and 1 (1-4), respectively (P = 0.50). The median number of total nucleated cells (TNC) collected per patient was greater for the 12 l group (7.47 x 10(8)/kg vs 3.90 x 10(8)/kg, P < 0.001), as was the median number of total mononuclear cells (TMNC) (4.26 x 10(8)/kg vs 2.16 x 10(8)/kg, P < 0.001), whereas there was no difference between the two groups for the median number of CD34(+)cells collected per patient (8.94 x 10(6)/kg vs 8.60 x 10(6)/kg, P = 0.85). The TNCs and TMNCs collected per leukapheresis were again greater for the 12 l group (3.64 x 10(8)/kg vs 1.91 x 10(8)/kg, P = 0.001 and 2.17 x 10(8)/kg vs 0.88 x 10(8)/kg, P < 0.001), whereas there was no difference between the two groups for the median number of CD34(+) cells collected per leukapheresis (3.98 x 10(6)/kg vs 3.26 x 10(6)/kg, P = 0.90). This study showed that there is no difference between 8 l and 12 l volumes in regard to collected CD34(+) cells/kg and also the use of a 12 l leukapheresis volume did not decrease the number of leukaphereses performed compared with a 8 l leukapheresis volume. In fact, the use of the larger leukapheresis volume had the disadvantage of adding 60 min to the time the patient was on the machine.

Adolescent↗
PubMed1995

Predictive factors for peripheral-blood progenitor-cell collections using a single large-volume leukapheresis after cyclophosphamide and granulocyte-macrophage colony-stimulating factor mobilization.

PURPOSE: (1) To study the ability of mobilized peripheral-blood progenitor cells (PBPC) collected in a single large-volume leukapheresis performed on a predetermined date to accelerate engraftment after high-dose cyclophosphamide and thiotepa; (2) to establish the minimum dose of PBPC associated with early engraftment; and (3) to identify parameters predictive of collection of large numbers of PBPC. PATIENTS AND METHODS: Twenty-three patients with breast cancer received cyclophosphamide (4 g/m2) and granulocyte-macrophage colony-stimulating factor ([GM-CSF] 5 micrograms/kg/d x 15 days) for PBPC mobilization. A single leukapheresis was performed 15 days after cyclophosphamide administration. Then, patients received high-dose cyclophosphamide and thiotepa followed by reinfusion of PBPC and 4-hydroperoxycyclophosphamide (4HC)-purged bone marrow. PBPC concentration was measured in serial peripheral-blood samples and in the leukapheresis product. Correlation analysis between PBPC dose and engraftment and between leukapheresis yield and patient characteristics was attempted. RESULTS: A single leukapheresis processed a median 36 L (range, 24 to 46) blood and collected 5 x 10(6) CD34+ cells/kg (< 0.3 to 24) and 6.2 x 10(5) colony-forming units granulocyte-macrophage (CFU-GM)/kg (< 0.001 to 29). All sixteen patients (70%) reinfused with > or = 2.9 x 10(6) CD34+ cells/kg reached a level of greater than 1,000 leukocytes/microL by day 13 and greater than 50,000 platelets/microL by day 15. All of these patients had a percentage of peripheral-blood CD34+ cells > or = 0.5%, and all but one, a level of greater than 100,000 platelets/microL, on the day of leukapheresis. The bone marrow CD34+ cell percentage at study entry predicted the number of CD34+ cells collected after PBPC mobilization (R2 = .42, P = .002). All patients with > or = 2.5% bone marrow CD34+ cells experienced early engraftment. CONCLUSION: Reinfusion of PBPC collected in a single leukapheresis accelerates engraftment in the majority of patients. Pretreatment bone marrow CD34+ cell content determines PBPC mobilization capacity and may help select hematopoietic rescue strategies.

Adult↗
PubMed2000

Human endothelial cell cultures from progenitor cells obtained by leukapheresis.

Although improved prosthetic graft patency with endothelial cell (EC) seeding has been shown in animal models, the clinical application of this technique requires a convenient source of ECs. We have evaluated EC cultures derived from the mononuclear cell (MNC) fraction obtained during large-volume leukapheresis and compared this with cultures grown from peripheral blood cells obtained by phlebotomy. Leukapheresis was performed in healthy adult volunteers (n = 7) using software designed to increase the percentage of MNCs harvested. Blood (40-293 mL) was drawn from a peripheral vein in healthy adult volunteers (n = 13), and the MNCs were obtained by differential centrifugation using a Lymphoprep gradient. Significantly more MNCs were obtained by leukapheresis than by phlebotomy. Each leukapheresis procedure yielded 12.5 to 23 mL, which contained 2.29 +/- 0.35 x 10(9) MNCs, compared with 2.16 +/- 0.50 x 10(8) MNCs, for each phlebotomy (P < 0.001). EC colonies developed in significantly more cultures from leukapheresis-derived MNCs (6 of 7) than phlebotomy-derived MNCs (4 of 13; P = 0.008). Leukapheresis-derived cells developed EC morphology at 15.5 +/- 2 days compared with 21 +/- 3.4 days for cells obtained by phlebotomy (P = not significant). EC were identified by positive factor VIII and vascular endothelial growth factor receptor immunostaining. Leukapheresis significantly increases the number of progenitor cells available for differentiation into EC compared with phlebotomy and avoids the need for any surgical procedure to harvest a peripheral vein as a direct source of ECs.

Adult↗
PubMed2005

Correlation of CD34+ cell yield in peripheral blood progenitor cell product with the pre-leukapheresis cell counts in peripheral blood.

INTRODUCTION: Accurate timing of the leukapheresis procedures is of paramount importance to get the best possible CD34+ cell yield in the minimum number of leukapheresis procedures. AIM: To find if pre-harvest CD34+ cell concentration in peripheral blood correlates with CD34+ cells in the product. MATERIAL AND METHODS: Sixty Leukapheresis procedures were performed for 25 patients (8 autologous and 17 allogeneic transplants) with hematological malignancies. Statistical analysis was performed to correlate the pre-harvest CD34+ cell count and the CD34+ cell yield. Volume processed during PBPC harvests was three times the blood volume. RESULTS: The best correlation was found between the leukapheresis product CD34+ cell count and the pre-harvest PB-CD34+ cell count (PCC=0.674) when compared with the other pre-harvest PB cell counts viz., WBC (PCC=0.229) and MNC (PCC=0.324). This correlation was better in the allogeneic harvest (PCC = 0.645) than the autologous harvest procedures (PCC = 0.348). Correlation analysis based on paired samples from the 60 leukapheresis procedures showed that when the pre-leukapheresis PB-CD34+ cell count was >20x10(3)/ul a yield of >1x10(6) CD34+ cells/Kg could be obtained in 95% of the cases and >2x10(6) CD34+ cells /Kg could be harvested in 68% of cases whereas when the pre-leukapheresis PB-CD34+ cell count was <5x10(3)/microl the yield was <1x10(6) CD34+ cells/Kg in 81% of the procedures. CONCLUSION: The yield of CD34+ cells in PBPC harvests depends on the pre-harvest CD34+ cell concentration and therefore it is more useful than the pre-harvest WBC or MNC counts for predicting the appropriate timing of the harvests and also to achieve the best possible yield of CD34+ cells.

Adolescent↗
PubMed1997

Decrease in tumor cell contamination and progenitor cell yield in leukapheresis products after consecutive cycles of chemotherapy for breast cancer treatment.

In this retrospective study, we assessed the impact of each of three consecutive cycles of conventional-dose chemotherapy on CD34+ cells, colony-forming units granulocyte-macrophage (CFU-GM), and contaminating breast cancer cells collected in the leukapheresis products of patients with metastatic breast cancer. The patients subsequently underwent high-dose chemotherapy followed by autologous blood progenitor cell transplantation. We analyzed 172 leukapheresis products from 17 patients and have correlated the long-term clinical outcome with tumor cell contamination. The induction chemotherapy regimen consisted of three cycles of cyclophosphamide 750 mg/m2 i.v., epirubicin 100 mg/m2, and 5-fluorouracil (5-FU) 750 mg/m2 i.v., followed by 5 microg/kg body weight of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) daily until leukapheresis was completed. An average of 10 leukapheresis products (three to four collections after each cycle of chemotherapy) were obtained from each patient. Numbers of CD34+ cells, CFU-GM, and mononuclear cells (MNCs) in the leukapheresis products were determined at the time of collection. Aliquots from the same products were frozen and breast cancer cells were detected by immunocytochemistry with a cocktail of anti-cytokeratin antibodies (AE-1, AE-3, CAM 5.2, Keratin 8+18+19) using a standardized immunoalkaline phosphatase method. A minimum of 10(6) cells were examined by light microscopy and by at least two blinded observers. Cells were considered positive when immunostaining was detected in the cytoplasm and on the cell membrane, and cellular morphology was consistent with a malignant phenotype. Of the 172 samples analyzed, 13 of 57 (23%) leukapheresis products collected after cycle I were positive for tumor cells; 3 of 60 (5%) after cycle II; and 4 of 55 (7%) after cycle III. The likelihood of contamination by breast cancer cells after cycle I was significantly higher than after subsequent cycles of chemotherapy (p = 0.0052). Simultaneously, there was a significant decrease in quantity of CD34+ cells and CFU-GM (p < 0.0001 for both comparisons). Our study indicated that leukapheresis products collected after the second or third cycles of induction chemotherapy carry a significantly lower likelihood of tumor cell contamination, albeit the quantity of CD34+ cells or CFU-GM collected was also significantly reduced.

Adult↗
PubMed1986

The effect of acute and chronic leukapheresis on the natural killer (NK) cell function of normal human volunteers.

Twenty-two normal volunteers had approximately eight, 2-hr-long leukapheresis procedures over a 2-year period and their natural killer (NK) cell function was prospectively measured. The NK activity of the preprocedure peripheral blood (pre-PB) was found to correlate well with the NK activity of the inital leukocytes removed by leukapheresis (I-Leuk). When the I-Leuk specimens were compared with the leukapheresis specimens removed at the termination of leukapheresis (T-Leuk), T-Leuk showed a consistent 10% increase in NK activity. When the pre-PB and the I-Leuk values were analyzed for each donor over the 2 years of the study, 18 donors revealed no significant change from their baseline NK activity, two donors showed a minimal increase in NK cell activity, and two donors displayed a minimal decrease in NK cell activity. We conclude that although leukapheresis appears acutely to boost NK cell activity, this increase is transient and small in magnitude. Most importantly, repeated leukapheresis does not appear adversely to effect this important effector function in normal donors.

Adolescent↗
PubMed2003

Modification of the leukapheresis procedure for use in rhesus monkeys (Macaca mulata).

One of the most serious problems in applying leukapheresis to human infants is the large extracorporeal blood volume (ECV), resulting in substantial loss of platelets and red blood cells (RBCs). In this study, we developed a safe and effective modified procedure to collect peripheral blood stem cells (PBSCs) from rhesus monkeys (Macaca mulata) using a Baxter CS3000+ Blood Cell Separator (Baxter, Deerfield, IL) with several devices that reduced chamber size and shortened the standard apheresis kit to decrease ECV from 130 to 70 ml. Pump speed was controlled by monitoring hematocrit values and platelet counts during leukapheresis. This system makes it possible to perform safe and effective leukapheresis in rhesus monkeys whose body weight is similar to that of human infants. A total of 12 leukapheresis procedures were performed in nine monkeys and resulted in the collection of sufficient numbers of white blood cells (mean, 1.38 x 10(9) cells/kg), CD34(+) cells (mean, 17.80 x 10(6) cells/kg), mononuclear cells (mean, 3.67 x 10(8) cells/kg), and colony forming units (mean, 75.02 x 10(6) cells/kg) in all cases. In addition, no complications, such as anemia or thrombocytopenia, occurred after leukapheresis. This modified leukapheresis procedure will be useful to test new approaches in gene therapy, perform organ transplantation using nonhuman primates, and collect PBSCs from human infants in a noninvasive manner. Our nonhuman primate model provides an important framework for such future clinical studies.

Animals↗