Safe and Efficient Peripheral Blood Stem Cell Collection in the Smallest of Children

Abstract: To clarify the factors that may affect the peripheral blood stem cell (PBSC) collection in children weighing ≤ 15 kg, a consecutive registry of 109 leukapheresis procedures was analyzed. Collections were performed on a COBE Spectra separator. In 65.1% of the procedures, the peripheral vein, together with a central catheter inserted routinely at diagnosis, or 2 peripheral veins were used to access/return. For 84.4% of the procedures, the extracorporeal line was primed with red blood cells. The median granulocyte-macrophage colony forming unit (CFU-GM) number derived from 1 patient's blood volume processed was 13.8 times 10⁴/kg. Six times, a collection series failed, al ways in children treated for ≥ 26 weeks and 4 of those times in children weighing ≤ 11 kg. The patient's age, diagnosis, duration of preleukapheresis treatment, and mobilization regimens did not significantly affect the collection yield. Twenty-four transplantations were performed. The median times to neutrophils > 0.5× 10⁹/L and platelets > 20 × 10⁹/L were 13 and 20 days, respectively. We conclude that even in very small children, leukapheresis can be performed safely, allowing adequate PBSC collection for transplantation and/or in vitro manipulations.     

Peripheral blood stem cell collection in 24 low-weight infants: experience of a single centre

Peripheral blood stem cells (PBSC) harvest may be difficult in young children. Extracorporeal separator line priming by red blood cells is usually required to improve haemodynamic tolerance and efficacy of collection. We present our experience with 24 children weighing less than 15 kg treated between January 1997 and September 1999, in whom we tried to avoid systematic blood priming. The median age and weight at the time of apheresis were 2.4 years and 12 kg, respectively. A total of 48 PBSC were performed. When haemoglobin was less than 12 g/dl, packed red cells were transfused before collection (40% of aphereses). The median cell yield per apheresis was 7.1 (2.2-30.6)x10(6)/kg CD34(+) cells and 16.0 (3.3-44.3)x10(5) CFU-GM/kg. Initial collection failed in three cases. Four children required an additional haematopoietic progenitor mobilization. This procedure allowed PBSC collection without transfusion in 37.5% of children, and was safe (two serious and five mild transient side effects) and effective (median CD34(+) cells collected per child: 7.1 x 10(6)/kg (4.6-30.6) and CFU-GM: 15.1 x 10(5)/kg (4.7-44.3)). Despite their low weight, insertion of a femoral catheter was avoided in 43% of children.     

A Comparative Study of a New,Fully Automated Procedure and the Standard Mononuclear Cell Program Using the Cobe Spectra for Peripheral Blood Stem Cell Collection

Abstract: Recently, a completely automated procedure, the AutoPBSC program for the COBE Spectra cell separator, has been developed for peripheral blood stem cell harvest (PBSCH). We compared the performance of the AutoPBSC program with the standard mononuclear cell (MNC) program in the same patients and in a donor. Peripheral blood stem cells (PBSC) were collected from 3 patients or a donor alternately using the MNC program and the AutoPBSC program in a course of PBSC mobilization. Equal blood volume was processed from each patient (200 ml/kg) and a donor (150 ml/kg). We used a harvest volume of 3 ml and a chase volume of 7 ml in all AutoPBSC procedures. The procedure duration was almost equivalent for both programs. The volume of products was significantly lower in the AutoPBSC program (71′± 13 ml) than in the MNC program (183 ± 30 ml). MNC yields were fewer, and total nucleated cell (TNC) and MNC collection efficiency was less for the AutoPBSC program compared to the MNC program. The CD34 + cell collection efficiency was less for the AutoPBSC program (26.5 ± 13.7%, compared with 77.7 ± 60.6%; p > 0.05). The contamination of platelets and red cells was significantly less in the AutoPBSC program than in the MNC program. In conclusion, we consider that the collection efficiency in the new program should be improved by modification of parameters because there exist great advantages to automated procedures.     

Clinical toxicity at the infusion of cryopreserved and thawed peripheral blood stem cell grafts in children]

To test the safety of infusing cryopreserved and thawed peripheral blood stem cells (PBSC) in children, toxicity assessment was made at 36 infusions in 33 children with various types of cancer. The mean volume of PBSC graft infused was 224 ml (range, 46-500 ml) or 8.0 ml/kg (1.7-23.8 ml/kg), in containing 10% dimethylsulfoxide (DMSO). Vomiting was the only toxic feature related to the amount of DMSO. However, eight patients developed transient shock, but recovered shortly afterward with or without supportive therapy. Attention should be drawn to increased risk in children receiving thawed blood cell grafts.     

Risk of complications during hematopoietic stem cell collection in pediatric sibling donors: a prospective European Group for Blood and Marrow Transplantation Pediatric Diseases Working Party study

We investigated prospectively factors influencing the safety of hematopoietic stem cell (HSC) collection in 453 pediatric donors. The children in the study donated either BM or peripheral blood stem cells (PBSCs) according to center policy. A large variability in approach to donor issues was observed between the participating centers. Significant differences were observed between BM and PBSC donors regarding pain, blood allotransfusion, duration of hospital stay, and iron supplementation; however, differences between the groups undergoing BM vs PBSC donation preclude direct risk comparisons between the 2 procedures. The most common adverse event was pain, reported mainly by older children after BM harvest, but also observed after central venous catheter (CVC) placement for PBSC collection. With regard to severe adverse events, one patient (0.7%) developed a pneumothorax with hydrothorax after CVC placement for PBSC collection. The risk of allotransfusion after BM harvest was associated with a donor age of < 4 years and a BM harvest volume of > 20 mL/kg. Children < 4 years were at higher risk than older children for allotransfusion after BM harvest and there was a higher risk of complications from CVC placement before apheresis. We conclude that PBSC and BM collection are safe procedures in children.     

Collection of peripheral blood stem cells mobilized by high-dose Ara-C plus VP-16 or aclarubicin followed by recombinant human granulocyte-colony stimulating factor.

We developed an effective method for harvesting large numbers of peripheral blood stem cells (PBSC) for use in autotransplantation. Twenty patients with hematological malignancies were treated with high doses of Ara-C (12 g/m2) and VP-16/aclarubicin followed by administration of rhG-CSF (50 micrograms/m2). The optimal time for starting PBSC collection was determined by monitoring the CD34-positive stem cells in blood using immunomagnetic beads. PBSC were collected with a CS-3000 blood cell separator. A total blood volume between 7000 and 9000 ml was processed in each apheresis. Under these conditions, a total of 64 apheresis procedures was performed in the 20 patients. The mean numbers of mononuclear cells and of CFU-GM harvested per apheresis were 4.1 x 10(8)/kg and 110 x 10(4)/kg, respectively. A number of CFU-GM sufficient for engraftment (> 30 x 10(4)/kg) could be harvested by a single apheresis in 15 of the 20 patients. So far, 11 patients have been transplanted with PBSC and obtained rapid hematopoietic recovery. The median time to recover neutrophils more than 0.5 x 10(9)/l was 10 days, and that for platelets 50 x 10(9)/l was 11 days. This method for harvesting large numbers of PBSC allows safer autotransplantation in patients with chemoradiosensitive tumors, and is applicable to older patients.     

COLLECTION AND TRANSPLANTATION OF PERIPHERAL BLOOD PROGENITOR CELLS MOBILIzED BY G-CSF ALONE IN CHILDREN WITH MALIGNANCIES

Results of collection and transplantation of peripheral blood progenitor cells (PBPC) mobilized by G-CSF in 31 children with different malignancies were analysed. A total of 43 aphereses were performed, following administration of granulocyte colony-stimulating factor (G-CSF), using a continuous flow blood cell separator (Cobe Spectra) through a central venous catheter. For patients weighing ≤25 kg the extracorporeal line was primed with red blood cells. The mean blood flow rate was 33.2ml/min (range 12–56ml/min). The mean number of mononuclear cells (MNC), granulocyte-macrophage colony-forming units (CFU-GM) and CD34⁺ cells collected were 7.22×10⁸/kg body weight (b.w.), 15.9×10⁴/kg and 5.44×10⁶/kg respectively.
The morbidity related to PBPC collection was low and the mean apheresis time was 302.7min (range 115–492). The volume of processed blood for apheresis (per kilogram body weight) ranged from 117 to 539.6 (mean 309.13ml/kg). 20 patients required only one apheresis to collect the minimum requirement of 5–7×10⁸/kg of MNC.
All patients subsequently underwent autografting with PBPC after myeloablative therapy. Days to achieve an absolute count of neutrophils (ANC) <0.5×10⁹/l and a platelet count of 20×10⁹2/l without platelet support were 9.5 and 18, respectively. The number of CD34⁺ cells infused correlated highly with engraftment kinetics. The extramedullary toxicity was low and manageable.     

Single vs twice daily G-CSF dose for peripheral blood stem cells harvest in normal donors and children with non-malignant diseases

The optimal dose and schedule of G-CSF for mobilization of peripheral blood stem cells (PBSC) is not well defined. G-CSF mobilization was performed in a group of healthy donors and paediatric patients for autologous back-up before receiving allogeneic stem cell transplant. Seventeen consecutive subjects who received G-CSF at 5 microg/kg/dose twice daily (group A) were compared with a historical control group of 25 subjects who received a single daily dose of 10 microg/kg/day G-CSF (group B). Double blood volume apheresis for PBSC collection was started on day 5. G-CSF was continued and apheresis repeated until the targeted CD34+ cell dose was achieved. Both groups were comparable for sex, age, body weight and reason for PBSC collection. Over two-thirds of the subjects in both groups were less than 16 years of age. The G-CSF priming and apheresis were well tolerated. When the first day apheresis products were analyzed, group A resulted in significantly higher yield of total nucleated cells (5.91 vs 3.92 x 108/kg, P = 0. 013), mononuclear cells (5.73 vs 3.92 x 108/kg, P = 0.017), CD34+ cells (2.80 vs 1.69 x 106/kg, P = 0.049) and colony-forming units (107 vs 54 x 104/kg, P = 0.010) as compared with group B. We conclude that the two dose schedule is more efficient in mobilizing PBSC in normal donors and children with non-malignant diseases. This approach may reduce the number of aphereses required and thus reduce the transplant cost.     

Safety and efficacy of allogeneic PBSC collection in normal pediatric donors: the pediatric blood and marrow transplant consortium experience (PBMTC) 1996-2003

The use of peripheral blood stem cells (PBSC) for allogeneic transplants in adults has greatly increased. This trend is reflected in pediatrics, where healthy children increasingly are donating PBSC or donor lymphocyte infusion (DLI) via apheresis for use by ill siblings. There is a potential concern that the risks of PBSC collection may differ for pediatric donors. However, no large studies have assessed safety issues in this population. To address this need, we reviewed 218 (213 PBSC, five DLI) collections in 201 normal pediatric donors (8 months to 17 years, median 11.8 years) at 22 institutions in the Pediatric Blood and Marrow Transplant Consortium. Donors received a median of 4 days of growth factor, and mean collection yield was 9.1 x 10(6) CD34+ cells/kg recipient weight. Younger age, days of apheresis, and male gender predicted increased yield of CD34+ cells/kg donor weight. Growth factor-induced pain was mild and reported in less than 15% of patients. Most donors <20 kg (23/25, 92%) required PRBC priming of the apheresis machine. This experience with over 200 collections demonstrates that PBSC collection is safe in normal pediatric donors and desired CD34 cell yields are easily achieved. Younger children utilize more medical resources and children <20 kg usually require a single blood product exposure.     

Technique for PBSC harvesting in children of weight under 10 kg

Peripheral blood stem cell (PBSC) harvesting in the smallest children (weight <10 kg) using separators is complicated by specific problems. The volume of the separation set exceeds 25% of the total blood volume and the vascular access is generally not sufficient. Therefore, a simple manual technique for PBSC harvesting was developed. Three children (6-9 kg), with newly diagnosed tumours were scheduled to be treated with three to six sequential courses of high-dose chemotherapy, each followed by PBSC support. PBSC harvests were started after mobilization using cyclophosphamide and G-CSF when the peripheral blood CD34+ cell count exceeded 50/microl. About 50 ml of blood was drawn from a venous catheter, injected into a transfer bag containing ACD-A, and centrifuged. The buffy coat obtained was pooled in a collection bag, remaining plasma and erythrocytes were immediately reinfused and a subsequent cycle started. From three to 13 cycles were performed in 1-3 days and 18.0-32.2 x 10(6) CD34+cells/kg were collected. We did not detect any bacterial contamination or any notable complications. Fifteen PBSC reinfusions have been performed to date, each with rapid engraftment taking between 7 and 13 days. Patients are in very good PR (18 months from diagnosis) or in CR (6 and 8 months). We can conclude that this procedure is feasible and safe.     

Collection and transplantation of peripheral blood stem cells in very small children weighting 20 kg or less

The safety and efficacy of harvesting peripheral blood hematopoietic stem cells (PBSC) were evaluated in 38 children weighing 20 kg or less, with the smallest patient weighing 7 kg. The patients had a median age of 42 months and included 26 children with acute leukemias or lymphoma and 12 with various solid tumors. A total of 81 aphereses were performed, mostly in the recovery phase of chemotherapy, with or without granulocyte colony-stimulating factor, using a CS-3000 cell separator and regular procedure no. 3. Blood was withdrawn at a mean rate of 30 mL/min (range, 17 to 46 mL/min) through a temporary radial arterial catheter (20 to 24 guage) and returned through a larger catheter in a peripheral vein. Morbidity related to PBSC harvest was low and all aphereses were completed within 3 hours. The volume of blood per kilogram processed for each apheresis ranged from 85 to 615 mL (median, 270 mL). The median number of colony-forming units-- granulocyte-macrophage (CFU-GM) and CD34+ cells collected were, respectively, 34 x 10(4)/kg and 15 x 10(6)/kg per apheresis and 126 x 10(4)/kg and 31 x 10(6)/kg per patient. Thirty-three patients (87%) required only a single apheresis to collect the minimum requirement of 10 x 10(4) CFU-GM/kg, including 28 patients (74%) from whom 30 x 10(4) CFU-GM/kg was obtained in a single apheresis. Twenty-three of the patients subsequently underwent autografts with PBSC. The median number of days required to achieve an absolute granulocyte count of 0.5 x 10(9)/L and a platelet count of 50 x 10(9)/L were, respectively, 10 (range, 6 to 15) and 14 (range, 9 to 46). The patients remained dependent on platelet transfusion support for a median of 10 days (range, 5 to 35). Thus, harvesting PBSC in very small children with active cancers is effective and safe and does not involve the risk of anesthesia or multiple invasive marrow aspirations.     

Differences between graft product and donor side effects following bone marrow or stem cell donation

We report graft product stem cell yields and donor safety results of a randomized multicenter study comparing allogeneic peripheral blood stem cell (PBSC) PBSC transplantation with BM transplantation. Matched HLA-identical sibling donors (n=329) were randomized to filgrastim-mobilized PBSC or bone marrow (BM) donation groups. Median yields per kg recipient weight of CD34(+) cells, T cells, and natural killer (NK) cells, respectively, were approximately two-fold, eight-fold, and greater than eight-fold in the PBSC group than in the BM group (CD34(+) cells, 5.8 x 10(6)/kg vs 2.7 x 10(6)/kg; T cells, 300.1 x 10(6)/kg vs 35.7 x 10(6)/kg; NK cells, 28.2 x 10(6)/kg vs 3.6 x 10(6)/kg; P<0.001 for each). In connection with the cell collection procedures, PBSC donors spent a shorter median time in hospital than BM donors (0 vs 2 days; median difference -2 days, 95% CI -2 to 2) and had fewer median days of restricted activity (2 vs 6 days; median difference -3 days, 95% CI -4 to 2). Overall, 65% of PBSC donors and 57% of BM donors reported at least one adverse event (AE), most of which were transient, mild-moderate in severity, and without clinical sequelae. PBSC donors experienced predominantly filgrastim-related AEs, while BM donors experienced predominantly harvest-related AEs.     

Successful mobilization of peripheral blood stem cells using recombinant human stem cell factor in heavily pretreated patients who have failed a previous attempt with a granulocyte colony-stimulating factor-based regimen

To assess the efficacy of recombinant human stem cell factor (rHuSCF), 48 patients who had failed to mobilize >2.0 x 10(6) CD34+ cells/kg with granulocyte colony-stimulating factor (G-CSF) (10 microg/kg twice daily) with, or without, concomitant chemotherapy (G-CSF-based regimen), were remobilized with the addition of rHuSCF (20 microg/kg/day). In all, 18/48 (38%) achieved a total of >2.0 x 10(6) CD34+ cells/kg with the second rHuSCF-based mobilisation alone and 29/48 (60%) achieved a cumulative total of >2.0 x 10(6) CD34+ cells/kg following remobilization. Inclusion of chemotherapy in the mobilization regimen resulted in a higher yield of CD34+ cells/kg for both the initial G-CSF-based and subsequent rHuSCF-based regimens (0.90 vs 0.54, P < 0.01 and 2.36 vs 1.34, P < 0.01, respectively). The total peripheral blood stem cells PBSC collected from the G-CSF-based regimen, performance status, baseline platelet count and albumin were significantly associated with successful remobilization. Patients with multiple myeloma were also more likely to successfully remobilize. There was no threshold of total collected from the failed G-CSF-based regimen below which successful remobilization with the rHuSCF-based regimen was not possible. We therefore propose a predictive model [PBSC expected = 0.6+(G-CSF-based total collection)+2 (rHuSCF-based day 1 collection)] to calculate the cumulative total of PBSC expected following a maximum of five leukaphereses. This algorithm may permit the early identification of patients who are unlikely to achieve sufficient PBSC for transplantation and allow physicians to direct the resources involved in PBSC collection in a more appropriate and economical manner.     

Cytotoxic drug and cytotoxic drug/G-CSF mobilization of peripheral blood stem cells and their use for autografting.

We analysed 99 courses of leukapheresis after the use of cytotoxic drugs or cytotoxic drugs plus G-CSF (cytotoxic/G-CSF) to mobilize peripheral blood stem cells (PBSC) in 68 patients with hematologic or solid malignancies. Mean yields of granulocyte-macrophage progenitor cells (CFU-GM) with cytotoxic/G-CSF mobilization were significantly higher than those with cytotoxic mobilization (18.6 vs 8.40 x 10(4)/kg). The optimal timing of collection was different between these two mobilizations; the mean number of days to a peak level of circulating CFU-GM after cytotoxic/G-CSF mobilization was less than that after cytotoxic mobilization (24.2 vs 27.7 days). The leukocyte level on the day of peak CFU-GM was significantly higher in cytotoxic/G-CSF mobilization than that in cytotoxic mobilization (mean 12.8 vs 2.7 x 10(9)/l), whereas the platelet level was not different (mean 132 vs 125 x 10(9)/l). Increasing patient age was not a major adverse factor for PBSC collection. Synchronous recovery of both leukocytes and platelets was critical for achieving a high CFU-GM yield in these two mobilizations. Following PBSC autotransplantation, the rate of trilineage hematologic reconstitution showed a significant correlation with the infused dose of CFU-GM, whether they were collected with cytotoxic or cytotoxic/G-CSF mobilization. These results suggest that G-CSF can expand the PBSC pool and that CFU-GM yield after cytotoxic/G-CSF mobilization may predict trilineage hemopoietic reconstitution after ABSCT, as well as cytotoxic mobilization.     

Factors associated with granulocyte colony-stimulating factor-induced peripheral blood stem cell yield in healthy donors

BACKGROUND AND OBJECTIVES: Poor collection results are a clinical problem in granulocyte-colony stimulating factor (G-CSF)-induced peripheral blood stem cell (PBSC) collection in healthy donors. It would be beneficial to be able to predict the PBSC yield from allogeneic donors before mobilization or harvesting. MATERIALS AND METHODS: We examined the relationship between certain donor characteristics and the effectiveness of G-CSF-induced PBSC collection in 59 healthy family donors aged 3-63 years old (median 16 years). G-CSF was administered subcutaneously at 10 microg/kg for mobilization, daily for 5 days, and PBSC harvest using a continuous blood cell separator was started on day 5 of G-CSF treatment. Total cell yields were calculated as the number per unit of processed blood (l) per unit weight of the donor (kg). RESULTS: In a univariate analysis, the donor's age, body mass index (BMI), white blood cell (WBC) count before mobilization, and platelet count before and during mobilization were significantly correlated with the yield of mononuclear cells (MNC), CD34(+) cells and granulocyte-macrophage colony-forming units (GM-CFU). Younger age (P < 0.001), a low BMI (P = 0.002), a high WBC count before mobilization (P = 0.004), a high platelet count before (P = 0.012) and during (P < 0.05) mobilization, and a low speed of withdrawal (P = 0.019) were associated with a higher CD34(+) cell yield. No significant correlation was found for gender, the type of G-CSF, the serum level of G-CSF, the type of cell separator, or the type of blood access. A multivariate forward and backward stepwise selection regression analysis showed that the factors associated with CD34(+) cell yield were age, platelet count before and during mobilization, and circulating CD34(+) cell concentration on day 2 of G-CSF treatment. CONCLUSION: In this small preliminary study, we found that donor age is the most important factor in predicting G-CSF-induced PBSC yields. Old age and low platelet counts before mobilization might be useful indicators for identifying poor mobilizers. Further validation of these findings in a larger number of donors are needed to establish whether these findings apply to other populations.     

Use of totally implantable catheters for peripheral blood stem cell apheresis

Collection of PBSC by leukapheresis requires one venous access (VA) for inflow and one for outflow. The use of implantable venous access devices (IVAD) has never been reported in this setting. We retrospectively analyzed the use of IVAD for performing apheresis. The study was conducted between January 2000 and June 2005 on 64 patients (41 children) requiring intensification for treatment of a solid tumor. Mean body weight was 26 kg (range 8-91 kg) for a median age of 8.5 years (range 0.7-66 years). A total of 121 aphereses were performed (mean 1.89 apheresis/patient). The second VA was in a cubital vein in 84 procedures and was a temporary central VA in 31. Mean duration of apheresis was 3 h (range 30-274 min). Mean flow rate was 41.3 ml/min (range 12-85 ml/min). Mean collection rate was 59.2% for CD34+ cells and 70% for mononuclear cells. The total number of CD34+ cells collected was 2.5 x 10(6)/kg per apheresis, and 5.9 x 10(6)/kg per patient. Several complications occurred: one catheter-related sepsis (0.86%), four catheter occlusions (3.47%) and eight hemodynamic instabilities related to extracorporeal volume. Weight <10 kg is a risk factor for complication (P=0.0006). IVAD are effective and safe for PBSC collection. Placement of a second central VA (requiring general anesthesia for children) could be avoided.     

Prospective evaluation of cell kinetics,yields and donor experiences during a single large-volume apheresis versus two smaller volume consecutive day collections of allogeneic peripheral blood stem cells

We report cell kinetics, yields and donation experiences of 20 demographically matched allogeneic peripheral blood stem cell (PBSC) donors who were prospectively assigned to undergo either a single 25 l or two consecutive daily 15 l (15 l x 2) apheresis procedures. Procedures were performed using prophylactic intravenous calcium administration after standard granulocyte colony-stimulating factor (GCSF) mobilization (10 microg/kg/d). Central line placements (two each), initial CD34 cell counts (0.077 vs 0.078 x 10(9)/l) and yields (7.9 vs 8.1 x 10(8) CD34 cells) were similar in the two groups; however, 25 l donors spent significantly less time both in the clinic (7.5 vs 10.8 h) and with central venous catheters in place (8.5 vs 29.5 h) than 15 l x 2 donors. End-procedure platelet counts were below 100 x 10(9)/l in one out of 10 25 l donors versus five out of 10 in 15 l x 2 donors (41%vs 53% mean decrease in platelet counts, P = 0.02). PBSC collection efficiency increased by 37% after 15 l of the 25-l volume had been processed, compared with no significant change during 15 l x 2 procedures. Results similar to these prospective findings were also observed in CD34 yields, symptoms and platelet counts in additional 25 l and 15 l procedures performed during the same period and evaluated retrospectively. This study indicates that a single 25-l apheresis procedure results in similar yields and symptoms, but less donor thrombocytopenia and inconvenience than two consecutive daily 15-l procedures.     

Automated collection of peripheral blood stem cells with the COBE spectra for autotransplantation

BACKGROUND: A convenient, effective and safe peripheral blood stem cell (PBSC) apheresis procedure is desirable to cope with the increasing requirements for PBSC collections. We performed PBSC harvesting with the novel COBE Spectra AutoPBSC(TM) system using the default software configuration recommended by the manufacturer. We analyzed collection parameters and clinical efficiency of harvested autografts following high-dose chemotherapy (HDCT). PATIENTS AND METHODS: Eighty-one patients underwent 102 harvests after standard chemotherapy plus filgrastim (5-10 microg/kg/day) to obtain a target of >/=2.5 x 10(6) CD34+ cells/kg for autologous blood stem cell transplantation. Conventional-volume leukaphereses (median: 11 liters) were performed using the manufacturer's standard software default regarding inlet flow, harvest/chase volume (3/7 ml) and number of collection cycles. The ratio of ACD-A to whole blood was initially set at 1:12 (56 collections), later at 1:10 (46 aphereses). RESULTS: With respect to preapheresis counts of 93 (9-876) CD34+ cells/microl, 69 patients (85.2%) achieved >/=2.5 x 10(6) CD34+ cells/kg by the first apheresis. PBSC products contained medians of 5.0 x 10(6) (0.7-77.3) CD34+ cells/kg and 13.8 x 10(4) (2.3-105.0) CFU-GM/kg. A preapheresis count of >/=40 CD34+ cells/microl predicted a single-apheresis yield of >/=2.5 x 10(6) CD34+ cells/kg. Apheresis products showed a high mononuclear cell (MNC) purity of >/=89%. The median overall collection efficiency of CD34+ cells (CD34-CE) was 42.6% (12.2-87.4). The CD34-CE decreased significantly with increasing numbers of circulating CD34+ cells: 52.5% at CD34+ cells <40/microl versus 41.0% at CD34+ cells >/=40/microl (p 0.5 x 10(3)/microl, 10 (8-13) days for WBC >1.0 x 10(3)/microl and 11 (8-17) days for platelets >20 x 10(3)/microl. CONCLUSIONS: As a result of efficient PBSC mobilization, a single conventional-volume leukapheresis with the COBE Spectra AutoPBSC system resulted in hematopoietic autografts with >/=2.5 x 10(6) CD34+ cells/kg in 85% of patients. Following the standard PBSC apheresis recommendations of the manufacturer, the AutoPBSC system assures PBSC products with a high MNC purity and a moderate CD34-CE that declines significantly at increasing levels of circulating CD34+ cells. Leukaphereses performed at an ACD-A to whole blood ratio of 1:10 should run without coagulation problems.     

Blood stem cell collection using chemotherapy with or without systematic G-CSF: experience in 52 patients with multiple myeloma.

Harvesting of peripheral blood stem cells (PBSCs) following chemotherapy and G-CSF administration is currently performed for hematological therapies. However, a procedure based on the use of a large quantity of G-CSF is relatively costly. Therefore, we retrospectively compared the effects of two PBSC mobilization procedures in a population with recently diagnosed multiple myeloma. The first procedure consisted of chemotherapy and systematic G-CSF administration (group 1: 24 patients). The second consisted of chemotherapy alone, G-CSF having been administered only in the case of failure of PBSC mobilization or delayed white blood cell (WBC) recovery (group 2: 28 patients). Leukapheresis was performed when WBC recovery reached 1 x 10(9)/l if the peripheral blood CD34+ cell count was over 10/microl. Leukapheresis was maintained until a total of 2.5 x 10(6) CD34+ cells/kg was harvested. A significant difference was observed between the two groups only in regard to the median period of WBC recovery (delayed for group 2) and the number of CD34+ cells/kg collected on the first leukapheresis (higher for group 1) but not to the proportion of patients with failure of PBSC collection. Ten group 2 patients, who had insufficient CD34+ cells after WBC recovery or delayed WBC recovery, received G-CSF which resulted in sufficient PBSC harvesting in nine. To obtain a sufficient CD34+ cell level, the patients without systematic G-CSF administration had more leukaphereses (2.1 vs 1.5) but the mean consumption of G-CSF per patient was eight times less than in the other group. Nonsystematic use of G-CSF before WBC recovery or preferentially its introduction just after, could be an interesting economical alternative in PBSC mobilization but should be assessed by a prospective controlled study of cost/efficacy.     

Comparison of marrow and blood cell yields from the same donors in a double-blind, randomized study of allogeneic marrow vs blood stem cell transplantation

Forty healthy adult donors underwent marrow (BM) as well as peripheral blood (PBSC) stem cell collections for their HLA-identical adult siblings with hematologic malignancies. BM was harvested on day 1 (target 3 x 108 nucleated cells/kg, 10 microg/kg lenograstim (glycosylated G-CSF) administered on days 2-6, and a single leukapheresis performed on day 6. The blood volume processed was the higher of 200% donor blood volume or 10 liters. The total nucleated cell (TNC) yields from PBSC were 1.1- to 4.3-fold higher than BM (median 7.0 vs 3.1 x 10(8)/kg, P < 0.0001). Although BM contained a higher proportion of CD34+cells (1.3% vs 0.7%, P < 0. 0001) and a comparable proportion of CD3+ cells (median 29% vs 26%, P = 0.4), the absolute numbers of CD34+ and CD3+ cells and their subsets were several times higher in PBSC. There was a poor correlation between BM and PBSC CD34 and TNC numbers, but a significant correlation between BM and PBSC CD3 numbers. Only five of 40 BM harvests contained >/=2 x 10(6) CD34+ cells/kg compared with 35 of 40 PBSC harvests (P < 0.0001). We conclude that the numbers of progenitor and immunocompetent cells in PBSC are several times higher than in BM. It is possible to collect adequate numbers of progenitor cells from blood after lenograstim stimulation more frequently than from marrow, and donors yielding low quantities of progenitor cells from BM usually deliver better quantities from PBSC. Bone Marrow Transplantation (2000) 25, 501-505.