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

Apheresis collection of mononuclear cells for chimeric-antigen receptor therapies

Collections of lymphocytes to be genetically modified to treat hematologic malignancies have seen a dramatic increase over the last few years as commercial products have been approved. Reports of new products in development that can possibly treat solid organ malignancies represent a massive change in the field. Apheresis is at the center of the collection of cells for the manufacture of these chimeric-antigen receptor therapy products. The expansion of these collections represents one of the areas of apheresis procedures growth. This review will summarize concepts important to this type of collection and variables that need to be optimized to obtain desired cell yields while increasing patients' safety.

An updated single center experience with plerixafor and granulocyte colony-stimulating factor for stem cell mobilization in light chain amyloidosis

The use of granulocyte-colony stimulating factor (G-CSF) with or without chemotherapy to mobilize hematopoietic progenitor cells (HPCs) can result in significant morbidity in light chain (AL) amyloidosis patients. Plerixafor, a strong inducer and mobilizer of HPCs, can be used as an adjunct to G-CSF to improve mobilization efficiency. We describe the outcomes for combined G-CSF/plerixafor mobilized patients with AL amyloidosis. We reviewed data of 53 consecutive AL amyloidosis patients who underwent combined G-CSF/plerixafor HPC mobilization between May 2011 and October 2017 at our institution. We evaluated patients for HPC collection efficiency, perimobilization toxicity and postautologous hematopoietic cell transplantation (autoHCT) outcomes. Median CD34⁺ cell collection was 12.4 × 10⁶  cells/kg (range 2.5 × 10⁶ to 34.1 × 10⁶  cells/kg) and 45 (85%) patients had collections of ≥5.0 × 10⁶ CD34⁺ cells/kg. There were no mobilization failures or perimobilization mortality. During mobilization, 37 (70%) patients had weight gain (median 1.3 kg, range 0.1-4) but none >10% body weight, 5 (10%) patients had diarrhea, and one patient each had hypotension and cardiac arrhythmia. Among the 31 patients analyzed for CD34 collection efficiency (CE), the median CD34 CE was 47% (range 36-62). At 5 years follow-up 82% and 84% of patients were progression-free and alive, respectively. Our results suggest that G-CSF/plerixafor mobilization is safe, well tolerated, and effective in AL amyloidosis.

Comparison of Two Apheresis Systems of COBE and Optia for Autologous Peripheral Blood Stem Cell Collection

Peripheral blood stem cell (PBSC) transplantation following myeloablative therapy is a mainstay of treatment for various types of malignancies. This study aimed to evaluate the differences between the Optia MNC and COBE Spectra MNC systems (Terumo BCT, Japan) according to apheresis procedures and the parameters of apheresis, products, and collection. The clinical data of 74 patients who underwent autologous PBSC collection from July 2012 to July 2015 were reviewed retrospectively. The patients comprised 48 (65%) men and 26 (35%) women with a median age of 56 yr (range, 23–66 yr). Of 216 procedures, 111 (51%) and 105 (49%) were processed by using COBE and Optia MNC, respectively. PBSC collection rates, throughput, numbers of stem cells retrieved, collection efficacy, and platelet loss were compared. There were no significant differences in the median CD34+ cell counts of collected products (0.61×10⁸ vs 0.94×10⁸), CD34 collection efficiency (43.5% vs 42.1%), and loss of platelets (40.1% vs 44.7%). The Spectra Optia MNC apheresis system was comparable to the COBE Spectra system in collecting autologous CD34+ hematopoietic stem cells and retention of platelets.

Delayed short-term administration of granulocyte colony-stimulating factor is a good mobilization strategy for harvesting autologous peripheral blood stem cells in pediatric patients with solid tumors

PBSCs have become the preferred source of autologous stem cells for supporting high-dose chemotherapy in childhood solid tumors. The aims of this retrospective study were to examine the optimal timing for administration of G-CSF after chemotherapy and to identify the patients from whom an optimal dose of PBSCs can be harvested. We evaluated the timing of G-CSF administration for harvesting PBSCs in patients with childhood solid tumors. G-CSF was administered immediately after chemotherapy in eight patients (11 harvests, long-term group) and following recovery from hematological nadirs in 17 patients (21 harvests, short-term group). The median duration of G-CSF administration was 22 vs. 5 days, respectively (p < 0.005), and the dose of harvested CD34(+) cells (×10(6) /kg) was 1.4 vs. 2.9, respectively (p = 0.023). Our results suggest that short-term G-CSF administration is a good strategy for harvesting PBSCs in these patients.

Peripheral blood progenitor cell collection by two programs for autologous and allogeneic transplantation

BACKGROUND

In the Spectra apheresis instrument (Terumo BCT), both manual (Spectra-MNC) and automated (Spectra-Auto) programs have been widely used to collect peripheral blood progenitor cells (PBPCs). However, direct comparison of these programs remains extremely limited.

STUDY DESIGN AND METHODS

We investigated 188 collections and products from autologous (patient) and allogeneic (donor) subjects and analyzed a subset of 89 allogeneic collections and products. Twenty-nine subjects who received apheresis for 2 consecutive days using both programs were also evaluated with a paired crossover comparison.

RESULTS

The two programs processed similar volumes, but run time was longer with Spectra-Auto. Yield and efficiency of CD34+ cell collection were similar between these programs in the whole cohort, although white blood cell (WBC) and mononuclear cell (MNC) yields were higher with Spectra-MNC. In the allogeneic cohort, yield and efficiency of WBC collection were greater in Spectra-MNC. However, collected WBCs, MNCs, and CD34+ cells were similar between these programs in paired comparison. Regardless of program, preapheresis peripheral WBC, MNC, and CD34+ cell counts correlated with the number of cells collected. In contrast, preapheresis WBC counts in the whole cohort were negatively correlated with collection efficiencies of CD34+ cells in Spectra-MNC but not Spectra-Auto. The products collected using Spectra-MNC contained more contaminating platelets (PLTs) than Spectra-Auto, with a corresponding reduction in postdonation circulating PLTs.

CONCLUSION

Spectra-MNC and Spectra-Auto showed distinct features that should be considered on a case-by-case basis. Similar investigations should be undertaken as new collection platforms are introduced.

Collection of peripheral blood progenitor cells for autologous use: performance enhancements of COBE spectra, auto-PBSC

Collection of peripheral blood stem cells (PBSC) must be performed in a safe and effective manner. Issues like automation, collection efficiency (CE), and adverse events must be considered. Auto-PBSC (COBE Spectra) is a fully automated program for PBSC collection. Changes in the protocol were made to achieve high CE, low product volume, and resulted in three groups of patients. Standard operating procedures (SOPs) were developed to reduce citrate toxicity and patients with central venous catheter. Twenty patients and 27 collections (Group 1), 88 patients and 112 collections (Group 2), and 158 patients and 194 collections (Group 3) were recorded. The protocol changes increased CE significantly from 31% (Group 1) to 57 and 59% (Group 2 and 3). Adjusting endpoint according to the preapheresis number of CD34+ cells reduced the collection time and the volume of the product significantly (median 227 min and 56 mL) without affecting CE. Mean level of ionized calcium before collection was 1.22 mmol/L, measured in 31 patients. This declined to a mean of 1.07 mmol/L after 1 h of collection and remained unchanged despite continuous calcium infusion. The number of patients with mild symptoms of citrate toxicity was reduced from 20 to 6%. A central venous catheter was used in 15%. Compared to peripheral access no differences in blood flow rate or time to perform the collection were found. Changes in the Auto-PBSC protocol resulted in an improved CE and a small product. SOPs reduced the number of patients with citrate toxicity and with central venous catheter.

Automatic interface-controlled apheresis collection of stem/progenitor cells: results from an autologous donor validation trial of a novel stem cell apheresis device

BACKGROUND

Cryopreserved hematopoietic progenitor cells collected by apheresis from granulocyte-colony-stimulating factor with or without chemotherapy-mobilized patients have become the preferred type of autograft to support treatment of diseases amenable to high-dose chemotherapy. A novel apheresis system, the Spectra Optia v.5.0 (CaridianBCT), was constructed to meet certain shortcomings of manual apheresis systems such as the COBE Spectra MNC (CaridianBCT), including the need for continuous optical or manual monitoring and readjustment of buffy coat position and sensitivity to inconsistent blood flow. By use of optical sensors, which provide real-time automatic interface (buffy coat) and collection line control, the Spectra Optia promises to automatically guide apheresis procedures, potentially freeing up operator time and reducing variability in collection efficiency (CE2).

STUDY DESIGN AND METHODS

In a two-center clinical trial, 35 autologous stem cell donors were subjected to apheresis with the Spectra Optia to validate feasibility and effectiveness of apheresis procedures. Results were compared to data from 80 autologous apheresis procedures with the COBE Spectra MNC.

RESULTS

Usability and function of the automatic interface management were excellent. CD34+ cell quality, assessed by viability staining, colony-forming unit-culture frequency, and engraftment kinetics, was equally good with both systems. CE2 of the Spectra Optia, calculated as CD34+ contents in the product divided by the number of CD34+ cells presented to the collection port, exceeded that of the COBE Spectra MNC. Spectra Optia product volumes were significantly smaller. Very high white blood cell and platelet counts modestly reduced CE2 with the Spectra Optia.

CONCLUSION

The Spectra Optia is a novel automatic apheresis system supporting autologous stem cell collection with at least equal efficiency and superior user-friendliness compared to the COBE Spectra MNC.

Optimization of leukocyte collection and monocyte isolation for dendritic cell culture

Leukapheresis is the method of choice to collect monocytes for dendritic cell (DC) culture. Improvement of cell separators and cell collection software have enabled the collection of 10(9) monocytes for the generation of monocyte-derived DCs, which is sufficient to prepare a DC vaccine series. However, leukapheresis works with the technique of differential centrifugation which is not applicable to selectively collect mononuclear cells of similar density. After leukapheresis, thus, additional preparation steps are required to isolate and enrich the desired monocyte population. The cell isolation and cultivation techniques depend on the quality of the original leukocyte harvest due to the monocyte yield and the content of residual erythrocytes and platelets. Monocyte elutriation from the leukapheresis product shows a high monocyte recovery of 80%. However, only 30% of the isolated monocytes can be developed into mature DCs. The factors responsible for DC maturation and the development of different DC subsets are the subject of current research.

Evaluation of the COM.TEC cell separator in predicting the yield of harvested CD34+ cells

BACKGROUND

This multicenter study was performed with the intention to evaluate the exactness of the predicted CD34+ cell yield calculated by two leukapheresis programs of the cell separator COM.TEC upon the number of donor's circulating CD34+ cells and the blood volume processed.

STUDY DESIGN AND METHODS

Patients and healthy donors (n = 166) received mobilization by chemotherapy and/or granulocyte colony-stimulating factor and underwent CD34+ cell harvest by the leukapheresis programs MNC or RV-PBSC (n = 203).

RESULTS

CD34+ cells were collected by 112 harvests on MNC and by 91 collections on RV-PBSC. The median collection efficiency of CD34+ cells was significantly better for the program MNC than for RV-PBSC (p < 0.001): 67% (31-109) vs. 42% (19-100). The collected CD34+ cell yield was in median more exactly by MNC than by RV-PBSC (p < 0.001): 85% (31-176) vs. 59% (22-110) of the predicted value. Concentrates obtained by RV-PBSC showed in median significantly higher percentages of mononuclear cells (p < 0.001) and CD34+ cells (p < 0.001), 86% (43-99) vs. 56% (25-95) and 1.2% (0.2-14.3) vs. 0.4% (0.1-6.0), and had lower contaminations by erythrocytes (p < 0.001) and platelets (p < 0.001), 13 mL (4-48) vs. 25 mL (5-60) and 1.9 x 1011 vs. 3.1 x 1011, than those harvested by MNC.

CONCLUSION

The significantly better collection efficiency of CD34+ cells and the more exact prediction of the harvested CD34+ cell yield make the leukapheresis program MNC a safe and efficient procedure. However, concentrates collected by RV-PBSC are of a better cellular quality with a significantly higher percentage of mononuclear and CD34+ cells and a lower contamination by erythrocytes and platelets.

CD14+ cell collection in non-cytokine-stimulated donors with the COM.TEC cell separator

BACKGROUND

The COM.TEC cell separator (Fresenius Hemocare), equipped with the MNC program (single-stage chamber) and the PBSC-LYM program (dual-stage chamber), was evaluated for CD 14+ cell collection regarding cell yields, collection efficiencies (CEs), and the content of residual cells in harvests.

STUDY DESIGN AND METHODS

Twenty-four non-cytokine-stimulated donors underwent 5-L mononuclear cell (MNC) collections on the COM.TEC device to compare both programs. Two software versions (v02.03.05 vs. v 03.00.04) were investigated for optimization of the CD 14+ cell collection process. Blood counts of donors and products were analyzed for CD 14+ cells by flow cytometry and for platelets (PLTs), white blood cells, and red blood cells (RBCs) by a blood cell counter.

RESULTS

In 5-L collections, the MNC program resulted in high CEs (83+/- 23%) and yields (1.2 x 10(9)+/- 0.6 x 10(9) per unit) of CD 14+ cells, but the products showed high residual PLTs. The use of a dual-stage chamber in the PBSC-LYM program produced a low content of residual PLTs (0.7 x 10(11) +/- 0.3 x 10(11) per unit) and RBCs but failed to reach a target of 1 x 10(9) CD 14+ cells. Modulated light to stabilize the buffy-coat detection by the interface monitor significantly improved CD 14+ cell enrichment. By use of the PBSC-LYM program, higher centrifuge velocity (1700 rpm [382 x g] vs. 1500 rpm [297 x g]) improved significantly CD 14+ cell yields (0.7 x 10(9) vs. 0.5 x 10(9) cells).

CONCLUSION

A pure CD 14+ cell product with low numbers of residual cells was obtained by the PBSC-LYM program, which could be useful for good manufacturing practice-conformed production within closed systems. The MNC program offers the collection of high CD 14+ cell yields with excellent CEs but also high residual PLT counts.

Can the stem cell mobilization technique influence CD34+ cell collection efficiency of leukapheresis procedures in patients with hematologic malignancies?

A total of 415 leukaphereses in 201 patients stimulated with growth factor (GF; n = 119) or chemotherapy-GF (n = 296) were studied to determine CD34+ cell collection efficiency (CE). The pre-apheresis leukocyte count was 1-93 x 10(9)/l (median 20), and peripheral blood CD34 count (PBCD34) was 1-1104/microl (median 19). The total number of CD34+ cells collected was 4-6531 x 10(6) (median 151); corresponding to 0.1-111.4 x 10(6) (median 2.3) per kg. There was strong correlation between PBCD34 and the number of CD34+ cells collected (r = 0.9; P < 0.0001). CE was 7-145% (median 46). On multiple regression analysis, a higher leukocyte count (P < 0.0001) was the most important predictor of lower CE. CE with leukocytes < 20 was 7-145% (median 53%) compared to 10-132% (median 40%) with leukocyte > or = 20 (P < 0.0001). In all, 61% of the apheresis procedures performed after chemotherapy-GF occurred when leukocytes were < 20 compared to 21% of those performed after GF alone (P < 0.0001). We conclude that mobilizing patients with the combination of chemotherapy and GF rather than GF alone leads to leukapheresis being performed when the leukocyte count is low -- in a range that results in optimum CD34+ cell CE. Autologous stem cells should be mobilized with chemotherapy-GF rather than GF alone whenever possible.

Collection of peripheral progenitor cells: a comparison between Amicus and Cobe-Spectra blood cell separators

The authors compared the efficiency of two different blood cell separators (Amicus and Cobe-Spectra) in collecting peripheral blood progenitor cells for autologous or homologous transplantation. A total number of 129 procedures were performed, 36 with Spectra, 93 with Amicus. There was no difference between Spectra and Amicus efficiencies for CD34+ cell collection (46.685% vs 46.235%; p=n.s) but the platelet efficiencies were 17.31% and 12.54% respectively (p=0.04) and, if autologous and allogeneic collections were considered separately, a marked difference resulted in allogeneic platelet efficiency between 6 Spectra and 23 Amicus procedures (26.83% vs 8.68%, p=0.0004). The authors were able to demonstrate that in 70 Amicus autologous collections there was a different platelet efficiency, if peripheral count was considered: 12 procedures performed with a platelet count > 100 x 10(9)/l had a very low efficiency (6.86%), but this value increased if platelet count lowered (13.02% if between 100 and 50 x 10(9)/l, 22.63% if between 50 and 0 x 10(9)/l, 23 and 35 procedures respectively). The study is preliminary and the number of collections is little, but the overall data suggest that Spectra (AutoPBSC, V 6.0) and Amicus separators have the same efficiency for collecting CD34+ cells while Amicus procedures have a very low platelet contamination, especially with donors.

Impact of chemotherapy regimen and hematopoietic growth factor on mobilization and collection of peripheral blood stem cells in cancer patients

Various chemotherapy regimens, combined with recombinant human granulocyte colony-stimulating factor(rhG-CSF) or recombinant granulocyte-macrophage CSF (rhGM-CSF) are used in cancer patients to mobilize and collect peripheral blood stem cells (PBSC). In this retrospective study, we evaluated and compared the efficacy of such regimens in 262 patients with different types of malignant diseases. The following chemotherapy regimens were applied: ifosfamide-etoposide-cisplatin or bleomycin (n = 96; mainly patients with testicular cancer); ifosfamide-etoposide plus or minus cytosine arabinoside (Ara-C) or vincristine (VCR)(n = 52; mainly patients with lymphoma); cyclophosphamide-anthracycline (n = 53; mainly patients with breast cancer); intermediate to high dose (ID-HD) cyclophosphamide (n = 37; mainly patients with breast or ovarian cancer. or multiple myeloma; and others (n = 24). rhG-CSF or rhGM-CSF, each at an average daily dose of 5 microg/kg body weight, were used in 166 and 96 patients, respectively. The study evaluated and compared the efficacy of these two cytokines. In patients receiving rhG-CSF, CD34+ cells could be collected earlier (median: day 14 versus day 16) and there was a significantly higher white blood cell count (WBC)(median 11,350 versus 5550/microl) and CD34+ cell count (median 88 versus 43/microl) at the start of apheresis, and a significantly higher CD34+ cell yield (median 7.4 x 10(6) versus 4.6 x 10(6)/kg) than in patients who receivedrhGM-CSF. Among the various chemotherapeutic regimens used, each combined with rhG-CSF, ifosfamide-etoposide plus or minus Ara-C or VCR mobilized a significantly higher number of CD34+ cells (median 119/microl) and produced a significantly higher harvest of these cells (median 13 x 10(6)/kg) than cyclophosphamide-anthracycline (median 87/microl and 7 x 10(6)/kg, respectively) or ID-HD cyclophosphamide (median 59/microl and 5 x I 0(6)/kg, respectively). Ifosfamide-etoposide plus or minus Ara-C or VCR was also superior to ifosfamide-etoposide-cisplatin or bleomycin (median 78/microl and 9 x 10(6)/kg, respectively), but at borderline significance. The outcome of PBSC mobilization and collection appeared to be negatively influenced by the number of relapses before the current salvage treatment. These data indicate that mobilization and collection of PBSCstrongly depend on the type of hematopoietic growth factor and chemotherapeutic regimen used. The data further show rhG-CSF is a more effective growth factor than rhGM-CSF and ifosfamide-etoposide-based regimens, particularly ifosfamide-etoposide plus or minus Ara-C or VCR, are highly effective regimens in mobilizing and collecting CD34+ cells.

Influence of preapheresis clinical factors on the efficiency of CD34+ cell collection by large-volume apheresis

We evaluated 120 leukapheresis procedures (93 patients), in order to detect clinical factors that influence the efficiency of CD34+ collection using Cobe Spectra trade mark cell separators. Hematocrit was >27% and platelet count >30 000/microl in >95% of patients. Platelet transfusions were given if the postprocedure count was &<20 000/microl. Multiple regression analysis was used to analyze putative factors, and a predictive equation defined by stepwise regression modeling. The mean efficiency was 0.59 (s.d. 0.27). Sex (M>F; P=0.01), the volume processed (inversely; P=0.01) and CD34+ cell count (inversely; P=0.04) were associated with efficiency, whereas hematocrit, platelet or leukocyte count, catheter type and patient weight were not. The effect size for predictive factors was small (R(2)=0.21). Adverse events were limited to hypocalcemia. We conclude that female sex, volume processed and CD34+ cell count adversely influence the efficiency of CD34+ cell leukapheresis. However, the impact of volume and CD34+ cell count is small, and likely to be offset by the influence of these same factors on overall yield. Leukapheresis appears to be safe and efficient for autologous blood and marrow transplantation patients with hematocrit >27% and platelet count >30 000/microl.

Comparison of two leukapheresis programs for computerized collection of blood progenitor cells on a new cell separator

BACKGROUND

Peripheral blood progenitor cells (PBPCs) can be collected on various cell separators. Two leukapheresis programs (LP-MNC and LP-PBSC-Lym) were evaluated for computerized collection of PBPCs on a new cell separator.

STUDY DESIGN AND METHODS

Leukapheresis assisted by the LP-MNC or LP-PBSC-Lym software was performed for the harvesting of PBPCs in 52 oncology patients after chemotherapy plus G-CSF treatment and in 18 healthy subjects after G-CSF mobilization alone.

RESULTS

A total of 38 components from 33 donors via LP-MNC and 43 components from 37 donors via LP-PBSC-Lym were collected with a median of one (range, one to two) standard-volume leukapheresis procedures (9.2-13.3 L) per donor. There were no significant differences between the two groups concerning median counts of WBCs, CD34+ cells, CD34+ cell yields per harvest, and CD34+ cell yields of cumulative harvests. The blood cell counts after leukapheresis revealed that the LP-MNC resulted in significantly higher platelet loss than LP-PBSC-Lym (p = 0.024): 35.9 percent (range, 19.2%-66.1%) versus 29.7 percent (11.6%-52.3%). Regarding the CD34+ cell collection efficiency, the LP-MNC program was significantly better than the LP-PBSC-Lym program (p < 0.001): 77.5 percent (range, 35.5%-98.9%) versus 58.3 percent (range, 20.4%-98.9%). However, concentrates collected by the LP-PBSC-Lym program had significantly higher percentages of MNCs (p < 0.001) and CD34+ cells (p = 0.028) than harvests with the LP-MNC program: 90 percent (range, 69%-99%) versus 70 percent (range, 35%-98%) and 1.2 percent (range, 0.2%-7.3%) versus 0.7 percent (range, 0.2%-6.0%), respectively. No leukapheresis-related serious adverse events were seen, and time for hematopoietic engraftment was equivalent to data published in the literature.

CONCLUSION

The LP-MNC program shows a significantly better CD34+ cell collection efficiency than the LP-PBSC-Lym program. However, collections with the LP-MNC program result in PBPC components with a lower MNC and CD34+ cell concentrations and a higher apheresis-related loss of patient's platelets.

Cobe Spectra is superior to Fenwal CS 3000 Plus for collection of hematopoietic stem cells

One hundred and seventy-seven stem cell apheresis procedures performed on 91 patients using the Fenwal CS 3000 Plus cell separator and 61 procedures performed on 37 patients using the Cobe Spectra cell separator were studied to compare the CD34(+) cell collection efficiencies (CE; the proportion of the total CD34(+) cell content in the blood volumes processed that is harvested) of the two machines. The absolute peripheral blood CD34(+) cell count was comparable for the two groups (P = 0.27). A strong correlation was seen between the blood CD34(+) cell count and the total number of CD34(+) cells collected for the Spectra (r(2) = 0.59; P < 10(-6)) and for the CS 3000 Plus (r(2) = 0.60; P < 10(-6)). No significant correlation emerged between the peripheral blood CD34(+) cell count and the CE of either machine. The total number of CD34(+) cells collected per procedure was comparable (P = 0.51): median 113 x 10(6) for CS 3000 Plus and median 218 x 10(6)for Spectra. CE was significantly higher with the Spectra (median 45.7%, range 9.8-98.6%) than the CS 3000 Plus (median 30.3%, range 1.7-89.3%; P < 0.00001). We conclude that the CD34(+) cell CE of the Spectra is superior to that of the CS 3000 Plus. Therefore, under the usual clinical conditions, Cobe Spectra should be used preferentially for peripheral blood progentor cell collection to maximize the number of hematopoietic stem cells collected.