Comparison of two apheresis systems for granulocyte collection without hydroxyethyl starch

BACKGROUND AND OBJECTIVES

Granulocyte transfusion (GTX) is a treatment option for severe infections in patients with neutropenia. In previous studies, hydroxyethyl starch (HES) was used to enhance red blood cell sedimentation for granulocyte collection (GC). However, there are safety concerns about HES, and HES is not readily available in some countries. Therefore, we compared the granulocyte counts and GC efficiency achieved by two apheresis systems without HES.

MATERIALS AND METHODS

All consecutive GC procedures performed between July 2011 and March 2018 at our hospital were analysed. COBE Spectra was used until 5 February 2016, and Spectra Optia was used afterwards. HES was not used.

RESULTS

Twenty-six GC procedures were performed, including 18 performed using COBE Spectra and 8 using Spectra Optia. When Spectra Optia was used, >1 × 1010 neutrophils were collected from seven of the eight (88%) procedures. Although there was no significant difference in the granulocyte yield between COBE Spectra-based and Spectra Optia-based GC procedures, the collection efficiency of Spectra Optia was significantly higher than that of COBE Spectra (p = 0.021). Furthermore, the granulocyte yields of Spectra Optia-based GC tended to be more strongly correlated with the peripheral blood neutrophil count on the day of apheresis than those of COBE Spectra-based GC.

CONCLUSION

Our results suggest that Spectra Optia achieves greater GC efficiency than COBE Spectra, even without HES. GTX may be a therapeutic option for severe neutropenia, even in places where HES is not available.

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.

Analysis of stem cell collections in adult patients with Ewing sarcoma

BACKGROUND

Ewing sarcoma is one of the most frequent soft-tissue tumors in pediatric patients. The current treatment protocols recommend stem cell apheresis (SCA) after completion of the second course of induction therapy with vincristine, ifosfamide, doxorubicine, and etoposide (VIDE). The feasibility of SCA and graft compositions in adult patients with Ewing sarcoma have not been previously analyzed.

METHODS AND MATERIALS

The authors analyzed 29 stem cell collections of 19 adult patients (9 male, 10 female) at a median age of 27 (range 19-53) years mobilized after VIDE (n = 17), cyclophosphamide/topotecan (n = 1) or vincristine, dactinomycin and ifosfamide (n = 1) chemotherapy. All patients were mobilized with filgrastim 5 μg/kg twice daily from day +7 of chemotherapy. The collections were performed if CD34+ cell count in peripheral blood was >10/μL. The target yields were ≥4×10⁶ CD34+ cells/kg body weight.

RESULTS

Median CD34+ cells/μL in peripheral blood before SCA were 45.8 (range 6.7-614.4)/μL. The median cumulative yields were 10.6 (range 1.5-38.8) CD34+ cells/kg body weight and ≥2×10⁶ in all but two patients (89%). CD34, CD3, and CD56 yields in collections after the third VIDE and after later courses did not differ. Four patients underwent high-dose therapy with autologous transplantation, and all were engrafted.

DISCUSSION

Stem cell mobilization is feasible in most Ewing sarcoma patients. Additionally, the present study's data suggest that it is safe to postpone stem cell collection to a later VIDE chemotherapy cycle if medically indicated.

Comparison of hematopoietic progenitor cell collection using different inlet flow rates with the Fenwal Amicus

PURPOSE

We have used a hematopoietic progenitor cell (HPC) algorithm (standard [STD]) that restricted the inlet flow rate to 65 mL/min for peripheral white blood cell count (PWBC) >35 × 109 /L (STD). In this study, we evaluated a technique that allows 85 mL/min, regardless of the PWBC count (high). For patients with PWBC >35 × 109 /L, a prospective, randomized comparison of the high flow rate vs the STD PWBC-based flow rate (65 mL/min) was performed, comparing CD34+ and lymphocyte yields, collection efficiencies (CE1), mononuclear cells (MNC), and granulocytes, red blood cell (RBC), and platelet content.

METHODS

The Fenwal Amicus version 4.5 with a heparinized ACD-A anticoagulant (AC) delivered at a 26:1 AC ratio was used. Paired comparisons between high and STD techniques were assessed with Wilcoxon signed rank tests, with P < .05 considered significant. Data are summarized as medians.

RESULTS

Forty patient pairs (autologous) were compared. Diagnoses included primarily multiple myeloma (60%) and lymphoma (37.5%). High had significantly higher median average inlet rates (69 vs 55 mL/min), whole blood processed (20 vs 16 L), and cycles (15 vs 14) than STD. There were no significant differences in pre-procedure counts. Collection contents were (high/STD): 306/328 × 106 CD34+ cells, 48/59% CD34+ CE1 (significant), 0.2/0.2 × 109 /kg lymphocytes, 45/57% lymphocyte CE1, 63/59 × 109 WBC, 15/16 × 109 granulocytes, and 1.9/1.7 × 1011 platelets.

CONCLUSIONS

The simpler, standardized high flow technique did not significantly increase or decrease CD34+ cells or lymphocyte yields, but did significantly decrease CD34+ CE1. The effects on cross-cellular content were minimal and not clinically significant.

Stem-cell mobilization of healthy sibling donors with pegfilgrastim-A prospective open-label phase II trial (EudraCT no: 2005-004971-39)

BACKGROUND

Pegfilgrastim is a covalently bound conjugate of filgrastim and mono-methoxypolyethylene glycol with a longer half-life.

STUDY DESIGN AND METHODS

We report on phase II prospective monocentric trial examining the feasibility of stem cell mobilization with 12 mg single dose pegfilgrastim in related donors. The objectives were to determine the optimal collection day, defined as CD34+ concentration in peripheral blood (PB) >50 cells/μl, the number of donors collected with single leukapheresis, and the peak level of pegfilgrastim in donor-serum. Furthermore, the cell composition of grafts was assessed and compared to published data.

RESULTS

The results included about 28 matched related donors. The median pegfilgrastim serum level remained >200 ng/mL for 48 hours before declining, with the maximal measured concentration of 259.49 ng/ml 24 h after application. The median white blood cell count and CD34 count in PB peaked on day four with 52.6 (range 22.8-85.0) Gpt/l and 66.25 (range 22.9-136.6) cells/μl, respectively. A CD34+ count >50 cells/μl on day four was detected in 75% of donors. 79% of the donors underwent a single collection. Conventional filgrastim was administered additionally in two donors, due to insufficient CD 34+ concentration in PB. 89% of donors showed CD34+ yields ≥4 (median 6.5, range 4.6-14.5) × 10/kg body weight of the recipient. All grafts were administered without rejections.

DISCUSSION

The results of this trial showed that stem cell mobilization with pegfilgrastim is a feasible, and attractive option. This is the first trial presenting the kinetics of pegfilgrastim serum levels in healthy donors.

Retrospective comparison between COBE SPECTRA and SPECTRA OPTIA apheresis systems for hematopoietic progenitor cells collection for autologous and allogeneic transplantation in a single center

INTRODUCTION

COBE SPECTRA [COBE] (Terumo, BCT Lakewood CO) apheresis system has been the most used device for hematopoietic progenitor cells (HPC) collection. Recently, it has been replaced by the SPECTRA OPTIA [OPTIA] (Terumo, BCT Lakewood CO) apheresis system. The aim of our study is to compare both methods for HPC collection.

MATERIAL AND METHODS

We retrospectively compared 302 HPC collection apheresis procedures (115 allogeneic donors and 187 autologous). The study cohort was divided according to the apheresis system used to analyze the differences between COBE and OPTIA, specifically efficacy of apheresis procedure and product characteristics.

RESULTS

OPTIA collections result in a higher CD34⁺ collection efficiency in both groups (autologous 45.3% vs 41%, P < .006; allogeneic 54.9% vs 45%, P < .0001). The total of CD34⁺ cells ×10⁶ /kg recipient collected in the product were comparable in both groups (autologous 2.9 in OPTIA group vs 2.8 in COBE group, P = .344; allogeneic 6.2 in OPTIA group vs 5.8 in COBE group, P = .186). The percentage of platelet loss in autologous donors was significantly lower (35.7% vs 40.8%, P < .01). Regarding quality of the product, we observed a significantly lower hematocrit in products collected with OPTIA in both groups (1.8% vs 4%, P < .0001) as well as significantly lower amount of leukocytes (median 153.4 vs 237.2 × 10⁹ /L in autologous, P < .0001; 239.5 vs 340.2 × 10⁹ /L in allogeneic P < .0001).

CONCLUSION

Both apheresis systems are comparable in collection of hematopoietic progenitor cells, with significantly higher collection efficiency with the OPTIA system. Collection products obtained with OPTIA contain significantly lower hematocrit and leukocytes.

α-Synuclein concentration increases over time in plasma supernatant of single donor platelets

OBJECTIVES

In platelets, α-synuclein is important in calcium-dependent granule release. Notably, cells release α-synuclein in setting of cell damage or death. Therefore, we investigated α-synuclein levels in plasma of single donor platelet (SDP) units during storage.

METHODS

Aliquots were obtained from same SDP units for 7 days from day of donation. Additionally, randomly sampled SDP units at same storage time points were also assayed by enzyme-linked immunosorbent assay.

RESULTS

α-Synuclein in SDP plasma increased continuously over time at each assayed time point. Significant increases were measured on day 3 (11.7 ± 9.6 ng/mL, P = 0.025), day 5 (15.3 ± 5.9 ng/mL, P = 0.002), and highest on day 7 (23.7 ± 5.6 ng/mL, P < 0.0001) compared to day 0 (1.1 ± 0.8 ng/mL). Similar significant results were obtained in randomly sampled SDP units at same corresponding time points. Flow cytometry showed that platelets had strong expression of α-synuclein and lacked expression of other synucleins.

CONCLUSIONS

Increases of α-synuclein during SDP storage is a steady and continuous process that increases with time. Our findings indicate that α-synuclein may represent a biomarker of platelet biological state during storage. Further research will be needed to determine how α-synuclein increases correlate with platelets' function.

Hurdles Associated with the Translational Use of Genetically Modified Cells

Purpose of Review

Recent advancements in the use of genetically modified hematopoietic stem cells (HSCs) and the emergent use of chimeric antigen receptor (CAR) T-cell immunotherapy has highlighted issues associated with the use of genetically engineered cellular products. This review explores some of the challenges linked with translating the use of genetically modified cells.

Recent Findings

The use of genetically modified HSCs for ADA-SCID now has European approval and the U.S. Food and Drug Administration recently approved the use of CAR-T cells for relapsed/refractory B-cell acute lymphoblastic leukemia. Current good manufacturing processes have now been developed for the collection, expansion, storage, modification, and administration of genetically modified cells.

Summary

Genetically engineered cells can be used for several therapeutic purposes. However, significant challenges remain in making these cellular therapeutics readily available. A better understanding of this technology along with improvements in the manufacturing process is allowing the translation process to become more standardized.