Comparison between intermittent and continuous spectra optia leukapheresis systems for autologous peripheral blood stem cell collection

Evaluating the efficiency and safety of large-volume leukapheresis using the Spectra Optia continuous mononuclear cell collection protocol for peripheral blood stem cell collection from healthy donors: A retrospective study

BACKGROUND

Large-volume leukapheresis (LVL) refers to processing of more than three volumes of blood in a single session for peripheral blood stem cell collection. Recently, continuous mononuclear cell collection (cMNC) protocol has been developed using the Spectra Optia system, which is a widely used apheresis device. LVL using the novel protocol has been investigated in patients. However, the efficiency and safety of LVL in healthy donors using this protocol has not been characterized. Therefore, this study aimed to evaluate the efficiency and tolerability of CD34+ collection of LVL with the cMNC protocol in healthy donors.

STUDY DESIGN AND METHODS

We retrospectively collected data on LVL (>3 total blood volume) and normal-volume leukapheresis (NVL) performed in healthy donors between October 2019 and December 2021. All procedures were performed using the cMNC protocol.

RESULTS

Although pre-apheresis CD34+ cell count was lesser in LVL (23.5 vs. 58.0/μL, p < .001), CD34+ collection efficiency was comparable between LVL and NVL (61.2% vs. 61.4%, p = .966). Platelet loss was significantly higher in LVL compared to NVL (38.0% vs. 29.4%, p < .001), with no correlation between attrition of platelet and processing blood volume. Moreover, the incidence of citrate toxicity during procedures was comparable between the two groups (31.6% vs. 21.4%, p = .322). All LVL procedures could be completed without any adverse events.

CONCLUSION

Allogeneic LVL procedure using Spectra Optia cMNC protocol was well tolerated by the donors and resulted in efficient collection of CD34+ cells, which was comparable to that of NVL.

Predicting Successful Hematopoietic Stem Cell Collection in Healthy Allogeneic Donors

Introduction

Collection of peripheral blood stem cells (PBSCs) from healthy donors is a well-established process. We aimed to identify factors predictive of successful CD34+ PBSC collection and established a formula capable of predicting CD34+ cell yield.

Methods

We retrospectively evaluated 588 healthy adult donors (median age 29 years, range 18-69 years) at our institution from 2017 to 2022. The predicted minimal number of CD34+ cells was calculated as follows: (peripheral CD34+ cells/µL × adjusted collection efficiency of 30%) × total liters processed. This formula was further modified according to donor and recipient body weight (BW).

Results

Median total collection was 8.0 × 106 CD34+ cells/kg BW (range 1.0-47.1 × 106 cells/kg BW) with 522 donors (89%) collecting ≥5.0 × 106 cells/kg of recipient BW. A second leukapheresis (LP) was performed in 49 donors. Need for two LPs was more common in female donors (OR 6.68, 95% CI, 2.62-17.05; p < 0.001), donors with higher age (OR for 10 years difference 1.53, 95% CI, 1.15-2.03, p = 0.003), donors with WBC count <30 × 109/L after 5 days of granulocyte-colony stimulating factor (G-CSF) stimulation (OR, 4.33; 95% CI, 1.59-11.83; p = 0.004), and a donor/recipient weight ratio <1 (OR 6.21, 95% CI, 2.69-14.34; p < 0.001). Predictive factors for optimal LP (i.e., ≥5.0 × 106 CD34+ cells/kg of recipient BW) were peripheral blood (PB) CD34+ cell count >50/µL (OR 12.82, range 6.34-25.92, p < 0.001), male donor (OR 2.77, range 1.06-7.23, p = 0.04), and a donor/recipient weight ratio >1 (OR 3.12, range 1.57-6.24, p = 0.001). WBC, platelets, hemoglobin, and age had no significant predictive value. Predicted versus observed number of CD34+ cells/kg BW collected demonstrated a very strong linear correlation (r = 0.925, 95% CI, 0.912-0.936, p < 0.0001).

Conclusions

Of the routinely monitored indicators in PBSC donors, CD34+ cell count in PB is the most important factor in predicting G-CSF-induced PBSC yields. Higher age, female sex, WBC <30 × 109/L, and a donor/recipient weight ratio <1 are useful indicators for identifying suboptimal mobilizers. The modified formula has shown successful and consistent performance in the prediction of key outcome measures including the minimum CD34+ cell collection, determination of the required length of apheresis, and whether a second day of PBSC collection was necessary to achieve the respective collection goal.

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.

Low hematocrit reduces the efficiency of CD34+ cell collection when using the Spectra Optia continuous mononuclear cell collection procedure

BACKGROUND

CD34⁺ cell collection efficiency (CE) is the determining factor when calculating processed blood volume (PBV) for leukapheresis (LP). However, the factors affecting CE in the continuous mononuclear cell collection (cMNC) protocol performed by the Spectra Optia apheresis system are not well established.

STUDY DESIGN AND METHODS

We retrospectively collected the data from 147 consecutive apheresis procedures across 106 healthy donors and 27 patients completed between July 2016 and December 2020 at the Okayama University Hospital. All procedures were performed using the Optia cMNC protocol.

RESULTS

The median CD34⁺ CE2 was significantly higher in the donor samples (64.3%) than in the patient samples (46.8%) (p < .0001). WBC counts, hematocrit, and platelet counts were all significantly higher in the donors than in the patients, and there was a moderate positive correlation between CD34⁺ CE2 and hematocrit (r = .47, p < .0001), with the equation of the line being y = 1.23x + 12.23. In contrast, there was only a very weak correlation between CD34⁺ CE2 and WBC or platelet count. In addition, low hematocrit correlated with an increased time to interface formation.

CONCLUSION

These data revealed the negative impact of low hematocrit on the efficiency of CD34⁺ cell collection when using the Optia cMNC protocol and suggest that hematocrit values should also be considered when determining PBV.

Optimizing leukapheresis product yield and purity for blood cell-based gene and immune effector cell therapy

PURPOSE OF REVIEW

A critical common step for blood-based ex-vivo gene and immune effector cell (IEC) therapies is the collection of target cells for further processing and manufacturing, often accomplished through a leukapheresis procedure to collect mononuclear cells (MNCs). The purpose of this review is to describe strategies to optimize the apheresis product cell yield and purity for gene and IEC therapies. Relevant data from the conventional bone marrow transplant literature is described where applicable.

RECENT FINDINGS

Product yield is affected by three main factors: the peripheral blood concentration of the target cell, optimized by mobilizing agents, donor interventions or donor selection; the volume of peripheral blood processed, tailored to the desired product yield using prediction algorithms; and target cell collection efficiency, optimized by a variety of device and donor-specific considerations. Factors affecting product purity include characteristics of the donor, mobilizing agent, device, and device settings.

SUMMARY

Strategies to optimize product yield and purity for gene and IEC therapies are important to consider because of loss of target cell numbers or function with downstream steps and detrimental effects of nontarget cells on further manufacturing and patient outcome.

Mobilization and collection of cells in the hematologic compartment for cellular therapies: Stem cell collection with G-CSF/plerixafor, collecting lymphocytes/monocytes

An essential and influential first step in all cellular therapies is collecting donor or patient cells. In hematopoietic progenitor cell transplantation, autologous or allogeneic hematopoietic progenitor cells (HPCs) are collected from either the bone marrow or the peripheral blood. Peripheral blood collection by apheresis requires mobilization with chemotherapy, granulocyte colony stimulating factor (G-CSF), plerixafor, or a combination. The modalities of mobilization and collection each carry a unique set of risks and benefits for both the donor and the recipient. In other types of cell therapy, most notably chimeric antigen receptor T cells, lymphocytes or monocytes are collected from the peripheral blood. The risks of collecting these cells by apheresis are similar to HPCs, but less is known about the composition, timing and qualitative cell characteristics which contribute to an optimal collection. Here, we review the mobilization and collection of HPCs and the collection of lymphocytes and monocytes. Donor safety is of primary importance when collecting material for any type of cell therapy. Every aspect of mobilization and collection can be studied and potentially optimized to improve patient outcomes.

Mobilization and Collection of Peripheral Blood Stem Cells in Adults: Focus on Timing and Benchmarking

Peripheral blood stem cells (PBSCs) are preferentially used as a hematopoietic stem cell source for autologous blood stem cell transplantation (ABSCT) upon high-dose chemotherapy (HDT) in a variety of hemato-oncologic diseases. As a prerequisite, hematopoietic stem cells have to be mobilized into the peripheral blood (PB) and collected by leukapheresis (LP). Despite continuous improvements, e.g., the introduction of plerixafor, current challenges are the further optimization regarding the leukapheresis procedure, preventing collection failures, as well as benchmarking and harmonization of mobilization approaches between institutions.This chapter summarizes the current PBSC mobilization and collection approaches and is focusing on timely orchestration of mobilization therapy, granulocyte colony-stimulating factor (G-CSF) application, and peripheral blood (PB) CD34⁺ cell assessment. Moreover, strategies for prediction and performance assessment of the PBSC collection yield are discussed.

Therapeutic white blood cell and platelet depletions using the spectra OPTIA system continuous mononuclear cell protocol

The Spectra Optia apheresis system has only recently been approved by the Food and Drug Administration (FDA) for therapeutic white blood cell (WBC) depletions and is not yet approved for platelet depletions. Prior to FDA-approval of the WBC depletion protocol, when our available COBE Spectra apheresis systems were out of service, we successfully performed WBC depletion using a modified Spectra Optia apheresis system Continuous Mononuclear Cell (CMNC) protocol. Using this modified Spectra Optia CMNC protocol, we created institutional protocols for WBC and platelet depletions. We performed 10 WBC depletions in 9 patients and 2 platelet depletions in 2 patients. We compared pre- and post-procedure WBC, platelet count, and hemoglobin to the same data from patients previously treated on the COBE Spectra and found no difference in % WBC and platelet reduction. We also found no significant difference in post-procedural hematocrit decline. Additionally, adverse reactions were not increased. Therefore, we conclude that the Spectra Optia CMNC protocol can be successfully modified for effective WBC and platelet depletions without increase in adverse reactions.

Collection of hematopoietic stem cells and immune effector cells in small children

Apheresis procedures are standard of care for a wide range of indications in children, collection of hematopoietic stem cells being the most frequent one. With increasing numbers of hematopoietic stem cell transplants, advances in graft manipulation techniques and the development of innovative therapies using immune effector cells and gene therapy, apheresis within the pediatric population is growing in demand. While young children have higher circulating white blood cell counts and robustly mobilize hematopoietic stem cells, apheresis machines were designed for use within the adult population and apheresis procedures in children, particularly small children, can be more challenging as vascular access, collection techniques and impact of extracorporeal volumes increase the rate of adverse events. In this article we review topics of particular relevance to hematopoietic stem cell and immune effector cell collections in small children.

Low-Volume Leukapheresis in Non-Cytokine-Stimulated Donors for the Collection of Mononuclear Cells

Background

There is an increasing demand for products containing mononuclear cells (MNCs) for cellular immune therapy. Hence, leukapheresis is increasingly performed in healthy volunteer donors.

Methods

We evaluated 147 low-volume leukapheresis procedures from 77 healthy non-cytokine-stimulated donors. Complete blood counts (CBCs) of the donors were measured before and directly after the procedures as well as from the MNC products. Follow-up CBCs were collected from donors within 21 days.

Results

The product hematocrit within a range from 1.2 to 6.0% did not correlate with the collection efficiency of any cell population or the granulocyte and platelet yield. There was a strong correlation between the CBC values before leukapheresis and the cell yield of lymphocytes and monocytes as well as a perfect negative correlation between cell recruitment and cell loss in all cell populations. Furthermore, we observed a significant decrease in the CBC values in all cell populations directly after leukapheresis, which recovered within a mean of 16.1 days (SD ± 2.1 days) and even showed a significant increase in granulocytes and platelets.

Conclusion

Low-volume leukapheresis is feasible for the collection of MNCs in which the product hematocrit is negligible for the collection efficiency, cell yield, or contamination of residual cells under operational settings recommended by the manufacturer. Our data suggests that cell recruitment is regulated by the number of cells removed, which may also be the stimulus to induce granulo- and thrombopoiesis within the first days after leukapheresis.

Orchestration of Chemomobilization and G-CSF Administration for Successful Hematopoietic Stem Cell Collection

Successful collection of peripheral blood stem cells (PBSCs) depends on the optimal orchestration of mobilization chemotherapy, granulocyte colony stimulating factor (G-CSF) application, and CD34⁺ cell number assessment in the peripheral blood (PB). However, determining the optimal timing in accordance to the applied chemomobilization regimen can be challenging. Although most centers apply their own local timing schedules, a reliable timetable including the currently most often used mobilization regimens is lacking. We present a comprehensive analysis of the timing modalities for 11 of the most commonly used chemomobilization regimens. A retrospective analysis was performed on the clinical and PBSC collection parameters (including duration of G-CSF application, time point of CD34⁺ assessment, PB CD34⁺ cell count, number of leukapheresis [LP] sessions, processed blood volume, and CD34⁺ collection results) of 91 representatively selected patients who had undergone stem cell mobilization at 2 collection centers. Six to 10 patients were analyzed per regimen with a variety of diagnoses, including multiple myeloma, malignant lymphoma, and sarcoma. No collection failures (<2 × 10⁶ CD34⁺ cells/kg body weight) were observed. All analyzed patients successfully reached their individual collection goal in adherence to the given schedule of chemotherapy, application of G-CSF, measurement of CD34⁺ cells, and subsequent LP. The presented data on the timing of chemomobilization, G-CSF application, and stem cell collection may be helpful in clinical decision making and contribute to a more transparent and predictable treatment process.

A hospital based retrospective study of factors influencing therapeutic leukapheresis in patients presenting with hyperleukocytic leukaemia

Therapeutic leukapheresis is a rapid and effective method to reduce early mortality of patients with hyperleukocytic leukaemia (HLL). However, few studies on factors influencing the efficiency have been reported. In this study, 67 cases who underwent leukapheresis were retrospectively analysed and factors related to the collection efficiency of leukapheresis (CE_WBC) were also evaluated. Paired t test showed that there was a significant decrease in statistics of white blood cell (WBC) counts after apheresis. The results of two independent samples nonparametric test suggested that WBC counts, platelet (PLT) counts, haematocrit (HCT), hemoglobin (HGB), serum chlorine (Cl) and globulin (GLB) before leukapheresis correlated with the CE_WBC. Multiple linear regression analysis with background stepwise variable selection indicated that only WBC and HCT before leukapheresis had an influence on CE_WBC significantly. Kaplan-Meier analysis and Cox regression model indicated that lymphocyte (LY) and mean corpuscular hemoglobin (MCH) pre-apheresis as independent factors significantly affected the prognostic survival of patients with HLL. Moreover, platelets and red blood cell were contaminated in the product of leukapheresis. It is an urgent problem to be solved in order to realise higher efficacy and higher purity of WBC collection to improve the survival of patients with HLL through optimising instruments.

Platelet Count before Peripheral Blood Stem Cell Mobilization Is Associated with the Need for Plerixafor But Not with the Collection Result

BACKGROUND

A low platelet count before mobilization has recurrently been identified as risk factor for poor mobilization.

METHODS

To determine the relevance of this finding for peripheral blood stem cell (PBSC) mobilization, including pre-emptive or rescue plerixafor in the case of poor mobilization, we retrospectively analyzed all patients undergoing PBSC collection at our institution between January 2014 and December 2015 (n = 380).

RESULTS

In total, 99% of the patients (377/380) successfully collected a minimum of 2 × 106 CD34+ cells/kg body weight sufficient for a single transplant. Rescue or pre-emptive plerixafor was administered to 11% of the patients (42/380). No correlations between the platelet count before mobilization and the number of peripheral blood CD34+ cells or the CD34+ cell collection result were detected in the entire population or the subgroups according to diagnosis (newly diagnosed multiple myeloma, relapsed multiple myeloma, lymphoma, amyloid light-chain amyloidosis, sarcoma, or germ cell tumor). However, patients requiring pre-emptive or rescue plerixafor had a significantly lower platelet count before mobilization (217/nl vs. 245/nl; p = 0.004).

CONCLUSION

With the current state of the art PBSC mobilization strategies, the platelet count before mobilization was not associated with the CD34+ cell collection result but was associated with the need for pre-emptive or rescue application of plerixafor.

Evolution of MNC and lymphocyte collection settings employing different Spectra Optia® Leukapheresis systems

BACKGROUND AND OBJECTIVES

The Spectra Optia^® continuous mononuclear cell (CMNC apheresis) system has emerged as the preferred device in peripheral blood stem cell collections over the original two-step Spectra Optia^® mononuclear cell (MNC apheresis) system. Until now, no comparative data were available for non-stimulated MNC collections that are required for immunotherapy.

MATERIALS AND METHODS

We compared collection parameters and product composition for Spectra Optia MNC- as well as CMNC-apheresis systems in non-stimulated MNC collections from 35 registry donors intended for donor lymphocyte infusions. In a subsequent analysis, different centrifugation forces (determined as packing factor or PF) were investigated regarding target cell yield and contamination in 61 collections using the CMNC device only.

RESULTS

Comparable collection efficiencies as well as target cell yields could be achieved with the Spectra Optia MNC- versus CMNC program. Similar numbers of MNC, T, B and NK cells could be collected with both devices. This led to a more than twofold lymphocyte recruitment from lymphatic tissue into the blood during apheresis. However, significantly more blood had to be processed with longer procedure time using the MNC program resulting in larger product volumes compared to the CMNC setting. Red blood cell and platelet (PLT) contamination were similar. Lowering the centrifugation force from PF4·5 to PF4·0 significantly reduced PLT contamination without affecting target cell yield in the product.

CONCLUSION

The Spectra Optia^® CMNC device using lower centrifugal force (PF4·0) showed similar target cell yield and composition as well as collection efficiencies with superior performance parameters and lower PLT contamination compared to the MNC setting.

Collection of hematopoietic CD34 stem cells in rhesus macaques using Spectra Optia

BACKGROUND

Nonhuman primates, particularly rhesus macaques, are ideal preclinical large animal models to investigate organ tolerance induction protocols using donor hematopoietic stem cells (HSCs) to induce chimerism. Their relatively small size poses some challenges for the safe and effective collection of peripheral blood HSCs through apheresis procedures. We describe our experiences using the Spectra Optia apheresis unit to successfully obtain HSCs from mobilized peripheral blood of rhesus macaques.

METHOD

Mobilization of peripheral blood HSCs was induced using granulocyte stimulating factor (G-CSF) and Mozobil. The Spectra Optia unit was used in 18 apheresis procedures in 13 animals (4.9-10 kg). Animal health was carefully monitored during and after the procedure. Changes in peripheral blood cells before, during and after procedure were determined by complete blood count and flow cytometry.

RESULTS

The automatic settings of the Spectra Optia unit were applied successfully to the procedures on the rhesus macaque. All animals tolerated the procedure well with no mortality. Mobilization of HSCs were most consistently achieved using 50 μg/kg of G-CSF for 5 days and a single dose of Mozobil on the 5th day, followed by collection of cells 3 h after Mozobil injection. The final apheresis product contained an average of 23 billion total nucleated cells with 47% granulocytes, 3,871 million total CD3 cells and 77 million CD34 cells which resulted in an average of 10 million CD34+ cells/kg of donor weight.

CONCLUSION

Apheresis of peripheral blood mobilized HSCs in rhesus macaques using Spectra Optia is a safe and effective procedure.

Prospective randomized and crossover comparison of two apheresis machines for peripheral blood stem cell collection: a multicenter study

BACKGROUND

Improving apheresis technology may lead to an efficient and safe peripheral blood stem cell (PBSC) collection. Recently, the Spectra Optia (Optia, Terumo BCT) was introduced as an automated apheresis instrument, but comparisons with other instruments have been few. This is the first randomized multicenter and crossover comparison of the Optia with the automated program of the established apheresis instrument, the Spectra (Spectra-Auto, Terumo BCT).

STUDY DESIGN AND METHODS

A total of 233 apheresis procedures performed in 46 autologous patients and 108 allogeneic donors were investigated. Apheresis performed in the first day for all subjects using the Spectra-Auto (n = 79) and the Optia (n = 75) were evaluated as first-day analysis. Seventy-nine subjects, who required another session on the second day, underwent apheresis using the other instrument than the first-day instrument and were compared with each other in a paired crossover analysis.

RESULTS

The two instruments processed similar volumes with comparable run times and volumes of acid-citrate-dextrose used. The volumes of collected products were greater in the Optia. Yields of mononuclear cells and CD34+ cells were not different, but collection efficiencies were higher in the Optia (p = 0.008 in CE1 of crossover analysis). Spectra-Auto-collected products contained more contaminating red blood cells (RBCs), whereas there was a trend of more contaminating platelets (PLTs) in the Optia-collected products. Slight reductions were noted in the RBC or PLT counts of subjects who underwent apheresis with the Spectra-Auto or the Optia, respectively.

CONCLUSION

The Optia is safe and more efficient in the PBSC collection compared with the Spectra-Auto.