A Comparison of Fresenius Com.Tec Cell and Spectra Optia Cell Separators for Autologous and Allogeneic Stem Cell Collections: Single Center Experience

Stem cell mobilizating effect of heparin in patients undergoing autologous stem cell transplantation

BACKGROUND

Adequate stem cell collection is essential for successful stem cell transplantation. Heparin enhances stem cell mobilization by competing with heparin sulfate proteoglycans. Heparin is also used as an anticoagulant before leukapheresis. Here, we evaluated the effects of heparin on stem cell mobilization in patients who underwent autologous stem cell transplantation (ASCT).

METHODS

We evaluated patients who underwent ASCT. Patients were divided into two groups: those who received heparin plus citrate (heparinized patients) and those who received citrate only (nonheparinized patients) for anticoagulation. Univariate and multivariate analyses were also performed. The collection efficiency 2 (CE2) for CD34+ cells was calculated and compared between heparinized and nonheparinized patients.

RESULTS

This study included 1017 patients. There were 478 (47%) heparinized and 539 (53%) nonheparinized patients. The number of collected CD34+ cells was significantly higher in heparinized patients (P < .00001). The multivariate analyses showed that using heparin was an independent positive factor for collected CD34+ cells (adj-R2  = 0.744; F = 369.331, P < .00001). CE2 was significantly higher in heparinized patients than in nonheparinized patients (66.8% vs 52.1%; P < .00001). The rate of collecting at least 2 × 106 /kg CD34+ cells was 3.3 times higher for heparinized patients in poor mobilizers (P < .00001). Heparinized patients had significantly higher total nucleated and mononuclear cell counts (P < .00001 and <.00001, respectively).

CONCLUSION

Heparin enhances stem cell collection and increases CE2. The use of heparin may reduce the need for other strategies to increase stem cell mobilization.

Retrospective comparison of two different cell separators for autologous peripheral blood stem cell collection: Single center experience

INTRODUCTION

Autologous peripheral blood stem cell (PBSC) transplantation has become a standard treatment option for certain hematological malignancies. The collection of PBSCs for transplantation is a well-established process and the effectiveness can vary depending on the cell separator.  We aimed to compare the effectivity of two  devices, the Spectra Optia and the Amicus for autologous PBSC collection. We also evaluated the effect of the peripheral white blood cell (WBC) count on the CD34+ collection efficiency (CE2).

METHODS

We retrospectively evaluated 262 apheresis procedures performed in patients between 2015 and 2021 at the Apheresis Unit of our transplantation center. The PBSCs were collected by the Spectra Optia cell separator with continuous Mononuclear Collection (cMNC) (128 procedures) or the Amicus (MNC) (134 procedures). In addition to the apheresis parameters and product characteristics, we also evaluated the effect of the pre-apheresis peripheral WBC count on the CE2.

RESULTS

There was no significant difference in the CD34+ CE2 between the Spectra Optia and Amicus devices (median 65.06% and 68.24%, respectively, p = 0.070). In the Amicus group, the CE2 ratio was found to be statistically significantly higher in patients with a pre-apheresis peripheral WBC count of 15 × 10⁹/L (median 81.70%, 68.06%, 61.35% and 58.13%, respectively, p < 0.001).

CONCLUSION

While both devices collected autologous PBSC effectively and safely, the Amicus provided a higher rate of CE2 at low pre-apheresis WBC counts. To our knowledge, this is the first study to evaluate the CE2 in autologous PBSC collection devices based on pre-apheresis WBC counts.

Impact of Mobilization Strategies on Peripheral Blood Stem Cell Collection Efficiency and Product Quality: A Retrospective Single-Center Study

Autologous stem cell transplantation is routinely used in the management of several hematological diseases, solid tumors, and immune disorders. Peripheral blood stem cell (PBSC) collection performed by apheresis is the preferred source of stem cells. In this study, the potential impact of mobilization regimens on the performance of the Spectra Optia^® continuous mononuclear cell collection system was evaluated. We performed a retrospective data analysis for patients undergoing autologous PBSC collection at the Medical University Vienna, Vienna General Hospital between September 2016 and June 2018. Collections were divided into two main groups according to the mobilization regimen received: without (210 collections) or with (99 collections) plerixafor. Assessed variables included product characteristics and collection efficiency (CE). Overall, product characteristics were similar between the groups. Median CD34+ CE2 was 50.1% versus 53.0%, and CE1 was 66.9% versus 69.9% following mobilization without and with plerixafor, respectively; the difference was not statistically significant. Simple linear regression showed a very weak positive correlation between the mobilization method and CE1 or CE2 (mobilization with plerixafor increased CE2 by 4.106%). In conclusion, the Spectra Optia^® apheresis system led to high CE and a good quality of PBSC products when mobilization regimens with or without plerixafor were used.

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.