A Single Center Comparison between Two Apheresis Systems for Allogeneic Granulocytes Collections: Report of 72 Procedures

Introduction: Granulocytes (PMNs) collection from healthy donors is routinely used to be infused into patients with PMNs functional defects or transient neutropenia with high risk of bacterial or fungal exacerbations. PMNs are collected by apheresis systems from healthy donors after administrating granulocyte-colony-stimulating factor and/or steroids for mobilizing neutrophils. Since Caridian BCT, lately named Terumo BCT, decided to cease providing support for the most commonly used cell separator, COBE Spectra^® Apheresis System, our collection center, at King Hussein Cancer Center (KHCC) as many other centers worldwide, that used COBE Spectra^® was obliged to switch to another system. The decision for replacement was to start PMNs collection using the relatively new Spectra Optia (Terumo-BCT). The objective of this study is to assess the performance of the PMNs cell aphaeresis protocol on the Spectra Optia device (Terumo-BCT) in comparison to COBE Spectra^® (Terumo BCT) in terms of collection efficiency and cell-product composition.

Methods: An ongoing and retrospective case file review of 72 PMNs collection procedures from healthy donors collected in KHCC from October 2009 up to June 2018, were analyzed including 53 with COBE Spectra^® and 19 with the new Spectra Optia system. All collections on both devices have been monitored for pre-collection parameters, post-collection parameters, and final PMNs product criteria.

Results: Subjects underwent collections, on both devices, have been confirmed to be homogeneous healthy donors after checking the pre-collected donor's total blood volumes (TBV), white blood cells (WBCs) count, PMNs count, and total PMNs in total donor's TBV (i.e. P > 0.05). COBE Spectra^® showed a less final PMNs product volume compared to Spectra Optia (353 mL vs. 515 mL, P < 0.0001, respectively). Although the concentration of WBCs per milliliter in the final product using COBE Spectra^® device was significantly higher (136 x10⁶ / mL) compared to Spectra Optia (68 x10⁶ / mL), P = 0.001, but the difference in the overall WBCs in the final products was insignificant (4.85 x10¹⁰ vs. 3.54 x10¹⁰,P = 0.09). On the other hand, both the product's PMNs percentage (81 % vs. 64 %, P = 0.001) and the total PMNs in the final product (4.07 x10¹⁰ vs. 2.58 x10¹⁰, P = 0.04) showed higher values in COBE Spectra^® compared to Spectra Optia. The residual red blood cells (RBCs) in the final PMNs product using COBE Spectra^® showed to have the less RBC (48 mL) compared to Spectra Optia (152 mL), P < 0.0001, which implicating less RBCs quantities infused into patients (1.0 mL/kg vs. 2.1 mL/kg, P < 0.0001, respectively). For the PMNs recovery, although COBE Spectra^® has higher recovery percentage (20 %) compared to Spectra Optia (14%), but these values did not different significantly (P = 0.09). The same trend was seen in WBCs recovery when COBE Spectra^® (22 %) compared to Spectra Optia (19 %), P = 0.40.

Conclusions: The higher PMNs product volume produced by Spectra Optia compensate for the COBE Spectra^® better product criteria, making both apheresis systems are similarly capable of generating PMNs concentrates in good doses.