Pre-clinical assessment of the Lovo device for dimethyl sulfoxide removal and cell concentration in thawed hematopoietic progenitor cell grafts.

BACKGROUND: Cryopreserved hematopoietic progenitor cell (HPC) grafts are widely infused to patients with malignant and nonmalignant conditions. Despite reduction of immediate side effects linked to dimethyl sulfoxide (DMSO), cell debris-containing grafts and comparable hematopoietic engraftment between washed and unwashed cryopreserved products, bedside infusion of thawed HPC grafts is still preferred. Introduction of automated devices is important for standardization and consistency of graft manipulation. Additionally, these techniques are likely to be useful for the delivery of innovative cell-based medicinal products that are currently under development. METHODS: In this study, we evaluated three consecutive versions of the Lovo device (Fresenius Kabi) for automated washing of thawed HPC products. A total of 42 HPC products intended for destruction were used. Measured outcomes included viable CD34+ cell recovery, viability, total processing time and post-washing stability. RESULTS: Preliminary data using the prototype Lovo 0.0 to process a single HPC unit showed better recovery and viability of CD34+ cells using a two-cycle than a three-cycle wash, with >95% DMSO elimination. The Lovo 1.0 performed equally well. When simultaneously processing two HPC units, the upgraded Lovo 2.0 device demonstrated comparable CD34+ recovery, DMSO elimination efficiencies and time-saving capacity. Furthermore, washed cell products were stable for 4 hours at room temperature. DISCUSSION: Lovo device satisfies clinically relevant issues: ability to efficiently wash two HPC units simultaneously and compatibility with transport to nearby transplantation centers.

A new single-platform method for the enumeration of CD34+ cells.

Guidelines for flow cytometric enumeration of CD34(+) hematopoietic stem cells (HSC) recommend the use of a single-platform assay. The SCE kit has recently been commercialized by BD Biosciences. Results obtained with this newly available kit were compared with CD34(+) cell enumerations obtained in parallel with already commercialized diagnostic kits; fresh peripheral blood, apheresis, cord blood (CB) and bone marrow (BM) samples, as well as thawed apheresis and CB samples, were assayed. The SCE kit produced data for CD34(+) enumeration that correlate well with data produced with the older assays (r(2) > or = 0.9). Practical advantages were the ability to enumerate viable CD34 cells in all kinds of HSC products, the absence of bead pipetting (which decreases results precision) and a gating strategy complying with international recommendations. A major disadvantage was the absence of specific software for data analyses and presentation of results.