DKMS Collection Center (CC) gGmbH, established in 2023, completes the value chain within DKMS by offering apheresis of stem cells. We aim to minimize apheresis time for best donor safety and maximize capacities for more second life chances of blood cancer patients. The bottleneck is the CD34+ stem cell quantification time due to transportation to an external laboratory. Process insourcing is considered to be a potential alternative. Comparative testing for reliability has been conducted.

Peripheral blood samples from donors were collected at day of apheresis. Viable CD34+ stem cells were quantified using Fluorescence CD34 Counter ADAMII™ by NanoEntek according to manual. Briefly, 20 µl of blood was incubated with 5 µl staining solution for 20 min. Then, 35 µl cell lysis buffer was added and incubated for 10 min. Finally, 35 µl sample was applied to specimen slide and incubated for 3 min while device calibrated. Single sample per run measurements were conducted. Results were validated against traditional FACS analysis, conducted at external, qualified testing laboratory via Navios EX by Beckman Coulter. Statistical analysis was performed in GraphPad Prism using linear regression testing.

Viable CD34+ cells/µl were measured in n=43 blood samples of stem cell donors. Results from ADAMII™ and traditional FACS were plotted against each other (figure 1). Linear regression (y= 0.8596x + 11.69) was conducted. A correlation of r²=0.9065 between the two methodologies was demonstrated. Measuring several samples at a time revealed to be time-consuming.

The strong correlation of 90.65 % demonstrates reliability of ADAMII™ to evaluate donors" mobilized stem cells for apheresis time extrapolation. Tests with apheresis products for indication of drug dose and official authorization are required before implementation of the technology. We consider it to be a potential in-house alternative that maintains high product quality. In general, the system is well suited for low-throughput analysis without extensive training and experience needed.

Nothing to disclose