CD34⁺ cell selection using small-volume marrow aspirates: A platform for novel cell therapies and regenerative medicine

Background aims. This study was initiated to determine whether CD34 ⁺ cell selection of small-volume bone marrow (BM) samples could be performed effectively on the Isolex® 300i Magnetic Cell Selection System® device and whether the results obtained from these samples were comparable with results from large standard-volume samples. The impact on CD34⁺ recovery using a full versus half vial of Isolex® CD34 reagent and the effects of shipping a post-selection product were evaluated. Methods. A protocol to evaluate CD34⁺ cell selection with two ranges of smaller volume BM samples (c. 50 mL and c. 100 mL) was developed and instituted at three Production Assistance for Cellular Therapies (PACT) facilities. The study was performed in two phases. Results. In phase I, the mean post-selection CD34⁺ recoveries from the two sizes of samples were 104.1% and 103.3% (smallest and largest volumes, respectively), and mean CD34⁺ recoveries were 115.6% and 88.7%, with full and half vials of reagent, respectively. Mean CD34⁺ recoveries for post-shipment smaller volume samples were 106.8% and for larger volume samples 116.4%; mean CD34⁺ recoveries were 99.9% and 127.4% for post-shipment samples processed with full and half vials of reagent, respectively. In phase II, mean CD34⁺ recovery was 76.8% for post-selection samples and 74.0% for post-shipment samples. Conclusions. The results suggest that smaller volume BM sample processing on the Isolex® system is as efficient or more efficient compared with standard-volume sample processing. Post-processing mean CD34 ⁺ recovery results obtained using a full or half vial of CD34 reagent were not significantly different.