Evaluation of a New Method of Leukocyte Extractions from the Leukoreduction Filter

This study's purpose was to optimize the leukocyte extraction protocol and evaluate the efficacy of this new protocol. 12BioR blood filters were collected from Tehran Blood Transfusion Center. A twosyringe system and Multi-step rinsing were designed for cell extraction. The final purpose of this optimization was: (1) removed the residual RBCs, (2) reversed the leukocyte trapping process, and (3) remove the microparticles to obtain the high yield of target cells. Finally, Extracted cells were evaluated by Automated Cell count; Samples smear differential cell count, Trypan blue, and Annexin-PI staining. The results showed that on average 11.88 × 10⁸ ± 3.32 leukocytes recovered after indirect washing and that the mean count of granulocytes, lymphocytes, and Monocyte in this sample was 5.24 ± 2.18 × 10⁸, 5.57 ± 1.74 × 10⁸, and 0.56 ± 0.38 × 10⁸ respectively. Also, the mean percent of manual differential cell count after concentration was 42.81%, 41.80%, and 15.82% for granulocytes, lymphocytes, and monocytes respectively. Moreover, viability and apoptosis assay showed > 95% viability in mononuclear cells recovered from LRFs. It is concluded that the use of a double-syringe system and RBC and microparticles removal from leukoreduction filters lead to acceptable viable leukocyte count that can be used in in vitro and in vivo studies.