Impact of mobilization regimen on multiday collection of peripheral blood CD34+ cells by large volume leukapheresis

Background: The collection yield of hematopoietic progenitors cell (HPC) by leukapheresis is critical for a successful transplantation, which often requires multiday collections to achieve the collection goal. Study Design and Methods: Collection procedures of 181 patients who underwent leukapheresis for more than 1 day were reviewed. Patients were separated into six groups based on the mobilization regimen: G-CSF on day 1 (D1) and day 2 (D2) (G-G); G-CSF on D1 and G-CSF and plerixafor on D2 (G-GP); G-CSF and plerixafor on day D1 and D2 (GP-GP); G-CSF and plerixafor on D1 and G-CSF on D2 (GP-G); chemotherapy and G-CSF on D1 and D2 (GC-GC); and chemotherapy, G-CSF, and plerixafor on D1 and D2 (GCP-GCP). Patient's pre-collection CD34 count (pre-CD34) on D1 and D2 were compared in the same individual and among groups. Results: We found D2 pre-CD34 were significantly decreased in G-G, GP-G, and GP-GP groups and significantly increased in G-GP group (p <.001) using a repeated measures ANOVA analysis. D2 pre-CD34 remained at similar levels as D1 in GC-GC and GCP-GCP groups. A multiple regression analysis showed that the mobilization regimen was the only factor that significantly affected pre-CD34 D2/D1 ratio (p <.001). There was a significant difference in the pre-CD34 D2/D1 ratio (p <.001) among these six groups with the lowest in GP-G group (0.40 ± 0.45), and the highest in G-GP group (2.35 ± 0.36). Discussion: Mobilization regimen has significant impact on pre-collection CD34 count. Apheresis facilities may change mobilizing drugs accordingly to achieve a specific HPC goal.