Objective: To monitor the variety of lymphocytes and CD34(+) cell subsets in peripheral blood (PB) and peripheral blood progenitor cell (PBPC) during mobilization and collection, and determine the optimal time for PBPC collection.
Methods: Flow cytometry (FCM) was used to detect the concentration of lymphocyte subsets, such as CD3, CD4, CD8, NK and CD19, as well as CD34(+) cell subsets, such as CD34(+)CD38(-), CD34(+)Thy1(+) and AC133(+) in PB or PBPC during autologous peripheral blood stem cell transplantation (APBSCT) during high dose chemoradiotherapy (HDC) with recombinant human granulocyte colony-stimulating factor (rhG-CSF) in 47 consecutive patients with malignant solid tumor. Colony culture in vitro was performed when evaluating the clonogenic capacity of the PBPC.
Results: After mobilization, the concentration of lymphocyte subsets in PB decreased to the level below the baseline with CD3 (P = 0.007) and CD8 (P = 0.016) decreased significantly. On the contrary, the total CD34(+) cell and the other CD34 subsets in PB increased significantly (P < 0.05). CD34(+) cell peak of the blood was observed with the median time of 16 d (15-17 d) from the mobilization. The concentration of progenitor cell was the highest in the first apheresis. There was no significant change in PBPC lymphocyte subsets, except CD4 and CD4/CD8 which decreased below PB (P < 0.000 5). There was a significant linear correlation between PB CD34(+) cells and PBPC CD34(+) cells, CD34(+)CD38(-), CFU-GM or BFU-E (P < 0.05), but none between PB CD34(+) cells and PBPC MNC, CD34(+)Thy1(+) or AC133(+) cells. There was a significant correlation between PBPC CD34(+) cells and PBPC CD34(+)CD38(-), CD34(+)Thy1(+), MNC, CFU-GM or BFU-E (P < 0.05), but none between PBPC CD34(+) cells and AC133(+) cells. After transplantation, the CD4/CD8 ratio decreased markedly and CD19 cells returned to the normal range rapidly.
Conclusion: PBPC increases significantly during mobilization by HDC and rhG-CSF. The immunosuppressed state exists after APBSCT. The peripheral blood CD34 cell count is able to predict autograft yield reliably and can be the best indicator for the clinical collection of PBPC.