Work

Can the stem cell mobilization technique influence CD34+ cell collection efficiency of leukapheresis procedures in patients with hematologic malignancies?

Year: 2004

Type: article

Abstract: CD34+ cell collection efficiency (CE) reflects the proportion of CD34+ cells that is harvested during apheresis. Higher CE results in a bigger stem cell collection per procedure; reducing the number of procedures required to reach the target. 415 leukaphereses done on 201 patients (1–11 each; median 2) using Cobe Spectra cell separators over 26 months were studied to determine CD34+ cell CE. Apheresis was done for leukemia (n = 54), lymphoma (n = 130), and plasma cell dyscrasias (n = 231). Aphereses done with pre-apheresis peripheral blood CD34+ cell count (PBCD34) <0.02% were excluded to reduce variability and calculation error. Stem cells were mobilized with growth factor (GF; n = 119) or chemotherapy-GF (n = 296). 15 (n = 202) or 20 (n = 213) L blood volume was processed. The pre-apheresis WBC count was 1–93 × 109/L (median 20), and PBCD34 was 1-1104/mm3 (median 19). The total number of CD34+ cells collected was 4–6531 × 106 (median 151); corresponding to 0.1–111.4 × 106 (median 2.3) per kg. There was strong correlation between PBCD34 and the number of CD34+ cells collected (r2 = 0.80; P < 10−100). CE was 7–145% (median 46). On multiple regression analysis, higher WBC (continuous variable; P < 0.0001), higher PBCD34 (continuous variable; P = 0.009), and greater blood volume processed (categoric variable; P = 0.02) resulted in lower CE. Age, sex, weight, diagnosis, year, mobilization technique, Hct, and platelets did not affect CE. PBCD34 counts were higher (median 22 vs 15; P = 0.036) in patients mobilized with chemotherapy-GF compared to GF alone despite lower WBC counts (median 16 vs 30; P < 0.0001) because of higher %PBCD34 (median 0.16% vs 0.05%; P = 0.0001). CE with WBC <20 was 7–145% (median 53%) compared to 10–132% (median 40%) with WBC 20 (P < 0.0001), suggesting that WBC <20 may be optimum for apheresis in terms of maximizing CE. Since PBCD34 increases early during WBC recovery after chemotherapy, 61% of the apheresis procedures performed after chemotherapy-GF occurred when WBC was <20 compared to 21% of those performed after GF alone (P < 0.0001). With GF alone, mobilization is optimal after 4–5 days of therapy when WBC is likely to be ≥20. We conclude that mobilizing patients with the combination of chemotherapy and GF rather than GF alone is likely to lead to leukapheresis being performed when the WBC count is in a range that results in optimum CD34+ cell CE. Autologous stem cells should be mobilized with chemotherapy-GF rather than GF alone if this is clinically feasible.

Source: Transplantation and Cellular Therapy

DOI: 10.1016/j.bbmt.2003.12.027