Predictors for successful mobilization of peripheral blood progenitor cells with ESHAP + G-CSF in patients with pretreated non-hodgkin's lymphoma

Background: ESHAP (etoposide/methylprednisolone/cytarabine/cisplatin) plus granulocyte-colony stimulating factor (G-CSF) is an effective regimen of therapy for advanced non-Hodgkin's lymphoma (NHL) and peripheral blood progenitor cell (PBPC) mobilization. However, the timing of PBPC harvest following immobilization and factors to predict optimal PBPC yield remain to be explored. We herein analyzed the factors potentially correlated to optimal PBPC mobilization. Methods: Twenty patients with pretreated advanced NHL were recruited and mobilized with ESHAP+G-CSF followed by 2 leukaphereses, which were initiated once the white blood cell count (WBC) in peripheral blood exceeded 10 × 10⁹/L. Results: Total CD34⁺ cells collected by 2 leukaphereses were > 2 × 10⁶/kg body weight in 16 patients; between 1.0 and 2.0 × 10⁵/kg in another 3, and < 1 × 10⁶/kg in the remaining 1 patient. The pre-leukapheresis peripheral blood CD34⁺ cell counts, available for 28 leukaphereses, correlated linearly with the CD34⁺ cell yields (r² = 0.870, p<0.001). The CD34⁺ cell yield with pre-leukapheresis peripheral blood CD34⁺ cell count ≥ 50 × 10⁶/L was higher than that with < 50 × 10⁶/L (5.60 ± 4.32 vs. 0.96 ± 0.56 × 10⁶/kg/leukapheresis; p = 0.004). Other factors predictive of favorable PBPC yield included preceding chemotherapy cycles < 6 and peripheral blood WBC > 3,500/μL on the day of mobilization chemotherapy (p = 0.032 and 0.013, respectively). Conclusion: The pre-leukapheresis peripheral blood CD34⁺ cell count correlates well with PBPC yields. Less than 6 chemotherapy cycles before mobilization and adequate peripheral blood WBC before mobilization chemotherapy also predict a favorable PBPC yield.