We have recently demonstrated the feasibility of collecting CD34+ cells in heavily pre-treated lymphomas and Multiple Myeloma (MM) patients mobilized with intermediate-dose cytarabine (Ara-C) plus G-CSF for hematopoietic rescue in autologous Hematopoietic Stem Cell Transplantation (auto-HSCT). We now report back data of Peripheral Blood Stem Cells (PBSC) harvest from a larger sample of patients who underwent auto-HSCT. Materials and Methods. From January 2016 to July 2023, 311 patients (204 MM, 64 non-Hodgkin's lymphoma, 35 Hodgkin's lymphoma, 5 germ cell tumor and 3 acute non-promyelocytic leucemia, median age of 56 years, range 17‒74) were mobilized with Ara-C plus G-CSF. On days 1 and 2 Ara-C was administered as 2h i.v. infusion at a dose of 0.4 g/m2 twice daily. From day 6 to day 14, G-CSF (12 μg/Kg) was daily administered on an outpatient basis. On day 14, patients who met the circulating CD34+ cells criteria (> 10 μL) started leukapheresis in a limited number of two sessions. PBSC were collected with the intermittent-flow blood cell separator Haemonetics MCS+ 9000E (Haemonetics Corporation, Massachusetts, USA).

Overall, with the aim of collecting > 2.0×106 cells/kg an optimal CD34+ cell yield was achieved in 94% of patients with a single apheresis > first harvest parameters and results were expressed as median (min‒max) ‒ pre-leukapheresis: hemoglobin 10.1 g/dL (6.1‒13.7), neutrophils 7.6×109/L (1.3‒39.4), platelets 43×109/L (2‒234), CD34+cells/μL 84.2 (3‒1123); leukapheresis: volume processed 7256 mL (4338‒10,180), ACD-A 743 mL (498‒1026), time 231 minutes (185‒345); leukapheresis product: volume 151 mL (106-195), WBC 341.2‒109/L (112.7‒793.1), cell viability 98% (82‒99), CD34+ cells 8.1×106/Kg (0.8‒46.9). Moreover, patients exhibited few adverse events, approximately a quarter required platelet transfusion; the median time to neutrophil and platelet recovery after PBSC infusion was 11 days (range 9‒12) and 13 days (range 9‒15), respectively.

Although obtained from a single institution, the results were comparable with those previously reported. The outpatient administration of G-CSF, the reliable prediction of the day to begin harvesting, the optimal CD34+ cell yield obtained with a single apheresis even in heavily pre-treated patients and the fewer occurrences of adverse events denoted the benefits of this regimen.

Our findings confirmed the effectiveness of CD34+ cell collection through the mobilization with intermediate-dose cytarabine plus G-CSF.