Peripheral Blood Stem Cell Collection in One Day Is Preferable to Two Days in Unrelated Donors

Abstract

Peripheral blood stem cells (PBSC) have been increasingly used for allogeneic hematopoietic cell transplantation compared to bone marrow stem cells. Currently, the National Marrow Donor Program (NMDP) policy recommends 5 days of daily filgrastim followed by either 1 day of large volume apheresis or 2 days of smaller volume apheresis for unrelated donors, according to collection center choice. To date, there are no studies to compare the difference between one and two days of apheresis. We examined 22,348 adult unrelated donor collections in 184 centers from 2006-2016. 20,004 (89.5%) donors were collected in 1 day vs. 2,344 (9.5%) in 2 days. There were both patient and collection center differences between the two groups (Table 1). In general, patients who underwent apheresis over 2 days were more likely to be women, older and had a lower body-mass index (BMI)/ weight. Centers performing 2-day collections performed fewer annual collections on average (162 vs 265). Donors undergoing 2-day collections were more likely to experience citrate toxicity (52% vs 36%) and more likely to be hospitalized (6% vs 1%). Successful collection of the requested CD34 count was achieved on the first day in 82% of one day collection (vs 16% of 2-day collections). Despite not administering filgrastim the evening after the first day of collection, in patients who underwent 2 days of apheresis, the median concentration of CD34+cells/L in the product on the second day of apheresis was higher than the first day (23.8 × 106 CD34+/L 1st day vs. 28.7 × 106 CD34+/L 2nd day, p