Automated collection of peripheral blood stem cells with the COBE spectra for autotransplantation

Background: A convenient, effective and safe peripheral blood stem cell (PB SC) apheresis procedure is desirable to cope with the increasing requiremen ts for PBSC collections. We performed PBSC harvesting with the novel COPE S pectra AutoPBSC(TM) system using the default software configuration recomme nded by the manufacturer. We analyzed collection parameters and clinical ef ficiency of harvested autografts following high-dose chemotherapy (HDCT). P atients and Methods: Eighty-one patients underwent 102 harvests after stand ard chemotherapy plus filgrastim (5-10 mu g/kg/day) to obtain a target of g reater than or equal to 2.5 x 10(6) CD34+ cells/kg for autologous blood ste m cell transplantation. Conventional-volume leukaphereses (median: 11 liter s) were performed using the manufacturer's standard software default regard ing inlet flow, harvest/chase volume (3/7 mi) and number of collection cycl es. The ratio of ACD-A to whole blood was initially set at 1:12 (56 collect ions), later at 1:10 (46 aphereses). Results: With respect to preapheresis counts of 93 (9-876) CD34+ cells/mu l, 69 patients (85.2%) achieved greater than or equal to 2.5 x 10(6) CD34+ cells/kg by the first apheresis. PBSC p roducts contained medians of 5.0 x 10(6) (0.7-77.3) CD34+ cells/kg and 13.8 x 10(4) (2.3-105.0) CFU-GM/kg. A preapheresis count of greater than or equ al to 40 CD34+ cells/mu l predicted a single-apheresis yield of greater tha n or equal to 2.5 x 10(6) CD34+ cells/kg. Apheresis products showed a high mononuclear cell (MNC) purity of greater than or equal to 89%. The median o verall collection efficiency of CD34+ cells (CD34-CE) was 42.6% (12.2-87.4) . The CD34-CE decreased significantly with increasing numbers of circulatin g CD34+ cells: 52.5% at CD34+ cells < 40/mu l versus 41.0% at CD34+ cells g reater than or equal to 40/mu l (p less than or equal to 0.002). Coagulatio n problems occurred in 3 of 56 procedures at an ACD-A to whole blood ratio of 1:12, but in no case at 1:10. Patients who underwent HDCT and autologous blood stem cell transplantation (n = 40) engrafted in a median time of 9 ( 8-13) days for absolute neutrophil counts > 0.5 x 10(3)/mu l, 10 (8-13) day s for WBC > 1.0 x 10(3)/mu l and 11 (8-17) days for platelets > 20 x 10(3)/ mu l. Conclusions: As a result of efficient PBSC mobilization, a single con ventional-volume leukapheresis with the COBE Spectra AutoPBSC system result ed in hematopoietic autografts with greater than or equal to 2.5 x 10(6) CD 34+ cellsl kg in 85% of patients. Following the standard PBSC apheresis rec ommendations of the manufacturer, the AutoPBSC system assures PBSC products with a high MNC purity and a moderate CD34-CE that declines significantly at increasing levels of circulating CD34+ cells. Leukaphereses performed at an ACD-A to whole blood ratio of 1:10 should run without coagulation probl ems. Copyright (C) 2000 S. Karger AG, Basel.