A new protocol for improving efficiency of autologous peripheral blood stem cell collection in patients with high white blood cell counts.

Background: Collection efficiency (CE) of peripheral blood stem cell (PBSC) collections is negatively affected by increasing white blood cell (WBC) counts of the patient. This study compared a new optimized mononuclear cell (MNC) collection protocol (OPP) to the standard MNC collection protocol recommended by the manufacturer (STP) for PBSC collection in patients with WBC counts >35 000/μL.

Study Design And Methods: Single-center, retrospective, and observational study of 81 autologous PBSC collections on Fenwal Amicus cell separators in 70 adult patients.

Results: Median peripheral WBC count (×10 /μL; 44.2 in OPP group vs 46.5 in STP group) and median CD34 count (105/μL in OPP group vs 40/μL in STP group) at the beginning of PBSC collection did not differ significantly. Median CE2 (45% vs 31%; P < .001) as well as CD34 yield of the apheresis product both with regards to median absolute CD34 content (×10 ; 793 vs 188; P = .001) as well as median CD34 content (×10 )/kg body weight (8.93 vs 2.51; P = .002) were significantly higher for the OPP. Overall, 18/21 (86%) patients with the OPP obtained their target CD34 amount with a single apheresis session, compared to 25/50 (50%) with the STP (P = .005). PBSC collections using OPP lasted significantly longer (median 377 minutes vs 260 minutes; P < .001) than with the STP.

Conclusions: The OPP significantly improves CE2 for PBSC collections on Fenwal Amicus cell separators in patients with pre-apheresis WBC counts >35 000/μL and significantly reduces the necessity for multiple apheresis sessions. The OPP is therefore suited to reduce both patient burden and cost in autologous PBSC collection.