Recommendations for optimized settings of the Amicus Crescendo cell separator for the collection of CD34+ progenitor cells

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 (×10³ /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 (×10⁶ ; 793 vs 188; P = .001) as well as median CD34⁺ content (×10⁶ )/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.

Evaluation of the COM.TEC cell separator in predicting the yield of harvested CD34+ cells

BACKGROUND

This multicenter study was performed with the intention to evaluate the exactness of the predicted CD34+ cell yield calculated by two leukapheresis programs of the cell separator COM.TEC upon the number of donor's circulating CD34+ cells and the blood volume processed.

STUDY DESIGN AND METHODS

Patients and healthy donors (n = 166) received mobilization by chemotherapy and/or granulocyte colony-stimulating factor and underwent CD34+ cell harvest by the leukapheresis programs MNC or RV-PBSC (n = 203).

RESULTS

CD34+ cells were collected by 112 harvests on MNC and by 91 collections on RV-PBSC. The median collection efficiency of CD34+ cells was significantly better for the program MNC than for RV-PBSC (p < 0.001): 67% (31-109) vs. 42% (19-100). The collected CD34+ cell yield was in median more exactly by MNC than by RV-PBSC (p < 0.001): 85% (31-176) vs. 59% (22-110) of the predicted value. Concentrates obtained by RV-PBSC showed in median significantly higher percentages of mononuclear cells (p < 0.001) and CD34+ cells (p < 0.001), 86% (43-99) vs. 56% (25-95) and 1.2% (0.2-14.3) vs. 0.4% (0.1-6.0), and had lower contaminations by erythrocytes (p < 0.001) and platelets (p < 0.001), 13 mL (4-48) vs. 25 mL (5-60) and 1.9 x 1011 vs. 3.1 x 1011, than those harvested by MNC.

CONCLUSION

The significantly better collection efficiency of CD34+ cells and the more exact prediction of the harvested CD34+ cell yield make the leukapheresis program MNC a safe and efficient procedure. However, concentrates collected by RV-PBSC are of a better cellular quality with a significantly higher percentage of mononuclear and CD34+ cells and a lower contamination by erythrocytes and platelets.