Collection of MNCs with two cell separators for adoptive immunotherapy in patients with stage IV melanoma

BACKGROUND: MNCs for adoptive immunotherapy may be collected by leukocytaph eresis with a cell separator. STUDY DESIGN AND METHODS: Six healthy cytapheresis donors donated two MNC c oncentrates on a cell separator (AS.TEC 204, Fresenius): one on the standar d MNC program and one on a modified MNC program with reduced centrifuge vel ocity that leads to a lower platelet contamination. Seventeen patients with malignant melanoma donated 26 MNC concentrates: 5 on the AS.TEC 204 MNC pr ogram, 9 on the modified AS.TEC 204 MNC program, and 12 on another modified MNC program (Spectra, COBE). RESULTS: In the course of cultivation of MNCs to dendritic cells (DCs), the donor MNC concentrates with the lower platelet contamination (475 +/- 85 x 10(9)/L) had a significantly higher relative DC yield (low platelet contam ination: 3.9 +/- 1.6% of the plated cells; high platelet contamination: 2.5 +/- 1.8% of the plated cells; p = 0.019) than the concentrates with the hi gher platelet contamination (2364 +/- 448 x 10(9)/L). No significant differ ence was found in the yields of MNCs and CD14+ cells in the three protocols used for the collection of MNCs from patients with melanoma. The component s obtained by the standard AS.TEC 804 MNC program had a significantly highe r platelet contamination (1768 +/- 994 x 10(9)/L) than the components obtai ned by the modified AS.TEC MNC program (360 +/- 98 x 10(9)/L; p<0.05) and t he modified Spectra MNC program (636 +/- 266 x 10(9)/L); p<0.05). Because o f the low number of investigated components, no significant difference in t he DC yield of the three protocols could be detected (mean DC yield after c ultivation: 746 +/- 429 x 10(6)). CONCLUSION: A high platelet contamination of MNC concentrates intended for adoptive immunotherapy can lead to a significant impairment of the DC yield after cultivation. Both the modified AS.TEC 204 and the modified Spectra M NC programs are well suited for collecting MNC concentrates with high MNC y ields and low platelet contamination from patients with malignant melanoma.