Background: G-CSF-mobilized whole blood (WB) is a cost-reducing and simple alternative for peripheral blood progenitor cell transplantation. Recently, it was demonstrated that mobilized WB supplemented with Leibovitz's L15 medium permitted prolonged preservation of clonogenic cells at ambient temperature. In this study, an infusable-grade L15 medium (IG-L15) was developed, and the safety profile of mobilized WB after 7 days of storage was investigated.
Study design and methods: IG-L15 was manufactured in a closed system under good manufacturing practice conditions. Proinflammatory cytokine levels and hemolysis in mobilized WB were determined after 7 days of storage in different containers and were compared with current clinical mobilized WB values after 1 to 3 days of storage at 4 degrees C.
Results: IG-L15 and L15 maintained clonogenic cells equally. In the samples of mobilized WB that were returned to the patient, cytokine levels were not elevated in comparison with freshly collected mobilized WB. By using IG-L15 in polystyrene-coated cell culture bags, median (range) levels of 9.4 (2.2-69.8) pg per mL (IL-1beta), 31.6 (6.1-146.5) pg per mL (TNF-alpha), 76.9 (15.5-934.9) pg per mL (IL-6), and 7195 (104-205,600) pg per mL (IL-8) were found after 7 days. Higher cytokine levels were found with L15 and different containers. He- molysis was less than 0.5 g per dL in all cases.
Conclusion: The storage of mobilized WB for 7 days in IG-L15 at ambient temperature is possible with adequate preservation of clonogenic cells, but cytokine levels may require plasma removal before return.