Storage of unprocessed G-CSF-mobilized whole blood in a modified Leibovitz's L15 medium preserves clonogenic capacity for at least 7 days

Autologous stem cell transplantation using unprocessed, G-CSF-mobilized who le blood (WB) is a simple, cost-reducing procedure and supports high-dose c hemotherapy regimens not exceeding 72 h. Thereafter, clonogenic capacity ra pidly decreases if routine anticoagulants are used for storage. In order to increase clinical applicability, we investigated the requirements for opti mal preservation of unprocessed WB for 7 days. During storage at 22 degrees C in CPDA-1, a decrease in pH was noted, which was at least partially respo nsible for the low recovery of clonogenic cells. Subsequently, WB cells wer e stored in various cell culture media (RPMI 1640, a-MEM, X-VIVO15, CellGro SCGM and Leibovitz's L15 medium) containing either serum, serum-free subst itutes or no additives. Leibovitz's L15 showed significantly better CFU-GM recoveries than the other media. Using a calcium-free modification of L15 m edium (added 3:10 to WB), 94 +/- 24% of CD34(+) cells, 41 +/- 14% of BFU-E, 56 +/- 17% CFU-GM and 90 +/- 14% of LTC-IC were preserved during storage f or 7 days at 22 degreesC. Storage at 4 degreesC was also feasible, but show ed less optimal recoveries of 52 +/- 29% (CD34),32 +/- 10% (BFU-E), 13 +/- 7% (CFU-GM) and 58 +/- 9% (LTC-IC). The expression of CD38, Thy-1, c-kit, A C133, L-selectin and CXCR4 on CD34-positive cells remained unchanged. In co nclusion, a modified Leibovitz's L15 medium better meets the metabolic requ irements of a high-density cell culture and allows safe storage of G-CSF mo bilized WB for at least 7 days. The results encourage further exploration o f WB transplants stored for 7 days for clinical use.