Transportation of peripheral blood progenitor cell products: effects of time, temperature and cell concentration

Peripheral blood progenitor cell (PBPC) products are often transported at high cell concentrations (>200x10(9)/L) over long distances, requiring >36 h transport time.

Fresh PBPC samples from 12 healthy donors were studied with various viability assays regarding the effects of temperature, cell concentration and duration of storage.

Trypan blue exclusion was far less sensitive to cell damage than two-color fluorescence for CD34 and 7-AAD, and colony-forming unit-granulocyte-macrophage (CFU-GM) assays; the latter assay proved the most sensitive. All products stored at 4 degrees C maintained their viability for up to 4 days. Thus, at 96 h, recovery of viable CD34(+) cells was still 82%, and of CFU-GM 57%, even at concentrations of 200x10(9)/L. Higher storage temperatures rapidly decreased the viability, with extensive variation between donors. At room temperature 80% of viable CD34(+) cells and >90% of CFU-GM were lost after 48 h of storage at 200x10(9)/L. Lower cell concentrations allowed storage at higher temperatures: at 17 degrees C a concentration of 50x10(9)/L resulted in only 5% loss of viable CD34(+) cells after 48 h, while the loss was >30% at 200x10(9)/L.

PBPC products should be transported at 4 degrees C. Dilution of the product may partly compensate for slightly higher temperatures. Trypan blue exclusion should be abandoned as a method for assessing viability after prolonged transportation. Proliferative assays should be used to validate transportation conditions.