The alterations of the activities of coagulation inhibitors and fibrinolytic factors in stored cord blood could affect the yield of progenitor cells during processing.

We assessed the changes in the activities of hemostatic variables by the storage temperature and time interval between collection and separation of cord blood (CB) and analyzed their relationship with the yield of progenitor cells during processing. Total nucleated cell (TNC) and CD34(+) cell counts were significantly higher in the CB stored at ambient temperature than at 4 degrees C. The significant loss of TNC and CD34(+) cells continued to 24 h after collection in CB stored at 4 degrees C, but loss of TNC began only after 24 h at ambient temperature. There were no changes in the plasma activities of antithrombin III (ATIII) and plasminogen. The activity of protein C was decreased significantly until 24 h after collection, particularly in CB stored at 4 degrees C. The activity of az-antiplasmin was decreased until 24 h in CB stored at 4 degrees C and from 24 h in CB stored at ambient temperature. These data suggest that the alterations in the activities of coagulation inhibitors and fibrinolytic factors could be an important factor in coagulability, particularly in CB stored at 4 degrees C compared to ambient temperature, and also affect the yield of progenitor cells in processed CB.