CRYOPRESERVATION OF RED-BLOOD-CELLS WITH THE NONPENETRATING CRYOPROTECTANT HYDROXYETHYL STARCH

After promising results obtained in experiments with German shepherd d ogs (n = 6, 400 ml of whole blood were replaced by frozen/thawed RBC w ithout any postthaw treatment), initial autologous studies were carrie d out on 7 healthy volunteers. The retransfusion of cryopreserved auto logous RBC was performed without any postthaw washing step. 500 mi of whole blood was replaced by a suspension of cryopreserved autologous R BC (2 aliquots of 216 ml each, hematocrit (HCT) 43% +/- 2% (v/v), HES concentration 11.5% (w/w), NaCl concentration 45 mmol/l). Viability of the red cells after thawing in terms of saline stability reached 92% +/- 1%. In all 7 cases the frozen/thawed autologous RBC were tolerated very well. The level of free plasma hemoglobin increased initially by a factor of 2, and then decreased to normal levels within 20 h. More. than 85% of the HES was eliminated from the plasma within the first d ay.