Kryokonservierung von Erythrozyten mit Hydroxyethylstärke (HES) - Vom Laborversuch zur klinischen Anwendung

Cryopreservation of red blood cells using hydroxyethyl starch (HES) - From laboratory investigations to clinical application. Introduction: Cryopreservation of red blood cells (RBC) is appropriate in case of rare blood groups, problems due to multiple antibodies and possibly as an interim aid during temporary shortages, especially in case of civil or military disasters. Additionally, RBC deep freezing may be useful for quarantine purposes. For routine clinical practice, cryopreservation may help to overcome the outdating of autologous blood deposits for elective surgery. In contrast to the established cryoprotectant glycerol, the colloid HES need not be removed after thawing. Methods and results: After in vitro and animal experiments, autologous studies using an optimised HES protocol were carried out on 7 healthy volunteers. The first clinical application was the case of a 16 year old female patient. Recently, a clinical study to determine the safety and tolerance of red blood cells cryopreserved with the HES has been performed. The first RBC concentrate obtained from each of 36 patients undergoing preoperative autologous blood donation was randomly assigned to the conventional storage method (4° C, PAGGS-mannitol = group 1) or to cryopreservation with HES (MW = 200,000, MS = 0.5) at a final concentration of 11.5% (w/ w) using liquid nitrogen (= groups 2, 3). Group 2: postthaw washing step, group 3: no postthaw washing step. No significant differences after autologous re-infusion of the respective unit between the 3 groups could be detected regarding hemodynamic or blood gas parameters and tissue oxygenation. No adverse reactions after reinfusion of washed or unwashed cryopreserved RBC were observed. The data suggested that the administration of one autologous unit of RBC after cryopreservation with HES is save and well tolerated. Outlook: Further investigations are necessary to evaluate the effects of the transfusion of larger volumes of homologous HES cryopreserved RBC.