PACKED RED-CELLS WASHED WITH AND RESUSPENDED IN SAG-M SOLUTION AND THEIR QUALITY ASSESSMENT BY RHEOLOGICAL PARAMETERS

Background: A 24-hour shelf life is imposed on saline-washed red blood cells (RBC), because the closed system is broached and the preservati ve solution is depleted during usual processing. With the availability of a sterile docking device a sterile production of washed RBC has be come possible. In addition to a previous study of biochemical paramete rs, the quality of RBC washed with and resuspended in SAG-M solution w as elucidated by analysis of their rheological properties. Materials a nd Methods: 16 units of RBC in SAG-M medium were divided each into two aliquots of equal volume. One of these aliquots was washed twice with 200 ml SAG-M solution by means of a sterile docking device and stored in SAG-M medium, the other was carried with as control. Sterility, er ythrocyte aggregation and deformability, blood viscosity, and filter c logging rates were determined at definite times during 4 weeks. Result s: No bacterial contamination could be observed in all washed products . During storage both preparations showed an increase of blood viscosi ty and filter clogging rates as well as a decrease of erythrocyte aggr egation and deformability. The washing procedure caused a deterioratio n of mechanical cell properties with high blood viscosity and reduced erythrocyte aggregation and deformability of washed RBC. In contrast t o these findings, a reduction of the filter clogging rate could be obs erved. Conclusions: From the point of view of biochemical and rheologi cal cell properties, it appears that the shelf life of RBC washed with and stored in a SAG-M solution can be safely extended from 24 h to at least 2 weeks.