Further Studies on the Rapid and Slow Components of Chromium Elution in vivo from Preserved Erythrocytes

Abstract

51Cr is commonly used to label red cells in estimating the 24-hour posttransfusion survival of preserved red cells and the lifespan of autologous and homologous red cells. With this procedure, however, there is spontaneous loss of chromium label from the circulating red cells in vivo. In order to evaluate this phenomenon, the survival in vivo of previously frozen washed red cells and liquid-stored washed and nonwashed red cells was studied with a 51Cr labelling procedure and an automated differential agglutination procedure (ADA) following therapeutic transfusions. Loss of the chromium label in vivo from circulating red cells during the 24-hour posttransfusion period is referred to as the ‘rapid component of chromium elution’. Loss of the 51Cr label from the circulating red cells during measurement of red cell lifespan is referred to as the 6 ‘slow component of chromium elution’. In liquid-stored nonwashed and washed red cells the 51Cr uptake in vitro was greater than 94%. In previously frozen red cells washed by different methods the 51Cr uptake in vitro ranged from 44 to 95%. The rapid component of 51Cr elution from nonwashed and washed liquid-stored red cells and from previously frozen washed red cells was at least 10% of the chromium label. Variable rates of the slow component of chromium elution from nonwashed and washed liquid-stored red cells and from previously frozen washed red cells were observed: the average rate was 1.06% per day, and in some patients no elution was observed. Factors that influence the 51Cr uptake in vitro and the rapid and slow components of 51Cr elution in vivo are not known.