The method described here using a centrifuge and Coulter Cell Counter for the quantitative differential agglutination of human red cells uses commercial anti-A and anti-B antisera for the ABO system, and for the Rh system a commercial anti-D serum, a low ionic strength solution and an anti-human IgG antiserum. We compared this Coulter Counter method with the Technicon Auto Analyzer method which utilizes bromelin and polyvinyl pyrrolidone, and anti-A, anti-B and anti-CD antisera, and found this new method to be the simpler of the two. The nonagglutinable count with the Coulter Counter was 1.07% for A(1) red cells, 2.26% for A(2) red cells, 1.06% for B red cells, and 1.78% for Rh-positive red cells, results similar to those seen with the Technicon Auto Analyzer. Results with the Coulter Counter method were consistently accurate whether the ACD red cells were studied on the day of collection, after 10 days of 4 °C storage, or after 4 °C storage for up to 6 days followed by cryopreservation with 40% (w/v) glycerol at -80 °C, thawing and washing. In this study, red cell samples obtained from recipients who had received compatible but identifiable donor red cells were frozen with 40% glycerol and stored at -80 °C for 10 months, thawed and washed. Survival measurements on these washed previously frozen red cells were similar to the values in liquid-stored red cells.

Using an automated differential agglutination procedure, 218 red cell survival studies were performed in patients requiring therapeutic transfusion. Blood was collected in acid-citrate-dextrose (ACD) or citrate-phosphate-dextrose (CPD). Some of the blood was stored as such and some as concentrated red cells. Adverse effects of storage on both washed and nonwashed whole blood and concentrated red cells were determined by 24-hour posttransfusion survival measurements. There were no significant differences in the storage limitations of non-washed ACD- and CPD-collected whole blood, and concentrated red cells. Washing stored red cells with either buffered or nonbuffered 0.9% sodium chloride solution with or without glucose did not significantly affect 24-hour survival. However, there was a significant decrease in survival when stored red cells were washed with CPD solution or with a buffered 0.9% sodium chloride solution supplemented with calcium and magnesium.

Forty-four long-term red cell survival studies were performed in 39 patients, the majority of whom had either traumatic injuries or carcinoma. With the aid of a computer, the lifespan and the rate of random destruction of preserved red cells were estimated in each recipient. The 24-hour survival was a satisfactory measurement of the percent of viable red cells in the transfusion. The mean red cell lifespan (97 days) was not affected by either the method of preservation (liquid or freeze preservation) or the length of storage at +4 or — 80°C. Accelerated linear removal of red cells was seen in severely injured patients; improved red cell survival was associated with improvement in the recipient’s health. The correlation between the lifespan of transfused red cells and the recipient’s general health suggests that the decreased long-term survival noted in these recipients was produced by some extracorpuscular ‘toxic’ factor.

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.