Drawing of blood into a citrate-phosphate-dextrose (CPD) solution with a reduced citrate concentration has been shown to improve the maintenance of coagulation factor VIII (F VIII) in plasma and to give possibilities to improve erythrocyte preservation. We studied the quality of plasma obtained from whole blood drawn under continuous mixing into CPD in which the citrate concentration was reduced by 50% (0.5CPD). The blood was stored at room temperature for 8 h before component preparation. We confirmed improved stability of F Vili by 0.5CPD. We found no clinically significant changes in inhibitors to the coagulation and kallikrein systems, and no signs of activation of these systems, during the 8-hour holding time. In control blood drawn into CPD, F Vili and coagulation factor IX decreased by 0.09 IU/ml (8%) and 0.07 U/ml (7%), respectively, otherwise we found no significant differences between 0.5CPD plasma and CPD plasma.

Background: Red blood cells stored as concentrates or suspensions in additive solutions change rapidly their oxygen affinity mainly due to the loss of 2,3-diphosphoglycerate (2,3-DPG). When collected in CPD with half of the normal concentration of citrate and citric acid (0.5 CPD) and stored in a new additive solution (Erythro-Sol), 2,3-DPG is better maintained. No studies of the oxygen affinity of red cells stored under these conditions have been published. In Erythro- Sol, red cells have a satisfactory in vivo recovery for 49 days but the conditions after 28 days, within which time most red cell units are transfused, have not been investigated. Of importance is also to be able to make platelet concentrates (PCs) from 0.5 CPD blood. Little data are available concerning the clinical usefulness of platelets prepared from 0.5 CPD buffy coats (BCs). Methods: Blood was collected in 0.5 CPD, held at 20°C for 3-4 h, then separated with the bottomand- top technique into red cells, plasma and BC. In a storage experiment with 6 U the 2,3-DPG and P(50) values were determined weekly and a number of in vitro parameters were tested on day 28. In 6 donors the in vivo recovery and survival of red cells were determined using a single-chromium technique. Transfusions of 212 0.5 CPD-Erythro-Sol red cell units were given to hematological patients under supervision. PCs derived from pools of 0.5 CPD BCs suspended in PAS2 (T-Sol) were transfused to 20 thrombocytopenic patients and compared with CPD-BC- PCs suspended in PAS 1. Corrected count increments (CCI) were determined. Results: The erythrocyte 2,3-DPG and P(50) values were normal or slightly subnormal initially but increased to supernormal levels during the 1 week, and remained at these levels for a further 1-3 weeks; the 2,3-DPG was two thirds of normal after 28 days, the P(50) was 3.72 ± 0.28 kPa after 14 days and 2.84 ± 0.41 after 28 days (mean ± SD). The P(50), values corresponded closely (r^2 = 0.903) to 2,3- DPG. The in vivo recovery of 4-week-stored red cells was 89.6 ± 5.5% and the T(50) was 32.2 ± 2.0 days. No adverse effects were observed in the transfusions. The CCI values did not differ between test and control groups; in both, 3- to 5-daystored PCs gave lower CCI than fresh (0-2 days) PCs. Patients with acute myeloid leukemia AML (n = 11) had significantly lower CCI values than patients with myelodysplastic syndrome, myeloma and lymphoma (n = 9; CCI(1h): p = 0.001; CCI(24h),: p = 0.006). Conclusions: Red cells stored in Erythro-Sol sustain a normal or slightly lowered oxygen affinity for 2-4 weeks, their viability is excellent, and they are well tolerated in clinical transfusions. Platelets prepared from 0.5 CPD-BCs cause CC1(S) of the same magnitude as CPD-BCs.