The Bottom and Top System: A New Technique for Blood Component Preparation and Storage

Abstract

A new, automated technique for the preparation of blood components is described. A system of 3 or 4 integrally connected plastic containers (Optipac®) is handled by a new type of extractor (Optipress®). The container in which the blood is collected has an outlet at the top and another at the bottom. After normal centrifugation to obtain separation of the blood components, these are squeezed out from the top and bottom simultaneously under control of a photocell. The primary separation step results in three components: a leukocyte-poor red-cell suspension in SAGM medium, CPD plasma, and a buffy-coat preparation. The system has been tested in two laboratories (lab A and lab B). A ‘heavy-spin’ centrifugation to obtain a maximum yield of cell-poor plasma gave the best removal of leukocytes from the red cells; the remaining leukocyte content was 0.46±0.25 (lab A) and 0.5±0.4 (lab B)x 10^9/redcell unit. Platelet concentrates can be prepared either the normal way via platelet-rich plasma or from buffy coat. Red-cell 24-hour autologous posttransfusion survival using labeling with 51Cr was 87.5±4.1% (lab A) after 35 days, and 84.2±4.2% (lab A) and 77.5±1.5% (lab B) after 42 days. Red-cell morphology and fluidity compared favorably to previous studies using the same additive solution in traditional plastic-bag systems. The total adenine nucleotide concentration was maintained normal for 42 days. Storage hemolysis after 6 weeks was slightly higher after a heavy spin, 0.52±0.19% (lab A) and 0.23±0.10% (lab B), than after a light spin, 0.31±0.15 and 0.20±0.09%, respectively. The formation of fibrinopeptide A was very low during the first 2 weeks and then increased to 15±15 nmol/1 after a heavy spin and to 33±11 nmol/1 after a light spin. Kallikrein and spontaneous proteolytic activity increased from day 14 on in the light-spun units but not in the heavy-spun ones. Clinical studies were made in two hospitals. A total of 1,492 transfused blood components prepared with the new system were compared with 1,169 components prepared with a traditional four-container system for making buffy-coat poor red-cell suspensions. No unexpected transfusion reactions occurred. The frequency of febrile reactions was 3/516 (new method) and 2/466 (controls) in a group of patients with predominantly myeloproliferative diseases. The system appears to be a significant improvement for automated preparation of high-quality blood components.

A multicenter randomized study of the efficacy of transfusions with platelets stored in platelet additive solution II versus plasma

“…22,23 After collection of a unit of whole blood, BCs were prepared through high-speed centrifugation. Five BCs together with 1 unit of PAS II or 1 unit plasma from one of the BC donors were coupled to a BC pool set (containing a transfer bag, leukocyte filter, and a PL-2410 storage container; Baxter) through a sterile connection device.…”

Platelet Concentrates in an Additive Solution Prepared from Pooled Buffy Coats

“…Recently methods have been invented which allow im proved BC removal [7,8], making this way of preparing PC more attractive. In this paper we present a new method using pooled BCs from hard-spun blood units, suspended in an additive solution.…”

Cytokines in Platelet Concentrates Prepared from Pooled Buffy Coats

“…Concern has been raised that this could lead to lymphopro lifération in the sense of a mixed lymphocyte culture (MLC) with concomitant release of cytokines which might cause severe side effects after transfusion. During allogeneic stimulation, a variety of immunologically active cells are Soon after the introduction of a new technique for blood component preparation in 1988, the top-and-bottom system by Högman [1], an alternative approach for platelet prep aration by pooling of buffy coats (BC) was described [2,3], Pools of buffy coats from 4 to 6 different donors served as starting material for consecutive preparation of platelet con centrates (BC-PC). Using a sterile docking device, these involved and several cytokines are released [4][5][6].…”