Platelet Concentrates in an Additive Solution Prepared from Pooled Buffy Coats.

Abstract

A new method for the preparation of platelet concentrates (PCs) is described. The source material is buffy coat (BC), prepared after keeping standard CPD whole-blood units at room temperature for 6-12 h, followed by centrifugation at 3,500 rpm for 10 min (first series) or 4,000 rpm for 12.5 min (second series). BC, separated from plasma and red cells, was kept at room temperature for a further 8-12 h without agitation. Pools of 6 (first series) and 4 (second series) BCs were prepared using a sterile docking device and suspended in a platelet-additive solution (PAS) containing sodium/potassium chloride, citrate, phosphate, and mannitol. After gentle centrifugation, the platelet-rich supernatant was expressed to and stored in one (first series) or two (second series) 1-liter polyolefine (PL-732) containers. In the first series, the total number of platelets was 316 +/- 59 x 10(9) per PC (yield 65%). However, when the method was applied at a routine scale, the yield varied considerably and was shown to be strongly dependent on the hematocrit of the BCs. A number of steps were taken to standardize the technique which resulted in an improved yield (77.3 +/- 8.7%) with 316 +/- 52 x 10(9) platelets (mean +/- SD, range 203-490, n = 134), obtained from 4 BC pools and lower leukocyte contamination than before, 18 +/- 17 X 10(6) per preparation (range 1-73, microscopic counting, n = 38). The storage medium consisted of a mixture of plasma and PAS.(ABSTRACT TRUNCATED AT 250 WORDS)

Preparation of Leukodepleted Platelet Concentrates from Pooled Buffy Coats: Prestorage Filtration with Autostop^™BC

“…However, in contrast to the described ‘train’ of BC [7]we designed a pooling bag with multiple leads to avoid sterile connections of two wet tubes, because the Food and Drug Administration (FDA) does not approve this method in the USA.…”

Procoagulant platelets: are they necrotic?

“…Much of the current effort into improving the viability of stored platelet concentrates has focused on reducing platelet activation, maintaining pH, buffering lactate production and enhancing gas exchange. This has been achieved with the use of platelet activation inhibitors (NO, phosphodiesterase inhibitors, apyrase and prostacyclin, protease inhibitors), [50][51][52][53][54][55][56][57] through inclusion of additives such as acetate, phosphate, gluconate, potassium, and magnesium 41,[43][44][45][46][47][58][59][60] and through the implementation of modified storage bags with agitation. 61 However, these measures have provided only modest improvements in platelet viability.…”

Clinical Evaluation of Platelet Concentrates Either in Plasma or in Additive Solution

“…In a prospective study a comparison of the corrected post transfusion increment was made between fresh (1-2 days) and stored (3-5 days) preparations, fresh BC-PCs gave higher increments than stored BC-PCs [7]. A major concern related to the use of PAS-2-PCs could be lost of its therapeutic properties translated into an increase of bleeding episodes; in our study, use of PAS-2 resulted in good CCI in both groups and without differences in clinical effectiveness (measured by bleeding).…”

“…Depending on the time of storage, Eriksson et al [7] divided PCs in fresh (one or two days) and stored (more than two days), we adopted this classification with slight changes; before transfusion PCs transfused the first 3 days of storage were considered fresh, while PCs transfused on day 4 or 5 were considered stored. PCs were analyzed for platelet count at each centre pre and post filtration with an automatic counter (Sysmex K800) and WBC count by means of a cytometer (FACS Calibur-Becton-Dickinson).…”