Maria I.C. Gyongyossy-Issa

Implementation of buffy coat platelet component production: comparison to platelet-rich plasma platelet production

BACKGROUND: Buffy coat (BC) production of platelets (PLTs) has been successfully used in Europe for more than two decades. Currently, Canadian Blood Services is implementing the BC method. This article summarizes results of the validation testing performed to qualify the process of PLT production from whole blood and compares the quality of PLTs produced in routine production by either the PLT‐rich plasma method (PRP‐PCs) or the BC method (BC‐PCs).

Buffy-coat platelet variables and metabolism during storage in additive solutions or plasma

BACKGROUND: Buffy‐coat processing allows for the use of platelet additive solutions (PASs). PASs reduce plasma‐associated transfusion reactions and conserve plasma for transfusion or fractionation. Platelet (PLT) storage in plasma was compared to storage in three commercially available PASs compared to assess their influence on in vitro laboratory variables.

Effects of trehalose-loaded liposomes on red blood cell response to freezing and post-thaw membrane quality.

We are investigating the use of liposomes, which are synthetic, microscopic vesicles, for the intracellular delivery of trehalose into mammalian cells. This study focuses on the effects trehalose-containing liposomes improve the recovery and membrane quality of human RBCs following cryopreservation. Unilamellar liposomes consisting of a lipid bilayer composed of DPPC, PS and cholesterol (60:30:10 mol%) were synthesized using an extrusion method. Liposome-treated RBCs (l-RBCs) were resuspended in either physiological saline, 0.3M trehalose or liposome solution, then cooled with slow (0.95+/-0.02 degrees C/min), medium (73+/-3 degrees C/min) and fast (265+/-12 degrees C/min) cooling rates and storage in liquid nitrogen, followed by a 37 degrees C thawing step. RBC post-thaw quality was assessed using percent recovery, RBC morphology, PS and CD47 expression. Liposome treatment did not adversely affect the RBC membrane. Post-thaw recovery of l-RBCs was significantly higher (66%+/-5% vs 29%+/-4%) compared to control RBCs (c-RBC, p=0.003). Medium and high cooling rates resulted in significantly higher cell recovery compared to a slow cooling rate (p=0.039 and p=0.041, respectively). The recovery of l-RBCs frozen in liposome solution and trehalose solution was significantly higher than that of l-RBCs frozen in NaCl solution for all three cooling rates (p=0.021). Flow cytometry and morphology assessment showed that liposome treatment resulted in improved post-thaw membrane quality. There was no statistically significant difference in the post-thaw recovery between RBCs treated with liposomes containing trehalose in their aqueous core and RBCs treated with liposomes containing saline in their aqueous core (p=0.114). Liposome treatment significantly improves the recovery and membrane integrity of RBCs following low temperature exposure.

Effects of prestorage white cell reduction on platelet aggregate formation and the activation state of platelets and plasma enzyme systems.

BACKGROUND: The introduction of prestorage white cell (WBC) reduction in random‐donor platelet concentrates in Canada has increased the occurrence of particulate material in PCs. The effects of filtration on platelet activation state and the activation of plasma enzyme systems were assessed.

Riboflavin and ultraviolet light treatment potentiates vasodilator-stimulated phosphoprotein Ser-239 phosphorylation in platelet concentrates during storage

BACKGROUND: Pathogen reduction technologies (PRTs) were developed to improve the safety of platelet concentrates (PCs) for transfusion purposes; however, several studies report a negative impact on the in vitro and in vivo platelet (PLT) quality. Therefore, analyses of the underlying molecular processes triggered by PRT treatments are necessary to understand their effects on PLT function.

Plasma and cryoprecipitate manufactured from whole blood held overnight at room temperature meet quality standards.

BACKGROUND: With buffy coat (BC) processing of whole blood (WB) donations, the preparation of plasma occurs within 24 hours rather than 8 hours of collection. The effect of this change on coagulation factor function in plasma and cryoprecipitate was evaluated during the validation of this production method and with routine production.

Effect of platelet additive solution on bacterial dynamics and their influence on platelet quality in stored platelet concentrates

BACKGROUND: Platelet additive solutions (PASs) are an alternative to plasma for the storage of platelet concentrates (PCs). However, little is known about the effect of PAS on the growth dynamics of contaminant bacteria. Conversely, there have been no studies on the influence of bacteria on platelet (PLT) quality indicators when suspended in PAS.

Novel system for storage of buffy-coat-derived platelet concentrates in a glucose-based platelet additive solution: parameters and metabolism during storage and comparison to plasma.

Background  In Europe, buffy‐coat processing allows for the use of platelet additive solutions (PAS). These solutions, however, have long been questioned for their lack of glucose, a potentially essential nutrient for platelet storage. Using a novel, practical, two‐part system for incorporation of glucose into an additive solution (PAS‐G), this study compares platelet storage in plasma to storage in PAS‐G.

Prestorage leukoreduction and low‐temperature filtration reduce hemolysis of stored red cell concentrates

BACKGROUND:  Universal prestorage leukoreduction in Canada created the perception that stored red cells (RBCs) are more hemolyzed than their unfiltered predecessors. A pool‐split design tested the effects of leukoreduction on hemolysis of stored RBCs.

Liposomes and blood cells: A flow cytometric study

To clarify the interactions of liposomes with blood cells, this study examined the behaviour of liposomes of a range of compositions in the presence of purified human blood cells in buffer or plasma; or in whole blood, or in mice in vivo. Liposomes, labeled with the hydrophilic fluorochrome, carboxy fluorescein (CF), or with membrane‐sequestering R18 or FITC‐labeled phospholipids, were mixed with blood cells and the appearance of the fluorochromes in the blood cell population was monitored by flow cytometry. Irrespective of composition, with or without poly(ethylene glycol), all types of liposomes were found to interact rapidly and dose‐dependently with red cells, leukocytes and platelets, both in vitro and in vivo. This took place equally in the presence and the absence of plasma proteins and functional enzyme cascades, suggesting that the prime facie interaction is opsonization‐independent and is consistent with liposome‐blood cell fusion.