L’introduction de solutions de conservation dans les concentrés plaquettaires : vers une diminution des réactions transfusionnelles

Improving platelet transfusion safety: biomedical and technical considerations

Platelet concentrates account for near 10% of all labile blood components but are responsible for more than 25% of the reported adverse events. Besides factors related to patients themselves, who may be particularly at risk of side effects because of their underlying illness, there are aspects of platelet collection and storage that predispose to adverse events. Platelets for transfusion are strongly activated by collection through disposal equipment, which can stress the cells, and by preservation at 22 °C with rotation or rocking, which likewise leads to platelet activation, perhaps more so than storage at 4 °C. Lastly, platelets constitutively possess a very large number of bioactive components that may elicit pro-inflammatory reactions when infused into a patient. This review aims to describe approaches that may be crucial to minimising side effects while optimising safety and quality. We suggest that platelet transfusion is complex, in part because of the complexity of the "material" itself: platelets are highly versatile cells and the transfusion process adds a myriad of variables that present many challenges for preserving basal platelet function and preventing dysfunctional activation of the platelets. The review also presents information showing--after years of exhaustive haemovigilance--that whole blood buffy coat pooled platelet components are extremely safe compared to the gold standard (i.e. apheresis platelet components), both in terms of acquired infections and of immunological/inflammatory hazards.

Removal of biological response modifiers associated with platelet transfusion reactions by columns containing adsorption beads

BACKGROUND

Biological response modifiers (BRMs), such as soluble CD40 ligand (sCD40L); regulated upon activation, normal T-cell expressed, and secreted (RANTES); and transforming growth factor-β1 (TGF-β1), are released from platelets (PLTs) during storage and may trigger adverse effects after PLT transfusion. Although washing PLTs is effective at reducing the level of BRMs and the incidence of transfusion reactions, the washing procedure is time-consuming and may induce PLT activation. Furthermore, some BRMs continue to accumulate during the storage of washed PLTs. A method to remove BRMs using adsorbent columns has not yet been developed.

STUDY DESIGN AND METHODS

We evaluated the ability of columns packed with Selesorb and Liposorber beads, which are both clinically used, to remove BRMs from PLT concentrates (PCs) stored for 5 days. The levels of these BRMs were determined before and after adsorption.

RESULTS

The adsorption columns significantly reduced the levels of RANTES and sCD40L and partially reduced TGF-β1. There were no significant effects on PLT activation, aggregation, morphology, and plasma lactate dehydrogenase (an indicator of PLT lysis) levels, or hypotonic shock response. Adsorption, however, reduced the PLT recovery to approximately 60% of the untreated value.

CONCLUSIONS

This study showed that the levels of BRMs were substantially reduced using columns of clinically available adsorption beads. PLT functions and the quality of PCs were maintained after adsorption. The use of adsorption columns may be useful in reducing the incidence of nonhemolytic transfusion reactions.

Evaluation of the performance of Trima Accel® v5.2 for the collection of concentrated high-dose platelet products and concurrent plasma from high platelet count donors, in Germany

BACKGROUND AND OBJECTIVES

This study was undertaken to test the ability of Trima Accel® version 5.2 to simultaneously collect concentrated high-dose leukoreduced platelet products and double doses of plasma.

MATERIALS AND METHODS

Random volunteers (18-65 years of age) with preprocedure platelet counts above 270 × 10(3) /μl were recruited among the blood center's apheresis donors. All complied with the center's donor selection criteria.

RESULTS

One hundred fourteen (114) collections were performed. Depending on which definition of single platelet dose is used (2.0 × 10(11) as prevalent standard in most European countries, and 3.0 × 10(11) as prevalent standard in the United States and Canada) in 107/114 (single dose = 2.0 × 10(11) ) and 39/114 (single dose = 3.0 × 10(11) ) instances, a triple platelet product was obtained. In 87 cases (76%), a double plasmaproduct (>430 ml) was collected, and in seven cases (6%), a single plasma product (>220 ml) was collected. In 20 procedures, only platelets without concurrent plasma were collected (18%). Overall procedure time was 87 ± 13 min and average platelet yield per procedure was 8.5 ± 1.4 × 10(11) (final storage concentration, 1,279 ± 153 × 10(3) /μl). The median residual leukocyte content per transfusion dose was 0.13 × 10(6) (0.02-0.98 × 10(6) ) for a single dose of 2.0 × 10(11) and 0.14 × 10(6) (0.02-0.98 × 10(6) ) for a single dose of 3.0 × 10(11) .

CONCLUSIONS

Trima Accel® version 5.2 allows for collection of concentrated high yield platelet products. It offers high productivity and reliably achieves the configured yield targets. Leukoreduction performance complied with both US and EU legal requirements. Collection as hyperconcentrates furthermore allowed for concurrent collection of double dose plasma in the majority of the procedures.

Removal by adsorbent beads of biological response modifiers released from platelets, accumulated during storage, and potentially associated with platelet transfusion reactions

BACKGROUND

Recent studies have demonstrated that biological response modifiers (BRMs) released from platelets (PLTs) during storage may have a clinical significance in PLT transfusion reactions. Washing PLTs and partial substitution of plasma with artificial solutions reduce transfusion reactions, but the washing procedure is time-consuming, and partial plasma substitution is not sufficient to completely eliminate transfusion reactions.

STUDY DESIGN AND METHODS

This study determined the levels of three BRMs: soluble CD40 ligand (sCD40L); regulated upon activation, normal T-cell expressed, and secreted (RANTES, CCL5); and transforming growth factor-beta1 (TGF-beta1). These BRMs were released from PLTs during storage up to Day 10. To selectively remove these BRMs, four types of cellulose beads were investigated. The levels of these three BRMs in plasma derived from PLT concentrates (PCs) stored for 10 days or in PCs stored for 5 days were determined after treatment with or without each adsorbent bead for 3 hours.

RESULTS

These three BRMs accumulated in proportion to the storage duration. The 3-hour treatment with cellulose beads possessing sulfate ester groups (A) or phosphate ester groups (B) effectively removed sCD40L and RANTES and partly removed TGF-beta1. In addition, although PLT activation was minimally induced, PLT counts decreased by approximately 13% to 30%, after these treatments.

CONCLUSIONS

This study revealed that Cellulose Beads A or B are effective in removing the three BRMs that accumulate during PLT storage. Additional in vitro assays and in vivo studies are required to evaluate whether this method is effective in reducing transfusion reactions.