Cytokine levels as performance indicators for white blood cell reduction of platelet concentrates.

Background And Objectives: With the implementation of universal white blood cell (WBC) reduction in the UK, in-process WBC-reduction filters for pooled buffy coat (BC)-derived platelet concentrates (PCs) and apheresis methods are used routinely for the production of WBC-reduced PCs. While these strategies meet the specification for WBC reduction (< 5 x 10(6) WBCs/unit), the products from these processes may differ depending on the process employed and its performance. The aim of this study was therefore to investigate whether PCs prepared using various WBC-reduction processes are sufficiently depleted of WBCs to limit cytokine accumulation during storage and to assess if cytokine levels detected in platelet products can serve as indicators of acceptable platelet activation as a result of the WBC-reduction process.

Cytokines in WBC-reduced apheresis PCs during storage: a comparison of two WBC-reduction methods.

Background: Several studies have suggested that cytokine accumulation during storage of platelet concentrates (PCs) may mediate nonhemolytic febrile transfusion reactions and that a reduction in WBC numbers prevents the generation of cytokines. Despite efforts to minimize WBC contamination in apheresis PCs, high numbers of WBCs and increased cytokine levels may still occur, depending on the quality of the apheresis device employed.

Study Design And Methods: This study was undertaken to investigate whether PCs collected with WBC-reduction devices (Spectra LRS, COBE;or MCS+ LDP, Haemonetics) were sufficiently depleted of WBCs to limit cytokine accumulation during storage.

Cytokine accumulation in stored red cell concentrates: effect of buffy-coat removal and leucoreduction.

The accumulation of cytokines in stored red blood cell concentrates (RCCs) has been implicated as a potential cause of transfusion reactions associated with the use of such products. At present, it is unclear whether there is any link between residual leukocyte and/or platelet content with cytokine levels in various RCCs. In this study, we have therefore assessed cytokine levels of leukocyte (e.

Update on leucocyte depletion of blood components by filtration.

It has long been recognized that allogenic leucocytes from donor blood are responsible for serious untoward effects in some transfused patients such as alloimmunization, febrile reactions, platelet refractoriness, transfusion associated acute lung injury, immunosuppression as well as transmission or reactivation of viruses such as CMV, HTLV or EBV. Leucocytes are also known to accelerate the rate of storage lesion. The optimal method to remove leucocytes from blood components has been shown to be filtration.

Stem cells: what's happening? Current concepts and recent advances.

Allogeneic haemopoietic stem cells, as alternative to bone marrow transplantation and platelet therapy remains the focus of the current area of research/development in transfusion science/medicine. This brief progress report on "Stem Cells: What's Happening?" is focused on the advances and some unresolved problems associated with cellular therapy and haemopoietic progenitor cells from various sources.

The quality of clinical FFP, cryoprecipitate and cryosupernatant derived from single donor apheresis procedures and random donations collected in a BAT system: assessment of the activity states of FVIII, contact activation, microvesicle content and cytokines.

In establishing the best practice and/or evaluating any new process or procedures it is essential that apart from the compliance to specification, provided by the Guidelines (i.e. AABB or UK-BTS/ NIBSC), the changes that might occur in the activation states, and other regulatory mechanisms should be considered.

Effect of pH and buffering condition on dMPV of three types of platelet concentrates.

Normal platelets display a log normal size distribution pattern when analysed by an automated cell counter. Considerable changes in the platelet size distribution occurs during collection, processing and storage. This is easily monitored by the variation seen in the cellular indices or size distribution patterns.

Cytokines in platelet concentrates: a comparison of apheresis platelet (haemonetics) and filtered and unfiltered pooled buffy-coat derived platelet concentrates.

Variable degrees of platelet activation, shape changes, microvesiculation and fragmentation may occur during collection, processing and storage of platelet concentrates (PCs), contributing to different rate of platelet storage lesion. Leukocytes contribute to both the frequency of transfusion reactions and the acceleration of the rate of platelet storage lesion hence leukocyte removal of platelet concentrates has been introduced to overcome these problems. However transfusion reaction can still occur with the use of leuko-reduced products and it is not fully elucidated that the rate of storage lesion is equivalent for filtered and unfiltered counter parts.

Effect of cold exposure on platelet concentrates: changes in platelet indices and aggregation states.

Samples from platelet concentrates (filtered/non-filtrated, at the beginning/the end of shelf life) were exposed to 4 degrees C overnight, subsequent to dilution in platelet storage media (PSM) and/or exposure to EDTA to induce shape changes. Paired sampling protocol (+/- EDTA) was used and changes in cellular indices and induced-aggregation states were measured by Technicon H*1. Cold induced changes in platelets as identified by increase in MPV (0.

New horizons in blood transfusion medicine: present status and future trends.

In the past two decades, we have witnessed enormous advances in all areas of transfusion medicine, from simple and practical aspects of blood component collection and processing to the development of "designer products" and the use of recombinant products or other alternatives. Considerable efforts were directed, in particular, towards transfusion support for specific categories of patients, such as neonates and those undergoing transplant procedures, where patients' clinical states ultimately influence the choice of product(s) and where emphasis should be placed on both the optimisation of clinical effectiveness and safety, as well as minimising the adverse/untoward effects of transfusion. The objective of this Forum Discussion is to provide an overview of what is currently on the horizon and then describe the potential changes that are expected on the new horizon, within the next decade.

Cytokine levels in platelet concentrates: quantitation by bioassays and immunoassays.

Some adverse reactions to the transfusion of platelet concentrates (PCs) cannot be attributed to antibodies against blood cells or to subclinical microbial agents. It has been suggested that leucocyte-derived inflammatory cytokines such as interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF) may contribute to a larger number of unexplained non-antibody-mediated adverse reactions. Three types of PCs, containing different levels of leucocytes, are currently produced.