An inhibition of p38 mitogen activated protein kinase delays the platelet storage lesion.

Background And Objectives: Platelets during storage undergo diverse alterations collectively known as the platelet storage lesion, including metabolic, morphological, functional and structural changes. Some changes correlate with activation of p38 mitogen activated protein kinase (p38 MAPK). Another MAPK, extracellular signal-related kinase (ERK), is involved in PLT activation.

Maintenance of storage properties of pediatric aliquots of apheresis platelets in fluoroethylene propylene containers.

Background: Platelet (PLT) aliquots for pediatric use have been shown to retain in vitro properties when stored in gas-impermeable syringes for up to 6 hours. As an alternative, PLT aliquots can be stored for longer periods in containers used for storage of whole blood-derived PLTs. These containers are not available separate from whole blood collection sets and PLT volumes less than 35 mL either have not been evaluated or may be unsuitable for PLT storage.

A rest period before agitation may improve some in vitro apheresis platelet parameters during storage.

Background: Whole blood-derived platelets (PLTs) prepared by the PLT-rich plasma method are subjected to a recommended 1-hour rest period after the second centrifugation to avoid excessive PLT activation. Different apheresis PLT preparation methods demonstrate different levels of PLT activation and ability to form macroscopic aggregates immediately after collection. PLT collections are lost on Day 1 of storage if aggregates are not dispersed.

Comparative in vitro evaluation of apheresis platelets stored with 100% plasma or 65% platelet additive solution III/35% plasma and including periods without agitation under simulated shipping conditions.

Background: A comparative study evaluated the retention of apheresis platelet (A-PLT) in vitro properties prepared with PLT additive solution (PAS)-III or 100% plasma and stored with continuous agitation (CA) and without continuous agitation (WCA).

Study Design And Methods: PLTs collected with the Amicus cell separator (Fenwal, Inc.) were utilized to prepare two matched components, each with approximately 4 × 10(11) PLTs.

Mitochondrial dysfunction of platelets stored in first- and second-generation containers is, in part, associated with elevated carbon dioxide levels.

Background: The gas permeability of platelet (PLT) storage bags influences the retention of in vitro PLT parameters during storage. The aim of this study was to evaluate mitochondrial function of PLTs stored in first- and second-generation bags with different gas permeabilities.

Study Design And Methods: Identical whole blood-derived PLT concentrates were stored in second-generation CLX (Pall Corp.

Influence of apheresis container size on the maintenance of platelet in vitro storage properties after a 30-h interruption of agitation.

We have previously conducted studies investigating maintenance of apheresis platelet in vitro quality measures during storage under simulated shipping conditions in which agitation was interrupted. This study examines the effect of increasing bag surface area on the preservation of in vitro platelet properties during storage with continuous agitation and with a 30 h interruption of agitation. Apheresis platelets were collected in 100% plasma with the Amicus separator to provide two identical platelet products, each with approximately 4-5 x 10(11) platelets.

Calcium is a key constituent for maintaining the in vitro properties of platelets suspended in the bicarbonate-containing additive solution M-sol with low plasma levels.

Background: Commercially available additive solutions (ASs) require 30% to 35% plasma for optimal storage of platelets (PLTs). PLTs suspended in M-sol, a bicarbonate-based experimental platelet additive solution (PAS), maintain in vitro PLT properties during storage with low levels of plasma (< or =5%).

Study Design And Methods: Four different formulations of M-sol were prepared at the optimal pH (6.

Periods without agitation diminish platelet mitochondrial function during storage.

Background: Prolonged periods without agitation produce platelet (PLT) storage lesions that result in reduced in vitro assay parameters and an increase of apoptotic markers during storage. The aim of this study was to evaluate the influence of periods without agitation on PLT mitochondrial function, blood gases, and activation.

Study Design And Methods: Apheresis PLT units (n = 12) were collected using a cell separator and each was equally divided among five storage bags (50 mL of PLT suspension in 300-mL nominal volume containers).

Evaluation of in vitro storage properties of prestorage pooled whole blood-derived platelets suspended in 100 percent plasma and treated with amotosalen and long-wavelength ultraviolet light.

Background: Amotosalen, a psoralen, has been utilized for photochemical treatment (PCT) of apheresis platelets (PLTs) and pooled buffy coat PLTs suspended in additive solution. In the United States, the source of many PLT transfusions is from whole blood-derived PLTs prepared by the PLT-rich plasma (PRP) method. This study investigated the in vitro PLT properties of amotosalen-PCT of leukoreduced pools of PLTs prepared by the PRP method and suspended in 100 percent plasma.

Maintenance of platelet in vitro properties during 7-day storage in M-sol with a 30-hour interruption of agitation.

Background: Extensive periods without agitation can occasionally occur during platelet (PLT) shipment and can affect PLT quality during 5- to 7-day storage. The use of buffer-containing PLT additive solutions (ASs) may better preserve PLT quality during storage by maintaining PLT pH and other in vitro variables. A newly described bicarbonate-containing AS, M-sol, was compared to plasma for preservation of whole blood-derived PLT concentrates in which a 30-hour interruption of agitation was included.

Toward closed-system culture of blood origin endothelial cells.

Background: Blood outgrowth endothelial cells (BOECs) are thought to arise from very rare progenitors that are present in the mononuclear fraction of marrow or peripheral blood. Recently, BOECs have been expanded from progenitors present in buffy coat into confluent monolayers on fibronectin- or collagen-coated polystyrene surfaces. A method for sterile closed-system culture of these cells has not been described, however.

Monocyte enrichment of mononuclear apheresis preparations with a multistep back-flush procedure on a cord blood filter.

Introduction: Monocytes or mononuclear cells have been investigated for the treatment of chronic wounds and spinal cord injuries, as well as serve as a source for dendritic or endothelial cell culture. Because these cells may have clinical benefit yet no rapid and inexpensive closed system for monocyte purification is commercially available, a method was investigated to enrich monocytes from mononuclear apheresis units using a cord blood filter.

Methods: A 4-step method for monocyte enrichment was developed which involved 1) filtering a mononuclear apheresis unit through a cord blood filter, 2) chasing with medium to remove non-adherent residual cells and plasma, 3) back-flushing under low shear conditions to remove loosely adherent lymphocytes, and 4) back-flushing under high shear conditions to collect a fraction enriched in monocytes.

Sterile isolation and cryopreservation of human adherent monocytes/macrophages from mononuclear cell apheresis preparations.

There is evidence from animal and human study that suggests clinical use of monocytes/macrophages may be of benefit in wound healing, tissue regeneration, and cancer therapy. To facilitate further study, a method was developed for sterile isolation and cryopreservation of adherent monocyte/macrophages from mononuclear cell apheresis units collected from unstimulated normal human donors. Preparations contained approximately 1 x 108 total cells and were comprised of approximately 60% monocytes, 38% lymphocytes, and 2% granulocytes.