Protein composition of clots detected in pooled cryoprecipitate units.

Background: On rare occasions, upon thawing of stored cryoprecipitate components, clots are observed on visual inspection. Although it has been assumed that the clot reflects fibrinogen to fibrin conversion, there are few published studies that document that this assumption is correct. Our studies were conducted to further identify the protein characteristics of the clotted material.

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.

Storage of aliquots of apheresis platelets for neonatal use in syringes with and without agitation.

Background: To facilitate volume control in neonates, platelets (PLTs) are aliquoted and stored for short periods in non-gas-permeable syringes before infusion. Although agitation of PLTs during storage in gas-permeable bags is performed to maintain their quality, the effect of syringe agitation during storage is unknown.

Study Design And Methods: Double apheresis PLTs (n = 6) were collected and split, providing two identical products.

Characterizing the variation in pH measurements with apheresis platelets.

Background: pH measurements of platelet (PLT) components remain a key parameter when assessing how storage and shipping conditions influence the retention of PLT properties. Studies were conducted to characterize variations in pH measured with two pH meters and a blood gas analyzer.

Study Design And Methods: Samples were obtained from apheresis PLT units that were stored with or without continuous agitation to measure a range of pH values.

Evaluation of the properties of components prepared and stored after holding of whole blood units for 8 and 24 hours at ambient temperature.

Background: The capability of holding whole blood (WB) units at ambient temperature, overnight, should help in platelet (PLT) concentrate preparation logistics. We summarize the results of a study conducted in the early 1990s that compared, in particular, PLT and red blood cell (RBC) in vivo viability properties following storage after preparation after 8- and 24-hour WB hold periods.

Study Design And Methods: Individuals donated units of WB on two occasions.

Storing apheresis platelets without agitation with simulated shipping conditions during two separate periods: immediately after collection and subsequently between Day 2 and Day 3.

Background: Apheresis platelet (PLT) units are not routinely agitated during transit. Our study compared the in vitro properties of apheresis PLT units that were stored with continuous agitation (CA) and without continuous agitation (WCA) during two separate periods, immediately after collection and between Day 2 and Day 3 of storage.

Study Design And Methods: Two identical apheresis PLTs units were prepared from collections with Amicus (n = 11, Fenwal, Inc.

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.

The influence of conditions utilized to hold apheresis and whole blood-derived platelet samples before platelet enumeration with three hematology analyzers.

Background: The Advia 120 (Siemens Diagnostics) hematology analyzer is different from other hematology analyzers in that it requires platelets (PLTs) to be "effectively spherical" to be counted. Our study evaluated how PLT counts with this hematology analyzer and two other models were influenced by the holding of PLT product samples.

Study Design And Methods: Samples were prepared from apheresis PLT products (APs) collected in ACD-A and from whole blood-derived PLT concentrates (PCs) in CP2D or ACD-A.

A comparison of two robotic platforms to screen plateletpheresis donors for HLA antibodies as part of a transfusion-related acute lung injury mitigation strategy.

Background: Efforts to minimize white blood cell alloantibodies, responsible for transfusion-related acute lung injury (TRALI) in components with high-volume single-donor plasma include consideration of plateletpheresis donor screening for human leukocyte antigen (HLA) antibodies. High-throughput screening platforms make this feasible for large blood centers. Which platform to use, donor subgroups to screen, characteristics of detected antibodies, and operational impact of deferring reactive donors are important questions.

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.

Long-term storage of peripheral blood stem cells frozen and stored with a conventional liquid nitrogen technique compared with cells frozen and stored in a mechanical freezer.

Background: Cryopreservation of hematopoietic progenitor cells using liquid nitrogen and controlled-rate freezing requires complex equipment and highly trained staff and is expensive. We compared the liquid nitrogen method with methods using a combination of dimethyl sulfoxide (DMSO) and hydroxyethyl starch (HES) for cryopreservation followed by storage in mechanical freezers.

Study Design And Methods: Peripheral blood stem cells (PBSCs) were collected from normal donors by apheresis and allocated to one of four preservation and storage conditions: 1) 10% DMSO with freezing in liquid nitrogen and storage in liquid nitrogen, 2) 5% DMSO and 6% HES with freezing and storage in a -80 degrees C mechanical freezer, 3) 5% DMSO and 6% HES with freezing in a -80 degrees C mechanical freezer and storage in a -135 degrees C mechanical freezer, or 4) 5% DMSO and 6% HES with freezing and storage both in a 135 degrees C mechanical freezer.

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).

Maintenance of in vitro properties of leukoreduced whole blood-derived pooled platelets after a 24-hour interruption of agitation.

Background: Continuous agitation during platelet concentrate (PC) storage is frequently interrupted during shipping. Studies have evaluated the effects of interrupted agitation in apheresis and single whole blood-derived PCs, but not PC pools. This study evaluated in vitro properties of pooled whole blood-derived platelets (PLTs) after a 24-hour interruption of agitation.

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.

Comparison of the in vitro properties of apheresis platelets during 7-day storage after interrupting agitation for one or three periods.

Background: Many platelet (PLT) components undergo multiple periods of shipment before transfusion. We have previously conducted studies investigating maintenance of apheresis PLT in vitro quality measures during a single 24- or 30-hour interruption of agitation, but data are not available for multiple periods without agitation.

Study Design And Methods: Apheresis PLTs were collected with both the Amicus (Fenwal, Inc.

Platelet products prepared by different methods of sedimentation undergo platelet activation differently during storage.

Background: The activation marker CD40 ligand (CD40L) has recently been demonstrated to be released from the cytoplasm of platelets (PLTs) during storage. CD40L may be associated with some adverse transfusion reactions including febrile responses and transfusion-related acute lung injury. CD62P has been traditionally measured to assess PLT activation.

The influence of simulated shipping conditions (24- or 30-hr interruption of agitation) on the in vitro properties of apheresis platelets during 7-day storage.

Background: Platelet (PLT) components undergo interruption of agitation during shipment. Studies have demonstrated maintenance of PLT quality of whole blood-derived PLT concentrates during a 24-hour interruption of agitation, but data are not available for apheresis PLTs in 100 percent plasma.

Study Design And Methods: Apheresis PLTs were collected with one of two commercially available separators (Amicus, Fenwal, Inc.

Assessment of cord blood hematopoietic cell parameters before and after cryopreservation.

Background: The testing of cord blood (CB) progenitor and stem cell units for transplantation suitability involves enumeration of total nucleated cells before freezing. CD34+ cell counts may also be a means of determining suitability. Studies have been conducted to evaluate how specific storage conditions influence cell counts.

Multi-laboratory evaluation of procedures for reducing the volume of cord blood: influence on cell recoveries.

Background: Various procedures can be used to isolate stem and progenitor cells from cord blood. This study evaluated the hydroxyethyl starch sedimentation (HES) with two centrifugation steps, and the top and bottom (T&B) isolation of buffy coat following a single centrifugation, and two filter systems for processing cord blood, one developed by Asahi Kasei Medical (filter A) and the second by Terumo (filter B).

Methods: Each of seven laboratories was randomly assigned the evaluation of either the HES or T&B method and one of the filter methods (n=8 cord blood units, per laboratory, for each method).

Reevaluation of the resting time period when preparing whole blood-derived platelet concentrates with the platelet-rich plasma method.

Background: The resting of platelet (PLT) pellets during the preparation of whole blood-derived PLT concentrates (PCs) is considered an essential step. A reevaluation of the rest period was conducted because preparation and storage conditions have been modified during the past 20 years.

Study Design And Methods: A two-site in vitro study (Study 1) was conducted with rest times of 0 to 5 minutes, 1 hour, and 4 hours (n = 31-33 per rest period).

Multiple-laboratory comparison of in vitro assays utilized to characterize hematopoietic cells in cord blood.

Background: Understanding the variability in results obtained by multiple laboratories is important because cord blood units are distributed worldwide for transplantation.

Study Design And Methods: Four exercises were conducted by multiple laboratories to assess assay variability on nucleated cell (NC), mononuclear cell (MNC) by hematology analyzers [HAs], and CD34+ cell (flow cytometry) measurements. Exercise 1 was an intralaboratory exercise in which the reproducibility of cell measurements was determined.

Evaluation of the reactivity of apoptosis markers before and after cryopreservation in cord blood CD34(+) cells.

Umbilical cord blood (CB) CD34(+) cells, on the basis of flow cytometry analysis, are comprised of multiple populations. In in vitro assays, only CD34(regular) FSC(high) cells are functional and low percentages of nonfunctional CD34(regular) FSC(low) cells were determined to be present in liquid-stored CB. Liquid-stored CD34(regular) FSC(high) cells prior to cryopreservation were judged to be functional by the formation of erythroid and myeloid colonies and transmigration assays.