Comparison of plateletpheresis concentrates produced with Spectra LRS version 5.1 and LRS Turbo version 7.0 cell separators

Monitoring of platelet activation in platelet concentrates using transmission electron microscopy

OBJECTIVE

The quality of platelet concentrates (PC) is important for the in vivo recovery of thrombostasis in patients suffering from bleeding disorders and in tumor patients after chemotherapy. In this respect, activated platelets (PLT) cannot display their full functionality in the recipient and even can cause adverse effects. Therefore, we developed a transmission electron microscopy (TEM) method for quality assessment of PC.

METHODS

Score values taken from panorama TEM images describe the progress of PLT activation. To exemplify this method, i) 19 apheresis PC isolated with the Baxter Amicus system (BA) were compared with 14 PC obtained from pooled buffy coats (BC). ii) The score values of 33 PC derived from BA as well from BC were compared with flow-cytometric CD62P determinations by cross correlation. iii) Changes in the score value profiles during storage of a single pathogen-reduced BA PC were monitored over a period of 7 days.

RESULTS

The TEM evaluation described allows for demonstrating particular PLT activation stages. i) Significant differences between the percentages of the score values 0, 1 and 2 could be demonstrated in both processing groups. No significant differences were found comparing these two groups. ii) A weak correlation could be shown when comparing the percentages of score values 2 plus 3 with the percentage of CD62P-positive PLT. iii) The pathogen reduction affected slightly the score profiles during storage due to an increase of dead PLT.

CONCLUSION

Our investigations demonstrate the unique detailed quality information of PC obtained by the TEM method. This method can be performed in every routine electron microscopy laboratory.

High concentration plasma-reduced plateletapheresis concentrates

Single-donor hyperconcentrated plateletapheresis (dry-platelets) collection has been introduced in the 90's as a part of the newly developed multi-component collection strategy. This approach allowed to safely collect multiple components from a single apheresis donation, i.e. RBC, FFP and/or plateletpheresis units. Dry-platelets are usually resuspended in additive solution to maintain an adequate pH during the storage period until use. Some concern existed about possible higher degrees of platelet activation in dry-platelets units when compared to standard concentration (1.0-1.6 × 10(6)/μL platelets) units and its possible correlation with lower in vivo efficiency and/or survival of the former units. Several authors investigated this specific issue, and dry-platelets units proved to be equally effective than standard concentration plateletpheresis units in recipients. The use of dry-platelets units may reduce (i) the risk of passive infusion of naturally occurring ABO-related hemolytic antibodies when donor O platelets are given to group A, B, or AB recipient, (ii) the risk of TRALI when multiparous donors undergo plateletpheresis. Furthermore, dry-platelet collection may allow for an increased amount of FFP sent to industry. Finally, hyperconcentrated platelet units may be used for "niche" indications, such as intrauterine platelet transfusion or, in case of autologous dry-platelet collection, for further freezing for long term storage in selected patients within onco-hematological settings.

Efficacy of Fenwal Amicus blood cell separator in double dose platelet collection

BACKGROUND

The aim of this retrospective study was to document our double dose platelet collection experience using the Fenwal Amicus (version 2.51) continuous flow apheresis device and to obtain information on the donors selected for this device.

MATERIALS AND METHODS

Between January and December 2004, double dose collection procedures were performed on a total of 479 donors (474 male and 5 female). Donors with a pre-procedure platelet count 225 x 10(9) L(-1) and body weight of 63 kg were directed to the Fenwal Amicus for double dose platelet collection (> 6.0 x 10(11)).

RESULT

More than 500 procedures were performed. Four hundred and seventy-nine procedures were included in this evaluation. 21 procedures were not included either because the procedures were not completed due to a donor reaction or lack of data. In 289 of 479 (60.3%) donors, double dose collection was achieved. The average leukocyte contamination was 0.31 x 10(6) in 22 randomly selected products.

CONCLUSIONS

The cost of platelet apheresis can be reduced by directing donors with high pre-platelet counts to suitable double dose collection devices in blood centers.

Blood component collection by apheresis

Apheresis component collection is a rapidly growing area in the blood collection field. Several instruments with varying capabilities are available. This is a brief review of the equipment available for granulocyte and apheresis component collection and indications for their use. In the United States, granulocytes are collected with the Fenwal CS3000, Fenwal CS3000 Plus, COBE (Gambro) Spectra, Haemonetics LN9000, and Fresenius AS 104. The use of hetastarch for sedimenting agent and stimulation with G-CSF and G-CSF plus dexamethasone have substantially increased granulocyte yields. Plateletapheresis is performed in the United States on the Fenwal CS3000, Fenwal CS3000 Plus, Fenwal Amicus, COBE (Gambro) Spectra, Gambro Trima Version 4, Gambro Trima Accel (Version 5), and Haemonetics LN9000. Automated red blood cell (RBC) collections are performed with the Haemonetics MCS+LN8150, Gambro Trima Version 4, Gambro Trima Accel (Version 5), Amicus, and Baxter Alyx. The RBC can be collected concurrently (with other components) in some instruments or separately in others. Plasma is collected concurrently on several instruments. Plasmapheresis for plasma only is performed on the Fenwal Autopheresis C and Haemonetics PCS2. Granulocyte yields range from 0.46 x 10(10) to 1.0 x 10(10) for unstimulated donors and 2.1 x 10(10) to 2.6 x 10(10) for donors stimulated with dexamethasone or prednisone. The use of G-CSF and G-CSF with dexamethasone has substantially increased granulocyte yields with yields of 4.1 x 10(10) to 10.8 x 10(10) reported. Platelet collection rates of 0.045-0.115 x 10(11) plt/min have been reported. Collection efficiencies of 46-85.7% have been reported. Automated (apheresis) component collection has the advantages of controlled volumes or doses of component, efficient use of the donor, multiple components from the same donor, better inventory control, and better quality control due to less manipulation of the individual components. Disadvantages of automated component collection include the use of expensive equipment and disposables, the need for specially trained machine operators, and lower capacity to collect large volumes of blood compared to whole blood donation. The use of apheresis component collection is rapidly growing to provide the best blood components in the most efficient manner.

Hyperconcentrated platelets stored in additive solution: aspects on productivity and in vitro quality

BACKGROUND AND OBJECTIVES

New platelet (PLT) additive solutions (PASs) allow a plasma carryover of < 30% in PLT concentrates. This implicates the need to collect apheresis PLT concentrates at very high PLT concentrations: so-called dry PLTs (DPs). We used the TRIMA, with software version 4 (TRIMA V4), to collect such DPs and investigated the in vitro quality of these PLTs when stored in the new modified PAS-III (PAS-IIIM).

MATERIALS AND METHODS

TRIMA V4 was programmed to collect 6.0 x 10(11) PLTs at a concentration of 5000 x 10(3) PLTs/microl. Two DPs were pooled, split into four equal parts and diluted to obtain secondary pools (SPs) consisting of 70% PAS-III/30% plasma, 70% PAS-IIIM/30% plasma, 80% PAS-IIIM/20% plasma or 100% plasma. In vitro testing was performed on days 0, 1, 5 and 7. Collection efficiency (CE), collection rate (CR) and PLT yield were calculated for each donation.

RESULTS

Thirty-two runs with TRIMA V4 were performed, collecting 6.58 +/- 0.74 x 10(11) PLTs at a concentration of 4255 +/- 914 x 10(3)/microl in 99 +/- 19.9 min, resulting in a CE of 65.3 +/- 8.2% and a CR of 6.92 +/- 1.6 x 10(9) PLTs/min. On day 0, 34-37% of the PLTs in the units prepared for storage were already activated. PLTs stored in 70% or 80% PAS-IIIM showed superior in vitro quality compared to PLTs stored in PAS-III.

CONCLUSIONS

TRIMA V4 is a suitable device for the collection of DPs. Nevertheless, improvements are desirable to further increase the ability to concentrate PLTs at very high levels. The storage of apheresis-derived PLTs in PAS III-M is a very promising approach, even at a plasma carryover of < 30%.

First comparison of productivity and citrate donor load between the Trima version 4 (dual-stage filler) and the Trima Accel (single-stage filler) in the same donors

BACKGROUND AND OBJECTIVES

Aside from new software the blood cell separator TRIMA (GambroBCT) also received a newly designed separation chamber offering a novel single stage separation technology, called Trima Accel. We evaluated this new system focusing on productivity and donor comfort by comparing it to the previous version (Trima version 4) in collecting single-donor platelet concentrates (SD-PCs) and plasma.

MATERIALS AND METHODS

Each of 20 donors underwent platelet apheresis using both devices. We compared the collection efficiency (CE), the collections rate (CR), the volume of the collected plasma and the residual leukocytes. Furthermore we compared donor comfort in terms of duration of the donation, flow of citrate back to the donor and platelet and white blood cell (WBC) loss.

RESULTS

While the number of collected platelets and the platelet concentration did not differ significantly between both techniques the time of the procedure was reduced by 15.6% with Trima Accel. This results in an increase of the CR and CE of 25% and 15% respectively when using Trima Accel. Log normal probability plotting of WBC counts showed that both techniques complied with the European and the US leukoreduction guidelines. The mean flow of ACDA to the donor per minute and per litre blood volume was also reduced by 20%.

CONCLUSION

These data show that the Trima Accel represents a further improvement in apheresis platelet production with a better productivity and donor comfort, especially regarding the mean flow of ACDA to the donor.

Mononuclear cell collection in patients undergoing extra-corporeal photo-chemotherapy for acute and chronic graft-vs.-host-disease (GvHD): comparison between COBE Spectra version 4.7 and 6.0 (AutoPBSC)

A constant improvement in the performance of blood cell separators has been observed in recent years, allowing better yields in peripheral blood stem cell collection (PBSC) either from healthy donors or for autologous purposes. Nevertheless, to our knowledge, no reports on the efficiency of mononuclear cell (MNC) collection in patients undergoing extra-corporeal photochemotherapy (ECP) for graft-vs.-host-disease (GvHD) have been published. We retrospectively investigated the efficiency of 167 MNC collections performed consecutively in 12 patients between January 1999 and June 2001 by means of the COBE Spectra version 4.7 (V 4.7) or version 6.0 (V 6.0), for 109 and 58 procedures, respectively. MNC fractional extraction (FE) was higher in the V 6.0 group compared to the V 4.7 group : 0.59 +/- 0.21 vs. 0.51 +/- 0.22 (P < 0.05). However, platelet contamination was lower in the products obtained with V.6.0 compared to those obtained with V.4.7: 740 ( 630 x 10(3)/(L vs. 2,073 ( 1,429 x 10(3)/(L (P < 0.05). Only two patients with acute GvHD, both from V 4.7 group, required post-ECP platelet transfusion. The recently released version 6.0 allowed a satisfactory MNC yield with minimal platelet contamination in patients scheduled to undergo ECP for acute or chronic GvHD.

Plateletpheresis concentrates produced with the COMTEC cell separator: the French experience

The latest generation of cell separators such as Trima (Gambro), Amicus (Baxter) and AS-TEC 204 (Fresenius), allow the collection of leucocyte-reduced platelet concentrates without secondary filtration. Fresenius has recently developed the COMTEC cell separator whose performance has been evaluated by several teams in France. This new cell separator is an improved version of the Fresenius AS-TEC 204 cell separator, designed to allow more efficient platelet collections. This study reports on the experience of six French teams (from Bordeaux, Clermont-Ferrand, Creteil, Dijon, Lille and Nancy) who obtained 696 leucocyte-reduced plateletpheresis concentrates in the course of collection using the new Fresenius COMTEC cell separator. All healthy volunteer donors fulfilled French selection criteria for platelet apheresis. Donors were eligible if they had suitable venous accesses, if their bodyweight was *50 kg and if their pre-apheresis platelet count was >150 x 10(9) l(-1). Between 4606 and 5229 ml of blood were processed. The mean volume of the platelet concentrates was between 439 and 493 ml (mean 460 +/- 63 ml). The platelet yield was of the order of 5.18 +/- 1.02 x 10(11) with only one platelet concentrate below the norm of 2 x 10(11) platelets (0.91 x 10(11)). No plausible explanation for this was found. The residual leucocyte levels conform to current norms. The platelet concentrates contained less than 1 x 10(6) leucocytes per concentrate (mean 0.233 +/- 0.150 x 10(6) leucocytes) in more than 97% of the components produced with >95% statistical confidence. The efficacy of the cell separator (52.44 +/- 7.35%) is comparable to that of other separators. The Fresenius COMTEC cell separator makes it possible to obtain leucocyte-reduced platelet concentrates which comply with current standards both in terms of platelet content and residual leucocyte level.