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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 thein vitroquality of these PLTs when stored in the new modified PAS-III (PAS-IIIM).TRIMA V4 was programmed to collect 6·0 × 1011 PLTs at a concentration of 5000 × 103 PLTs/µl. 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 vitrotesting was performed on days 0, 1, 5 and 7. Collection efficiency (CE), collection rate (CR) and PLT yield were calculated for each donation.Thirty-two runs with TRIMA V4 were performed, collecting 6·58 ± 0·74× 1011 PLTs at a concentration of 4255 ± 914 × 103/µl in 99 ± 19·9 min, resulting in a CE of 65·3 ± 8·2% and a CR of 6·92 ± 1·6 × 109 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 superiorin vitroquality compared to PLTs stored in PAS-III.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%. [ABSTRACT FROM AUTHOR]

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. 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 whit blood cell (WBC) loss. 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 perminute and per litre blood volume was also reduced by 20%. 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. [ABSTRACT FROM AUTHOR]

Autologous platelet concentrate (PC) is applied locally to improve wound healing and tissue repair. Previous measurements of the growth factor content of platelets have given conflicting results. To date, there is no information on the influence of different preanalytical sample-preparation methods on the detectable amount of growth factors. We measured the level of growth factors in PCs obtained by plateletpheresis and by leukapheresis. We subjected aliquots of these components to six different preparation methods: freezing/thawing once or twice; dissolution in 0·5% Triton-X-100; and clot formation by the addition of calcium and thrombin with subsequent incubation for 1 h, for 24 h, or for 1 h followed by freezing and thawing. In samples dissolved in Triton-X-100, higher levels of growth factors were detected than in the other specimens. In comparison to clot formation, freezing and thawing platelets twice was equivalent with respect to the release of platelet-derived growth factor (PDGF) but superior with respect to the release of transforming growth factor-β1 (TGF-β1). Overall, mean levels of 4·77 × 10−16 g of PDGF-AB, 2·2 × 10−17 g of PDGF-BB, and 2·41 × 10−16 g of TGF-β1 were found per single human platelet in white blood cell (WBC)-poor samples dissolved in Triton-X-100. Dissolving PC in Triton-X-100 releases maximum quantities of growth factors from platelets. The release of each growth factor by any sample preparation method should be investigated and interpreted separately. The preanalytical sample-preparation method, as well as the platelet and WBC content, influence the measurable levels of growth factors in PCs. The results implicate the need to correct, considerably upwards, previous estimations of the PDGF content of platelets. [ABSTRACT FROM AUTHOR]

Thrombo LUX ( TLX)-Score was compared with hypotonic shock response ( HSR) and extent of shape change ( ESC) in 99 samples from 42 platelet concentrates. Tests were performed in parallel and duplicate. Mean values for TLX Score, HSR and ESC were 30·3 ± 3·8%, 69·0 ± 12·2% and 23·2 ± 4·9%, respectively. We found no significant correlation between TLX Score and HSR or ESC ( r = −0·158, P = 0·118 and r = −115, P = 0·255, respectively), whereas HSR and ESC correlated significantly ( r = 0·351, P < 0·001). As TLX Score did not show significant correlation with HSR and ESC, the value of TLX for platelet quality testing remains unclear. Studies comparing these parameters with transfusion outcome are needed. [ABSTRACT FROM AUTHOR]

Thrombo LUX ( TLX)-Score was compared with hypotonic shock response ( HSR) and extent of shape change ( ESC) in 99 samples from 42 platelet concentrates. Tests were performed in parallel and duplicate. Mean values for TLX Score, HSR and ESC were 30·3 ± 3·8%, 69·0 ± 12·2% and 23·2 ± 4·9%, respectively. We found no significant correlation between TLX Score and HSR or ESC ( r = −0·158, P = 0·118 and r = −115, P = 0·255, respectively), whereas HSR and ESC correlated significantly ( r = 0·351, P < 0·001). As TLX Score did not show significant correlation with HSR and ESC, the value of TLX for platelet quality testing remains unclear. Studies comparing these parameters with transfusion outcome are needed. [ABSTRACT FROM AUTHOR]