The buffy coat method as a source for platelet concentrates was developed in the 1970s and is still used in many blood centres around the world. Development of the method sparked various technological advances in blood collection, processing and storage. At the time, the need for platelet concentrates sharply increased because of better treatment regimens for (onco)haematological diseases, which forced blood centres to standardize and automate their production processes as much as the technology would allow. In this review, a historical overview of the Dutch experiences is provided in the context of the international developments.

The Rh blood group system represents a major immunodominant protein complex on red blood cells (RBC). Recently, the Rh homologues RhAG and RhCG were shown to promote ammonium ion transport in yeast. In this study, we showed that also in RBC the human Rh complex functions as an exporter of ammonium ions. We measured ammonium import during the incubation of RBC in a solution containing a radiolabelled analogue of NH4Cl (14C-methyl-NH3Cl). Rhnull cells of the regulator type (expressing no Rh complex proteins) accumulated significantly higher levels (P = 0.05) of radiolabelled methyl-ammonium ions than normal RBC, at room temperature. Rhnull cells of the amorph type (expressing limited amounts of Rh complex proteins) accumulated an intermediate amount of methyl-ammonium ions. To show that decreased ammonium export contributes to its accumulation, the release of intracellular methyl-ammonium from the cells was measured over time. In 30 s, normal RBC released 87% of the intracellular methyl-ammonium ions, whereas Rhnull cells of the regulator type released only 46%. We conclude that the Rh complex is involved in the export of ammonium from RBC.

Background and Objectives: The buffy‐coat (BC) method for platelet concentrate (PC) preparation was modified in order to obtain leukodepleted PCs from single BCs without filtration. Materials and Methods: BCs were centrifuged in cylindrical BC bags and the optimal centrifugation conditions and optimal hematocrit were determined. Results: With optimal conditions, a tenfold lower leukocyte contamination was obtained compared with the conventionally shaped, wide BC bag (0.3 ± 0.19 versus 3.0 ± 1.71 × 106 leukocytes per unit; 85‐ml BCs). The platelet yield obtained with the cylindrical bag did not differ significantly from the yield obtained with the conventional bag (56 ± 16.4 versus 61 ± 15 × 109 platelets per PC). Furthermore, when PCs were prepared from 100‐ml BCs in cylindrical bags, a leukocyte contamination of 0.2 ± 0.11 × 106 and a platelet content of 6 ± 13.5 × 109 per PC were obtained. Conclusion: The use of cylindrical BC bags reduced the leukocyte contamination in PCs to a level required for leuko‐depletion without affecting platelet recovery.

Non-woven polyethylene terephthalate (PET) filter fabric, usually used for leukocyte reduction of red cell concentrates, is not compatible with platelets. To increase the compatibility for platelets the surface of non-woven PET fabric was modified by gas plasma treatment. After modification and eventual subsequent γ-sterilization and storage under different conditions, biological evaluation was performed using different kinds of platelet concentrates (PCs). From 500ml blood, stored overnight at 20°C, different types of PC were prepared. PCs prepared from platelet-rich-plasma (PRP-PC) and overnight stored and fresh buffy-coat (BC) derived PCs were tested, either from single BCs or from pooled BCs. Filterps were tested with PC in a miniaturized set-up. The product recovery (P), platelet recovery (T), the percentage of leukocyte reduction and the platelet morphology were determined. There was no significant difference in overall platelet recovery (PxT) between either freshly prepared (0.77±0.049, mean±SD) or overnight stored single EC-PC (0.78±0.031) or overnight stored PRP-PC (0.75±0.082). The pooled BC-PC, either freshly prepared or after overnight storage, showed a significant higher platelet recovery (0.84±0.030) compared to the other types of PC. The leukocyte depletion (92-97%) did not differ significantly between the different types of PC. For non of the tested PCs, changes in morphology were induced by filtration. Compared to untreated PET material the gas plasma treatment gave a major improvement of PxT from 0.57 to about 0.80. γ-sterilization and subsequent storage for 3, 12 and 24 weeks at 20°C or 37°C had no significant influence on the filtration results.

Pooled platelet concentrates (PC) prepared by the platelet-rich plasma (PRP) method were filtered with three different filters and stored for 8 days at room temperature. The effect of filtration on leukocyte contamination, platelet concentration, and the in vitro function, morphology, metabolism and activation of platelets were studied. Eight pools of 20 PRP-PC were used, each pool was split into 4 equal volumes; 3 were filtered over a PL50HF, a PL-10A and a Bio P10 filter, the 4 served as a control. After filtration, leukocyte counts exceeded 3x10(5) in none of the pooled PC. Platelet loss induced by filtration was about 17%. During storage, no differences in pH, PCO2, and lactate and glucose concentration were found between the filtered and the unfiltered units, nor were any differences observed between filtered and unfiltered pooled PC in aggregation upon stimulation with collagen and/or ADP, adhesion capacity to collagen in flowing blood, nucleotide content of the platelets and nucleobase concentration in the plasma, expression of activation-dependent antigens, or platelet morphology as observed by light microscopy and by the swirling effect. Selective removal of beta-thromboglobulin (22%) by the PL50HF filter was observed. Pooled PC prepared by the PRP-method can be filtered and stored for 8 days without detrimental effect on platelet function, metabolism or activation.

Pooled platelet concentrates (PC) prepared by the platelet-rich plasma (PRP) method were filtered with three different filters and stored for 8 days at room temperature. The effect of filtration on leukocyte contamination, platelet concentration, and the in vitro function, morphology, metabolism and activation of platelets were studied. Eight pools of 20 PRP-PC were used, each pool was split into 4 equal volumes; 3 were filtered over a PL50HF, a PL-10A and a Bio P10 filter, the 4 served as a control. After filtration, leukocyte counts exceeded 3 x 10(5) in none of the pooled PC. Platelet loss induced by filtration was about 17%. During storage, no differences in pH, PCO2, and lactate and glucose concentration were found between the filtered and the unfiltered units, nor were any differences observed between filtered and unfiltered pooled PC in aggregation upon stimulation with collagen and/or ADP, adhesion capacity to collagen in flowing blood, nucleotide content of the platelets and nucleobase concentration in the plasma, expression of activation-dependent antigens, or platelet morphology as observed by light microscopy and by the swirling effect. Selective removal of beta-thromboglobulin (22%) by the PL50HF filter was observed. Pooled PC prepared by the PRP-method can be filtered and stored for 8 days without detrimental effect on platelet function, metabolism or activation.

Platelet concentrates (PC) were stored for 6 days in either polyolefin (PO) or polyvinylchloride/di-(2-ethylhexyl)phtalate (PVC/DEHP) bags in 100% plasma or in a synthetic medium with 35 or 10% plasma. For all conditions studied the usual in vitro parameters were well maintained, with a pH above 6.8. In both bag types platelets can be satisfactorily stored for 6 days in a synthetic medium with minimal amounts of residual plasma. For this medium, the PO bag offers a slight advantage with respect to the preservation of platelet ATP content (>80 versus >70% in the PVC bags) and aggregation and adhesion capacity. The adhesion capacity increased in the PO bags, while it decreased in the PVC bags.

Background: Posttransfusion complications can be prevented by pretransfusion removal of donor white cells from platelet concentrate. The filtration used for this removal seems to have little effect on platelet function and activation, but more information is needed on its effect on function during subsequent long-term storage of concentrate.Study Design and Methods:The effect of prestorage filtration of buffy coat-prepared platelet concentrates (PCs) on platelet function, metabolism, and activation was investigated. A pool of three PCs, each made of four buffy coats, was split into three equal volumes; two were filtered over two different filters and the third served as a control. Variables monitored immediately after filtration and during the subsequent 8-day storage period at 22 degrees C included aggregation upon stimulation with collagen and/or ADP, platelet adhesion capacity to collagen and fibrinogen in flowing blood, nucleotide content of and nucleobase release by the platelets, expression of activation-dependent antigens, and beta-thromboglobulin release by the platelets.Results: No differences were observed between the PCs filtered over two different filters and the nonfiltered control PCs immediately after filtration and during storage, except for a selective removal (20%) of beta-thromboglobulin by one filter.Conclusion: PCs prepared from a pool of four buffy coats can be filtered and subsequently stored for 8 days (starting +/- 24 hours after whole blood collection) without detriment to platelet function, metabolism, or activation.

The effect of filtration on the quality of platelet concentrates (PC) during storage was investigated. Two leukocyte depletion filters (Pall PL50HF and Sepacell PL-10A) were applied to filter PC made from a pool of 4 buffy coats. For each experiment 3 PC were pooled and divided into 3 identical PC to eliminate differences between the PC. Two PC were filtered, and the third PC served as an unfiltered control. A total of 12 experiments was performed. Before filtration, volumes of the PC were 263 +/- 11.7 ml (mean +/- SD). Platelet and leukocyte counts per PC were 241 +/- 25.9 x 10(9) and 7.2 +/- 1.8 x 10(6), respectively. After filtration leukocyte counts did not exceed 5 x 10(4) in any of the PC. In the PC filtered with the Pall PL50HF the mean platelet loss was approximately 14% and with the Sepacell PL-10A, 17%. During a 9-day storage period the pH, PO2, PCO2, bicarbonate, lactate and glucose concentration and LDH release as well as the morphology, examined by the swirling effect and microscopically, were not significantly different in filtered and unfiltered units. Filtration through the 2 investigated leukocyte depletion filters for PC did not adversely affect in vitro viability of the platelets during storage.

Vox SanguinisVolume 67, Issue s3 p. 77-79 THE QUALITY OF BLOOD STARTS WITH ITS COLLECTION J.A. LOOS, J.A. LOOS Central Laboratory of the Netherlands Red Cross Blood Transfusion Service Department Transfusion Technology Plesmanlaan 125 1066 CX Amsterdam the NetherlandsSearch for more papers by this author J.A. LOOS, J.A. LOOS Central Laboratory of the Netherlands Red Cross Blood Transfusion Service Department Transfusion Technology Plesmanlaan 125 1066 CX Amsterdam the NetherlandsSearch for more papers by this author First published: July 1994 https://doi.org/10.1111/j.1423-0410.1994.tb04548.xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume67, Issues3July 1994Pages 77-79 RelatedInformation

The effect of platelets on the removal of white cells (WBCs) from 16 to 24‐hour‐old red cell (RBC) concentrates by filtration was studied. RBC concentrates with various concentrations of platelets and WBCs were filtered on a cellulose acetate column filter and on three polyester flatbed filters. The microscopic study revealed that lymphocytes and most monocytes were captured in the smaller pores of the fiber network, irrespective of the brand of filter, the type of filter material, or the prefiltration platelet amount in the RBC concentrates. In contrast, efficient granulocyte depletion depended on granulocyte‐platelet interaction and on the filter material. In the presence of platelets, granulocytes were captured in the top part of the column filter or in the coarse layers of two of the flatbed filters, where platelets covered the fibers. Platelet depletion of the RBC concentrates prior to filtration diminished the contribution of these parts of the filters to granulocyte capture. A larger part of the column filter or the fine layers of the flatbed filters were now required for granulocyte capture. In one of the flatbed filters, granulocyte‐platelet interaction occurred mainly in the fine layers, which ended in blockage of this filter after the filtration of variable volumes (250‐600 mL) of standard RBC concentrates. A quantitative estimation of the effect of platelets on the WBC‐reduction capacity found that all three flatbed filters had a highly significant decrease (p = 0.001) in WBC‐reduction capacity for platelet‐depleted or buffy coat‐depleted RBC concentrates, as compared with standard RBC concentrates.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of warming (37 degrees C) of stored platelet concentrates (PC) on the post-transfusion platelet function as measured by the adhesion capacity in a rectangular perfusion system under flow conditions was analyzed in 22 patients undergoing transfusion for stable thrombocytopenia. Nine patients received a PC stored at 22 degrees C and incubated at 37 degrees C for 1 h before transfusion, 10 patients received a non-warmed PC, 3 patients received both a pre-warmed and a non-warmed PC. In the PC the platelet adhesion capacity to collagen was higher in the pre-warmed PC than in the non-warmed PC (33 +/- 5.9% coverage vs. 22 +/- 4.7% coverage, respectively, in a selected group with the same platelet concentration). The adhesion capacity to collagen of the platelets in the patient's blood, measured 10 min after transfusion, had increased considerably in both patient groups and 4 h later the adhesion capacity in both patient groups was similar to that of the pre-warmed PC before transfusion. We conclude that though pre-warming of stored PC had a beneficial effect on the adhesion capacity to collagen of the platelets in the PC, the clinical significance is questionable because already 10 min after transfusion the adhesion capacity to collagen of stored non-warmed platelets had improved to the level of the pre-warmed platelets and 4 h after transfusion this improvement was still present.

Abstract. The effect of rapid cooling to 20–24 °C of whole blood immediately after collection, using ‘cooling units' with butane‐1,4‐diol and prolonged storage up to 24 h at ambient temperature was investigated in the whole blood and the subsequently prepared plasma, buffy coat and buffy‐coat‐poor red cell concentrate (BC‐poor RCC) in saline‐adenine‐glucose‐mannitol (SAGM) solution. Factor VIII:C content of the plasma (n=10), after 24 h storage was 80± 3% of the initial value. In routine procedures factor VIII:C content in the plasma (n= 129 pools of 20 donor units plasma) was 0.77 ± 0.078 IU/ml, after storage of the whole blood for 16–20 h. In whole blood (n=10), the 2,3‐diphosphoglycerate (2,3‐DPG) content of the red cells decreased from 4.36 ± 0.55 to 1.47 ± 0.6 μmol/ml red cells after 24 h storage at 20–24°C. After storage of the BC‐poor RCC (n=10) at 2–6°C for 1 week, the 2,3‐DPG had dropped to 0.76 ± 0.46 μmol/ml red cells. During the first 24 h of storage of whole blood, the adenine triphosphate (ATP) levels of the red cells remained stable. A mean increase of 20% of the initial value was observed after addition of SAG M solution. In the BC‐poor RCC the ATP slowly decreased to 81 ± 5% after 5 weeks and to 68 ± 6.6% of the initial value after 6 weeks storage. In citrate‐phosphate‐dextrose blood the yield of platelets in the buffy coat was found to be 84 ± 6% (mean ± SD) of the original value when whole blood (n= 12) was stored for 16–20 h at 20–24 °C, as compared to 76 ± 18%, when buffy coats were prepared within 3 h after collection of whole blood without rapid cooling (n= 12). Rapid cooling of whole blood to 20–24 °C immediately after collection and subsequent storage of the whole blood up to 24 h contributes to the quality and standardization of the subsequently prepared blood components and will diminish processing at irregular hours.