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Background. Demographic changes in Poland, mainly population ageing and the health status of the general population, have direct impact on the number of donors/donations, and therefore on the possibility of securing appropriate amounts of blood and blood components for clinical use. The health status of the population is largely affected by diseases responsible for donor deferral. Recent years have witnessed increment in the percentage of temporary donor deferrals due to various types of allergies, civilization diseases, drug intake as well as frequent travels to areas threatened with new and emerging pathogens likely to be transmitted through blood transfusion. The first and crucial step towards safe blood/blood components and recipient safety is rigorous donor qualification. The structure of the population of Polish donors is not homogeneous, moreover has undergone changes during the period under investigation. It is therefore worthwhile to analyze the dynamics of changes in the number and structure of the donor population to determine the direction and intensity of the phenomenon both in spatial and temporal terms. Equally important is identification of the possible causes. The study aim is to present the demographic characteristics of the donor population found eligible for donation and donated blood/blood components for clinical purposes in the years 1997–2017. Material and methods: Records for the period 1997–2017 included about 11 million voluntary donors of blood/blood components for clinical use and 31.000 remunerated donors. Most study analyses were based on data from the 2005–2017 as not all relevant data were available for the period 1997–2004 period. In the 2005–2017 period donations were collected from over 87% of donors who reported to all RBTCs. Slight year-to-year differences were observed (from approx. 85% to 94%). Donations were mainly collected from voluntary un-remunerated donors (99.8%). The largest number of donors eligible for donation was reported in 2005 (94.1%), and the smallest in 2015 (84.2%). Deferred from donation were 22.0% of women willing to donate and only 9.2% of men. Similar tendency was observed for each year of the study period. Results: Study outcome shows reversal of trends for donor age groups; currently most donors are recruited from the 25–44 age category while several years back it was the youngest age group. For many years now actions promoting voluntary blood donation have been ongoing in Poland. Study-outcome shows big differences in numbers of blood donors reporting to individual RBTCs. Despite many years of nationwide voluntary blood donation promoting campaigns , it is the regional policy of donor acquisition and retention that counts most. Conclusions: A problem that sooner or later will have to be faced by most countries (Poland included) is the decline in the number of working-age population. The demographic structure of the population within areas of activity of each RBTC should be subjected to in depth analysis and include the characteristic microeconomic and demographic conditions as well as macroeconomic and demographic conditions for neighbor regions and the country as a whole. Decisions regarding marketing strategy could then be taken. The research outcome may be a valuable source of information to support effective management of donor service and effective planning of marketing strategy targeted at donors and prospective blood donors.

Transfusion of blood and blood components is one of the widely used medical procedures. The responsibility for provision of blood and blood components lies with Polish blood transfusion centers (CKiK) substantively supervised by the Institute of Hematology and Transfusion Medicine. Hospital based blood banks, hospital wards, immunohematology laboratories are supervised by CKiK. Every year approximately 600 thousand people donate blood, more than 75% of which are regular donors. The annual number of donations is maintained at a constant level of about 1.3 million. The aim of this position paper is to present the current status, achievements and advancement in collection, preparation and testing procedures and methods used to obtain the best possible quality blood components dedicated for clinical use. The aim is also to show the structure of blood transfusion service in Poland. Collaboration of all organizational units involved in transfusion medicine is crucial for providing high quality health care for patients. Polish transfusiologists and blood transfusion officers have largely contributed to transfusion science with numerous publications and significant research work. The implementation of novel methods and ongoing research positions Polish blood transfusion service among those of highly developed countries.

Background: In this study we evaluated the basic aspects of the activity of the Polish Blood Transfusion Service (hereinafter referred to as Centers) in 2019. Materials and methods: Retrospective analysis of the 2019-data supplied by the Centers. Results: In 2019, blood and blood components were collected in 21 Polish Centers and 129 local collection sites as well as during 13 048 mobile collections. The overall number of blood donors was estimated at 590 893, the majority of which were non-remunerated donors (590 280 — including 40 738 responders to donation appeals), as well as 57 remunerated donors and 556 autologous donors. Most frequent were whole blood collections (1 202 079) and least frequent — granulocyte concentrate collections (94) and RBCs collections by apheresis (48 donations). Whole blood was collected mostly in local collection sites (45.25%), in Centers (28.75%) and mobile collection sites (26%). Most frequently prepared blood components were RBCs — 1 180 333 units) and fresh frozen plasma (FFP — 1 344 092 units, 21.42% dedicated for clinical use). Platelet concentrates (PCs) collected by apheresis amounted to 53 379 units and 81 905 were whole blood-derived. Additional processing methods (leukocyte depletion, irradiation) were more frequently applied to PCs (43.34% leukocyte-depleted, 0.04% irradiated, 54.63% both leukocyte-depleted and irradiated) than to RBCs (18.71% leukocyte-depleted, 0.06% irradiated, 9.17% both leukocytedepleted and irradiated). Pathogen reduction technologies were applied to 20.76% of FFP units issued for clinical use (transfusion) and 11.87% of PCs. In 2019 — for a variety of reasons — 14 013 units of whole blood, 32 798 units of RBCs, 49 285 units of FFP, 1334 units of cryoprecipitate, 4778 units of pooled PCs and 1279 of apheresis PCs were wasted. Conclusions: Our study data may be considered as starting point for assessment of the tendencies observed in the Polish blood transfusion service and may serve practical-benchmarking with benefit to the transfusion community as a whole.

Background: The ongoing demographic changes in Poland affect the number of donors and donations with direct impact on provision of blood and blood components for transfusion. With predicted population-decline, the number of potential donors is likely to decrease while the demand for blood is bound to increase as more people will require blood therapy. The structure of the Polish donor population reporting for blood donation is not uniform, moreover it has undergone additional changes within the study period. So it seems justified to perform in-depth analysis of the dynamics of changes in the number and structure of donor group as well as determine the direction and intensity of these changes in spatial and temporal terms. Identification of the possible causes of change is also important. Aim: presentation of the structure characteristics of the donor group who reported at the Polish regional blood transfusion centers (RBTCs) in the period 2005–2017 with the intention of donating blood/ blood components. Materials and methods: Analyses of available data-sets — annual reports from 21 Polish RBTCs forwarded to the IHTM. The following tools were used for statistical analysis: Microsoft Office: Access and Excel, Microsoft Power Business Intelligence (Power BI) software and STATISTICA version 13.3 software (TIBCO Software Inc.). Results: In 2005–2017 the total number of donors amounted to 8 691 611 including 2 542 621 (29.3%) women and 6 148 990 (70.7%) men. Voluntary non-remunerated donors were estimated at 8 684 069 (99.9%). The average annual number of donors per RBTC was 31 837 and included 31 809 voluntary non-remunerated donors; 22 524 men and 9314 women. Countrywide, the highest number was reported for the period 2011–2013; 701 882 (8.08%), 707 578 (8.14%) and 706 246 (8.13%) for respective years and for the period 2015–2016 the numbers were 718 887 (8.27%) and 706 476 (8.13%) respectively. The highest number for the period was reported by 5 RBTCs: Warsaw (951 068 — 10.94%), Katowice (748 841; 8.62%), Poznan (702 087; 8.08%), Krakow (651 057; 7.49%) and Wroclaw (556 357; 6.40%). In the number of 2 352 099 donors who have recently reported for blood donation at the RBTCs the 25–44 age group was the largest (48%). The least numerous was the 45–65 age group — 548 885 (ca. 11%). There were 2 030 692 donors in the 18–24 age category ( > 41% of the total donor-population).Trend-analysis demonstrated an upward tendency for the category of 25–44 age donors and a downward one for the 18–24 age category. No explicit trend was observed for the 45–65 age group. Conclusion: The number of blood donations in Poland has recently reached the limit of approximately 1 200 000 donations per year. To exceed this limit will be no easy task. All efforts must therefore be focused on promoting people’s willingness to donate blood. The analysis indicates a falling tendency for the 18–24 age group and a rising one for higher age groups, which only raises concern for the future. The priority is therefore to motivate people of all agegroups to donate blood and become multiple donors with special emphasis however on the very young people as they are the potential source for many years to come. Promotion of voluntary non-remunerated blood-donation among children is equally important; in several years’ time transfusion medicine will depend on their willingness to donate blood.

Quality assurance and safety of hematopoietic stem cells (HSC) with special emphasis on bacterial and fungal contamination is the prerequisite for any transplantation procedure. The aim was to determine the incidence rate of such contamination during processing of transplantation material with regard to HSC source: peripheral blood stem cell (PBSC), bone marrow (BM), or cord blood (CB). Analysis involved autologous and allogenic products dedicated for patients and comprised in all 4135 donations, including 112 BM (2.70%), 3787 PBSC (91.60%), and 236 CB (5.70%) processed in cell bank over the period 1996–2016. Aerobic and anaerobic contamination was determined.Analysis of the 20-year data revealed 42 contaminated products: 25 PBSC (0.66% of tested units) and 17 CB (7.20% of tested units). No microbial contamination of BM products was detected. Overall percentage of contaminated products was 1.01%, mostly with Staphylococcus epidermidis (61.36%). Bacterial contamination rate at cell bank is relatively low and processing in a closed system does not seem as crucial as might be expected. This is particularly true for BM components. Equally important are evaluation of donor’s medical status and condition of the puncture site for collection of source material. Implementation of appropriate sample collection procedures should help minimize the risk of false-positive results due to environmental contamination.

Background: Assessment of the basic aspects of the activity of the Polish Regional Blood Transfusion Centers (hereinafter referred to as Centers) in 2018. Materials and methods: Retrospective analysis of the 2018-data supplied by the Centers. Results: In 2018, blood and blood components were collected in 21 Centers and 132 local collection sites as well as during 13 189 mobile collections. The overall number of blood donors was estimated at 590 470; the majority were non-remunerated donors (589 897 — including 37 824 responders to donation appeals), 73 remunerated donors and 500 autologous donors. Most frequent were whole blood collections (1 184 311), least frequent — granulocyte concentrate collections (116) and red blood cell (RBC) collection by apheresis (31 donations). Whole blood was collected mostly in local collection sites (44.85%), less frequently in Centers (28.47%) and at mobile collection sites (26.67%). Most frequently prepared blood components were RBC — 1 161 600 units) and fresh frozen plasma (FFP — 1 298 216 units; 20.93% dedicated for clinical use). Platelet concentrates (PCs) collected by apheresis amounted to 50 255 units and 83 598 were whole blood-derived. Additional processing methods such as leukocyte depletion and irradiation were more frequently applied to PCs (32.56% leukocyte depleted, 1.37% irradiated, 58.07% both leukocyte depleted and irradiated) than to RBCs (17.29% leukocyte depleted, 0.31% irradiated, 8.94% both leukocyte depleted and irradiated). Pathogen reduction technologies were applied to 11.74% of PCs and 10.23% units of FFP issued for transfusion. In 2018 — for various reasons — 14 067 units of whole blood, 30 521 units of RBC, 49 979 units of FFP, 1376 units of cryoprecipitate, 5186 units of pooled PCs and 1625 of apheresis PCs were wasted. Conclusions: The study data may contribute to evaluation of the tendencies observed in Centers and may serve practical-benchmarking which in turn may prove beneficial to the transfusion community as a whole.

Background The quality of platelet concentrates (PCs) is affected by preparation, storage, the type of container, and pathogen reduction technology (PRT). The Mirasol® Pathogen Reduction Technology (PRT) system (Terumo BCT Inc., Lakewood, USA), which uses riboflavin and ultraviolet (UV) light, has recently been proven effective against bacteria, viruses, parasites, and leukocytes. Objectives The aim of the study was to evaluate the effect of the Mirasol® PRT system, based on riboflavin and UV light exposure, on the most common in vitro platelet quality parameters of PCs prepared from whole blood-derived buffy coats. Material and methods The study included 15 trials (n = 15). For each trial, 2 PCs were used: 1 for treatment with the Mirasol® PRT system (M) and 1 for a control (C). In the M group, PCs were illuminated. In the C group, saline solution was added. PCs from groups M and C were stored at 20-24°C, with agitation. Samples were collected on days 1, 3 and 5 to determine platelet concentration, total platelet count/unit, mean platelet volume (MPV), power of hydrogen (pH), glucose and beta-thromboglobulin concentration (BTG), hypotonic shock response (HSR), aggregation, CD42b and CD62P expression, pCO2, and pO2. Results No significant differences in HSR or CD42b expression were observed between groups M and C. All pH values were stable during the whole storage period (7.1-7.5). On storage day 1, CD62P expression in group C was significantly higher than in group M. In the Mirasol® group, significantly higher glucose consumption was noted on storage days 3 and 5. On day 5, a 2-3-fold increase in BTG was observed in both groups as compared to day 1; on day 5, BTG concentration was 32% higher in group M than in group C. On all storage days, pCO2 was comparable in groups M and C; lower pO2 values were reported for group M. Conclusions In vitro results demonstrated that pH, HSR, aggregation, CD42b antigen expression, and MPV and platelet count parameters were comparable in groups M and C.

Background Until now, markers of hepatitis E virus (HEV) infection have not been studied in blood donors throughout Poland, and no acute case of HEV infection has been closely documented or confirmed by HEV RNA detection. The prevalence of HEV infection markers, including HEV RNA in Polish blood donors and virus genotypes was investigated. Study design and methods In total, 12,664 individual donations from 22 Polish blood transfusion centers were tested for HEV RNA by transcription-mediated amplification. In addition, 3079 first-time donors sampled throughout Poland also were screened for antibodies to HEV. HEV RNA and immunoglobulin M-positive donations were confirmed using real-time reverse transcription-polymerase chain reaction and Western blotting, respectively. Results Ten donors were identified as RNA initial reactive (one of 1266 donors), and six (one of 2109) were identified as repeat reactive and confirmed by real-time reverse transcription-polymerase chain reaction or seroconversion. Sequence analysis identified HEV Genotype 3c in one donor and Genotype 3i in two others. On average, 43.5% of donors were immunoglobulin G-positive. Immunoglobulin G seroprevalence ranged from 22.7% to 60.8% in group ages 18 to 27 years and 48 to 57 years, respectively and differed between administrative regions from 28.9% in Podlasie to 61.3% in Wielkopolska. Thirty-nine of the donors were immunoglobulin M-positive, and seven donors were IgM positive only (0.2%). Of 37 immunoglobulin M-reactive samples tested by Western blot, 24 (64.9%) were confirmed. Conclusions The current results indicate a high level of HEV endemicity throughout Poland compared with other countries. There is an urgent need to consider the protection of recipients of blood components against transfusion-transmitted HEV infection.

Source at https://doi.org/10.5114/aoms.2016.63600. Licensed CC BY-NC-ND 4.0. Introduction: Pregnant women negative for human platelet antigen 1a (HPA-1a) are at risk of alloimmunization with fetal HPA-1a antigen inherited from the father, and their offspring may develop fetal and neonatal alloimmune thrombocytopenia (FNAIT). The aim of this study was to analyze the frequency of HPA-1a alloimmunization in pregnant Polish women, the feasibility of using maternal platelets for intrauterine transfusions in women subjected to diagnostic fetal blood sampling (FBS) and to discuss potential consequences of alloimmunization. Material and methods: Fifteen thousand two hundred and four pregnant women were typed for HPA-1a; HPA-1a negative were screened for anti-HPA-1a. Alloimmunized women received specialist perinatology care; some of them were subjected to FBS, followed by transfusion of HPA-1a negative platelet concentrates (PC) prepared from maternal blood. Results: Three hundred seventy-three (2.5%) women were HPA-1a negative, and 32 (8.6%) tested positively for anti-HPA-1a. Antibodies were detected in 22 women during pregnancy. Diagnostic FBS followed by PC transfusion was performed in 14 woman, who were platelet donors for their 16 unborn babies. Blood donations were tolerated well by the patients, and also intrauterine platelet transfusions were uneventful. Pharmacotherapy with intravenous immunoglobulins was implemented in 11/22 patients. Conclusions: HPA-1a negative women (ca. 2.5% of all pregnant patients) are at risk of alloimmunization with HPA-1a antigen and developing FNAIT. Alloimmunized women can be donors of platelets for their offspring providing removal of antibodies from PC. Owing to potential complications, special care should be taken if an alloimmunized woman was qualified as a blood or stem cell recipient.

Until now, markers of hepatitis E virus (HEV) infection have not been studied in blood donors throughout Poland, and no acute case of HEV infection has been closely documented or confirmed by HEV RNA detection. The prevalence of HEV infection markers, including HEV RNA in Polish blood donors and virus genotypes was investigated.In total, 12,664 individual donations from 22 Polish blood transfusion centers were tested for HEV RNA by transcription-mediated amplification. In addition, 3079 first-time donors sampled throughout Poland also were screened for antibodies to HEV. HEV RNA and immunoglobulin M-positive donations were confirmed using real-time reverse transcription-polymerase chain reaction and Western blotting, respectively.Ten donors were identified as RNA initial reactive (one of 1266 donors), and six (one of 2109) were identified as repeat reactive and confirmed by real-time reverse transcription-polymerase chain reaction or seroconversion. Sequence analysis identified HEV Genotype 3c in one donor and Genotype 3i in two others. On average, 43.5% of donors were immunoglobulin G-positive. Immunoglobulin G seroprevalence ranged from 22.7% to 60.8% in group ages 18 to 27 years and 48 to 57 years, respectively and differed between administrative regions from 28.9% in Podlasie to 61.3% in Wielkopolska. Thirty-nine of the donors were immunoglobulin M-positive, and seven donors were IgM positive only (0.2%). Of 37 immunoglobulin M-reactive samples tested by Western blot, 24 (64.9%) were confirmed.The current results indicate a high level of HEV endemicity throughout Poland compared with other countries. There is an urgent need to consider the protection of recipients of blood components against transfusion-transmitted HEV infection.

Background Leukocytes in transfused blood components, particularly residual lymphocytes, have been shown to contribute to the occurrence of various adverse reactions. One of the most severe is transfusionassociated graft versus host disease (TA-GvHD) following transfusion of blood components contaminated with immunocompetent T lymphocytes. Irradiation is a routine method for protection against TA-GvHD. According to the literature, some pathogen reduction methods have also been proven effective for the inactivation of T lymphocytes, and so they may be considered as an alternative to irradiation. Objectives Comparison of CD69 antigen expression and the integrity of the leukocyte cellular membrane in stored platelet concentrates (PCs) following irradiation with the Gammacell 3000 Elan (Nordion Inc., Ottawa, Canada) and treatment with the Mirasol® Pathogen Reduction Technology (PRT) System (Terumo BCT, Lakewood, USA). Material and methods The study included seven experiments. For each experiment we used 3 PCs, for Mirasol® PRT System treatment (M), for Gammacell 3000 Elan irradiation (R), and for the control (C). 7-amino-actinomycin D (7-AAD, Becton Dickinson, Franklin Lakes, USA) permeability was used to determine lymphocyte viability while CD69 antigen expression was the marker of lymphocyte activation. Analyses of 7-AAD and CD69 antigen expression were performed in a FACS Canto I flow cytometer (Becton Dickinson, USA). Results During 6 storage days, viable lymphocyte count decreased to 28% (p = 0.001) in the Mirasol® PRT System treated PCs and to 65% (p = 0.004) in the irradiated PCs. A statistically significant increase in CD69 expression in the irradiated PCs was observed; 1.3-fold on day 3 and 1.5-fold on day 6. In the Mirasol ® PRT System treated PCs, no statistically significant increase was observed. Conclusions The in vitro results suggest that the Mirasol® PRT System is as effective as irradiation due to donor leukocyte inactivation capacity.

Background Cord blood (CB) is a valuable source of hematopoietic stem cells (HSCs). Extended storage of CB is possible provided that validated cryopreservation procedures are used. The study objective was to determine optimal methods of CB cryopreservation. Study design and methods In the study we 1) compared the effect of two-step cryopreservation and controlled-rate freezing method on the postthaw quality of CB (Study A) and 2) evaluated the postthaw quality of HSC fractions isolated from CB with various methods and frozen with controlled-rate freezing method (Study B). The same cryoprotectant mixture was used for 20 CB units (Study A) and 122 CB units (Study B). Results In Study A, 13.79 × 10(8) and 13.29 × 10(8) initial white blood cell (WBC) counts decreased to 6.38 × 10(8) and 6.02 × 10(8) after thaw for the two methods, respectively. The mononuclear cell (MNC) counts decreased from 5.90 × 10(8) to 3.71 × 10(8) and from 5.64 × 10(8) to 3.47 × 10(8) dependent on the method. MNC viability decreased from 99.0% to 97.4% for the former and from 98.5% to 97.2% for the latter method. The differences were insignificant. In Study B, postthaw WBC recovery in HSC fractions was 74.4% to 103.5%, MNC recovery 106.4% to 118.5%, CD34+ cell recovery 102.5% to 150.2%, and MNC viability 94.1% to 97.4%. Conclusion Neither the cryopreservation procedure nor the freezing of isolated HSCs affected product quality, which may indicate that various freezing methods can be used for cell banking provided the they follow recommendations of good manufacturing practice and Directive 2004/33/EC.

The activity of the Polish Blood Transfusion Service (BTS) is based on the Public Blood Transfusion Service Act sanctioned by the Polish Parliament. There are 21 regional Blood Transfusion Centers

To study whether the adhesion of colon cancer cells to E-selectin can be directly affected by changes in the expression level of sialosyl Le(a) antigen we created a specific loss-of-function phenotype. A stable subclone (CX-1.1) with high expression of sialosyl Le(a) structure, obtained from a heterogenous population of colon carcinoma CX-1 cells, was transfected with an expression vector containing a fragment of cDNA for alpha1,3/4-fucosyltransferase in antisense orientation. After transfection, the cell line was isolated which did not express sialosyl Le(a) antigen and lacked the alpha1,3/4-fucosyltransferase activity, despite an unchanged level of mRNA specific for this enzyme. It was found that the specific lack of expression of sialosyl Le(a) carbohydrate structure on the surface of colon cancer cells completely abolished their adhesion to E-selectin. To evaluate which cellular glycoconjugates carry sialosyl Le(a) antigen, glycoproteins as well as glycolipids of CX-1.1 cells were analysed for the expression of this structure. Anti-sialosyl Le(a) antibodies detected multiple glycoprotein bands with apparent molecular masses of 65-280 kDa on western blots, and an intense band representing sialosyl Le(a)-ganglioside on a thin-layer chromatogram. Using O-sialoglycoprotease from Pasteurella haemolytica and an alkaline beta-elimination procedure, it was shown that protein-linked sialosyl Le(a) structures are carried mostly by mucin-type glycoproteins. However, treatment of CX-1.1 cells with O-sialoglycoprotease did not decrease either their binding to E-selectin-expressing Chinese hamster ovary cells, or binding of anti-sialosyl Le(a) antibodies to the cell surface. These results suggested that cleavage of sialomucins uncovered cryptic sialosyl Le(a)-ganglioside, which was inaccessible for the antibody and E-selectin in untreated cells. This hypothesis was confirmed to some extent by the higher accessibility of gangliosides to galactose oxidase on the surface of O-sialoglycoprotease-treated CX-1.1 cells, comparing to untreated cells. We propose that glycoproteins as well as gangliosides carrying sialosyl Le(a) structures, when properly exposed and present in high density on surface of cancer cells, can effectively support the adhesion of cancer cells to E-selectin.

Cord blood (CB) is a valuable source of hematopoietic stem cells (HSCs). Extended storage of CB is possible provided that validated cryopreservation procedures are used. The study objective was to determine optimal methods of CB cryopreservation.In the study we 1) compared the effect of two-step cryopreservation and controlled-rate freezing method on the postthaw quality of CB (Study A) and 2) evaluated the postthaw quality of HSC fractions isolated from CB with various methods and frozen with controlled-rate freezing method (Study B). The same cryoprotectant mixture was used for 20 CB units (Study A) and 122 CB units (Study B).In Study A, 13.79 × 10(8) and 13.29 × 10(8) initial white blood cell (WBC) counts decreased to 6.38 × 10(8) and 6.02 × 10(8) after thaw for the two methods, respectively. The mononuclear cell (MNC) counts decreased from 5.90 × 10(8) to 3.71 × 10(8) and from 5.64 × 10(8) to 3.47 × 10(8) dependent on the method. MNC viability decreased from 99.0% to 97.4% for the former and from 98.5% to 97.2% for the latter method. The differences were insignificant. In Study B, postthaw WBC recovery in HSC fractions was 74.4% to 103.5%, MNC recovery 106.4% to 118.5%, CD34+ cell recovery 102.5% to 150.2%, and MNC viability 94.1% to 97.4%.Neither the cryopreservation procedure nor the freezing of isolated HSCs affected product quality, which may indicate that various freezing methods can be used for cell banking provided the they follow recommendations of good manufacturing practice and Directive 2004/33/EC.

H. W. Reesink, S. Panzer, C. A. Gonzalez, N. Lena, P. Muntaabski, S. Gimbatti, E. Wood, M. Lambermont, V. Deneys, D. Sondag, T. Alport, D. Towns, D. Devine, P. Turek, M.-K. Auvinen, T. Koski, C. K. Lin, C. K. Lee, W. C. Tsoi, E. Lawlor, G. Grazzini, V. Piccinini, L. Catalano, S. Pupella, H. Kato, S. Takamoto, H. Okazaki, I. Hamaguchi, J. C. Wiersum-Osselton, A. J. W. van Tilborgh, P. Y. Zijlker-Jansen, K. M. Mangundap, M. R. Schipperus, D. Dinesh, P. Flanagan, O. Flesland, C. T. Steinsvag, A. Espinosa, M. Letowska, A. Rosiek, J. Antoniewicz-Papis, E. Lachert, M. B. C. Koh, R. Alcantara, M. Corral Alonso & E. Muniz-Diaz

The activity of serum alpha-6-fucosyltransferase, a platelet derived enzyme, determined in sera of 22 normal individuals and 86 patients with various disorders was positively correlated with platelet counts. When the enzyme activity in 1 microliters serum was calculated per 1000 of platelets in blood (coefficient F/P) an inverse correlation became evident in that F/P was proportionally the higher the lower was platelet count in blood. The F/P values were in a good agreement with the results of direct assays of enzyme activities in isolated platelets. Neither granulocytes, lymphocytes nor red cells significantly contributed to serum enzyme activity though granulocytes enhanced the thrombin-induced enzyme release from platelets. In platelets separated by centrifugation in density gradients the enzyme was shown to be present in platelets of intermediate and high density but missing from the light ones. It is suggested that alpha-6-fucosyltransferase of platelets may be a marker of the ploidy level of megakaryocytes.

Abstract 2113 Poster Board II-90 The presence of white blood cells, particularly lymphocytes, in blood products has been shown to contribute to the development of a variety of adverse events including both donor anti-recipient and recipient anti-donor responses. Therefore leukoreduction of blood products or inactivation of leukocytes is necessary. We are currently using gamma-irradiation (Radiator Gammacell 3000 Elan) to inactivate leukocytes in blood components. This study shows the comparison of irradiation and PRT treatment (Mirasol*®) on lymphocyte survival and inactivation in non-leukoreduced platelet concentrates (PCs). PRT treatment is a pathogen reduction technology that targets nucleic acids after exposure to riboflavin and UV-light. We analyzed 7 untreated (C), 7 PRT treated (M) and 7 irradiated PCs (RD) in our study. Non-leukoreduced buffy coats (mean volume 65 ml) were obtained from the Regional Blood Center, Warsaw. PCs were prepared by pooling 15 buffy coats (ABO identical) suspended in 3 plasma units, and dividing the pool into 3 equal-weight units in bags made of the same material. Following addition of 35 ml of riboflavin solution, M units were illuminated. The same volume of saline solution, was added to the C group and RD units. All PCs were then stored at 22°C with agitation for 5 days. Samples were removed on days 1, 3 and 6 for analysis. The lymphocyte survival rate was determined by 7AAD (7-amino-actinomycin D staining of dead cells, Becton Dickinson) and their activation by anti-CD69-APC staining (Becton Dickinson). Samples were also stained with anti-CD45-PE antibodies to identify and gate on lymphocytes. Samples were analyzed on the Becton Dickinson Cytometer FACSCanto I. No increase in the number of dead cells was observed during 6 days of storage in the C group. After 3 days of storage however, in the M group the percentage of dead cells was significant higher than in C and RD groups (Student t-test, p=0.004 and p=0.03, respectively). After 6 days, the percentage of dead cells in the M samples was 72% vs. 30% following irradiation. The percentage of 7AAD-positive cells was significantly higher compare to C samples, both in M (p=0,001) and in RD samples (p=0,004). The percentage of dead lymphocytes was also observed to be statistically higher in M samples than in RD (p= 0,001). Analysis of lymphocyte activation was performed on live (7AAD-negative, CD45-positive) cells only. CD69 expression ranged between 20% and 40% in all tested samples (C, M, RD) during 6 days of storage. On days 1 and 3 of storage, Mirasol treatment significantly reduced lymphocyte activation as shown by the ratio (test/control) of %CD69-positive cells (p=0,004 and p=0,001, respectively) and mean fluorescence expression intensity of CD69. Interestingly, after 6 days of storage, RD samples showed significant higher lymphocyte activation then C and M samples (p=0,03 and p=0,02, respectively). In summary, a significant increase of dead lymphocytes after 6 days of storage was observed in PRT-treated PCs. This increase was two-fold higher than in gamma-irradiated PCs. At the same time a decrease in lymphocyte activation during 6 days of storage was observed in PRT-treated PCs. Overall, the use of PRT achieves better leukocyte inactivation than gamma-irradiation. Disclosures: No relevant conflicts of interest to declare.