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Background and Objectives: Bacterial contamination represents the major infectious hazard associated with transfusion of platelet concentrates (PCs). As bacterial screening of PCs is not mandatory in Germany, the BactiFlow flow cytometry test has been introduced as a rapid detection method to increase product safety., Materials and Methods: During a period of 25 months, a total of 34 631 PCs (26 411 pooled and 8220 apheresis-derived PCs) were tested at the end of day 3 of their shelf life using the BactiFlow system. PCs initially reactive in BactiFlow testing and expired PCs not reactive in BactiFlow on day 3 were also investigated by the BacT/ALERT system and by microbiological cultivation in order to identify the contaminating bacterial species and to confirm reactive BactiFlow results., Results: Two hundred and twenty-eight PCs (0.7%) had an initially reactive result, 24 of them remained reactive in a second test run. Out of these reproducible reactive BactiFlow results, 12 could not be verified by parallel BacT/ALERT culturing, resulting in a confirmed false-positive rate of 0.03%. The bacterial species were identified as S. aureus, S. epidermidis, S. dysgalactiae ssp. equisimilis and B. cereus. In 10 out of 9017 expired PCs (0.11%), a confirmed-positive result was obtained in the BacT/ALERT system which had a negative result in the BactiFlow system., Conclusion: Testing of PCs by BactiFlow was successfully implemented in our blood donation service and proved sufficient as a rapid and reliable screening method. False reactive results are in an acceptable range since the transfusion of 12 bacterially contaminated PCs was prevented., (© 2014 International Society of Blood Transfusion.)

Background: There is growing concern on the residual risk of bacterial contamination of platelet concentrates in Germany, despite the reduction of the shelf-life of these concentrates and the introduction of bacterial screening. In this study, the applicability of the BactiFlow flow cytometric assay for bacterial screening of platelet concentrates on day 2 or 3 of their shelf-life was assessed in two German blood services. The results were used to evaluate currently implemented or newly discussed screening strategies., Materials and Methods: Two thousand and ten apheresis platelet concentrates were tested on day 2 or day 3 after donation using BactiFlow flow cytometry. Reactive samples were confirmed by the BacT/Alert culture system., Results: Twenty-four of the 2,100 platelet concentrates tested were reactive in the first test by BactiFlow. Of these 24 platelet concentrates, 12 were false-positive and the other 12 were initially reactive. None of the microbiological cultures of the initially reactive samples was positive. Parallel examination of 1,026 platelet concentrates by culture revealed three positive platelet concentrates with bacteria detected only in the anaerobic culture bottle and identified as Staphylococcus species. Two platelet concentrates were confirmed positive for Staphylcoccus epidermidis by culture. Retrospective analysis of the growth kinetics of the bacteria indicated that the bacterial titres were most likely below the diagnostic sensitivity of the BactiFlow assay (<300 CFU/mL) and probably had no transfusion relevance., Conclusions: The BactiFlow assay is very convenient for bacterial screening of platelet concentrates independently of the testing day and the screening strategy. Although the optimal screening strategy could not be defined, this study provides further data to help achieve this goal.

Background and Objectives: National guidelines for monitoring bacterial contamination of blood components were introduced in Germany in 1997. Between 1998 and 2002, numerous measures were implemented to prevent bacterial contamination. This study investigates their impact on contamination rates., Materials and Methods: Culture-based testing for bacterial detection on a random sample of blood components is part of routine quality control in German blood establishments. Using standardized questionnaires, data from the production periods 1998, 2001 and 2005/2006 were collected and analysed., Results: The bacterial contamination rate of RBCs was reduced from 0·157% in 1998 to 0·029% in 2005/2006 (P<0·001). While the contamination rate of apheresis PCs remained nearly unchanged over the years, it dramatically decreased for pooled PCs by 70% to a contamination rate of 0·158% (P=0·001) within the last observation period, similar to that of apheresis PCs. The contamination rate of plasma decreased from 0·100% in 1998 to 0·019% in 2005/2006 (P=0·002)., Conclusions: Precautionary measures significantly reduced bacterial contamination rates of blood components. Long-term monitoring with standardized methods is appropriate to evaluate the cumulative effect of contamination-preventing measures., (© 2010 The Author(s). Vox Sanguinis © 2010 International Society of Blood Transfusion.)

SUMMARY: Requirements for bacterial testing of blood components on a defined quantity as part of routine quality control were introduced in Germany by the National Advisory Committee Blood of the German Federal Ministry of Health in 1997. The philosophy was to establish standardized methods for bacterial testing. Numerous measures to reduce the risk of bacterial contamination were implemented into the blood donation and manufacturing processes between 1999 and 2002. German Blood establishments performed culture-based bacterial testing on random samples of platelet concentrates (PCs), red blood cells (RBCs) and fresh frozen plasma (FFP) and reported data out of the production periods 1998, 2001 and 2005/2006. While the bacterial contamination rate of apheresis PCs remained nearly unchanged, it decreased by 70% for pooled PCs to a rate of 0.158% in the last observation period. Leukocyte-depleted RBCs with diversion of the initial blood volume showed a contamination rate of 0.029% which is significantly lower than that of RBCs without leukocyte depletion and diversion (0.157%). The contamination rate of plasma decreased by 80%. Preventive measures resulted in a significant reduction of bacterial contamination of blood components. Long-term monitoring with standardized methods for bacteria testing supports evaluation of the cumulative effect of contamination reducing measures.

A critical aspect of blood transfusion is the timely provision of high quality blood products. This task remains a significant challenge for many blood services and blood systems reflecting the difficulty of balancing the recruitment of sufficient donors, the optimal utilization of the donor's gift, the increasing safety related restrictions on blood donation, a growing menu of specialized blood products and an ever-growing imperative to increase the efficiency of blood product provision from a cost perspective. As our industry now faces questions about our standard practices including whether or not the age of blood has a negative impact on recipients, it is timely to take a look at our collective inventory management practices. This International Forum represents an effort to get a snap shot of inventory management practices around the world, and to understand the range of different products provided for patients. In addition to sharing current inventory management practices, this Forum is intended to foster an exchange of ideas around where we see our field moving with respect to various issues including specialty products, new technologies, and reducing recipient risk from blood transfusion products.

Screening of platelet concentrates (PCs) for bacterial contamination with cultivation methods is carried out as a routine procedure in some countries. The aim is to prevent the transfusion of contaminated PCs. The German Evaluation of Regular Monitoring Study Group conducted a prospective multicenter study on 52,243 PCs to investigate the prevalence of bacteria (BacT/ALERT, bioMerieux). This study describes the detected bacterial spectrum, the proportion of PCs with a positive test result that had been transfused, and the results of the clinical follow-up. One hundred thirteen (67%) of 169 potentially or confirmed positive units had already been transfused at the time of the first positive signal. The transfusion of units contaminated by Staphylococcus aureus, Serratia marcescens, and 73% of the units contaminated with Staphylococcus epidermidis, Staphylococcus capitis, or Staphylococcus saccharolyticus was prevented. In contrast, 85% of units with Propionibacterium acnes were transfused. A clonal relationship of the isolates from the pooled PCs and from the associated red blood cell concentrates was found in all investigated cases. The follow-up revealed six febrile reactions to culture-positive PCs not classified as transfusion reaction (TRs) by treating physicians. This demonstrates the importance of hemovigilance. Serious septic reactions due to Klebsiella pneumoniae in two units of one apheresis PC that had tested false-negative were reported; one had a fatal outcome. Culture systems reduce the risk of transfusion of contaminated PCs but cannot guarantee sterility. Physicians must be aware of bacterial contamination of PCs as a potential cause of TRs and must report all adverse events.

Successful reduction of the risk of viral transmission via blood components has focused attention on the risk of transfusion-associated bacterial sepsis. The incidence of transfusion reactions due to bacteria is currently estimated at between 1 per 100,000 and 1 per 1,000,000 units in the case of packed red blood cells and between 1 per 900 and 1 per 100,000 units in the case of platelet concentrates. For autologous transfusion, only isolated case reports are available which do not permit a quantitative risk assessment. No reliable data on the risk of morbidity and mortality due to transfusion-associated bacterial infection are available for Germany at present. As platelet concentrates provide more favourable conditions for bacterial growth by virtue of being stored at room temperature, these blood components are thought to bear a considerably greater risk of bacterial contamination than red blood cells. The rate of contamination of platelet concentrates is cited at between 0.02% and 1.2%, depending on the production and bacterial culture techniques used, whereas the rate for packed red blood cells is between 0.1% and 0.2%. Risk reduction strategies include careful selection of blood donors, optimisation of donation and production techniques, and detection of bacteria in samples of blood components prior to transfusion. Also of importance for patient safety are quality assurance measures in the preparation for transfusion, in measures of patient monitoring, and investigation of transfusion reactions.

Background: The GERMS Group initiated a prospective multicenter study to assess prevalence and nature of bacterial contamination of pooled buffy-coat platelet concentrates (PPCs) and apheresis platelet concentrates (APCs) by routine screening with a bacterial culture system., Study Design and Methods: In nine centers overall, 52,243 platelet (PLT) concentrates (15,198 APCs, 37,045 PPCs) were analyzed by aerobic and anaerobic cultures (BacT/ALERT, bioMérieux)., Results: In 135 PLT concentrates (PCs; 0.26%), bacteria could be identified in the first culture (0.4% for APCs vs. 0.2% for PPCs; p < 0.001). In 37 (0.07%) of these PC units, the same bacteria strain could be identified in a second culture from the sample bag and/or the PC unit. The rate of confirmed-positive units did not differ significantly between APC (0.09%; 1/1169) and PPC units (0.06%; 1/1544). Bacteria from skin flora (Propionibacterium acnes, Staphylococcus epidermidis) were the most prevalent contaminants. Median times to first positive culture from start of incubation were 0.7 and 3.7 days in aerobic and anaerobic cultures for confirmed-positive units. With a "negative-to-date" issue strategy, most PC units (55%) had already been issued by time of the first positive culture., Conclusion: The rate of confirmed bacterial contamination of PC units was low. Nevertheless, clinicians must be aware of this risk. The risk of bacterial contamination does not warrant universal preference of APCs. It must be questioned whether routine bacterial screening by a culture method can sufficiently prevent contaminated products from being transfused due to the delay until a positive signal in the culture system and due to false-negative results.

Background and Objectives: Since 2004, bacterial screening of platelets has been required in the USA and is also done on a voluntary basis in many European countries. The German Red Cross blood donor services conducted a prospective multicentre study in order to investigate the prevalence of bacterially contaminated pool platelet concentrates and apheresis platelet concentrates. This substudy compares three different bacterial detection systems., Study Design and Methods: Platelet concentrates were tested in parallel with BacT/ALERT, Scansystem and Pall eBDS (n = 6307) in pool platelets. Apheresis platelets were tested in parallel with BacT/ALERT and Pall eBDS (n = 4730). All initially positive results were evaluated by a standardized procedure including evaluation by a microbiology reference laboratory., Results: One in 6307 pool platelets were confirmed positive by BacT/ALERT, whereas Pall eBDS and Scansystem failed to detect these samples. Only three samples were initially reactive with Pall eBDS without proof of any bacteria strains. The rate of false-positive results was substantially higher for BacT/ALERT (0.25%, 28 in 11,037 tested samples) than for eBDS (0.03%, 3 in 11 037 tested samples) or Scansystem (0.0%, 0 in 6307 tested samples). Three of 4730 apheresis platelets were confirmed positive by BacT/ALERT. These were negative with Pall eBDS., Conclusion: Sensitivity was best for BacT/ALERT, whereas specificity was enhanced for Pall eBDS and Scansystem. Scansystem required specially trained staff, whereas BacT/ALERT and Pall eBDS were easy, quick, user-friendly and objective methods.

Background and Objectives: National guidelines for monitoring the bacterial contamination rate of blood components were introduced in Germany in 1997. The objective of this study was to present and evaluate the results of sterility testing of platelet concentrates (PCs) prepared by different methods., Materials and Methods: The analysis of results of sterility testing of blood component production from transfusion medicine centres in Germany in 1998 and 2001 was based on information collected using standardized questionnaires., Results: The bacterial contamination rates for single-donor PCs derived from whole blood and apheresis (0.210% vs. 0.156%) were comparable and showed no significant difference. However, pooled PCs produced from four buffy coats using the sterile docking procedure showed a significantly higher bacterial contamination rate compared with single-donor PCs derived from whole blood and apheresis (0.184% vs. 0.604%)., Conclusions: Use of standardized methods for sterility monitoring is sufficient to assess collection and production processes in terms of hygiene and yields reliable data on bacterial contamination rates of blood components. The methods described are suitable for using to analyse the efficiency of newly introduced methods to reduce bacterial contamination rates of blood components (e.g. diversion, bacteria screening and pathogen inactivation).

Objective of the Study: The most common form of autologous blood transfusion is where blood is donated in anticipation of elective surgery. The aim of this study is to critically evaluate the product safety of autologous blood units., Methods: The results are based on an analysis of the documented data and records of 22,630 cases with 21,553 patients and 49,650 autologous blood donations, blood processing and testing protocols, and reported transfusion reactions following autologous transfusions., Results and Conclusions: Autologous blood components are prepared individually, and an established system of quality assurance with controls of processes and products is particularly important to meet quality standards. The red cell content of autologous units cannot be standardized as in allogeneic components. Due to the differences between the laboratory screening programmes for patients and donors, the risk of transmission of virus infections is different from that of allogeneic blood components. The quality of stored autologous red cells is comparable to that of allogeneic products. Results of systematic sterility monitoring lead to the conclusion that under the conditions practised the risk of transfusion-associated sepsis is not higher to that of allogeneic products. Soluble biological response modifiers which accumulate during storage, are assumed to be the cause of reactions that occur in one of 4,500 autologous transfusions. Incorrect allocation and handling errors continue to be a serious problem in autologous transfusions.

Ten years of quality control in routine have led to a standardized platelet concentrate (PC). Mean parameters of the preparations are in the range of pH 6.7-7.3, (1.0-1.5) x 10(9)/ml platelet concentration, 80 x 10(9) platelets/PC and 2 x 10(7) leukocytes/PC. To judge the function of PCs, three methods were compared: the morphologic score, platelet aggregation tests, and the hypotonic shock reaction. The result is: The hypotonic shock reaction is a simple, well reproducible and sensitive method to judge the cell integrity.

For transfusion therapy of premature infants special packed red cells '0 rh-negative, anti-CMV-negative, hemolysin-free' are of great value. To optimize the preparations, we examined the influence of leukocyte depletion, suspension in SAGM and irradiation on ATP level, pH, free hemoglobin and potassium level. Results show the advantage of filtration and SAGM solution especially in respect to the ATP level. Irradiation leads to an increase of potassium to a twofold level, but is not of clinical significance in running time.

The baroreceptor endings of the sinus nerve extend into the region of the external media, to the media-adventitia border, and into the adventitia of the wall of the carotid sinus. The size of the receptors, tightly filled with mitochondria, varies between 600 and 5,700 nm in diameter. The endings are accompanied by densely structured Schwann's cells, come into contact with the muscular-elastic system or are surrounded by the collagenous material of the vessel wall. This functional junction makes the reception of the tension in the vessel wall possible. Glycogen granules could be demonstrated in some axon endings. In kittens and older cats, numerous receptors were regularly found with various degrees of structural change: homogeneous and lamellar transformation of mitochondria, lamellar aggregates, lysis of axoplasm matrix, irregularities of tubules and vesicles. These modifications may be evaluated as the morphological expression of degeneration and regeneration processes. Physiological detrition is considered to be the cause for this.