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Background and Objectives: Blood safety measures used by blood establishments to increase blood component safety can be validated using Transfusion‐Relevant Bacterial Reference Strains (TRBRS). Ultra‐cold storage conditions and manual preparation of the current TRBRS may restrict their practical use. To address this issue, the ISBT Transfusion‐Transmitted Infectious Diseases Working Party's Bacterial Subgroup organized an international study to validate TRBRS in a user‐friendly, lyophilised format. Materials and Methods: Two bacterial strains Klebsiella pneumoniae PEI‐B‐P‐08 and Staphylococcus aureus PEI‐B‐P‐63 were manufactured as lyophilised material. The lyophilised bacteria were distributed to 11 different labs worldwide to assess the robustness for enumeration, identification and determination of growth kinetics in platelet concentrates (PCs). Results: Production of lyophilised TRBRS had no impact on the growth properties compared with the traditional format. The new format allows a direct low‐quantity spiking of approximately 30 bacteria in PCs for transfusion‐relevant experiments. In addition, the lyophilised bacteria exhibit long‐term stability across a broad temperature range and can even be directly rehydrated in PCs without losing viability. Interlaboratory comparative study demonstrated the robustness of the new format as 100% of spiked PC exhibited growth. Conclusion: Lyophilised TRBRS provide a user‐friendly material for transfusion‐related studies. TRBRS in the new format have improved features that may lead to a more frequent use in the quality control of transfusion‐related safety measures in the future. [ABSTRACT FROM AUTHOR]

Background and Objectives: Platelet concentrates (PC) are stored at 20–24°C to maintain platelet functionality, which may promote growth of contaminant bacteria. Alternatively, cold storage of PC limits bacterial growth; however, data related to proliferation of psychotrophic species in cold‐stored PC (CSP) are scarce, which is addressed in this study. Materials and Methods: Eight laboratories participated in this study with a pool/split approach. Two split PC units were spiked with ~25 colony forming units (CFU)/PC of Staphylococcus aureus, Klebsiella pneumoniae, Serratia liquefaciens, Pseudomonas fluorescens and Listeria monocytogenes. One unit was stored under agitation at 20–24°C/7 days while the second was stored at 1–6°C/no agitation for 21 days. PC were sampled periodically to determine bacterial loads. Five laboratories repeated the study with PC inoculated with lyophilized inocula (~30 CFU/mL) of S. aureus and K. pneumoniae. Results: All species proliferated in PC stored at 20–24°C, reaching concentrations of ≤109 CFU/mL by day 7. Psychrotrophic P. fluorescens and S. liquefaciens proliferated in CSP to ~106 CFU/mL and ~105 CFU/mL on days 10 and 17 of storage, respectively, followed by L. monocytogenes, which reached ~102 CFU/mL on day 21. S. aureus and K. pneumoniae did not grow in CSP. Conclusion: Psychrotrophic bacteria, which are relatively rare contaminants in PC, proliferated in CSP, with P. fluorescens reaching clinically significant levels (≥105 CFU/mL) before day 14 of storage. Cold storage reduces bacterial risk of PC to levels comparable with RBC units. Safety of CSP could be further improved by implementing bacterial detection systems or pathogen reduction technologies if storage is beyond 10 days. [ABSTRACT FROM AUTHOR]

Background: Blood donors at the extremes of the age spectrum (16–19 years vs. ≥75 years) are characterized by increased risks of iron deficiency and anemia, and are often underrepresented in studies evaluating the effects of donor characteristics on red blood cells (RBC) transfusion effectiveness. The aim of this study was to conduct quality assessments of RBC concentrates from these unique age groups. Study design: We characterized 150 leukocyte‐reduced (LR)‐RBCs units from 75 teenage donors, who were matched by sex, and ethnicity with 75 older donors. LR‐RBC units were manufactured at three large blood collection centers in the USA and Canada. Quality assessments included storage hemolysis, osmotic hemolysis, oxidative hemolysis, osmotic gradient ektacytometry, hematological indices, and RBC bioactivity. Results: RBC concentrates from teenage donors had smaller (9%) mean corpuscular volume and higher (5%) RBC concentration compared with older donors counterparts. Stored RBCs from teenage donors exhibited increased susceptibility to oxidative hemolysis (>2‐fold) compared with RBCs from older donors. This was observed at all testing centers independent of sex, storage duration, or the type of additive solution. RBCs from teenage male donors had increased cytoplasmatic viscosity and lower hydration compared with older donor RBCs. Evaluations of RBC supernatant bioactivity suggested that donor age was not associated with altered expression of inflammatory markers (CD31, CD54, and IL‐6) on endothelial cells. Conclusions: The reported findings are likely intrinsic to RBCs and reflect age‐specific changes in RBC antioxidant capacity and physical characteristics that may impact RBC survival during cold storage and after transfusion. [ABSTRACT FROM AUTHOR]

Background: Structural and biochemical changes in stored platelets are influenced by collection and processing methods. This international study investigates the effects of platelet (PLT) processing and storage conditions on HMGB1, sCD40L, and sCD62P protein levels in platelet concentrate supernatants (PCs). Study Design/Methods: PC supernatants (n = 3748) were collected by each international centre using identical centrifugation methods (n = 9) and tested centrally using the ELISA/Luminex platform. Apheresis versus the buffy coat (BC‐PC) method, plasma storage versus PAS and RT storage versus cold (4°C) were investigated. We focused on PC preparation collecting samples during early (RT: day 1–3; cold: day 1–5) and late (RT: day 4–7; cold: day 7–10) storage time points. Results: HMGB1, sCD40L, and sCD62P concentrations were similar during early storage periods, regardless of storage solution (BC‐PC plasma and BC‐PC PAS‐E) or temperature. During storage and without PAS, sCD40L and CD62P in BC‐PC supernatants increased significantly (+33% and +41%, respectively) depending on storage temperature (22 vs. 4°C). However, without PAS‐E, levels decreased significantly (−31% and −20%, respectively), depending on storage temperature (22 vs. 4°C). Contrastingly, the processing method appeared to have greater impact on HMGB1 release versus storage duration. These data highlight increases in these parameters during storage and differences between preparation methods and storage temperatures. Conclusions: The HMGB1 release mechanism/intracellular pathways appear to differ from sCD62P and sCD40L. The extent to which these differences affect patient outcomes, particularly post‐transfusion platelet increment and adverse events, warrants further investigation in clinical trials with various therapeutic indications. [ABSTRACT FROM AUTHOR]

Platelet components are commonly transfused to patients for a variety of indications, including patients with low platelet counts or patients with platelet dysfunction who are bleeding or at high risk of bleeding. Although the risk of pathogen contamination of platelet components has declined significantly over the last 40 years, it remains a concern for the patients, for blood banks and for physicians. Pathogen inactivation (PI) technologies have been developed to mitigate this risk. This review focuses on the residual risks of transfusion‐transmitted bacterial infections by platelet transfusion after PI. We describe and assess the relationship between the bacterial load and the timing and capacity of reduction of the different PI technologies, as well as the risks that could represent spore‐forming microorganisms and the possible introduction of microorganisms after PI. [ABSTRACT FROM AUTHOR]

The use of a six-day multiple-simulation exercise in the military disaster medical services training program of the Uniformed Services University of the Health Sciences is described. It is the second part of a clerkship that includes a classroom/laboratory phase using a disaster problem-solving board game. (MSE)

Previously, the authors have shown that tracheal occlusion (TO) partially reverses the onset of congenital diaphragmatic hernia (CDH)-induced pulmonary hypertension (PH) and abnormal pulmonary vascular development whereas release of the occlusion (TR) abolishes these clinical benefits. As a consequence of their mitogenic and vasoactive properties, the authors hypothesize that the expression of endothelin (ET)-1 and ET receptor (ET A ) genes is increased in lungs of CDH lambs, and that this increase is abolished partially in CDH?+?TO but not in CDH?+?TO?+?TR. A surgical left-sided CDH was created in fetal lambs at 80 days of gestation (gd), followed by TO at 108?gd, and by TR at 129?gd. Four groups were compared: CDH, CDH?+?TO, CDH?+?TO?+?TR, and nonoperated controls (C). Assessment of mRNA expression by Northern blot showed significantly lower ET-1 and ET A levels in the CDH group than in the CDH?+?TO±TR groups ( P ? [ABSTRACT FROM AUTHOR]