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1.
Transfusion ; 2024 May 16.
Article de Anglais | MEDLINE | ID: mdl-38752406

RÉSUMÉ

BACKGROUND: Fetal and neonatal exposure to lead is associated with irreversible adverse effects on neural development. There is no reliable threshold for lead effect, so limiting exposure is recommended. A significant correlation has been reported between post-transfusion blood lead level (BLL) in infants and lead levels in transfused RBC units. We measured levels of lead, mercury, and cadmium, in Canadian donor blood to investigate if concerning levels for neonatal transfusion exist. STUDY DESIGN AND METHODS: Whole blood samples from blood donors (n = 2529) were shipped cold within 7 days of donation. All permanent blood donation clinics across Canada were sampled. Twelve of these permanent clinics and 8 mobile clinics with a greater potential for having higher lead or mercury levels were oversampled. Heavy metals were measured by inductively coupled plasma mass spectrometry. RESULTS: Of all donations, 2.2% (lead) and 0.4% (mercury) had levels higher than the recommended thresholds for safe neonatal transfusion. BLLs were higher in males but there was no significant difference in the blood mercury levels of males versus females. Cadmium levels were higher in females. There was a positive correlation between donor age and levels of heavy metals, with lead having the strongest correlation (r = 0.47, p < .0001). Three clinics in close proximity to two lead-producing mines were among the clinics with the highest BLLs. Significantly higher blood mercury levels were observed in coastal clinics. CONCLUSION: Our data on donor blood heavy metal levels supports considering blood transfusion as an exposure source to heavy metals and encourages informed selection of blood units for transfusion to vulnerable groups.

2.
Am J Physiol Lung Cell Mol Physiol ; 326(5): L589-L595, 2024 May 01.
Article de Anglais | MEDLINE | ID: mdl-38375568

RÉSUMÉ

Cold-stored (CS) platelets are once again being reintroduced for clinical use. Transfused CS platelets offer benefits over room temperature-stored (RTS) platelets such as increased hemostatic effects and prolongation of shelf-life. Despite these advantages little is known about their association with transfusion-related acute lung injury (TRALI). TRALI is associated with prolonged storage of RTS platelets and has a mortality of >15%. Determining the safety of CS platelets is important considering their proposed use in TRALI-vulnerable populations with inflammation such as surgical patients or patients with trauma. Donor platelet-derived ceramide causes TRALI, whereas donor platelet sphingosine-1-phosphate (S1P) is barrier protective. Females have higher plasma levels of S1P than males. Cold temperatures increase S1P levels in cells. Therefore, we hypothesized that female (donors or recipients) and/or CS platelets would decrease TRALI. To test this, we compared how male and female donor and recipient allogeneic platelet transfusions of CS (4°C) versus RTS (23°C) platelets stored for 5 days influence murine TRALI. Transfusion of CS platelets significantly reduced recipient lung tissue wet-to-dry ratios, bronchoalveolar lavage total protein, lung tissue myeloperoxidase enzyme activity, histological lung injury scores, and increased plasma sphingosine-1-phosphate (S1P) levels compared with RTS platelet transfusions. Female as opposed to male recipients had less TRALI and higher plasma S1P levels. Female donor mouse platelets had higher S1P levels than males. Mouse and human CS platelets had increased S1P levels compared with RTS platelets. Higher recipient plasma S1P levels appear protective considering females, and males receiving platelets from females or male CS platelets had less TRALI.NEW & NOTEWORTHY Transfusion-related acute lung injury (TRALI) though relatively rare represents a severe lung injury. The sphingolipid sphingosine-1-phosphate (S1P) regulates the severity of platelet-mediated TRALI. Female platelet transfusion recipient plasmas or stored platelets from female donors have higher S1P levels than males, which reduces TRALI. Cold storage of murine platelets preserves platelet-S1P, which reduces TRALI in platelet-transfused recipients.


Sujet(s)
Conservation de sang , Lysophospholipides , Sphingosine , Sphingosine/analogues et dérivés , Oedème pulmonaire lésionnel aigu post-transfusionnel , Lysophospholipides/sang , Lysophospholipides/métabolisme , Sphingosine/sang , Animaux , Femelle , Mâle , Souris , Conservation de sang/méthodes , Oedème pulmonaire lésionnel aigu post-transfusionnel/sang , Transfusion de plaquettes , Souris de lignée C57BL , Plaquettes/métabolisme , Humains , Lésion pulmonaire aigüe/sang , Lésion pulmonaire aigüe/étiologie , Lésion pulmonaire aigüe/prévention et contrôle
3.
Transfusion ; 64(1): 141-149, 2024 01.
Article de Anglais | MEDLINE | ID: mdl-38059437

RÉSUMÉ

BACKGROUND: Each unit of red blood cells (RBCs) produced represents a significant cost to the healthcare system. Unnecessary blood wastage should be minimized. In clinical settings, alterations to blood component bags after issue from the protected setting of the blood bank include pen markings, and those that are exposed to an infectious environment require surface disinfecting. These units may be discarded due to unclear effects on RBC quality. In this study, we investigate whether pen markings or surface disinfection negatively affects the quality of packed RBCs and whether pen ink diffuses through the blood bag. STUDY DESIGN AND METHODS: RBC bags were marked with pens (water, oil, or alcohol-based) or subjected to surface disinfection (ethanol, hydrogen peroxide [Preempt wipes], or benzalkonium chloride-based wipes [CaviWipes]) and sampled 24 h after applying the treatment and at day 42 post collection (n = 3 for each condition). The samples were analyzed for RBC in vitro quality markers. The presence of any ink in the RBC bags was investigated using mass spectrometry (n = 2). RESULTS: Data from 24 h and day 42 time points indicated no differences in RBC count, mean corpuscular volume, morphology, deformability, potassium content, or hemolysis for either pen markings or disinfectants when compared with their untreated controls (p > .05). No trace of ink was detected inside the bag. CONCLUSION: RBC units marked with ballpoint, gel, or Sharpie pens do not suffer a loss of in vitro quality, nor do RBC units which have been surface disinfected with 70% ethanol, Preempt wipes or CaviWipes.


Sujet(s)
Désinfectants , Humains , Désinfectants/pharmacologie , Encre , Conservation de sang/méthodes , Érythrocytes , Poly(chlorure de vinyle)/composition chimique , Poly(chlorure de vinyle)/pharmacologie , Éthanol/pharmacologie , Composés chimiques organiques
4.
Transfus Med Rev ; 38(1): 150807, 2024 01.
Article de Anglais | MEDLINE | ID: mdl-38114340

RÉSUMÉ

Major traumatic hemorrhage is now frequently treated by early hemostatic resuscitation on hospital arrival. Prehospital hemostatic resuscitation could therefore improve outcomes for bleeding trauma patients, but there are logistical challenges. Freeze-dried plasma (FDP) offers indisputable logistical advantages over conventional blood products, such as long shelf life, stability at ambient temperature, and rapid reconstitution without specialized equipment. We sought high level, randomized, controlled evidence of FDP clinical efficacy in trauma. A structured systematic search of MEDLINE/PubMed was carried out and identified 52 relevant English language publications. Three studies involving 607 patients met our criteria: Resuscitation with Blood Products in Patients with Trauma-related Hemorrhagic Shock receiving Prehospital Care (RePHILL, n = 501); Prehospital Lyophilized Plasma Transfusion for Trauma-Induced Coagulopathy in Patients at Risk for Hemorrhagic Shock (PREHO-PLYO, n = 150); and a pilot Australian trial (n = 25). RePHILL found no effect of FDP plus packed red blood cells (PRBC) concentrate transfusion versus saline on mortality. PREHO-PLYO found no effect of FDP versus saline on International Normalized Ratio (INR) at hospital arrival. The pilot trial found that study of PRBC versus PRBC plus FDP was feasible during long air transport times to an Australian trauma centre. Further research is required to determine under what conditions FDP might provide prehospital benefit to trauma patients.


Sujet(s)
Hémostatiques , Choc hémorragique , Plaies et blessures , Humains , Choc hémorragique/étiologie , Choc hémorragique/thérapie , Transfusion de composants du sang , Plasma sanguin , Australie , Hémorragie/étiologie , Hémorragie/thérapie , Réanimation , Plaies et blessures/complications , Plaies et blessures/thérapie
5.
Sci Adv ; 9(48): eadi0508, 2023 12.
Article de Anglais | MEDLINE | ID: mdl-38039367

RÉSUMÉ

Platelet transfusions are essential for managing bleeding and hemostatic dysfunction and could be expanded as a cell therapy due to the multifunctional role of platelets in various diseases. Creating these cell therapies will require modifying transfusable donor platelets to express therapeutic proteins. However, there are currently no appropriate methods for genetically modifying platelets collected from blood donors. Here, we describe an approach using platelet-optimized lipid nanoparticles containing mRNA (mRNA-LNP) to enable exogenous protein expression in human and rat platelets. Within the library of mRNA-LNP tested, exogenous protein expression did not require nor correlate with platelet activation. Transfected platelets retained hemostatic function and accumulated in regions of vascular damage after transfusion into rats with hemorrhagic shock. We expect this technology will expand the therapeutic potential of platelets.


Sujet(s)
Plaquettes , Hémostatiques , Humains , Rats , Animaux , ARN messager/génétique , ARN messager/métabolisme , Plaquettes/métabolisme , Donneurs de sang , Hémostatiques/métabolisme
6.
Can J Anaesth ; 70(10): 1682-1700, 2023 10.
Article de Anglais | MEDLINE | ID: mdl-37831350

RÉSUMÉ

PURPOSE: Cold-stored platelets (CSP) are an increasingly active topic of international research. They are maintained at 1-6 °C, in contrast to standard room-temperature platelets (RTP) kept at 20-24 °C. Recent evidence suggests that CSP have superior hemostatic properties compared with RTP. This narrative review explores the application of CSP in adult cardiac surgery, summarizes the preclinical and clinical evidence for their use, and highlights recent research. SOURCE: A targeted search of MEDLINE and other databases up to 24 February 2022 was conducted. Search terms combined concepts such as cardiac surgery, blood, platelet, and cold-stored. Searches of trial registries ClinicalTrials.gov and WHO International Clinical Trials Registry Platform were included. Articles were included if they described adult surgical patients as their population of interest and an association between CSP and clinical outcomes. References of included articles were hand searched. PRINCIPAL FINDINGS: When platelets are stored at 1-6 °C, their metabolic rate is slowed, preserving hemostatic function for increased storage duration. Cold-stored platelets have superior adhesion characteristics under physiologic shear conditions, and similar or superior aggregation responses to physiologic agonists. Cold-stored platelets undergo structural, metabolic, and molecular changes which appear to "prime" them for hemostatic activity. While preliminary, clinical evidence supports the conduct of trials comparing CSP with RTP for patients with platelet-related bleeding, such as those undergoing cardiac surgery. CONCLUSION: Cold-stored platelets may have several advantages over RTP, including increased hemostatic capacity, extended shelf-life, and reduced risk of bacterial contamination. Large clinical trials are needed to establish their potential role in the treatment of acutely bleeding patients.


RéSUMé: OBJECTIF: Les plaquettes conservées au froid (PCF) sont un sujet de recherche internationale de plus en plus populaire. Ces plaquettes sont maintenues à une température de 1-6 °C, contrairement aux plaquettes standard conservées à température ambiante (PTA), maintenues à 20­24 °C. Des données probantes récentes suggèrent que les PCF ont des propriétés hémostatiques supérieures aux PTA. Ce compte rendu narratif explore l'application de PCF en chirurgie cardiaque chez l'adulte, résume les données probantes précliniques et cliniques de leur utilisation, et met en évidence les recherches récentes. SOURCES: Une recherche ciblée dans MEDLINE et d'autres bases de données jusqu'au 24 février 2022 a été effectuée. Les termes de recherche combinaient des concepts en anglais tels que cardiac surgery, blood, platelet et cold-stored (soit chirurgie cardiaque, plaquette, et entreposage frigorifique). Des recherches dans les registres d'études ClinicalTrials.gov et le système d'enregistrement international des essais cliniques (ICTRP) de l'OMS ont été incluses. Les articles ont été inclus s'ils décrivaient des patient·es adultes de chirurgie en tant que population d'intérêt et une association entre les PCF et les issues cliniques. Les références des articles inclus ont fait l'objet d'une recherche manuelle. CONSTATATIONS PRINCIPALES: Lorsque les plaquettes sont conservées entre 1 et 6 °C, leur taux métabolique est ralenti, préservant la fonction hémostatique pour une durée d'entreposage accrue. Les plaquettes conservées au froid ont des caractéristiques d'adhésion supérieures dans des conditions de cisaillement physiologique et des réponses d'agrégation similaires ou supérieures aux agonistes physiologiques. Les plaquettes conservées au froid subissent des changements structurels, métaboliques et moléculaires qui semblent les « amorcer ¼ pour une activité hémostatique. Bien que préliminaires, les données probantes cliniques appuient la réalisation d'études comparant les PCF aux PTA chez la patientèle présentant des saignements liés aux plaquettes, tels que les personnes bénéficiant d'une chirurgie cardiaque. CONCLUSION: Les plaquettes conservées au froid peuvent présenter plusieurs avantages par rapport aux PTA, notamment une capacité hémostatique accrue, une durée de conservation prolongée et un risque réduit de contamination bactérienne. De grands essais cliniques sont nécessaires pour établir leur rôle potentiel dans le traitement de la patientèle en hémorragie aiguë.


Sujet(s)
Procédures de chirurgie cardiaque , Hémostatiques , Adulte , Humains , Conservation de sang , Plaquettes/métabolisme , Basse température , Hémorragie , Hémostatiques/métabolisme
7.
Biomolecules ; 13(8)2023 07 25.
Article de Anglais | MEDLINE | ID: mdl-37627230

RÉSUMÉ

Adsorbing toxins from the blood to augment membrane-based hemodialysis is an active area of research. Films composed of ß-cyclodextrin-co-(methacryloyloxy)ethyl phosphorylcholine (p(PMßCD-co-MPC)) with various monomer ratios were formed on magnetic nanoparticles and characterized. Surface chemistry effects on protein denaturation were evaluated and indicated that unmodified magnetic nanoparticles greatly perturbed the structure of proteins compared to coated particles. Plasma clotting assays were conducted to investigate the stability of plasma in the presence of particles, where a 2:2 monomer ratio yielded the best results for a given total surface area of particles. Total protein adsorption results revealed that modified surfaces exhibited reduced protein adsorption compared to bare particles, and pure MPC showed the lowest adsorption. Immunoblot results showed that fibrinogen, α1-antitrypsin, vitronectin, prekallikrein, antithrombin, albumin, and C3 correlated with film composition. Hemocompatibility testing with whole blood illustrated that the 1:3 ratio of CD to MPC had a negative impact on platelets, as evidenced by the increased activation, reduced response to an agonist, and reduced platelet count. Other formulations had statistically significant effects on platelet activation, but no formulation yielded apparent adverse effects on hemostasis. For the first time, p(PMßCD-co-MPC)-coated MNP were synthesized and their general hemocompatibility assessed.


Sujet(s)
Nanoparticules de magnétite , Phosphoryl-choline , Adsorption , Antithrombine-III , Coagulation sanguine
8.
Vox Sang ; 118(10): 817-824, 2023 Oct.
Article de Anglais | MEDLINE | ID: mdl-37470275

RÉSUMÉ

BACKGROUND AND OBJECTIVES: Plasma has become an essential ingredient for various medical treatments. Many blood collection agencies rely on voluntary non-remunerated donation when collecting plasma, but at present many do not collect sufficient plasma to meet domestic demands. This rapid review sought to explore the factors that have been found to influence people's decisions to donate plasma to inform future research. METHODS: Searches were conducted in PubMed, PsycINFO, Social Sciences Citation Index and CINAHL for peer-reviewed journal articles that discussed plasma donation and the factors associated with donor behaviour. Pertinent information from included articles was extracted and arranged in themes. RESULTS: In total, 33 articles were included in this review. Three main themes were identified by the authors. The first focused on site-level factors related to blood collection agencies' engagement with plasma donors and their influence on plasma donation experiences. The second theme considered how individual characteristics and experiences influence willingness to donate plasma. The third theme examined social and cultural-level factors, such as how social networks and community shape perceptions and experiences with donation. CONCLUSION: Our findings suggest that the current understanding of plasma donation is focused mainly on converting whole blood donors and also centres on individual-level factors to donation. Further research must examine what factors attract non-whole blood donors to become plasma donors, focusing on broader social-level influences. This review will inform policies and interventions for blood collection agencies to increase plasma donors.

9.
Transfusion ; 63(6): 1172-1183, 2023 06.
Article de Anglais | MEDLINE | ID: mdl-37218408

RÉSUMÉ

BACKGROUND: In 2021, Canada implemented a pilot plasma program allowing some sexually active men who have sex with men (including but not limited to gay and bisexual men; gbMSM) to donate plasma. Changes to plasma donation policy could help address inequities in access to plasma donation and increase Canada's domestically collected plasma supply if more gbMSM donate as a result. We aimed to (1) examine views regarding plasma donation and the pilot program prior to implementation and (2) identify modifiable theory-informed predictors of gbMSM's intention to donate plasma. METHODS: We developed, piloted, and disseminated a questionnaire informed by the Theoretical Domains Framework (TDF). We recruited gbMSM in London (ON) and Calgary (AB) to an anonymous, online cross-sectional survey. RESULTS: A total of 246 gbMSM completed the survey. On scales from 1 (strongly disagree) to 5 (strongly agree), general intention to donate was high (mean = 4.24; SD = 0.94). The pilot program itself was mostly acceptable (mean = 3.71, SD = 1.16), but the intention to donate under the unique requirements of the pilot program was lower than general intention (mean = 3.58; SD = 1.26). Two domains from the theoretical domains framework (TDF) (beliefs about consequences of donating plasma and social influences) were independently associated with general intention to donate. DISCUSSION: The pilot plasma program as an incremental step toward more inclusive policies was mostly viewed as acceptable by the impacted communities. Historical and ongoing exclusions create unique barriers to donation. There are clear opportunities for developing theory-informed interventions to support gbMSM to donate plasma as policies continue to become more inclusive and more become eligible to donate.


Sujet(s)
Homosexualité masculine , Minorités sexuelles , Mâle , Humains , Don de sang , Études transversales , Enquêtes et questionnaires , Politique (principe)
10.
BMC Public Health ; 23(1): 768, 2023 04 25.
Article de Anglais | MEDLINE | ID: mdl-37098497

RÉSUMÉ

BACKGROUND: Canada has incrementally reduced restrictions to blood and plasma donation that impact men who have sex with men, gay, bisexual, and queer men, and some Two Spirit, transgender and non-binary individuals (MSM/2SGBTQ+). Prior to the launch of a pilot program in 2021 enabling some MSM/2SGBTQ + to donate source plasma, we explored the acceptability of the program among individuals who could become eligible to donate in the program. METHODS: We invited men identifying as MSM/2SGBTQ + to participate in two consecutive semi-structured interviews to explore their views on blood and plasma donation policy, plasma donation, and the proposed Canadian plasma donation program. Interview transcripts were analyzed thematically and acceptability-related themes were mapped onto the Theoretical Framework of Acceptability. RESULTS: Twenty-seven men identifying as having sex with men participated in 53 interviews. Eighteen themes were mapped onto the seven construct domains of the Theoretical Framework of Acceptability. Underlying all aspects of acceptability was a tension between four primary values influencing participants' views: altruism, equity, supply sufficiency, and evidence-based policy. The program was viewed as welcome progress on a discriminatory policy, with many excited to participate, yet tension with inequitable aspects of the program undermined support for the program and interest to contribute to it. The high demands of the program are unique for MSM/2SGBTQ + and are only tolerable as part of a program that is an incremental and instrumental step to more equitable donation policies. CONCLUSION: Findings highlight past experiences of exclusion in Canada as a unique and critical part of the context of the donation experience among MSM/2SGBTQ+. Despite the program's goals of greater inclusivity of MSM/2SGBTQ + individuals, the anticipated experience of the program included continued stigmatization and inequities. Future research should seek to understand the experienced views of MSM/2SGBTQ + donors to ensure that as policies change, policies are implemented equitably.


Sujet(s)
Infections à VIH , Minorités sexuelles , Mâle , Humains , Homosexualité masculine , Don de sang , Canada , Bisexualité
11.
Transfus Clin Biol ; 30(1): 43-46, 2023 Feb.
Article de Anglais | MEDLINE | ID: mdl-35914702

RÉSUMÉ

The current implementation of Pathogen Reduction Technologies (PRTs) offers advantages and disadvantages to transfusion medicine. PRT rollout may significantly reduce the incidence of transfusion-transmitted infections and immune reactions, while offering a 'one-size-fits-all' solution to future pathogens in blood products. However, the decrease in transfusion efficacy of PRT-treated blood products suggests that the demand for blood products may increase, further straining the already limited supply of these cells. Conversely, cold-stored platelets and whole-blood transfusions have re-emerged, potentially granting more effective transfusion options to bleeding patients. The renewed focus on donor variability, storage quality, and transfusion outcome presents another avenue through which transfusion quality and supply may be improved.


Sujet(s)
Transfusion de composants du sang , Médecine transfusionnelle , Humains , Plaquettes , Hémorragie , Conservation de sang , Transfusion de plaquettes
12.
Transfusion ; 63(1): 217-228, 2023 01.
Article de Anglais | MEDLINE | ID: mdl-36453841

RÉSUMÉ

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.


Sujet(s)
Aphérèse , Protéine HMGB1 , Humains , Aphérèse/méthodes , Plaquettes/métabolisme , Conservation de sang/méthodes , Ligand de CD40/métabolisme , Protéine HMGB1/métabolisme , Transfusion de plaquettes
13.
Hematology Am Soc Hematol Educ Program ; 2022(1): 421-423, 2022 12 09.
Article de Anglais | MEDLINE | ID: mdl-36485096

RÉSUMÉ

This article reviews 3 products: pathogen-inactivated platelets, cold-stored platelets, and cryoplatelets. These are all coming to a transfusion service near you in the next few years. The article reviews the limitations of these new products and highlights the gaps in our understanding of their place in patient treatment.


Sujet(s)
Conservation de sang , Transfusion de plaquettes , Humains , Plaquettes
14.
Biochem J ; 479(22): 2351-2364, 2022 11 30.
Article de Anglais | MEDLINE | ID: mdl-36239738

RÉSUMÉ

Apoptosis is a critical process for the maintenance of cell populations, and involves mitochondrial depolarization, the sequential cleavage of caspase-9 and -3, followed by the externalization of phosphatidylserine (PS) on the plasma membrane. The actin cytoskeleton and its accessory proteins are known regulators of apoptotic signaling in nucleated cells but their roles in platelet apoptosis are undefined. Filamin A (FLNA) is a ubiquitously expressed actin-crosslinking protein that also serves as an intracellular signaling scaffold. Here we used platelets from mice with a platelet-specific FLNA deficiency (Flnafl/Y, Pf4-cre/+, termed platelet-specific knockout) to test the role of FLNA in platelet apoptosis. Treatment with the BH3-mimetic drug ABT-737 induced caspase-3 cleavage and PS exposure in platelets from floxed mice (Flnafl/Y, termed control) but these effects were essentially abrogated in FLNA-null platelets (platelet-specific knockout). Protein kinase C (PKC), a known FLNA ligand, was also activated by ABT-737, and PKC's phosphorylation of its downstream substrates was attenuated in FLNA-null platelets. The PKC inhibitor bisindolylmaleimide (BIM) also reduced caspase-3 cleavage, thus essentially phenocopying the FLNA-null platelets. Notably, the caspase-3 cleavage defect in FLNA-null platelets was rescued by the PKC-activating phorbol ester PMA, suggesting that FLNA and PKC share a common pathway in regulating platelet apoptosis. Mitochondrial depolarization and caspase-9 cleavage were unaffected by BIM treatment, suggesting that PKC specifically controls the downstream caspase-3 point of the pro-apoptotic signaling pathway. These data point to a novel role for FLNA in the regulation of platelet apoptosis, thus providing an improved understanding of how circulating platelet counts are maintained.


Sujet(s)
Plaquettes , Filamines , Protéine kinase C , Animaux , Souris , Apoptose , Plaquettes/métabolisme , Caspase-3/génétique , Caspase-3/métabolisme , Caspase-9/génétique , Caspase-9/métabolisme , Filamines/génétique , Filamines/métabolisme , Phosphatidylsérine/métabolisme , Protéine kinase C/métabolisme
15.
Transfusion ; 62(12): 2525-2538, 2022 12.
Article de Anglais | MEDLINE | ID: mdl-36285763

RÉSUMÉ

BACKGROUND: Equitable allocation of scarce blood products needed for a randomized controlled trial (RCT) is a complex decision-making process within the blood supply chain. Strategies to improve resource allocation in this setting are lacking. METHODS: We designed a custom-made, computerized system to manage the inventory and allocation of COVID-19 convalescent plasma (CCP) in a multi-site RCT, CONCOR-1. A hub-and-spoke distribution model enabled real-time inventory monitoring and assignment for randomization. A live CCP inventory system using REDCap was programmed for spoke sites to reserve, assign, and order CCP from hospital hubs. A data-driven mixed-integer programming model with supply and demand forecasting was developed to guide the equitable allocation of CCP at hubs across Canada (excluding Québec). RESULTS: 18/38 hospital study sites were hubs with a median of 2 spoke sites per hub. A total of 394.5 500-ml doses of CCP were distributed; 349.5 (88.6%) doses were transfused; 9.5 (2.4%) were wasted due to mechanical damage sustained to the blood bags; 35.5 (9.0%) were unused at the end of the trial. Due to supply shortages, 53/394.5 (13.4%) doses were imported from Héma-Québec to Canadian Blood Services (CBS), and 125 (31.7%) were transferred between CBS regional distribution centers to meet demand. 137/349.5 (39.2%) and 212.5 (60.8%) doses were transfused at hubs and spoke sites, respectively. The mean percentages of total unmet demand were similar across the hubs, indicating equitable allocation, using our model. CONCLUSION: Computerized tools can provide efficient and immediate solutions for equitable allocation decisions of scarce blood products in RCTs.


Sujet(s)
COVID-19 , Humains , COVID-19/thérapie , Canada , Québec
17.
Vox Sang ; 117(10): 1202-1210, 2022 Oct.
Article de Anglais | MEDLINE | ID: mdl-36102139

RÉSUMÉ

BACKGROUND AND OBJECTIVES: The use of coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) in the treatment of patients with severe acute respiratory syndrome-2 infection has been controversial. Early administration of CCP before hospital admission offers a potential advantage. This manuscript summarizes current trials of early use of CCP and explores the feasibility of this approach in different countries. MATERIALS AND METHODS: A questionnaire was distributed to the International Society of Blood Transfusion (ISBT) CCP working group. We recorded respondents' input on existing trials on early/outpatient CCP and out-of-hospital (OOH)/home transfusion (HT) practices in their countries and feedback on challenges in initiating home CCP infusion programmes. In addition, details of existing trials registered on clinicaltrials.gov were summarized. RESULTS: A total of 31 country representatives participated. Early/OOH CCP transfusion studies were reported in the United States, the Netherlands, Spain and Brazil. There were a total of six published and five ongoing trials on the prophylactic and therapeutic early use of CCP. HT was practised in Australia, the UK, Belgium, France, Japan, Nigeria, the Netherlands, Spain, Italy, Norway, the United States and some provinces in Canada. Thirty-four representatives indicated a lack of OOH CCP or HT in their institutions and countries. Barriers to implementation of OOH/HT included existing legislation, lack of policies pertaining to outpatient transfusion, and associated logistical challenges, including lack of staffing and resources. CONCLUSION: Early administration of CCP remains a potential option in COVID-19 management in countries with existing OOH/HT programmes. Legislation and regulatory bodies should consider OOH/HT practice for transfusion in future pandemics.


Sujet(s)
COVID-19 , COVID-19/thérapie , Études de faisabilité , Hôpitaux , Humains , Immunisation passive/effets indésirables , SARS-CoV-2 , Sérothérapie COVID-19
18.
Ann Intern Med ; 175(9): 1310-1321, 2022 09.
Article de Anglais | MEDLINE | ID: mdl-35969859

RÉSUMÉ

DESCRIPTION: Coronavirus disease 2019 convalescent plasma (CCP) has emerged as a potential treatment of COVID-19. However, meta-analysis data and recommendations are limited. The Association for the Advancement of Blood and Biotherapies (AABB) developed clinical practice guidelines for the appropriate use of CCP. METHODS: These guidelines are based on 2 living systematic reviews of randomized controlled trials (RCTs) evaluating CCP from 1 January 2019 to 26 January 2022. There were 33 RCTs assessing 21 916 participants. The results were summarized using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) method. An expert panel reviewed the data using the GRADE framework to formulate recommendations. RECOMMENDATION 1 (OUTPATIENT): The AABB suggests CCP transfusion in addition to the usual standard of care for outpatients with COVID-19 who are at high risk for disease progression (weak recommendation, moderate-certainty evidence). RECOMMENDATION 2 (INPATIENT): The AABB recommends against CCP transfusion for unselected hospitalized persons with moderate or severe disease (strong recommendation, high-certainty evidence). This recommendation does not apply to immunosuppressed patients or those who lack antibodies against SARS-CoV-2. RECOMMENDATION 3 (INPATIENT): The AABB suggests CCP transfusion in addition to the usual standard of care for hospitalized patients with COVID-19 who do not have SARS-CoV-2 antibodies detected at admission (weak recommendation, low-certainty evidence). RECOMMENDATION 4 (INPATIENT): The AABB suggests CCP transfusion in addition to the usual standard of care for hospitalized patients with COVID-19 and preexisting immunosuppression (weak recommendation, low-certainty evidence). RECOMMENDATION 5 (PROPHYLAXIS): The AABB suggests against prophylactic CCP transfusion for uninfected persons with close contact exposure to a person with COVID-19 (weak recommendation, low-certainty evidence). GOOD CLINICAL PRACTICE STATEMENT: CCP is most effective when transfused with high neutralizing titers to infected patients early after symptom onset.


Sujet(s)
COVID-19 , SARS-CoV-2 , COVID-19/thérapie , Hospitalisation , Humains , Immunisation passive/méthodes , Sérothérapie COVID-19
19.
Transfusion ; 62(8): 1571-1582, 2022 08.
Article de Anglais | MEDLINE | ID: mdl-35834537

RÉSUMÉ

BACKGROUND: Canadian Blood Services introduced new eligibility criteria that allows some sexually active gay, bisexual, and other men who have sex with men (gbMSM) to donate source plasma, marking a significant change from time-based deferral criteria. We aimed to identify potential barriers and enablers to implementing the new criteria from the perspective of donor center staff. STUDY DESIGN AND METHODS: We conducted Theoretical Domains Framework-informed interviews with staff from two source plasma donation centers in Canada. RESULTS: We completed 28 interviews between June 2020 and April 2021. Three themes representing eight domains captured key tensions. Valuing inclusive eligibility criteria: staff support inclusive criteria; many were concerned the new criteria remained discriminatory. Investing in positive donor experiences: staff wished to foster positive donor experiences; however, they worried gbMSM donors would express anger and disappointment regarding the new criteria, staff would experience unease over using stigmatizing criteria and convey nonverbal cues of discomfort, and recurring plasma donors may behave inappropriately. Supporting education, training, and transparency of eligibility criteria: participants believed providing in-person training (i.e., to explain criteria rationale, address discomfort, practice responding to donor questions) and ensuring donors and the public were well-informed of the upcoming changes would improve implementation. DISCUSSION: Participant views emphasize the importance of supporting staff through training and transparent communication to optimize the delivery of world-class equitable care for a new cohort of donors who have previously been excluded from plasma donation. Findings inform which staff supports to consider to improve implementation as policies continue to shift internationally.


Sujet(s)
Infections à VIH , Minorités sexuelles , Bisexualité , Canada , Homosexualité masculine , Humains , Mâle
20.
Transfusion ; 62 Suppl 1: S98-S104, 2022 08.
Article de Anglais | MEDLINE | ID: mdl-35748674

RÉSUMÉ

BACKGROUND: There is increasing interest in leukoreduced whole blood (WB) as a transfusion product for trauma patients. In some jurisdictions, few leukoreduced filters are approved or appropriate for WB leukoreduction and quality information is therefore limited. This study assessed the impact of filtration timing of WB collected in CPDA-1 versus CPD on in vitro quality. STUDY DESIGN AND METHODS: WB was collected in CPDA-1 or CPD and leukoreduction filtered either after 3-8 h (early) or 18-24 h (late) from stop bleed time. In vitro quality was assessed after filtration and throughout 5 weeks of storage at 4°C. Cell count and hemoglobin levels were determined by hematology analyzer, platelet activation and responsiveness to ADP by surface expression of P-selectin by flow cytometry, hemolysis by HemoCue, and metabolic parameters by blood gas analyzer. Hemostatic properties were assessed by rotational thromboelastometry. Plasma protein activities and clotting times were determined by automated coagulation. RESULTS: Although there were some data points which showed statistically significant differences associated with anticoagulant choices or the filtration timing, no general trend in inferiority/performance could be discerned. After 35 days' storage, only clotting time, alpha angle and factor II in the early filtration arm comparing anticoagulants and prothrombin time and factor II in the CPDA-1 study arm comparing filtration timing showed a significant difference. CONCLUSION: In vitro WB quality seems to be independent on the choice of anticoagulant and filtration timing supporting WB hold-times to up to 24 h, increasing operational flexibility for transfusion services.


Sujet(s)
Conservation de sang , Techniques de déleucocytation , Anticoagulants/métabolisme , Anticoagulants/pharmacologie , Plaquettes/métabolisme , Humains , Prothrombine
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