Predicting haemoglobin deferral using machine learning models: Can we use the same prediction model across countries?

BACKGROUND AND OBJECTIVES

Personalized donation strategies based on haemoglobin (Hb) prediction models may reduce Hb deferrals and hence costs of donation, meanwhile improving commitment of donors. We previously found that prediction models perform better in validation data with a high Hb deferral rate. We therefore investigate how Hb deferral prediction models perform when exchanged with other blood establishments.

MATERIALS AND METHODS

Donation data from the past 5 years from random samples of 10,000 donors from Australia, Belgium, Finland, the Netherlands and South Africa were used to fit random forest models for Hb deferral prediction. Trained models were exchanged between blood establishments. Model performance was evaluated using the area under the precision-recall curve (AUPR). Variable importance was assessed using SHapley Additive exPlanations (SHAP) values.

RESULTS

Across the validation datasets and exchanged models, the AUPR ranged from 0.05 to 0.43. Exchanged models performed similarly within validation datasets, irrespective of the origin of the training data. Apart from subtle differences, the importance of most predictor variables was similar in all trained models.

CONCLUSION

Our results suggest that Hb deferral prediction models trained in different blood establishments perform similarly within different validation datasets, regardless of the deferral rate of their training data. Models learn similar associations in different blood establishments.

Does cold storage of blood before transfusion prevent the transmission of syphilis? A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Although screening of donated blood for syphilis is almost universally applied, its cost-effectiveness is questioned because of the low prevalence of transfusion-transmitted syphilis and a widespread belief that the syphilis-causing bacterium Treponema pallidum is very vulnerable to cold storage. Since the latter claim is not yet supported by a systematic review, we investigated whether syphilis can be transmitted via transfusion following prolonged (cold or room temperature) storage of blood products.

MATERIALS AND METHODS

MEDLINE, PMC and NCBI bookshelf (PubMed interface), Cochrane Library, Embase, Web of Science and CINAHL were searched up to 17 January 2023.

RESULTS

Nine experimental animal studies and one observational human study were included. Meta-analysis showed that storing artificially infected human (six studies; risk ratio [RR] = 0.37, 95% confidence interval [CI]: 0.22-0.64, p = 0.0003) or rabbit (two studies; RR = 0.08, 95% CI: 0.01 to 0.55, p = 0.01) blood for more than 72 h before intratesticular injection significantly decreased the number of recipient animals that develop syphilis. Nonetheless, the possibility of syphilis transmission remained for up to 7 days. Differences could not be found for rabbit plasma (p = 0.60) or naturally infected rabbit blood (p = 0.28). There was limited evidence from one study in favour of the storage of artificially infected human platelets for over 72 h at cold temperatures (RR = 0.13, 95% CI: 0.03-0.52, p = 0.004) but not at room temperature (p = 0.12).

CONCLUSION

Even though the infectivity of T. pallidum-spiked blood may decrease after 72 h of cold storage, the possibility for transfusion-transmitted syphilis may remain for several days after. The evidence is very uncertain, and conclusions are hindered by a lack of sufficiently powered studies and studies in humans. In addition, T. pallidum concentrations used in animal studies may be unrealistically high.

Safety and protection of plasma donors: A scoping review and evidence gap map

BACKGROUND AND OBJECTIVES

As part of a large-scale project to safely increase plasma collection in Europe, the current scoping review identifies the existing evidence (gaps) on adverse events (AEs) and other health effects in plasmapheresis donors, as well as factors that may be associated with such events/effects.

MATERIALS AND METHODS

We searched six databases and three registries. Study characteristics (publication type, language, study design, population, outcomes, associated factors, time of assessment, duration of follow-up, number and frequency of donations, convalescent plasma [y/n], setting and location) were synthesized narratively and in an interactive evidence gap map (EGM).

RESULTS

Ninety-four research articles and five registrations were identified. Around 90% were observational studies (57 controlled and 33 uncontrolled), and most of them were performed in Europe (55%) or the United States (20%). Factors studied in association with donor health included donor characteristics (e.g., sex, age) (n = 27), cumulative number of donations (n = 21), donation frequency (n = 11), plasma collection device or programme (n = 11), donor status (first time vs. repeat) (n = 10), donation volume per session (n = 8), time in donation programme (n = 3), preventive measures (n = 2) or other (n = 9).

CONCLUSION

The current scoping review provides an accessible tool for researchers and policymakers to identify the available evidence (gaps) concerning plasmapheresis donation safety. Controlled prospective studies with long-term donor follow-up are scarce. Furthermore, additional experimental studies comparing the health effects of different donation frequencies are required to inform a safe upper limit for donation frequency.

Effects of plasmapheresis frequency on health status and exercise performance in men: A randomized controlled trial

BACKGROUND AND OBJECTIVES

Most research studies on the effects of repeated plasma donation are observational with different study limitations, resulting in high uncertainty on the link between repeated plasma donation and health consequences. Here, we prospectively investigated the safety of intensive or less intensive plasma donation protocols.

MATERIALS AND METHODS

Sixty-three male subjects participated in this randomized controlled trial and were divided into low-frequency (LF, once/month, n = 16), high-frequency (HF, three times/month, n = 16), very high-frequency (VHF, two times/week, n = 16) and a placebo (P, once/month, n = 15) groups. Biochemical, haematological, clinical, physiological and exercise-related data were collected before (D0), after 1½ months (D42) and after 3 months (D84) of donation.

RESULTS

In VHF, red blood cells, haemoglobin and haematocrit levels decreased while reticulocyte levels increased from D0 to D84. In both HF and VHF, plasma ferritin levels were lower at D42 and D84 compared to D0. In VHF, plasma levels of albumin, immunoglobulin G (IgG), immunoglobulin A (IgA) and immunoglobulin M (IgM) dropped from D0 to D42 and remained lower at D84 than at D0. In HF, plasma IgG, IgA and IgM were lower at D42, and IgG and IgM were lower at D84, compared to D0. Few adverse events were reported in HF and VHF. Repeated plasma donation had no effect on blood pressure, body composition or exercise performance.

CONCLUSION

VHF plasmapheresis may result in a large reduction in ferritin and IgG levels. HF and VHF plasmapheresis may result in little to no difference in other biochemical, haematological, clinical, physiological and exercise-related parameters.

Convalescent Plasma for Covid-19-Induced ARDS in Mechanically Ventilated Patients

BACKGROUND

Passive immunization with plasma collected from convalescent patients has been regularly used to treat coronavirus disease 2019 (Covid-19). Minimal data are available regarding the use of convalescent plasma in patients with Covid-19-induced acute respiratory distress syndrome (ARDS).

METHODS

In this open-label trial, we randomly assigned adult patients with Covid-19-induced ARDS who had been receiving invasive mechanical ventilation for less than 5 days in a 1:1 ratio to receive either convalescent plasma with a neutralizing antibody titer of at least 1:320 or standard care alone. Randomization was stratified according to the time from tracheal intubation to inclusion. The primary outcome was death by day 28.

RESULTS

A total of 475 patients underwent randomization from September 2020 through March 2022. Overall, 237 patients were assigned to receive convalescent plasma and 238 to receive standard care. Owing to a shortage of convalescent plasma, a neutralizing antibody titer of 1:160 was administered to 17.7% of the patients in the convalescent-plasma group. Glucocorticoids were administered to 466 patients (98.1%). At day 28, mortality was 35.4% in the convalescent-plasma group and 45.0% in the standard-care group (P = 0.03). In a prespecified analysis, this effect was observed mainly in patients who underwent randomization 48 hours or less after the initiation of invasive mechanical ventilation. Serious adverse events did not differ substantially between the two groups.

CONCLUSIONS

The administration of plasma collected from convalescent donors with a neutralizing antibody titer of at least 1:160 to patients with Covid-19-induced ARDS within 5 days after the initiation of invasive mechanical ventilation significantly reduced mortality at day 28. This effect was mainly observed in patients who underwent randomization 48 hours or less after ventilation initiation. (Funded by the Belgian Health Care Knowledge Center; ClinicalTrials.gov number, NCT04558476.).

Men who have sex with men and risk for transfusion-transmissible infections in blood donors in Western countries: A systematic review update

BACKGROUND AND OBJECTIVES

This systematic review update summarizes evidence concerning transfusion-transmissible infections (TTIs) in male blood donors reporting sex with another man (MSM) or after easing the MSM deferral period.

MATERIALS AND METHODS

We searched five databases, including studies comparing MSM versus non-MSM donors (Type I), MSM deferral periods (Type II) or infected versus non-infected donors (Type III) in Western countries, and used GRADE to determine evidence certainty.

RESULTS

Twenty-five observational studies were included. Four Type I studies suggest that there may be an increased risk for overall TTIs, human immunodeficiency virus (HIV), hepatitis B virus (HBV) and syphilis in MSM donors, but the evidence is very uncertain. There was insufficient evidence of MSM with low-risk sexual behaviour. A Type II study indicates that easing the MSM deferral period to 1 year may have little to no effect on TTI risk. TTI prevalence in blood donors under 5-year, 1-year, 3-month or risk-based deferral in eight other Type II studies was too low to provide clear conclusions on the effect of easing the deferral. Three Type III studies reported that MSM may be a risk factor for HIV. Increased risk of HBV, hepatitis C virus and HTLV-I/II could not be shown. The evidence from Type III studies is very uncertain.

CONCLUSION

There may be an increased risk of HIV in MSM blood donors. Shortening the deferral from permanent to 1 year may have little to no effect on TTI risk. However, there is limited, unclear evidence from observational studies concerning the impact of introducing 3-month or risk-based deferrals.

Cost Effectiveness of Different Platelet Preparation, Storage, Selection and Dosing Methods in Platelet Transfusion: A Systematic Review

BACKGROUND AND OBJECTIVE

Evidence-based guidelines on platelet transfusion therapy assist clinicians to optimize patient care, but currently do not take into account costs associated with different methods used during the preparation, storage, selection and dosing of platelets for transfusion. This systematic review aimed to summarize the available literature regarding the cost effectiveness (CE) of these methods.

METHODS

Eight databases and registries, as well as 58 grey literature sources, were searched up to 29 October 2021 for full economic evaluations comparing the CE of methods for preparation, storage, selection and dosing of allogeneic platelets intended for transfusion in adults. Incremental CE ratios, expressed as standardized cost (in 2022 EUR) per quality-adjusted life-year (QALY) or per health outcome, were synthesized narratively. Studies were critically appraised using the Philips checklist.

RESULTS

Fifteen full economic evaluations were identified. Eight investigated the costs and health consequences (transfusion-related events, bacterial and viral infections or illnesses) of pathogen reduction. The estimated incremental cost per QALY varied widely from EUR 259,614 to EUR 36,688,323. For other methods, such as pathogen testing/culturing, use of apheresis instead of whole blood-derived platelets, and storage in platelet additive solution, evidence was sparse. Overall, the quality and applicability of the included studies was limited.

CONCLUSIONS

Our findings are of interest to decision makers who consider implementing pathogen reduction. For other preparation, storage, selection and dosing methods in platelet transfusion, CE remains unclear due to insufficient and outdated evaluations. Future high-quality research is needed to expand the evidence base and increase our confidence in the findings.

Cost-Effectiveness of Thrombopoietin Mimetics in Patients with Thrombocytopenia: A Systematic Review

OBJECTIVES

Thrombopoietin (TPO) mimetics are a potential alternative to platelet transfusion to minimize blood loss in patients with thrombocytopenia. This systematic review aimed to evaluate the cost-effectiveness of TPO mimetics, compared with not using TPO mimetics, in adult patients with thrombocytopenia.

METHODS

Eight databases and registries were searched for full economic evaluations (EEs) and randomized controlled trials (RCTs). Incremental cost-effectiveness ratios (ICERs) were synthesized as cost per quality-adjusted life year gained (QALY) or as cost per health outcome (e.g. bleeding event avoided). Included studies were critically appraised using the Philips reporting checklist.

RESULTS

Eighteen evaluations from nine different countries were included, evaluating the cost-effectiveness of TPO mimetics compared with no TPO, watch-and-rescue therapy, the standard of care, rituximab, splenectomy or platelet transfusion. ICERs varied from a dominant strategy (i.e. cost-saving and more effective), to an incremental cost per QALY/health outcome of EUR 25,000-50,000, EUR 75,000-750,000 and EUR > 1 million, to a dominated strategy (cost-increasing and less effective). Few evaluations (n = 2, 10%) addressed the four principal types of uncertainty (methodological, structural, heterogeneity and parameter). Parameter uncertainty was most frequently reported (80%), followed by heterogeneity (45%), structural uncertainty (43%) and methodological uncertainty (28%).

CONCLUSIONS

Cost-effectiveness of TPO mimetics in adult patients with thrombocytopenia ranged from a dominant strategy to a significant incremental cost per QALY/health outcome or a strategy that is clinically inferior and has increased costs. Future validation and tackling the uncertainty of these models with country-specific cost data and up-to-date efficacy and safety data are needed to increase the generalizability.

Intranasal administration of convalescent plasma protects against SARS-CoV-2 infection in hamsters

BACKGROUND

Convalescent plasma (CP) transfusion is an early option for treating infections with pandemic potential, often preceding vaccine or antiviral drug rollout. Heterogenous findings from randomized clinical trials on transfusion of COVID-19 CP (CCP) have been reported. However, meta-analysis suggests that transfusion of high titer CCP is associated with a mortality benefit for COVID-19 outpatients or inpatients treated within 5 days after symptom onset, indicating the importance of early administration.

METHODS

We tested if CCP is an effective prophylactic against SARS-CoV-2 infection by the intranasal administration of 25 μL CCP/nostril (i.e. 0.01-0.06 mg anti-RBD antibodies/kg) in hamsters exposed to infected littermates.

FINDINGS

In this model, 40% of CCP treated hamsters were fully protected and 40% had significantly reduced viral loads, the remaining 20% was not protected. The effect seems dose-dependent because high-titer CCP from a vaccinated donor was more effective than low-titer CCP from a donation prior to vaccine rollout. Intranasal administration of human CCP resulted in a reactive (immune) response in hamster lungs, however this was not observed upon administration of hamster CCP.

INTERPRETATION

We conclude that CCP is an effective prophylactic when used directly at the site of primary infection. This option should be considered in future prepandemic preparedness plans.

FUNDING

Flanders Innovation & Entrepreneurship (VLAIO) and the Foundation for Scientific Research of the Belgian Red Cross Flanders.

An international comparison of haemoglobin deferral prediction models for blood banking

BACKGROUND AND OBJECTIVES

Blood banks use a haemoglobin (Hb) threshold before blood donation to minimize donors' risk of anaemia. Hb prediction models may guide decisions on which donors to invite, and should ideally also be generally applicable, thus in different countries and settings. In this paper, we compare the outcome of various prediction models in different settings and highlight differences and similarities.

MATERIALS AND METHODS

Donation data of repeat donors from the past 5 years of Australia, Belgium, Finland, the Netherlands and South Africa were used to fit five identical prediction models: logistic regression, random forest, support vector machine, linear mixed model and dynamic linear mixed model. Only donors with five or more donation attempts were included to ensure having informative data from all donors. Analyses were performed for men and women separately and outcomes compared.

RESULTS

Within countries and overall, different models perform similarly well. However, there are substantial differences in model performance between countries, and there is a positive association between the deferral rate in a country and the ability to predict donor deferral. Nonetheless, the importance of predictor variables across countries is similar and is highest for the previous Hb level.

CONCLUSION

The limited impact of model architecture and country indicates that all models show similar relationships between the predictor variables and donor deferral. Donor deferral is found to be better predictable in countries with high deferral rates. Therefore, such countries may benefit more from deferral prediction models than those with low deferral rates.

GPIbα shedding in platelets is controlled by strict intracellular containment of both enzyme and substrate

BACKGROUND

A disintegrin and metalloprotease 17 (ADAM17) catalyzes platelet glycoprotein (GP) Ibα ectodomain shedding, thereby releasing glycocalicin in plasma. The spatiotemporal control over the enzyme-substrate interaction and the biological consequences of GPIbα shedding are poorly understood.

OBJECTIVES

This study aimed to determine the spatiotemporal control over GPIbα shedding by ADAM17.

METHODS

Transmission electron microscopy with immunogold staining, immunoprecipitation, and quantitative western blotting were used.

RESULTS

Immunogold staining showed that all ADAM17 antigen is expressed intracellularly, irrespective of platelet activation. ADAM17 clustered in patches on a tortuous membrane system different from α- and dense granules. Mild activation by platelet adhesion to immobilized fibrinogen did not cause GPIbα shedding, whereas strong and sustained stimulation using thrombin and collagen (analogs) did. Glycocalicin release kinetics was considerably slower than typical hemostasis, starting at 20 minutes and reaching a plateau after 3 hours of strong stimulation. Inhibition of the ADAM17 scissile bond specifically in GPIbα receptors that reside on the platelet's extracellular surface did not prevent shedding, which is in line with the strict intracellular location of ADAM17. Instead, shedding was restricted to a large GPIbα subpopulation that is inaccessible on resting platelets but becomes partially accessible following platelet stimulation. Furthermore, the data show that proteinaceous, water-soluble ADAM17 inhibitors cannot inhibit GPIbα shedding, whereas membrane permeable small molecule ADAM inhibitors can.

CONCLUSION

The data show that platelets harbor 2 distinct GPIbα subpopulations: one that presents at the platelet's surface known for its role in primary hemostasis and one that provides substrate for proteolysis by ADAM17 with kinetics that suggest a role beyond hemostasis.

Single step method for high yield human platelet lysate production

BACKGROUND

We aimed to develop a single step method for the production of human platelet lysate (hPL). The method must result in high hPL yields, be closed system and avoid heparin use.

STUDY DESIGN AND METHODS

The method aimed at using glass beads and calcium. An optimal concentration of calcium and glass beads was determined by serial dilution. This was translated to a novel method and compared to known methods: freeze-thawing and high calcium. Quality outcome measures were transmittance, fibrinogen and growth factor content, and cell doubling time.

RESULTS

An optimal concentration of 5 mM Ca²⁺ and 0.2 g/ml glass beads resulted in hPL with yields of 92% ± 1% (n = 50) independent of source material (apheresis or buffy coat-derived). The transmittance was highest (56% ± 9%) compared to known methods (<39%). The fibrinogen concentration (7.0 ± 1.1 μg/ml) was well below the threshold, avoiding the need for heparin. Growth factor content was similar across hPL production methods. The cell doubling time of adipose derived stem cells was 25 ± 1 h and not different across methods. Batch consistency was determined across six batches of hPL (each n = 25 constituting concentrates) and was <11% for all parameters including cell doubling time. Calcium precipitation formed after 4 days of culturing stem cells in media with hPL prepared by the high (15 mM) Ca²⁺ method, but not with hPL prepared by glass bead method.

DISCUSSION

The novel method transforms platelet concentrates to hPL with little hands-on time. The method results in high yield, is closed system, without heparin and non-inferior to published methods.

Systematic reviews on platelet transfusions: Is there unnecessary duplication of effort? A scoping review

BACKGROUND AND OBJECTIVES

Platelet transfusions are used across multiple patient populations to prevent and correct bleeding. This scoping review aimed to map the currently available systematic reviews (SRs) and evidence-based guidelines in the field of platelet transfusion.

MATERIALS AND METHODS

A systematic literature search was conducted in seven databases for SRs on effectiveness (including dose and timing, transfusion trigger and ratio to other blood products), production modalities and decision support related to platelet transfusion. The following data were charted: methodological features of the SR, population, concept and context features, outcomes reported, study design and number of studies included. Results were synthesized in interactive evidence maps.

RESULTS

We identified 110 SRs. The majority focused on clinical effectiveness, including prophylactic or therapeutic transfusions compared to no platelet transfusion (34 SRs), prophylactic compared to therapeutic-only transfusion (8 SRs), dose, timing (11 SRs) and threshold for platelet transfusion (15 SRs) and the ratio of platelet transfusion to other blood products in massive transfusion (14 SRs). Furthermore, we included 34 SRs on decision support, of which 26 evaluated viscoelastic testing. Finally, we identified 22 SRs on platelet production modalities, including derivation (4 SRs), pathogen inactivation (6 SRs), leucodepletion (4 SRs) and ABO/human leucocyte antigen matching (5 SRs). The SRs were mapped according to concept and clinical context.

CONCLUSION

An interactive evidence map of SRs and evidence-based guidelines in the field of platelet transfusion has been developed and identified multiple reviews. This work serves as a tool for researchers looking for evidence gaps, thereby both supporting research and avoiding unnecessary duplication.

Adverse events of iron and/or erythropoiesis-stimulating agent therapy in preoperatively anemic elective surgery patients: a systematic review

BACKGROUND

Iron supplementation and erythropoiesis-stimulating agent (ESA) administration represent the hallmark therapies in preoperative anemia treatment, as reflected in a set of evidence-based treatment recommendations made during the 2018 International Consensus Conference on Patient Blood Management. However, little is known about the safety of these therapies. This systematic review investigated the occurrence of adverse events (AEs) during or after treatment with iron and/or ESAs.

METHODS

Five databases (The Cochrane Library, MEDLINE, Embase, Transfusion Evidence Library, Web of Science) and two trial registries (ClinicalTrials.gov, WHO ICTRP) were searched until 23 May 2022. Randomized controlled trials (RCTs), cohort, and case-control studies investigating any AE during or after iron and/or ESA administration in adult elective surgery patients with preoperative anemia were eligible for inclusion and judged using the Cochrane Risk of Bias tools. The GRADE approach was used to assess the overall certainty of evidence.

RESULTS

Data from 26 RCTs and 16 cohort studies involving a total of 6062 patients were extracted, on 6 treatment comparisons: (1) intravenous (IV) versus oral iron, (2) IV iron versus usual care/no iron, (3) IV ferric carboxymaltose versus IV iron sucrose, (4) ESA+iron versus control (placebo and/or iron, no treatment), (5) ESA+IV iron versus ESA+oral iron, and (6) ESA+IV iron versus ESA+IV iron (different ESA dosing regimens). Most AE data concerned mortality/survival (n=24 studies), thromboembolic (n=22), infectious (n=20), cardiovascular (n=19) and gastrointestinal (n=14) AEs. Very low certainty evidence was assigned to all but one outcome category. This uncertainty results from both the low quantity and quality of AE data due to the high risk of bias caused by limitations in the study design, data collection, and reporting.

CONCLUSIONS

It remains unclear if ESA and/or iron therapy is associated with AEs in preoperatively anemic elective surgery patients. Future trial investigators should pay more attention to the systematic collection, measurement, documentation, and reporting of AE data.

Whole blood donor return rates after deferral for tattooing or body piercing-Survey across blood donation services: The BEST collaborative study

BACKGROUND AND OBJECTIVES

To protect transfusion recipients from transfusion-transmissible infections, blood donors are deferred from donating after recent tattooing or piercing. To explore to what extent and how this deferral impacts donor availability, we performed an international study to investigate how many donors were deferred for a recent tattoo or piercing and how many of these donors returned to donate.

MATERIALS AND METHODS

We surveyed blood centre members of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative and the European Blood Alliance Donor Studies Working Group on their numbers of donations, tattoo and piercing deferrals, and return rates in the year 2017.

RESULTS

Eight blood centres participated. Overall, deferral rates were lower for repeat donors compared to new donors. Repeat donors were more likely to return than new donors. Women and young donors were more often deferred than male and older donors. Men were more demotivated by tattoo or piercing deferral, resulting in lower return rates compared to women. Return rates differed greatly between blood centres.

CONCLUSION

Tattoo and piercing deferrals lead to missed donations and result in lower return rates. However, the numbers vary largely internationally, probably due to cultural and policy differences. Shortening deferral periods after tattooing or piercing may reduce the impact on donor availability, which should be investigated in single-centre studies.

Prevalence and associated risk factors of HIV infections in a representative transgender and non-binary population in Flanders and Brussels (Belgium): Protocol for a community-based, cross-sectional study using time-location sampling

Introduction

HIV prevalence and sexual risk have been estimated very high for transgender people. However, the limited sampling and data collection methods used in current research on transgender people potentially led to overrepresentation and generalisation of people at risk for HIV. Current HIV prevalence estimates in transgender populations are generalised from studies mainly focusing on transgender women engaging in sex work. Moreover, studies focusing on non-binary people, who identify with a broad range of identities beyond the traditional male and female gender identities, are scarce.

Objectives

To estimate the HIV prevalence rate in the Flemish and Brussels (Belgium) transgender population, including transgender women, transgender men and non-binary people, and to identify the associated risk factors.

Methods

In this community-based cross-sectional study, self-identified transgender and non-binary (TGNB) people will be recruited through a two-stage time-location sampling approach. First, community settings in which TGNB people gather will be mapped to develop an accurate sampling frame. Secondly, a multistage sampling design is applied involving a stratification based on setting type (healthcare facilities vs outreach events), a selection of clusters by systematic sampling and a simple random selection of TGNB people within each cluster. Participants will complete an electronic self-reported survey to measure sociological, sexual and drug-using behaviors (risk factors) and oral fluid aliquots will be collected and tested for HIV antibodies. Logistic regression models will be used to evaluate risk factors independently associated with HIV infection. The presented study is registered at ClinicalTrials.gov (NCT04930614).

Discussion

This study will be the first to investigate the HIV prevalence rates and associated risk behaviors in an accurate representation of the TGNB population in a Western European country. The findings will globally serve as a knowledge base for identifying subgroups at risk for becoming infected with HIV within TGNB people and to set up targeted prevention programs.

Impact of disasters on blood donation rates and blood safety: A systematic review and meta-analysis

Background and Objectives

Timely and adequate access to safe blood forms an integral part of universal health coverage, but it may be compromised by natural or man‐made disasters. This systematic review provides an overview of the best available scientific evidence on the impact of disasters on blood donation rates and safety outcomes.

Materials and Methods

Five databases (The Cochrane Library, MEDLINE, Embase, Web of Science and CINAHL) were searched until 27 March 2020 for (un)controlled studies investigating the impact of disasters on blood donation rates and/or safety. Risk of bias and overall certainty of the evidence were assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

Results

Eighteen observational studies were identified, providing very low certainty of evidence (due to high risk of bias, inconsistency and/or imprecision) on the impact of natural (12 studies) and man‐made/technological (6 studies) disasters. The available evidence did not enable us to form any generalizable conclusions on the impact on blood donation rates. Meta‐analyses could not detect any statistically significant changes in transfusion‐transmissible infection (TTI) rates [hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV)‐1/2, human T‐lymphotropic virus I and II (HTLV‐I/II) and syphilis] in donated blood after a disaster, either in first‐time or repeat donors, although the evidence is very uncertain.

Conclusion

The very low certainty of evidence synthetized in this systematic review indicates that it is very uncertain whether there is an association between disaster occurrence and changes in TTI rates in donated blood. The currently available evidence did not allow us to draw generalizable conclusions on the impact of disasters on blood donation rates.

Association between convalescent plasma treatment and mortality in COVID-19: a collaborative systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX ).

METHODS

In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence.

RESULTS

A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis.

CONCLUSIONS

Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care.

Lack of Cost-Effectiveness of Preoperative Erythropoiesis-Stimulating Agents and/or Iron Therapy in Anaemic, Elective Surgery Patients: A Systematic Review and Updated Analysis

OBJECTIVES

For anaemic elective surgery patients, current clinical practice guidelines weakly recommend the routine use of iron, but not erythrocyte-stimulating agents (ESAs), except for short-acting ESAs in major orthopaedic surgery. This recommendation is, however, not based on any cost-effectiveness studies. The aim of this research was to (1) systematically review the literature regarding cost effectiveness of preoperative iron and/or ESAs in anaemic, elective surgery patients and (2) update existing economic evaluations (EEs) with recent data.

METHODS

Eight databases and registries were searched for EEs and randomized controlled trials (RCTs) reporting cost-effectiveness data on November 11, 2020. Data were extracted, narratively synthesized and critically appraised using the Philips reporting checklist. Pre-existing full EEs were updated with effectiveness data from a recent systematic review and current cost data. Incremental cost-effectiveness ratios were expressed as cost per (quality-adjusted) life-year [(QA)LY] gained.

RESULTS

Only five studies (4 EEs and 1 RCT) were included, one on intravenous iron and four on ESAs + oral iron. The EE on intravenous iron only had an in-hospital time horizon. Therefore, cost effectiveness of preoperative iron remains uncertain. The three EEs on ESAs had a lifetime time horizon, but reported cost per (QA)LY gained of 20-65 million (GBP or CAD). Updating these analyses with current data confirmed ESAs to have a cost per (QA)LY gained of 3.5-120 million (GBP or CAD).

CONCLUSIONS

Cost effectiveness of preoperative iron is unproven, whereas routine preoperative ESA therapy cannot be considered cost effective in elective surgery, based on the limited available data. Future guidelines should reflect these findings.

A novel competition ELISA for the rapid quantification of SARS-CoV-2 neutralizing antibodies in convalescent plasma

Background

COVID‐19 convalescent plasma (CCP) ideally contains high titers of (neutralizing) anti‐SARS‐CoV‐2 antibodies. Several scalable immunoassays for CCP selection have been developed. We designed an enzyme‐linked immunosorbent assay (ELISA) that measures neutralizing antibodies (of all isotypes) in plasma by determining the level of competition between CCP and a mouse neutralizing antibody for binding to the receptor binding domain (RBD) of SARS‐CoV‐2.

Methods

Plasma was collected from 72 convalescent individuals and inhibition of viral infection was determined by plaque reduction neutralization (PRNT50). The level of neutralizing antibodies was measured in the novel competition ELISA and in a commercially available ELISA that measures inhibition of recombinant ACE2 binding to immobilized RBD. These results were compared with a high throughput chemiluminescent microparticle immunoassay (CMIA).

Results

The results from both ELISAs were correlating, in particular for high titer CCP (PRNT50 ≥ 1:160) (Spearman r = .73, p < .001). Moderate correlation was found between the competition ELISA and CMIA (r = .57 for high titer and r = .62 for low titer CCP, p < .001). Receiver operator characteristic analysis showed that the competition ELISA selected CCP with a sensitivity and specificity of 61% and 100%, respectively. However, discrimination between low and high titer CCP had a lower resolution (sensitivity: 34% and specificity: 89%).

Conclusion

The competition ELISA screens for neutralizing antibodies in CCP by competition for just a single epitope. It exerts a sensitivity of 61% with no false identifications. These ELISA designs can be used for epitope mapping or for selection of CCP.

Early high antibody-titre convalescent plasma for hospitalised COVID-19 patients: DAWn-plasma

Background

Several randomised clinical trials have studied convalescent plasma for coronavirus disease 2019 (COVID-19) using different protocols, with different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralising antibody titres, at different time-points and severities of illness.

Methods

In the prospective multicentre DAWn-plasma trial, adult patients hospitalised with COVID-19 were randomised to 4 units of open-label convalescent plasma combined with standard of care (intervention group) or standard of care alone (control group). Plasma from donors with neutralising antibody titres (50% neutralisation titre (NT₅₀)) ≥1/320 was the product of choice for the study.

Results

Between 2 May 2020 and 26 January 2021, 320 patients were randomised to convalescent plasma and 163 patients to the control group according to a 2:1 allocation scheme. A median (interquartile range) volume of 884 (806–906) mL) convalescent plasma was administered and 80.68% of the units came from donors with neutralising antibody titres (NT₅₀) ≥1/320. Median time from onset of symptoms to randomisation was 7 days. The proportion of patients alive and free of mechanical ventilation on day 15 was not different between both groups (convalescent plasma 83.74% (n=267) versus control 84.05% (n=137)) (OR 0.99, 95% CI 0.59–1.66; p=0.9772). The intervention did not change the natural course of antibody titres. The number of serious or severe adverse events was similar in both study arms and transfusion-related side-effects were reported in 19 out of 320 patients in the intervention group (5.94%).

Conclusions

Transfusion of 4 units of convalescent plasma with high neutralising antibody titres early in hospitalised COVID-19 patients did not result in a significant improvement of clinical status or reduced mortality.

Early transfusion of 4 units of high neutralising antibody titre convalescent plasma in hospitalised COVID-19 patients does not reduce mortality or the need for mechanical ventilationhttps://bit.ly/3fiRY2I

Hepatitis B virus prevalence in first-time blood donors in Flanders, Belgium: Impact of universal vaccination and migration

BACKGROUND

Transfusion-transmissible infections such as hepatitis B virus (HBV) remain a major concern for the safety of blood transfusion. This cross-sectional study aimed to assess the trend of HBV prevalence and associated risk factors among a first-time donor population in a low endemic country.

STUDY DESIGN AND METHODS

Between 2010 and 2018, blood samples were collected from first-time donors presented at donor collection sites of Belgian Red Cross-Flanders. They were tested for hepatitis B surface antigen (HBsAg), hepatitis B core antibodies (anti-HBc), and HBV DNA, HIV and hepatitis virus C (HCV) antibodies and RNA, and syphilis antibodies.

RESULTS

A total of 211,331 first-time blood donors (43.7% males, median age 25 years) were analyzed. HBsAg prevalence decreased from 0.06% in 2010 to 0.05% in 2018 (p = .004) and this declining trend was accompanied by an increased number of donors in the HBV vaccinated birth cohort (p < .001). HBsAg prevalence was 0.33% in foreign-born donors and 0.02% in Belgian natives (p < .001). Multivariate risk profiling showed that anti-HBc positivity was significantly associated with mainly foreign-born donors (odds ratio [OR] = 9.24) but also with older age (OR = 1.06), male gender (OR = 1.32), year of blood donation (OR = 0.94), and co-infections with HCV (OR = 4.31) or syphilis (OR = 4.91).

DISCUSSION

The decreasing trend in HBV prevalence could mainly be explained by the introduction of the universal HBV vaccination. Being born in endemic areas was the most important predictor for HBV infection while the co-infections with syphilis suggest unreported sexual risk contacts.

A multicenter randomized trial to assess the efficacy of CONvalescent plasma therapy in patients with Invasive COVID-19 and acute respiratory failure treated with mechanical ventilation: the CONFIDENT trial protocol

Background

The COVID-19 pandemic reached Europe in early 2020. Convalescent plasma is used without a consistent evidence of efficacy. Our hypothesis is that passive immunization with plasma collected from patients having contracted COVID-19 and developed specific neutralizing antibodies may alleviate symptoms and reduce mortality in patients treated with mechanical ventilation for severe respiratory failure during the evolution of SARS-CoV-2 pneumonia.

Methods

We plan to include 500 adult patients, hospitalized in 16 Belgian intensive care units between September 2020 and 2022, diagnosed with SARS-CoV-2 pneumonia, under mechanical ventilation for less than 5 days and a clinical frailty scale less than 6. The study treatment will be compared to standard of care and allocated by randomization in a 1 to 1 ratio without blinding. The main endpoint will be mortality at day 28. We will perform an intention to treat analysis. The number of patients to include is based on an expected mortality rate at day 28 of 40 percent and an expected relative reduction with study intervention of 30 percent with α risk of 5 percent and β risk of 20 percent.

Discussion

This study will assess the efficacy of plasma in the population of mechanically ventilated patients. A stratification on the delay from mechanical ventilation and inclusion will allow to approach the optimal time use. Selecting convalescent plasmas with a high titer of neutralizing antibodies against SARS-CoV-2 will allow a homogeneous study treatment. The inclusion in the study is based on the consent of the patient or his/her legal representative, and the approval of the Investigational Review Board of the University hospital of Liège, Belgium. A data safety monitoring board (DSMB) has been implemented. Interim analyses have been planned at 100, 2002, 300 and 400 inclusions in order to decide whether the trail should be discontinued prematurely for ethical issues. We plan to publish our results in a peer-reviewed journal and to present them at national and international conferences.

Funding and registration

The trial is funded by the Belgian Health Care Knowledge Center KCE # COV201004

Trial registration

Clinicaltrials.gov registration number NCT04558476. Registered 14 September 2020—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04558476

A randomized, multicentre, open-label phase II proof-of-concept trial investigating the clinical efficacy and safety of the addition of convalescent plasma to the standard of care in patients hospitalized with COVID-19: the Donated Antibodies Working against nCoV (DAWn-Plasma) trial

BACKGROUND

The COVID-19 pandemic has imposed an enormous burden on health care systems around the world. In the past, the administration of convalescent plasma of patients having recovered from SARS and severe influenza to patients actively having the disease showed promising effects on mortality and appeared safe. Whether or not this also holds true for the novel SARS-CoV-2 virus is currently unknown.

METHODS

DAWn-Plasma is a multicentre nation-wide, randomized, open-label, phase II proof-of-concept clinical trial, evaluating the clinical efficacy and safety of the addition of convalescent plasma to the standard of care in patients hospitalized with COVID-19 in Belgium. Patients hospitalized with a confirmed diagnosis of COVID-19 are eligible when they are symptomatic (i.e. clinical or radiological signs) and have been diagnosed with COVID-19 in the 72 h before study inclusion through a PCR (nasal/nasopharyngeal swab or bronchoalveolar lavage) or a chest-CT scan showing features compatible with COVID-19 in the absence of an alternative diagnosis. Patients are randomized in a 2:1 ratio to either standard of care and convalescent plasma (active treatment group) or standard of care only. The active treatment group receives 2 units of 200 to 250 mL of convalescent plasma within 12 h after randomization, with a second administration of 2 units 24 to 36 h after ending the first administration. The trial aims to include 483 patients and will recruit from 25 centres across Belgium. The primary endpoint is the proportion of patients that require mechanical ventilation or have died at day 15. The main secondary endpoints are clinical status on day 15 and day 30 after randomization, as defined by the WHO Progression 10-point ordinal scale, and safety of the administration of convalescent plasma.

DISCUSSION

This trial will either provide support or discourage the use of convalescent plasma as an early intervention for the treatment of hospitalized patients with COVID-19 infection.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04429854 . Registered on 12 June 2020 - Retrospectively registered.

Potential human transmission of amyloid β pathology: surveillance and risks

Studies in experimental animals show transmissibility of amyloidogenic proteins associated with prion diseases, Alzheimer's disease, Parkinson's disease, and other neurodegenerative diseases. Although these data raise potential concerns for public health, convincing evidence for human iatrogenic transmission only exists for prions and amyloid β after systemic injections of contaminated growth hormone extracts or dura mater grafts derived from cadavers. Even though these procedures are now obsolete, some reports raise the possibility of iatrogenic transmission of amyloid β through putatively contaminated neurosurgical equipment. Iatrogenic transmission of amyloid β might lead to amyloid deposition in the brain parenchyma and blood vessel walls, potentially resulting in cerebral amyloid angiopathy after several decades. Cerebral amyloid angiopathy can cause life-threatening brain haemorrhages; yet, there is no proof that the transmission of amyloid β can also lead to Alzheimer's dementia. Large, long-term epidemiological studies and sensitive, cost-efficient tools to detect amyloid are needed to better understand any potential routes of amyloid β transmission and to clarify whether other similar proteopathic seeds, such as tau or α-synuclein, can also be transferred iatrogenically.

Eplet Mismatch Load and De Novo Occurrence of Donor-Specific Anti-HLA Antibodies, Rejection, and Graft Failure after Kidney Transplantation: An Observational Cohort Study

BACKGROUND

In kidney transplantation, evaluating mismatches of HLA eplets-small patches of surface-exposed amino acids of the HLA molecule-instead of antigen mismatches might offer a better approach to assessing donor-recipient HLA incompatibility and improve risk assessment and prediction of transplant outcomes.

METHODS

To evaluate the effect of number of eplet mismatches (mismatch load) on de novo formation of donor-specific HLA antibodies (DSAs) and transplant outcomes, we conducted a cohort study that included consecutive adult kidney recipients transplanted at a single center from March 2004 to February 2013. We performed retrospective high-resolution genotyping of HLA loci of 926 transplant pairs and used the HLAMatchmaker computer algorithm to count HLA eplet mismatches.

RESULTS

De novo DSAs occurred in 43 (4.6%) patients. Multivariable analysis showed a significant independent association between antibody-verified eplet mismatch load and de novo DSA occurrence and graft failure, mainly explained by DQ antibody-verified eplet effects. The association with DQ antibody-verified eplet mismatches was linear, without a safe threshold at which de novo DSA did not occur. Odds for T cell- or antibody-mediated rejection increased by 5% and 12%, respectively, per antibody-verified DQ eplet mismatch.

CONCLUSIONS

Eplet mismatches in HLA-DQ confer substantial risk for de novo DSA formation, graft rejection, and graft failure after kidney transplantation. Mismatches in other loci seem to have less effect. The results suggest that antibody-verified HLA-DQ eplet mismatch load could be used to guide personalized post-transplant immunosuppression. Adoption of molecular matching for DQA₁ and DQB₁ alleles could also help to minimize de novo DSA formation and potentially improve transplant outcomes.

Is sexual risk behaviour associated with an increased risk of transfusion-transmissible infections in blood donors from Western and Pacific countries? A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

The donor medical questionnaire is designed to aid blood establishments in supporting a safe blood supply. According to blood donor deferral policies, sexual risk behaviour (SRB) leads to a (temporary) deferral from blood donation. This systematic review aimed to scientifically underpin these policies by identifying the best available evidence on the association between SRB and the risk of transfusion transmissible infections (TTIs).

MATERIALS & METHODS

Studies from three databases investigating the link between SRB (excluding men who have sex with men (MSM)) and TTIs (HBV, HCV, HIV, Treponema pallidum) in donors from Western and Pacific countries were obtained and assessed on eligibility by two reviewers independently. The association between SRB and TTIs was expressed by calculating pooled effect measures via meta-analyses. The GRADE methodology (Grades of Recommendation, Assessment, Development and Evaluation) was used to assess the quality of evidence.

RESULTS

We identified 3750 references and finally included 15 observational studies. Meta-analyses showed that there is a significant (P < 0·05) positive association between the following SRB and HBV and/or HCV infection: having sex with an intravenous drug user (high-certainty evidence), receiving money or goods for sex (moderate-high certainty evidence), having a sex partner with hepatitis/HIV (moderate-certainty evidence) and paid for sex or anal sex (low-certainty evidence).

CONCLUSION

Sexual risk behaviour (including having sex with an intravenous drug user, receiving money or goods for sex or having a sex partner with hepatitis/HIV) is probably associated with an increased risk of HBV/HCV infection in blood donors from Western and Pacific countries.

The senotherapeutic nicotinamide riboside raises platelet nicotinamide adenine dinucleotide levels but cannot prevent storage lesion

BACKGROUND

Supplementation of the nicotinamide adenine dinucleotide (NAD) precursor nicotinamide riboside (NR) has recently been shown to increase life‐span of cells, tissues, and entire organisms. [Correction added on 13 December 2019, after first online publication: In the preceding sentence, “adenine nicotinamide” was revised to “nicotinamide adenine.”] The impact of NR on platelet longevity has not been tested.

STUDY DESIGN AND METHODS

A pool‐and‐split design of buffy coat derived platelet concentrates (PCs) was used. One arm was treated with cumulative doses of NR‐triflate, the control arm with sodium triflate. Storage lesion was monitored for 23 days. Platelet metabolic and functional parameters were tested. Clearance of human platelets was measured in a mouse model of transfusion.

RESULTS

Total intracellular NAD levels in platelets decreased two‐fold from 4.8 ± 0.5 fmol (mean ± SD, n = 6) to 2.1 ± 1.8 fmol per 10³ control cells, but increased almost 10‐fold to 41.5 ± 4.1 fmol per 10³ NR treated platelets. This high intracellular NAD level had no significant impact on platelet count, mean platelet volume, swirling, nor on lactate and glucose levels. Platelet aggregation and integrin α_IIbβ₃ activation declined steadily and comparably in both conditions. GPIbα levels were slightly lower in NR‐treated platelets compared to control, but this was not caused by reduced receptor shedding because glycocalicin increased similarly. Apoptotic markers cytochrome c, Bcl‐xL, cleaved caspase‐3, and Bak were not different throughout storage for both conditions. Platelet survival in a mouse model of transfusion was not different between NR‐treated and control platelets.

CONCLUSION

Platelets carry the cellular machinery to metabolize NR into NAD at rates comparable to other eukaryotic cells. Unlike those cells, platelet life‐span cannot be prolonged using this strategy.

Hepatitis E virus prevalence in Flemish blood donors

Transmission of hepatitis E virus (HEV) through transfusion of blood components has already been reported in several European countries. Here, we assessed the HEV prevalence in Flemish blood donors. This study is of importance in order to assess the risk of HEV transmission through blood transfusion. We analysed 38 137 blood donation samples that were collected by the Red Cross Flanders during the period May-June 2015. All samples were screened for the presence of HEV RNA and a selection for HEV-specific IgM/IgG. After pooling per 6, 11 pools reacted positive during RNA screening. Reactive pools were deconstructed, and individual samples were retested. After deconstruction, seven samples were confirmed as HEV RNA positive. Serological screening of the confirmed RNA-positive samples showed that six out of these seven samples were HEV IgM positive, of which three donors were also IgG positive. Serological screening was also performed on the samples that constituted the four initially HEV RNA reactive pools where RNA positivity was not confirmed on the individual level. In three pools, we found indirect evidence of recent HEV exposure. Within 356 randomly selected samples, 31 donations were HEV IgG positive. Here we show that at least 1:5448 of blood donations in Flanders may originate from donors that are actively infected with HEV. Upon transfusion, these donations may pose a major threat towards patients at risk. Finally, a serological analysis showed that the anti-HEV IgG prevalence in Flemish blood donors is 8.71%.

Impact of cold storage on platelets treated with Intercept pathogen inactivation

BACKGROUND

Pathogen inactivation and cold or cryopreservation of platelets (PLTs) both significantly affect PLT function. It is not known how PLTs function when both are combined.

STUDY DESIGN AND METHODS

Standard PLT concentrates (PCs) were compared to pathogen‐inactivated PCs treated with amotosalen photochemical treatment (AS‐PCT) when stored at room (RT, 22°C), cold (4°C, n = 6), or cryopreservation (−80°C, n = 8) temperatures. The impact of alternative storage methods on both arms was studied in flow cytometry, light transmittance aggregometry, and hemostasis in collagen‐coated microfluidic flow chambers.

RESULTS

Platelet aggregation of cold‐stored AS‐PCT PLTs was 44% ± 11% compared to 57% ± 14% for cold‐stored standard PLTs and 58% ± 21% for RT‐stored AS‐PCT PLTs. Integrin activation of cold‐stored AS‐PCT PLTs was 53% ± 9% compared to 77% ± 6% for cold‐stored standard PLTs and 69% ± 13% for RT‐stored AS‐PCT PLTs. Coagulation of cold‐stored AS‐PCT PLTs started faster under flow (836 ± 140 sec) compared to cold‐stored standard PLTs (960 ± 192 sec) and RT‐stored AS‐PCT PLTs (1134 ± 220 sec). Fibrin formation rate under flow was also highest for cold‐stored AS‐PCT PLTs. This was in line with thrombin generation in static conditions because cold‐stored AS‐PCT PLTs generated 297 ± 47 nmol/L thrombin compared to 159 ± 33 nmol/L for cold‐stored standard PLTs and 83 ± 25 nmol/L for RT‐stored AS‐PCT PLTs. So despite decreased PLT activation and aggregation, cold storage of AS‐PCT PLTs promoted coagulation. PLT aggregation of cryopreserved AS‐PCT PLTs (23% ± 10%) was not significantly different from cryopreserved standard PLTs (25% ± 8%).

CONCLUSION

This study shows that cold storage of AS‐PCT PLTs further affects PLT activation and aggregation but promotes (pro)coagulation. Increased procoagulation was not observed after cryopreservation.

Post-transfusion hemoglobin values and patient blood management

OBJECTIVES

The objective of this retrospective study was to evaluate the added value of communicating post-transfusion hemoglobin values to clinicians as a strategy to improve RBC utilization in a 500-bed hospital.

METHODS

The total number of RBC transfusions, the mean number of RBC units transfused per patient, the mean pre- and post-transfusion hemoglobin values, the ratio of patients transfused and the ratio of patients with a post-transfusion hemoglobin > 10.5 g/dL were calculated per service and per department for six months. The data were reported to each service and compared with the data of the department as peer group. The impact of this communication strategy was evaluated in the following six months.

RESULTS

In the six months pre-intervention, the mean post-transfusion hemoglobin value was 9.2 g/dL. Post-transfusion hemoglobin was > 10.5 g/dL in 13.4% of patients (112/835). Following communication of these data, RBC consumption decreased 21.0% (p < 0.01) and 21% (p < 0.01) fewer patients received transfusions despite an increase in mean post-transfusion hemoglobin value to 9.4 g/dL (p < 0.01).

CONCLUSION

Providing feedback on post-transfusion hemoglobin data and the global consumption of RBC units to prescribing physicians can be an additional, feasible and effective strategy to encourage self-assessment and to improve blood utilization.

Is there a risk of transfusion-transmissible infections after percutaneous needle treatments in blood donors? A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

The donor medical questionnaire identifies a blood donor's history of known blood safety risks. Current Australian, Canadian, European and USA legislation temporarily defers blood donors who received different percutaneous needle treatments (i.e. tattooing, acupuncture and piercing) from blood donation. This systematic review aimed to scientifically underpin these deferrals by identifying the best available evidence on the association between percutaneous needle treatments and the risk of transfusion-transmissible infections (TTIs).

MATERIALS AND METHODS

Studies from three databases investigating the link between percutaneous needle treatments and TTIs (HBV, HCV and HIV infection) in blood donors were retained and assessed on eligibility by two reviewers independently. The association between percutaneous needle treatments and TTIs was expressed by conducting meta-analyses and calculating pooled effect measures (odds ratios (ORs) and 95% CIs). The GRADE methodology (Grades of Recommendation, Assessment, Development and Evaluation) was used to assess the quality of evidence.

RESULTS

We identified 1242 references and finally included 21 observational studies. Twenty studies assessed the link between percutaneous needle treatments and HCV infection and found that blood donors receiving these treatments had an increased risk of HCV infection (tattooing: pooled OR 5·28, 95% CI [4·33, 6·44], P < 0·00001 (low-quality evidence); acupuncture: pooled OR 1·56, 95% CI [1·17, 2·08], P = 0·03 (very low-quality evidence); and piercing: pooled OR 3·25, 95% CI [1·68, 6·30], P = 0·0005 (low-quality evidence)).

CONCLUSION

Percutaneous needle treatments may be associated with an increased HCV infection risk. Further high-quality studies are required to formulate stronger evidence-based recommendations on percutaneous needle treatments as a blood donor deferral criterion.

A comparison of haematopoietic stem cells from umbilical cord blood and peripheral blood for platelet production in a microfluidic device

BACKGROUND AND OBJECTIVES

Several sources of haematopoietic stem cells have been used for static culture of megakaryocytes to produce platelets in vitro. This study compares and characterizes platelets produced in shear flow using precursor cells from either umbilical (UCB) or adult peripheral blood (PB).

MATERIALS AND METHODS

The efficiency of platelet production of the cultured cells was studied after perfusion in custom-built von Willebrand factor-coated microfluidic flow chambers. Platelet receptor expression and morphology were investigated by flow cytometry and microscopy, respectively.

RESULTS

Proliferation of stem cells isolated out of UCB was significantly higher (P < 0·0001) compared to PB. Differentiation of these cells towards megakaryocytes was significantly lower from PB compared to UCB where the fraction of CD42b/CD41 double positive events was 44 ± 9% versus 76 ± 11%, respectively (P < 0·0001). However, in vitro platelet production under hydrodynamic conditions was more efficient with 7·4 platelet-like particles per input cell from PB compared to 4·2 from UCB (P = 0·02). The percentage of events positive for CD42b, CD41 and CD61 was comparable between both stem cell sources. The mean number of receptors per platelet from UCB and PB was similar to that on blood bank platelets with on average 28 000 CD42b, 57 000 CD61 and 5500 CD49b receptors. Microscopy revealed platelets appearing similar to blood bank platelets in morphology, size and actin cytoskeleton, alongside smaller fragments and source megakaryocytes.

CONCLUSION

This characterization study suggests that platelets produced in vitro under flow either from UCB or from PB share receptor expression and morphology with donor platelets stored in the blood bank.

Comparison between manufacturing sites shows differential adhesion, activation, and GPIbα expression of cryopreserved platelets

BACKGROUND

Transfusion of cryopreserved platelets (cryoplatelets) is not common but may replace standard liquid-preserved platelets (PLTs) in specific circumstances. To better understand cryoplatelet function, frozen concentrates from different manufacturing sites were compared.

STUDY DESIGN AND METHODS

Cryoplatelets from Denver, Colorado (DEN); Sydney, Australia (SYD); and Ghent, Belgium (GHE) were compared (n = 6). A paired noncryopreserved control was included in Ghent. Microfluidic-flow chambers were used to study PLT adhesion and fibrin deposition in reconstituted blood. Receptor expression was measured by flow cytometry. Coagulation in static conditions was evaluated by rotational thromboelastometry (ROTEM).

RESULTS

Regardless of the manufacturing site, adhesion of cryoplatelets under shear flow (1000/sec) was significantly (p < 0.05) reduced compared to control. Expression of GPIbα was decreased in a subpopulation of cryoplatelets comprising 45% ± 11% (DEN), 63% ± 9% (GHE), and 94% ± 6% (SYD). That subpopulation displayed increased annexin V binding and decreased integrin activation. PLT adhesion, agglutination, and aggregation were moreover decreased in proportion to that subpopulation. Fibrin deposition under shear flow was normal but initiated faster (546 ± 163 sec GHE) than control PLTs (631 ± 120 sec, p < 0.01), only in the absence of tissue factor. In static conditions, clotting time was faster, but clot firmness decreased compared to control. Coagulation was not different between manufacturing sites.

CONCLUSION

Cryopreservation results in a subset of PLTs with enhanced GPIbα shedding, increased phosphatidylserine expression, reduced integrin response, and reduced adhesion to collagen in microfluidic models of hemostasis. The proportion of this phenotype is different between manufacturing sites. The clinical effects, if any, will need to be verified.

Biomolecular Consequences of Platelet Pathogen Inactivation Methods

Pathogen inactivation (PI) for platelet concentrates (PC) is a fairly recent development in transfusion medicine that is intended to decrease infectious disease transmission from the donor to the receiving patient. Effective inactivation of viruses, bacteria and eukaryotic parasites adds a layer of safety, protecting the blood supply against customary and emerging pathogens. Three PI methods have been described for platelets. These are based on photochemical damage of nucleic acids which prevents replication of most infectious pathogens and contaminating donor leukocytes. Because platelets do not replicate, the collateral damage to platelet function is considered low to non-existing. This is disputable however because photochemistry is not specific for nucleic acids and significantly affects platelet biomolecules as well. The impact of these biomolecular changes on platelet function and hemostasis is not well understood, but is increasingly being studied. The results of these studies can help explain current and future clinical observations with PI platelets, including the impact on transfusion yield and bleeding. This review summarizes the biomolecular effects of PI treatment on platelets. We conclude that despite a comparable principle of photochemical inactivation, all three methods affect platelets in different ways. This knowledge can help blood banks and transfusion specialists to guide their choice when considering the implementation or clinical use of PI treated platelets.

Comparison of three commercially available buffy coat pooling sets for the preparation of platelet concentrates

BACKGROUND

A disposable set for platelet concentrate (PC) preparation by the buffy coat method allows pooling of buffy coats, centrifugation and cell separation with in-line leucocyte filtration. This study compares three commercially available pooling sets in combination with INTERCEPT pathogen inactivation (PI).

MATERIALS AND METHODS

Sets for pooling of buffy coats were from Fresenius Kabi (FRE), Macopharma (MAC) and Terumo BCT (TER). Platelet yield, recovery and concentration were compared before and after PI (n = 20). Platelet quality was assessed by annexin V binding, P-selectin expression and PAC1 binding.

RESULTS

The TER pooling set had the highest platelet yield (5·39 ± 0·44 × 1011 ) compared with MAC (4·53 ± 0·77) and FRE (4·56 ± 0·51) prior to PI. This was the result of a significantly higher platelet concentration in the TER storage bag (1·41 ± 0·12 × 106 /μL) compared with MAC (1·18 ± 0·19) and FRE (1·28 ± 0·15). However, the TER platelet content decreased by 15·6% after PI, yielding 4·55 ± 0·47 × 1011 platelets compared with smaller reductions at 9·5% for MAC (4·10 ± 0·69) and 4·4% for FRE (4·36 ± 0·52). None of the individual PC contained >106 leucocytes. The pH in TER PC was lower compared with MAC and FRE caused by a higher lactic acid production rate. Consequently, PAC1 binding after TRAP activation was lowest for TER PC on day 6. P-selectin and annexin V were not different between suppliers.

CONCLUSION

This study demonstrates the added value of evaluating the entire component production process when introducing a new consumable. This study helped to inform a decision on what pooling set is ideally suited for routine implementation taking into account PI.

Phylogenetic analysis reveals three distinct epidemiological profiles in Dutch and Flemish blood donors with hepatitis B virus infection

During 2006-2016, hepatitis B virus (HBV) was detected in nearly 400 blood donors in the Netherlands and Flanders. Donor demographics and self-reported risk factors as disclosed during the donor exit interview were compared to HBV phylogenies of donor and reference sequences. First-time donors with chronic HBV-infection were often immigrants (67%) infected with genetically highly diverse strains of genotypes A (32%), B (8%), C (6%), D (53%) and E to H (1%). Each subtype was strongly associated with donor ethnicity. In contrast, 57/62 (93%) of acute/recent HBV infections occurred among indigenous donors, of whom 67% was infected with one specific widely circulating epidemic HBV-A2 lineage. HBV typing identified three distinct epidemiological profiles: the import of chronic HBV infections through migration, longstanding transmission of non-epidemic HBV-A2 strains within western-Europe, and the active transmission of one epidemic HBV-A2 strain most likely fueled by sexual risk behavior.

Glucocorticoid receptor DNA methylation and childhood trauma in chronic fatigue syndrome patients

OBJECTIVE

Although the precise mechanisms are not yet understood, previous studies have suggested that chronic fatigue syndrome (CFS) is associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation and trauma in early childhood. Consistent with findings suggesting that early life stress-induced DNA methylation changes may underlie dysregulation of the HPA axis, we previously found evidence for the involvement of glucocorticoid receptor (GR) gene (NR3C1) methylation in whole blood of CFS patients.

METHODS

In the current study, we assessed NR3C1-1F region DNA methylation status in peripheral blood from a new and independent sample of 80 female CFS patients and 91 female controls. In CFS patients, history of childhood trauma subtypes was evaluated using the Childhood Trauma Questionnaire short form (CTQ-SF).

RESULTS

Although absolute methylation differences were small, the present study confirms our previous findings of NR3C1-1F DNA hypomethylation at several CpG sites in CFS patients as compared to controls. Following multiple testing correction, only CpG_8 remained significant (DNA methylation difference: 1.3% versus 1.5%, p<0.001). In addition, we found associations between DNA methylation and severity of fatigue as well as with childhood emotional abuse in CFS patients, although these findings were not significant after correction for multiple testing.

CONCLUSIONS

In conclusion, we replicated findings of NR3C1-1F DNA hypomethylation in CFS patients versus controls. Our results support the hypothesis of HPA axis dysregulation and enhanced GR sensitivity in CFS.

Is an endoscopic examination associated with transfusion-transmissible infections? A systematic review and meta-analysis

BACKGROUND

The purpose of a donor medical questionnaire is to identify the blood donor's history relative to the current known blood-safety risks. A temporary deferral from blood donation after an endoscopic examination is enforced because of the reusable nature of the endoscope and close contact with the inner body. The objective of this systematic review was to find the best available evidence on the association between an endoscopic examination and the risk of transfusion-transmissible infections.

METHODS

Studies from five databases investigating the link between an endoscopic examination and transfusion-transmissible infections (hepatitis B virus, hepatitis C virus, human immunodeficiency virus infection, Treponema pallidum) were retained and assessed independently by two reviewers. The association between endoscopy and transfusion-transmissible infections was identified by conducting meta-analyses and calculating pooled effect measures (odds ratios and 95% confidence intervals). The Grading of Recommendations, Assessment, Development, and Evaluation methodology was used to assess the quality of evidence.

RESULTS

We identified 7571 references and finally included 29 observational studies. A significant association between an endoscopic examination and hepatitis B virus infection (pooled odds ratio [OR], 2.21; 95% confidence interval [CI], 1.26-3.86; p = 0.005) or hepatitis C virus infection (pooled OR 1.76, 95% CI, 1.45-2.14; p < 0.00001) was found. The level of evidence was considered as "very low" due to the type of study design (i.e., observational) and indirect study populations (i.e., no blood donor populations).

CONCLUSION

An endoscopic examination is associated with an increased hepatitis B virus or hepatitis C virus infection risk. Further high-quality trials are required to formulate stronger evidence-based recommendations on endoscopic examination as a blood donor deferral criterion.

High platelet content can increase storage lesion rates following Intercept pathogen inactivation primarily in platelet concentrates prepared by apheresis

BACKGROUND

Pathogen inactivation methods for platelet concentrates are increasingly being used in blood banks worldwide. In vitro studies have demonstrated its effects on storage lesion, but little routine quality control data on blood banking outcomes have been reported.

MATERIALS AND METHODS

Swirling of distributed products was monitored before and after implementation of Intercept pathogen inactivation. Metabolic parameters pH, glucose and lactic acid were determined in a random cohort of expired pathogen-inactivated products. Storage lesion indicators in apheresis concentrates with premature low swirling were compared to concentrates with normal swirling.

RESULTS

During validation for implementing Intercept pathogen inactivation, pH and glucose levels decreased faster in apheresis platelet concentrates with high platelet content than with low platelet content or than in pathogen-inactivated pooled buffy coat-derived products. In routine products, glucose exhaustion was more often found in apheresis compared to buffy coat-derived platelet concentrates despite 3-7% more plasma carryover in the former. Annual incidence of premature low swirling increased significantly by 50% following implementation of pathogen inactivation implementation for apheresis but not for pooled buffy coat platelet concentrates. In addition, apheresis concentrates with premature low swirling had a significantly higher median platelet count (5·0 × 10¹¹ ) than unaffected products (3·5 × 10¹¹ ).

CONCLUSION

The risk of increased storage lesion rates following Intercept pathogen inactivation is higher for apheresis than for buffy coat-derived platelet concentrates, especially when platelet contents are higher than 5·0 × 10¹¹ .