The efficacy of convalescent plasma for coronavirus disease 2019 (COVID-19) is unclear. Although most randomized controlled trials have shown negative results, uncontrolled studies have suggested that the antibody content could influence patient outcomes. We conducted an open-label, randomized controlled trial of convalescent plasma for adults with COVID-19 receiving oxygen within 12 d of respiratory symptom onset (NCT04348656). Patients were allocated 2:1 to 500 ml of convalescent plasma or standard of care. The composite primary outcome was intubation or death by 30 d. Exploratory analyses of the effect of convalescent plasma antibodies on the primary outcome was assessed by logistic regression. The trial was terminated at 78% of planned enrollment after meeting stopping criteria for futility. In total, 940 patients were randomized, and 921 patients were included in the intention-to-treat analysis. Intubation or death occurred in 199/614 (32.4%) patients in the convalescent plasma arm and 86/307 (28.0%) patients in the standard of care arm—relative risk (RR) = 1.16 (95% confidence interval (CI) 0.94–1.43, P = 0.18). Patients in the convalescent plasma arm had more serious adverse events (33.4% versus 26.4%; RR = 1.27, 95% CI 1.02–1.57, P = 0.034). The antibody content significantly modulated the therapeutic effect of convalescent plasma. In multivariate analysis, each standardized log increase in neutralization or antibody-dependent cellular cytotoxicity independently reduced the potential harmful effect of plasma (odds ratio (OR) = 0.74, 95% CI 0.57–0.95 and OR = 0.66, 95% CI 0.50–0.87, respectively), whereas IgG against the full transmembrane spike protein increased it (OR = 1.53, 95% CI 1.14–2.05). Convalescent plasma did not reduce the risk of intubation or death at 30 d in hospitalized patients with COVID-19. Transfusion of convalescent plasma with unfavorable antibody profiles could be associated with worse clinical outcomes compared to standard care.

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BACKGROUND: Adverse events during donation negatively impact the likelihood of subsequent donation. Syncope is a possible complication of blood donation in healthy individuals. This systematic review aims to identify risk factors for syncope in healthy blood donors. STUDY DESIGN AND METHODS: Medline, Embase,Cochrane, CINAHL, Web of Science, Transfusion Evidence Library, and PubMed libraries up to November 2016 were searched. Inclusion criteria were observational and interventional trials, case series including more than 10 participants, randomized controlled trials, and clinical trials. Papers required data pertaining to syncopal events separate from presyncope for inclusion. Incomplete text or non-English language versions were excluded. Papers were evaluated using the CHARMS 2014 checklist. RESULTS:From 3316 papers, 1297 unique citations were identified, and 11 were selected for data extraction. Sex, estimated blood volume, age, donor status, blood pressure, heart rate, weight, previous reaction, caffeine, sleep, and donation site were identified as risk factors for syncope during blood donation.CONCLUSION: Possible risk factors for syncope in healthy blood donors have been identified that could allow for improved screening prior to donation and potential reduction in donor attrition due to negative experiences.ABBREVIATION: EBV = estimated blood volume.From the

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In this pilot study, thrice weekly warfarin appears to be a safe and feasible dosing strategy in a select patient population. A randomized controlled trial of thrice weekly warfarin is warranted.