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1.
Haematologica ; 2022 Apr 07.
Article in English | MEDLINE | ID: covidwho-1779916

ABSTRACT

To improve the safety of COVID-19 vaccines, there is an urgent need to unravel the pathogenesis of vaccine-induced immune thrombotic thrombocytopenia (VITT), a severe complication of recombinant adenoviral vector vaccines used to prevent COVID-19, and likely due to anti-platelet factor 4 (PF4) IgG antibodies. In this study, we demonstrated that 1E12, a chimeric anti-PF4 antibody with a human Fc fragment, fully mimics the effects of human VITT antibodies, as it activates platelets to a similar level in the presence of platelet factor 4 (PF4). Incubated with neutrophils, platelets and PF4, 1E12 also strongly induces NETosis, and in a microfluidic model of whole blood thrombosis, it triggers the formation of large platelet/leukocyte thrombi containing fibrin(ogen). In addition, a deglycosylated form of 1E12 (DG-1E12), which still binds PF4 but no longer interacts with Fcy receptors, inhibits platelet, granulocyte and clotting activation induced by human anti-PF4 VITT antibodies. This strongly supports that 1E12 and VITT antibodies recognize overlapping epitopes on PF4. In conclusion, 1E12 is a potentially important tool to study the pathophysiology of VITT, and for establishing mouse models. On the other hand, DG-1E12 may help the development of a new drug that specifically neutralizes the pathogenic effect of autoimmune anti-PF4 antibodies, such as those associated with VITT.

4.
JAMA Neurol ; 78(11): 1314-1323, 2021 11 01.
Article in English | MEDLINE | ID: covidwho-1439655

ABSTRACT

Importance: Thrombosis with thrombocytopenia syndrome (TTS) has been reported after vaccination with the SARS-CoV-2 vaccines ChAdOx1 nCov-19 (Oxford-AstraZeneca) and Ad26.COV2.S (Janssen/Johnson & Johnson). Objective: To describe the clinical characteristics and outcome of patients with cerebral venous sinus thrombosis (CVST) after SARS-CoV-2 vaccination with and without TTS. Design, Setting, and Participants: This cohort study used data from an international registry of consecutive patients with CVST within 28 days of SARS-CoV-2 vaccination included between March 29 and June 18, 2021, from 81 hospitals in 19 countries. For reference, data from patients with CVST between 2015 and 2018 were derived from an existing international registry. Clinical characteristics and mortality rate were described for adults with (1) CVST in the setting of SARS-CoV-2 vaccine-induced immune thrombotic thrombocytopenia, (2) CVST after SARS-CoV-2 vaccination not fulling criteria for TTS, and (3) CVST unrelated to SARS-CoV-2 vaccination. Exposures: Patients were classified as having TTS if they had new-onset thrombocytopenia without recent exposure to heparin, in accordance with the Brighton Collaboration interim criteria. Main Outcomes and Measures: Clinical characteristics and mortality rate. Results: Of 116 patients with postvaccination CVST, 78 (67.2%) had TTS, of whom 76 had been vaccinated with ChAdOx1 nCov-19; 38 (32.8%) had no indication of TTS. The control group included 207 patients with CVST before the COVID-19 pandemic. A total of 63 of 78 (81%), 30 of 38 (79%), and 145 of 207 (70.0%) patients, respectively, were female, and the mean (SD) age was 45 (14), 55 (20), and 42 (16) years, respectively. Concomitant thromboembolism occurred in 25 of 70 patients (36%) in the TTS group, 2 of 35 (6%) in the no TTS group, and 10 of 206 (4.9%) in the control group, and in-hospital mortality rates were 47% (36 of 76; 95% CI, 37-58), 5% (2 of 37; 95% CI, 1-18), and 3.9% (8 of 207; 95% CI, 2.0-7.4), respectively. The mortality rate was 61% (14 of 23) among patients in the TTS group diagnosed before the condition garnered attention in the scientific community and 42% (22 of 53) among patients diagnosed later. Conclusions and Relevance: In this cohort study of patients with CVST, a distinct clinical profile and high mortality rate was observed in patients meeting criteria for TTS after SARS-CoV-2 vaccination.


Subject(s)
COVID-19 Vaccines/therapeutic use , Drug-Related Side Effects and Adverse Reactions/mortality , Registries , Sinus Thrombosis, Intracranial/mortality , Thrombocytopenia/mortality , Venous Thromboembolism/mortality , Adult , Aged , COVID-19 Vaccines/adverse effects , Cohort Studies , Female , Hospital Mortality , Humans , Male , Middle Aged , Outcome Assessment, Health Care , Sex Factors , Sinus Thrombosis, Intracranial/blood , Sinus Thrombosis, Intracranial/chemically induced , Syndrome , Thrombocytopenia/blood , Thrombocytopenia/chemically induced , Venous Thromboembolism/blood , Venous Thromboembolism/chemically induced , Young Adult
6.
Thromb Res ; 203: 163-171, 2021 07.
Article in English | MEDLINE | ID: covidwho-1230797

ABSTRACT

As of 4 April 2021, a total of 169 cases of cerebral venous sinus thrombosis (CVST) and 53 cases of splanchnic vein thrombosis were reported to EudraVigilance among around 34 million people vaccinated in the European Economic Area and United Kingdom with COVID-19 Vaccine AstraZeneca, a chimpanzee adenoviral vector (ChAdOx1) encoding the spike protein antigen of the SARS-CoV-2 virus. The first report of the European Medicines Agency gathering data on 20 million people vaccinated with Vaxzevria® in the UK and the EEA concluded that the number of post-vaccination cases with thromboembolic events as a whole reported to EudraVigilance in relation to the number of people vaccinated was lower than the estimated rate of such events in the general population. However, the EMA's Pharmacovigilance Risk Assessment Committee concluded that unusual thromboses with low blood platelets should be listed as very rare side effects of Vaxzevria®, pointing to a possible link. The same issue was identified with the COVID-19 Vaccine Janssen (Ad26.COV2.S). Currently, there is still a sharp contrast between the clinical or experimental data reported in the literature on COVID-19 and the scarcity of data on the unusual thrombotic events observed after the vaccination with these vaccines. Different hypotheses might support these observations and should trigger further in vitro and ex vivo investigations. Specialized studies were needed to fully understand the potential relationship between vaccination and possible risk factors in order to implement risk minimization strategies.


Subject(s)
COVID-19 , Thrombocytopenia , Thrombosis , COVID-19 Vaccines , Humans , SARS-CoV-2 , Thrombocytopenia/chemically induced , United Kingdom , Vaccination/adverse effects
9.
Alzheimers Dement ; 16(11): 1571-1581, 2020 11.
Article in English | MEDLINE | ID: covidwho-713873

ABSTRACT

We have provided an overview on the profound impact of COVID-19 upon older people with Alzheimer's disease and other dementias and the challenges encountered in our management of dementia in different health-care settings, including hospital, out-patient, care homes, and the community during the COVID-19 pandemic. We have also proposed a conceptual framework and practical suggestions for health-care providers in tackling these challenges, which can also apply to the care of older people in general, with or without other neurological diseases, such as stroke or parkinsonism. We believe this review will provide strategic directions and set standards for health-care leaders in dementia, including governmental bodies around the world in coordinating emergency response plans for protecting and caring for older people with dementia amid the COIVD-19 outbreak, which is likely to continue at varying severity in different regions around the world in the medium term.


Subject(s)
Alzheimer Disease/complications , Coronavirus Infections/complications , Dementia/complications , Pneumonia, Viral/complications , Aged , Aged, 80 and over , Alzheimer Disease/therapy , Betacoronavirus , COVID-19 , Coronavirus Infections/therapy , Female , Humans , Male , Pandemics , Pneumonia, Viral/therapy , Risk Factors , SARS-CoV-2
10.
Ther Adv Neurol Disord ; 13: 1756286420932036, 2020.
Article in English | MEDLINE | ID: covidwho-610846

ABSTRACT

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China and rapidly spread worldwide, with a vast majority of confirmed cases presenting with respiratory symptoms. Potential neurological manifestations and their pathophysiological mechanisms have not been thoroughly established. In this narrative review, we sought to present the neurological manifestations associated with coronavirus disease 2019 (COVID-19). Case reports, case series, editorials, reviews, case-control and cohort studies were evaluated, and relevant information was abstracted. Various reports of neurological manifestations of previous coronavirus epidemics provide a roadmap regarding potential neurological complications of COVID-19, due to many shared characteristics between these viruses and SARS-CoV-2. Studies from the current pandemic are accumulating and report COVID-19 patients presenting with dizziness, headache, myalgias, hypogeusia and hyposmia, but also with more serious manifestations including polyneuropathy, myositis, cerebrovascular diseases, encephalitis and encephalopathy. However, discrimination between causal relationship and incidental comorbidity is often difficult. Severe COVID-19 shares common risk factors with cerebrovascular diseases, and it is currently unclear whether the infection per se represents an independent stroke risk factor. Regardless of any direct or indirect neurological manifestations, the COVID-19 pandemic has a huge impact on the management of neurological patients, whether infected or not. In particular, the majority of stroke services worldwide have been negatively influenced in terms of care delivery and fear to access healthcare services. The effect on healthcare quality in the field of other neurological diseases is additionally evaluated.

11.
Eur Stroke J ; 5(3): 230-236, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-593473

ABSTRACT

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic has been placing an overwhelming burden on health systems, thus threatening their ability to operate effectively for acute conditions in which treatments are highly time sensitive, such as cerebrovascular disorders and myocardial infarction. As part of an effort to reduce the consequences of this outbreak on health service delivery to stroke patients, the European Stroke Organisation has undertaken a survey aimed at collecting information on the provision of stroke care during the pandemic. METHODS: Cross-sectional, web-based survey, conducted from 26 March through 1 April 2020 among stroke care providers, focused on reorganisation of health services, the delivery of acute and post-acute stroke care and the availability of personal protective equipment. RESULTS: A total of 426 stroke care providers from 55 countries completed the survey, most of whom worked in Europe (n = 375, 88%) and were stroke physicians/neurologists (n = 334, 78%). Among European respondents, 289 (77%) reported that not all stroke patients were receiving the usual care in their centres and 266 (71%) estimated that functional outcomes and recurrence rates of stroke patients would be negatively affected by the organisational changes caused by the pandemic. The areas considered as being most affected were acute care and rehabilitation. Most professionals had to adapt their activities and schedules and more than half reported shortage of protective equipment. DISCUSSION: Strategies to maintain availability of stroke care during the COVID-19 outbreak are crucial to prevent indirect mortality and disability due to suboptimal care. CONCLUSION: European Stroke Organisation proposes a set of targeted actions for decision makers facing this exceptional situation.

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