Risk of Arterial and Venous Thrombotic Events Among Patients with COVID-19: A Multi-National Collaboration of Regulatory Agencies from Canada, Europe, and United States

Vincent Lo Re III,1,2,* Noelle M Cocoros,3,4,* Rebecca A Hubbard,2 Sarah K Dutcher,5 Craig W Newcomb,2 John G Connolly,3,4 Silvia Perez-Vilar,5 Dena M Carbonari,2 Maria E Kempner,3,4 José J Hernández-Muñoz,5 Andrew B Petrone,3,4 Allyson M Pishko,6 Meighan E Rogers Driscoll,3,4 James T Brash,7 Sean Burnett,8,9 Catherine Cohet,10 Matthew Dahl,8,11 Terese A DeFor,12 Antonella Delmestri,13 Djeneba Audrey Djibo,14 Talita Duarte-Salles,15,16 Laura B Harrington,17 Melissa Kampman,18 Jennifer L Kuntz,19 Xavier Kurz,10 Núria Mercadé-Besora,15 Pamala A Pawloski,12 Peter R Rijnbeek,16 Sarah Seager,7 Claudia A Steiner,20,21 Katia Verhamme,16 Fangyun Wu,8,22 Yunping Zhou,23 Edward Burn,13 J Michael Paterson,8,22,* Daniel Prieto-Alhambra13,16,* 1Division of Infectious Diseases, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; 2Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; 3Department of Population Medicine, Harvard Medical School, Boston, MA, USA; 4Harvard Pilgrim Healthcare Institute, Boston, MA, USA; 5Office of Surveillance and Epidemiology, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA; 6Division of Hematology and Oncology, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; 7IQVIA, Real World Solutions, Brighton, UK; 8Canadian Network for Observational Drug Effect Studies (CNODES), Toronto, Ontario, Canada; 9Therapeutics Initiative, University of British Columbia, Vancouver, British Columbia, Canada; 10Data Analytics and Methods Task Force, European Medicines Agency, Amsterdam, Netherlands; 11Manitoba Centre for Health Policy, University of Manitoba, Winnipeg, Manitoba, Canada; 12HealthPartners Institute, Bloomington, MN, USA; 13Pharmaco- and Device Epidemiology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS), University of Oxford, Oxford, UK; 14CVS Health, Blue Bell, PA, USA; 15Fundació Institut Universitari per a la recerca a l’Atenció Primària de Salut Jordi Gol i Gurina (IDIAPJGol), Barcelona, Spain; 16Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, Netherlands; 17Kaiser Permanente Washington Health Research Institute, Seattle, WA, USA; 18Health Canada, Ottawa, Ontario, Canada; 19Kaiser Permanente Northwest Center for Health Research, Portland, OR, USA; 20Kaiser Permanente Colorado Institute for Health Research, Aurora, CO, USA; 21Colorado Permanente Medical Group, Denver, CO, USA; 22ICES, Toronto, Ontario, Canada; 23Humana Healthcare Research, Inc., Louisville, KY, USA*These authors contributed equally to this workCorrespondence: Vincent Lo Re III, Division of Infectious Diseases, Department of Medicine, Division of Epidemiology, Department of Biostatistics, Epidemiology, and Informatics, Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, 836 Blockley Hall, 423 Guardian Drive, Philadelphia, PA, 19104-6021, USA, Fax +1 215 573 5315, Email [email protected]: Few studies have examined how the absolute risk of thromboembolism with COVID-19 has evolved over time across different countries. Researchers from the European Medicines Agency, Health Canada, and the United States (US) Food and Drug Administration established a collaboration to evaluate the absolute risk of arterial (ATE) and venous thromboembolism (VTE) in the 90 days after diagnosis of COVID-19 in the ambulatory (eg, outpatient, emergency department, nursing facility) setting from seven countries across North America (Canada, US) and Europe (England, Germany, Italy, Netherlands, and Spain) within periods before and during COVID-19 vaccine availability.Patients and Methods: We conducted cohort studies of patients initially diagnosed with COVID-19 in the ambulatory setting from the seven specified countries. Patients were followed for 90 days after COVID-19 diagnosis. The primary outcomes were ATE and VTE over 90 days from diagnosis date. We measured country-level estimates of 90-day absolute risk (with 95% confidence intervals) of ATE and VTE.Results: The seven cohorts included 1,061,565 patients initially diagnosed with COVID-19 in the ambulatory setting before COVID-19 vaccines were available (through November 2020). The 90-day absolute risk of ATE during this period ranged from 0.11% (0.09– 0.13%) in Canada to 1.01% (0.97– 1.05%) in the US, and the 90-day absolute risk of VTE ranged from 0.23% (0.21– 0.26%) in Canada to 0.84% (0.80– 0.89%) in England. The seven cohorts included 3,544,062 patients with COVID-19 during vaccine availability (beginning December 2020). The 90-day absolute risk of ATE during this period ranged from 0.06% (0.06– 0.07%) in England to 1.04% (1.01– 1.06%) in the US, and the 90-day absolute risk of VTE ranged from 0.25% (0.24– 0.26%) in England to 1.02% (0.99– 1.04%) in the US.Conclusion: There was heterogeneity by country in 90-day absolute risk of ATE and VTE after ambulatory COVID-19 diagnosis both before and during COVID-19 vaccine availability.Plain Language Summary: Cohort studies of patients diagnosed with COVID-19 in both the ambulatory and hospital settings have suggested that SARS-CoV-2 infection promotes hypercoagulability that could lead to arterial or venous thromboembolism. However, few studies have examined how the risk of thromboembolism with COVID-19 has evolved over time across different countries. A new collaboration was established among the regulatory authorities of Canada, Europe, and the US within the International Coalition of Medicines Regulatory Authorities to evaluate the 90-day risk of both arterial and venous thromboembolism after initial diagnosis of COVID-19 in the ambulatory or hospital setting from seven countries across North America (Canada, US) and Europe (England, Germany, Italy, Netherlands, and Spain) within periods before and during COVID-19 vaccine availability. The study found that there was variability in the risk of both arterial and venous thromboembolism by month across the countries among patients initially diagnosed with COVID-19 in the ambulatory or hospital setting. Differences in the healthcare systems, prevalence of comorbidities in the study cohorts, and approaches to the case definitions of thromboembolism likely contributed to the variability in estimates of thromboembolism risk across the countries.Keywords: COVID-19, ischemic stroke, myocardial infarction, thromboembolism, venous thromboembolis

Recombinant human IL-16 inhibits HIV-1 replication and protects against activation-induced cell death (AICD)

The chemoattractant cytokine IL-16 has been reported to suppress lymphocyte activation and to inhibit HIV-1 replication in acutely infected T cells. We have cloned and expressed human IL-16 in Escherichia coli and investigated whether the recombinant protein could regulate the level of lymphocyte apoptosis from HIV-1-infected subjects. After purification and refolding, only 2–10% of the recombinant cytokine was present in a biologically active homotetrameric form. This could explain the need for high concentrations of the bacterially derived IL-16 to induce significant inhibition of HIV-1 replication. Addition of IL-16 to unstimulated peripheral blood mononuclear cell (PBMC) cultures from HIV-1-infected subjects did not modify the observed level of spontaneous lymphocyte apoptosis. In contrast, IL-16 added to PBMC cultures stimulated with anti-CD3, anti-CD95 or dexamethasone reduced significantly the percentage of lymphocytes undergoing AICD. This effect was found to correlate with the ability of the cytokine to decrease CD95 expression on activated CD4+ T cells. Comparative studies on PBMC from healthy individuals indicated that the regulation of apoptosis levels by IL-16 is a complex phenomenon and could depend on the nature of the activator used and/or the immune status of lymphocytes tested. The outcome of CD4 cross-linking on T cells by various ligands is discussed in the context of the observed beneficial activities of IL-16 and its potential role in the treatment of HIV disease

Hepatitis C virus infection in the immunocompromised host: a complex scenario with variable clinical impact

<p>Abstract</p> <p>The relationship between Hepatitis C Virus (HCV) infection and immunosuppression is complex and multifaceted. Although HCV-related hepatocytolysis is classically interpreted as secondary to the attack by cytotoxic T lymphocytes against infected cells, the liver disease is usually exacerbated and more rapidly evolutive in immunosuppressed patients. This generally occurs during the immunosuppression state, and not at the reconstitution of the host response after immunosuppressive therapy discontinuation. The field of immunosuppression and HCV infection is complicated both by the different outcome observed in different situations and/or by contrasting data obtained in the same conditions, with several still unanswered questions, such as the opportunity to modify treatment schedules in the setting of post-transplant follow-up. The complexity of this field is further complicated by the intrinsic tendency of HCV infection in itself to lead to disorders of the immune system. This review will briefly outline the current knowledge about the pathogenesis of both hepatic and extrahepatic HCV-related disorders and the principal available data concerning HCV infection in a condition of impairment of the immune system. Attention will be especially focused on some conditions - liver or kidney transplantation, the use of biologic drugs and cancer chemotherapy - for which more abundant and interesting data exist.</p