Patients diagnosed with coronavirus disease 2019 (COVID-19) become critically ill primarily around the time of activation of the adaptive immune response. Here, we provide evidence that antibodies... Show morePatients diagnosed with coronavirus disease 2019 (COVID-19) become critically ill primarily around the time of activation of the adaptive immune response. Here, we provide evidence that antibodies play a role in the worsening of disease at the time of seroconversion. We show that early-phase severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) spike protein-specific immunoglobulin G (IgG) in serum of critically ill COVID-19 patients induces excessive inflammatory responses by human alveolar macrophages. We identified that this excessive inflammatory response is dependent on two antibody features that are specific for patients with severe COVID-19. First, inflammation is driven by high titers of anti-spike IgG, a hallmark of severe disease. Second, we found that anti-spike IgG from patients with severe COVID-19 is intrinsically more proinflammatory because of different glycosylation, particularly low fucosylation, of the antibody Fc tail. Low fucosylation of anti-spike IgG was normalized in a few weeks after initial infection with SARS-CoV-2, indicating that the increased antibody-dependent inflammation mainly occurs at the time of seroconversion. We identified Fc gamma receptor (Fc gamma R) Ila and FeyRIII as the two primary IgG receptors that are responsible for the induction of key COVID-19-associated cytokines such as interleukin-6 and tumor necrosis factor. In addition, we show that anti-spike IgG-activated human macrophages can subsequently break pulmonary endothelial barrier integrity and induce microvascular thrombosis in vitro. Last, we demonstrate that the inflammatory response induced by anti-spike IgG can be specifically counteracted by fostamatinib, an FDA- and EMA-approved therapeutic small-molecule inhibitor of Syk kinase. Show less
Gimbel, M.; Qaderdan, K.; Willemsen, L.; Hermanides, R.; Bergmeijer, T.; Vrey, E. de; ... ; Berg, J. ten 2020
Background Current guidelines recommend potent platelet inhibition with ticagrelor or prasugrel in patients after an acute coronary syndrome. However, data about optimal platelet inhibition in... Show moreBackground Current guidelines recommend potent platelet inhibition with ticagrelor or prasugrel in patients after an acute coronary syndrome. However, data about optimal platelet inhibition in older patients are scarce. We aimed to investigate the safety and efficacy of clopidogrel compared with ticagrelor or prasugrel in older patients with non-STelevation acute coronary syndrome (NSTE-ACS).Methods We did the open-label, randomised controlled POPular AGE trial in 12 sites (ten hospitals and two university hospitals) in the Netherlands. Patients aged 70 years or older with NSTE-ACS were enrolled and randomly assigned in a 1:1 ratio using an internet-based randomisation procedure with block sizes of six to receive a loading dose of clopidogrel 300 mg or 600 mg, or ticagrelor 180 mg or prasugrel 60 mg, and then a maintenance dose for the duration of 12 months (clopidogrel 75 mg once daily, ticagrelor 90 mg twice daily, or prasugrel 10 mg once daily) on top of standard care. Patient and treating physicians were aware of the allocated treatment strategy, but the outcome assessors were masked to treatment allocation. Primary bleeding outcome consisted of PLATelet inhibition and patient Outcomes (PLATO; major or minor bleeding [superiority hypothesis]). Co-primary net clinical benefit outcome consisted of allcause death, myocardial infarction, stroke, PLATO major and minor bleeding (non-inferiority hypothesis, margin of 2%). Follow-up duration was 12 months. Analyses were done on intention-to-treat basis. This trial is registered with the Netherlands Trial Register (NL3804), ClinicalTrials.gov (NCT02317198), and EudraCT (2013-001403-37).Findings Between June 10, 2013, and Oct 17, 2018, 1002 patients were randomly assigned to clopidogrel (n=500) or ticagrelor or prasugrel (n=502). Because 475 (95%) patients received ticagrelor in the ticagrelor or prasugrel group, we will refer to this group as the ticagrelor group. Premature discontinuation of the study drug occurred in 238 (47%) of 502 ticagrelor group patients randomly assigned to ticagrelor, and in 112 (22%) of 500 patients randomly assigned to clopidogrel. Primary bleeding outcome was significantly lower in the clopidogrel group (88 [18%] of 500 patients) than in the ticagrelor group (118 [24%] of 502; hazard ratio 0.71, 95% CI 0.54 to 0.94; p=0.02 for superiority). Co-primary net clinical benefit outcome was non-inferior for the use of clopidogrel (139 [28%]) versus ticagrelor (161 [32%]; absolute risk difference -4%, 95% CI -10.0 to 1.4; p=0.03 for non-inferiority). The most important reasons for discontinuation were occurrence of bleeding (n=38), dyspnoea (n=40), and the need for treatment with oral anticoagulation (n=35).Interpretation In patients aged 70 years or older presenting with NSTE-ACS, clopidogrel is a favourable alternative to ticagrelor, because it leads to fewer bleeding events without an increase in the combined endpoint of all-cause death, myocardial infarction, stroke, and bleeding. Clopidogrel could be an alternative P2Y12 inhibitor especially for elderly patients with a higher bleeding risk. Show less
