Project description:BackgroundCOVID-19 patients carry an increased rate of thrombosis. It is controversial to which extent thrombi in the pulmonary arterial tree really contribute to disease severity with hypoxemia secondary to microvascular/lung parenchymal damage with viral alveolitis considered to play the main role in critical disease.ObjectivesThe primary objective was to compare post-mortem lung disease from fatal COVID-19 pneumonia in patients with macroscopically evident pulmonary arterial tree thrombosis and patients without, by characterizing the immunohistochemical nature of thrombi, and by comparing clinical and laboratory features of these patients with other COVID-19 patients who died but without evidence of pulmonary arterial thrombosis (controls).Patients and methods13 COVID-19 pneumonia cases (mean age ± standard deviation: 74 ± 6.5 years) with macroscopically visible pulmonary arterial thrombosis were compared to 14 controls. Hematoxylin and Eosin stained slides were reviewed choosing those with visible pulmonary thrombi which were further characterized by immunohistochemistry, in particular for the inflammatory infiltrates. Ante mortem serum markers relevant to pulmonary embolism were evaluated in both groups.ResultsTwenty arterial thrombi (5 cases with multiple thrombi) were selected for study and were composed by white blood cells (WBC) [median, IQR range: 10 % (5-12.25)], mainly neutrophils [58 % (35.2-64.5)]. Cases with thrombosis showed significantly higher levels of platelet count [median, IQR range: 195000/mmc (157750-274,500) vs 143,500 (113000-175,250), p = 0.011], LDH [854 U/L (731-1315) vs 539 (391.5-660), p = 0.003] at admission, and D-dimer at ICU transfer [25,072 FEU (6951-50,531) vs 1024 (620-5501), p = 0.003].ConclusionsImmunothrombotically driven arterial thrombi in COVID-19 patients are associated with D-Dimer and LDH elevations, thus linking inflammation, coagulopathy and organ damage in fatal COVID-19.
Project description:BACKGROUND:Coronavirus disease 2019 (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly become pandemic, with substantial mortality. OBJECTIVE:To evaluate the pathologic changes of organ systems and the clinicopathologic basis for severe and fatal outcomes. DESIGN:Prospective autopsy study. SETTING:Single pathology department. PARTICIPANTS:11 deceased patients with COVID-19 (10 of whom were selected at random for autopsy). MEASUREMENTS:Systematic macroscopic, histopathologic, and viral analysis (SARS-CoV-2 on real-time polymerase chain reaction assay), with correlation of pathologic and clinical features, including comorbidities, comedication, and laboratory values. RESULTS:Patients' age ranged from 66 to 91 years (mean, 80.5 years; 8 men, 3 women). Ten of the 11 patients received prophylactic anticoagulant therapy; venous thromboembolism was not clinically suspected antemortem in any of the patients. Both lungs showed various stages of diffuse alveolar damage (DAD), including edema, hyaline membranes, and proliferation of pneumocytes and fibroblasts. Thrombosis of small and mid-sized pulmonary arteries was found in various degrees in all 11 patients and was associated with infarction in 8 patients and bronchopneumonia in 6 patients. Kupffer cell proliferation was seen in all patients, and chronic hepatic congestion in 8 patients. Other changes in the liver included hepatic steatosis, portal fibrosis, lymphocytic infiltrates and ductular proliferation, lobular cholestasis, and acute liver cell necrosis, together with central vein thrombosis. Additional frequent findings included renal proximal tubular injury, focal pancreatitis, adrenocortical hyperplasia, and lymphocyte depletion of spleen and lymph nodes. Viral RNA was detectable in pharyngeal, bronchial, and colonic mucosa but not bile. LIMITATION:The sample was small. CONCLUSION:COVID-19 predominantly involves the lungs, causing DAD and leading to acute respiratory insufficiency. Death may be caused by the thrombosis observed in segmental and subsegmental pulmonary arterial vessels despite the use of prophylactic anticoagulation. Studies are needed to further understand the thrombotic complications of COVID-19, together with the roles for strict thrombosis prophylaxis, laboratory and imaging studies, and early anticoagulant therapy for suspected pulmonary arterial thrombosis or thromboembolism. PRIMARY FUNDING SOURCE:None.
Project description:Hospitalized patients with coronavirus disease 2019 (COVID-19), particularly those admitted to the intensive care unit (ICU) are at high risk of morbidity and mortality. Several observational studies have described hemostatic derangements and thrombotic complications in patients with COVID-19. The aim of this review article is to summarize the current evidence on pathologic findings, pathophysiology, coagulation and hemostatic abnormalities, D-dimer's role in prognostication epidemiology and risk factors of thrombotic complications, and the role of prophylactic and therapeutic anticoagulation in patients with COVID-19. While existing evidence is limited in quality, COVID-19 appears to increase micro-and macro-vascular thrombosis rates in hospitalized and critically ill patients, which may contribute to the burden of disease. D-dimer can be used for risk stratification of hospitalized patients, but its role to guide anticoagulation therapy remains unclear. Evidence of higher quality is needed to address the role of therapeutic anticoagulation or high-intensity venous thromboembolism prophylaxis in COVID-19 patients. TAKE-HOME POINTS.
Project description:Since the beginning of the SARS-CoV-2 pandemic, COVID-19 has appeared as a unique disease with unconventional tissue and systemic immune features. While COVID-19 severe forms share clinical and laboratory aspects with various pathologies such as hemophagocytic lymphohistiocytosis, sepsis or cytokine release syndrome, their exact nature remains unknown. This is severely impeding the ability to treat patients facing severe stages of the disease. To this aim, we performed an in-depth, single-cell RNA-seq analysis of more than 150.000 immune cells isolated from matched blood samples and broncho-alveolar lavage fluids of COVID-19 patients and healthy controls, and integrated it with clinical, immunological and functional ex vivo data. We unveiled an immune signature of disease severity that correlated with the accumulation of naïve lymphoid cells in the lung and an expansion and activation of myeloid cells in the periphery. Moreover, we demonstrated that myeloid-driven immune suppression is a hallmark of COVID-19 evolution and arginase 1 expression is significantly associated with monocyte immune regulatory features. Noteworthy, we found monocyte and neutro-phil immune suppression loss associated with fatal clinical outcome in severe patients. Additionally, our analysis discovered that the strongest association of the patients clinical outcome and immune phenotype is the lung T cell response. We found that patients with a robust CXCR6+ effector memory T cell response have better outcomes. This result is line with the rs11385942 COVID-19 risk allele, which is in proximity to the CXCR6 gene and suggest effector memory T cell are a primary feature in COVID-19 patients. By systemically quantifying the viral landscape in the lung of severe patients, we indeed identified Herpes-Simplex-Virus 1 (HSV-1) as a potential opportunistic virus in COVID-19 patients. Lastly, we observed an unexpectedly high SARS-CoV-2 viral load in an immuno-compromised patient, allowing us to study the SARS-CoV-2 in-vivo life cycle. The development of my-eloid dysfunctions and the impairment of lymphoid arm establish a condition of immune paralysis that supports secondary bacteria and virus infection and can progress to “immune silence” in patients facing death.
Project description:Information on the immunopathobiology of coronavirus disease 2019 (COVID-19) is rapidly increasing; however, there remains a need to identify immune features predictive of fatal outcome. This large-scale study characterized immune responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection using multidimensional flow cytometry, with the aim of identifying high-risk immune biomarkers. Holistic and unbiased analyses of 17 immune cell-types were conducted on 1,075 peripheral blood samples obtained from 868 COVID-19 patients and on samples from 24 patients presenting with non-SARS-CoV-2 infections and 36 healthy donors. Immune profiles of COVID-19 patients were significantly different from those of age-matched healthy donors but generally similar to those of patients with non-SARS-CoV-2 infections. Unsupervised clustering analysis revealed three immunotypes during SARS-CoV-2 infection; immunotype 1 (14% of patients) was characterized by significantly lower percentages of all immune cell-types except neutrophils and circulating plasma cells, and was significantly associated with severe disease. Reduced B-cell percentage was most strongly associated with risk of death. On multivariate analysis incorporating age and comorbidities, B-cell and non-classical monocyte percentages were independent prognostic factors for survival in training (n=513) and validation (n=355) cohorts. Therefore, reduced percentages of B-cells and non-classical monocytes are high-risk immune biomarkers for risk-stratification of COVID-19 patients.
Project description:BackgroundAlthough the incidence of venous and arterial thrombosis after a COVID-19 diagnosis and hospitalization has been well described using data available from electronic health records (EHR), little is known about their incidence after mild infections.ObjectivesTo characterize the cumulative incidence and risk factors for thrombosis after a COVID-19 diagnosis among those identified through the EHR and those with a self-reported case.MethodsWe calculated the cumulative incidence of thromboembolism diagnoses after EHR-identified and self-reported cases in the North Carolina COVID-19 Community Partnership, a prospective, multisite, longitudinal surveillance cohort using a Kaplan-Meier approach. We performed Cox regression to estimate the hazard of a thromboembolism diagnosis after COVID-19 by comorbidities, vaccination status, and dominant SARS-CoV-2 variant.ResultsOf a cohort of comprising more than 39,500 participants from 6 North Carolina sites, there were 6271 self-reported or EHR-diagnosed cases of COVID-19 reported between July 1, 2020, and April 30, 2022, of which 46 participants were diagnosed with a new-onset thromboembolism in the 365 days after their reported case. Self-reported cases had a lower estimated cumulative incidence of 0.15% (95% CI, 0.03-0.28) by day 90 and 0.64% (95% CI, 0.30-0.97) by day 365 compared with EHR-based diagnoses that had cumulative incidences of 0.73% (95% CI, 0.36-1.09) and 1.78 (95% CI, 1.14-2.46) by days 90 and 365 (log-rank test P value <.001). Those hospitalized and with pre-existing pulmonary and cardiovascular diseases were associated with the highest risk of a thromboembolism.ConclusionWe observed a higher cumulative incidence of thromboembolism after EHR-identified COVID-19 than self-reported cases.
Project description:Acute thromboembolic events have been frequently reported in patients with coronavirus disease 2019 (COVID-19) due to an increase in the coagulation system activity and endothelial dysfunction. This report describes a patient with COVID-19 who initially reported respiratory symptoms and developed acute lower limb ischemia secondary to extensive macrovascular arterial thrombosis, which was treated with thrombectomy. The development of such extensive arterial thrombosis with anticoagulants at therapeutic doses is a new sign of increased viral pathogenicity, and it is necessary to develop and apply updated prophylaxis protocols for thrombosis in these patients.
Project description:COVID-19-related thrombosis affects the venous and arterial systems. Data from 156 autopsies of COVID-19 patients were retrospectively analyzed to investigate the pattern of thrombotic complications and factors associated with pulmonary artery thrombosis and thromboembolism. Thrombotic complications were observed in a significant proportion (n = 68, 44%), with pulmonary artery thrombosis the most frequently identified thrombotic event (42, 27%). Multivariate analysis revealed that the length of hospital stay (OR 1.1, p = 0.004), neutrophil infiltration in the alveolar spaces (OR 3.6, p = 0.002), and the absence of hyaline membranes (OR 0.1, p = 0.01) were associated with thrombotic complications. Neutrophil infiltration in the alveolar spaces (OR 8, p < 0.001) and the absence of hyaline membranes (OR 0.1, p = 0.003) were also independent predictors of pulmonary artery thrombosis. The association of pulmonary artery thrombosis with an absence of hyaline membranes suggests it occurs later in the course of COVID-19 infection. As neutrophil infiltration in the alveolar spaces may indicate bacterial infection, our studies suggest the consideration of bacterial infections in these critically ill patients.