Project description:Lung transplantation can potentially be a life-saving treatment for patients with non-resolving COVID-19-associated respiratory failure. Concerns limiting transplant include recurrence of SARS-CoV-2 infection in the allograft, technical challenges imposed by viral-mediated injury to the native lung, and potential risk for allograft infection by pathogens associated with ventilator-associated pneumonia in the native lung. Most importantly, the native lung might recover, resulting in long-term outcomes preferable to transplant. Here, we report results of the first successful lung transplantation procedures in patients with non-resolving COVID-19-associated respiratory failure in the United States. We performed sm-FISH to detect both positive and negative strands of SARS-CoV-2 RNA in the explanted lung tissue, extracellular matrix imaging using SHIELD tissue clearance, and single cell RNA-Seq on explant and warm post-mortem lung biopsies from patients who died from severe COVID-19 pneumonia. Lungs from patients with prolonged COVID-19 were free of virus but pathology showed extensive evidence of injury and fibrosis which resembled end-stage pulmonary fibrosis. We used a machine learning approach to project single cell RNA-Seq data from patients with late stage COVID-19 onto a single cell atlas of pulmonary fibrosis, revealing similarities across cell lineages. There was no recurrence of SARS-CoV-2 or pathogens associated with pre-transplant ventilator associated pneumonias following transplantation. Our findings suggest that some patients with severe COVID-19 develop fibrotic lung disease for which lung transplantation is the only option for survival.
Project description:An in-depth focused study of specific cases of patients with recurrent thrombosis may help to identify novel circumstances, genetic and acquired factors contributing to the development of this disorder. The aim of this study was to carry out a detailed and sequential analysis of samples from a patient suffering from early and recurrent venous and arterial thrombosis. We performed thrombophilic tests, biochemical, functional, genetic and glycomic analysis of antithrombin and other plasma proteins. The patient carried a new type I antithrombin mutation (p.Ile218del), whose structural relevance was verified in a recombinant model. Experiments with N-glycosidase F and neuraminidase suggested a nearly full desialylation of plasma proteins, which was confirmed by mass spectrometry analysis of transferrin glycoforms. However, partial desialylation and normal patterns were detected in samples collected at other time-points. Desialylation was noticeable after arterial events and was associated with low antithrombin activity, reduced platelet count and glomerular filtration rate. This is the first description of a global and transient desialylation of plasma proteins associated with thrombosis. The decrease in the strong electronegative charge of terminal glycans may modulate hemostatic protein-protein interactions, which in combination with a strong prothrombotic situation, such as antithrombin deficiency, could increase the risk of thrombosis.
Project description:Analysis of COVID-19 hospitalized patients, with different kind of symptoms, by human rectal swabs collection and 16S sequencing approach.
Project description:Severe COVID-19 disease is associated with dysregulation of the myeloid compartment during acute infection. Survivors frequently experience long-lasting sequelae but little is known about the eventual persistence of this immune alteration. Herein, we evaluated Toll-like receptor-induced cytokine responses in a cohort of mild to critical patients during acute or convalescent phases (n=97). In the acute phase, we observed impaired cytokine production by monocytes in the most severe patients. This capacity was globally restored in convalescent patients. Yet, we observed increased responsiveness to TLR1/2 ligation in patients that recovered from severe disease, indicating that these cells display distinct functional properties at the different stages of the disease. We identified a specific transcriptomic and epigenomic state in monocytes from acute severe patients that can account for their functional refractoriness. The molecular profile of monocytes from recovering patients was distinct and characterized by increased chromatin accessibility at AP-1 and MAF loci. These results demonstrate that severe COVID-19 infection has a profound impact on the differentiation status and function of circulating monocytes both during the acute and the convalescent phases in a completely distinct manner. This could have important implications for our understanding of short and long-term COVID19-related morbidity.
Project description:Severe COVID-19 disease is associated with dysregulation of the myeloid compartment during acute infection. Survivors frequently experience long-lasting sequelae but little is known about the eventual persistence of this immune alteration. Herein, we evaluated Toll-like receptor-induced cytokine responses in a cohort of mild to critical patients during acute or convalescent phases (n=97). In the acute phase, we observed impaired cytokine production by monocytes in the most severe patients. This capacity was globally restored in convalescent patients. Yet, we observed increased responsiveness to TLR1/2 ligation in patients that recovered from severe disease, indicating that these cells display distinct functional properties at the different stages of the disease. We identified a specific transcriptomic and epigenomic state in monocytes from acute severe patients that can account for their functional refractoriness. The molecular profile of monocytes from recovering patients was distinct and characterized by increased chromatin accessibility at AP-1 and MAF loci. These results demonstrate that severe COVID-19 infection has a profound impact on the differentiation status and function of circulating monocytes both during the acute and the convalescent phases in a completely distinct manner. This could have important implications for our understanding of short and long-term COVID19-related morbidity.
Project description:Coronavirus disease 2019 (COVID-19) may predispose to venous thromboembolism. We determined factors independently associated with computed tomography pulmonary angiography (CTPA)-confirmed pulmonary embolism (PE) in hospitalised severe COVID-19 patients. Among all (n=349) patients hospitalised for COVID-19 in a university hospital in a French region with a high rate of COVID-19, we analysed patients who underwent CTPA for clinical signs of severe disease (oxygen saturation measured by pulse oximetry ≤93% or breathing rate ≥30 breaths·min-1) or rapid clinical worsening. Multivariable analysis was performed using Firth penalised maximum likelihood estimates. 162 (46.4%) patients underwent CTPA (mean±sd age 65.6±13.0 years; 67.3% male (95% CI 59.5-75.5%). PE was diagnosed in 44 (27.2%) patients. Most PEs were segmental and the rate of PE-related right ventricular dysfunction was 15.9%. By multivariable analysis, the only two significant predictors of CTPA-confirmed PE were D-dimer level and the lack of any anticoagulant therapy (OR 4.0 (95% CI 2.4-6.7) per additional quartile and OR 4.5 (95% CI 1.1-7.4), respectively). Receiver operating characteristic curve analysis identified a D-dimer cut-off value of 2590 ng·mL-1 to best predict occurrence of PE (area under the curve 0.88, p<0.001, sensitivity 83.3%, specificity 83.8%). D-dimer level >2590 ng·mL-1 was associated with a 17-fold increase in the adjusted risk of PE. Elevated D-dimers (>2590 ng·mL-1) and absence of anticoagulant therapy predict PE in hospitalised COVID-19 patients with clinical signs of severity. These data strengthen the evidence base in favour of systematic anticoagulation, and suggest wider use of D-dimer guided CTPA to screen for PE in acutely ill hospitalised patients with COVID-19.
Project description:We isolated PBMC from healthy, moderate ( Oxygen supply < 10L/min), and severe (Oxygen supply >= 10L/min) COVID-19 patients after their admission to Intensive Care Units (ICU), at two timepoints (Day-1 and Day-4); and performed both CD14+ Monocyte enrichment followed by a Pan-DC kit to retrieve all Antigen Presenting Cell (APC) subsets from these age-matched patients. We performed single cell RNA sequencing using 10X technology on the single cell suspensions and constracted a high-resolution map of 81,643 Antigen Presenting Cells (APC) from the three COVID-19 severity groups. We were able to retrieve all the known six APC subsets and deciphered the altered pathways and ati-viral mechanisms, correlated with the disease severity.
Project description:Background Hypercoagulability is a common complication seen in COVID-19 infection. However, arterial thrombosis such as acute limb ischemia (ALI) is far less common. Data on the incidence and nature of arterial thromboembolic complications in patients with COVID-19 is limited, originating from a few case reports and case series. Data in the African continent are very scarce. Method This is a case series of 10 patients with COVID-19 who developed ALI while on treatment at Eka Kotebe General Hospital, Addis Ababa, Ethiopia. All patients with ALI and COVID-19 admitted between February 1, 2021, and December 31, 2021, were retrospectively identified and reviewed. COVID-19 was confirmed by RT-PCR and ALI was confirmed by Doppler ultrasound and/or computed tomography angiography in the presence of clinical suspicion. Results A total of 3098 patients were hospitalized with confirmed COVID-19 during the study period. In a series of 10 patients, 8 (80%) males with a median age of 53.5 years were included. All except one (10%) had one or more risk factors for ALI and one had a ‘possible’ case of vaccine-induced thrombotic thrombocytopenia (VITT) associated with ALI. All were admitted with severe COVID-19 and most (80%) developed ALI during hospitalization (median of seven days from admission). The median duration between COVID-19 and ALI symptom onset was 14.5 days (IQR, 11–15). The majority (60%) were taking therapeutic anticoagulation at the time of ALI onset which is the standard of care for patients with severe disease. Five (50%) were successfully revascularized (median time of 3.5 days) and the rest underwent amputation. All survived and were discharged improved. Conclusion ALI can occur in the context of COVID-19 even while a patient is on therapeutic dose anticoagulation and in the absence of traditional risk factors. It is wise to be vigilant of this complication for timely intervention and better treatment outcomes.