scholarly journals Release of endothelial activation markers in lungs of patients with malaria-associated acute respiratory distress syndrome

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Thao-Thy Pham ◽  
Chuchard Punsawad ◽  
Supattra Glaharn ◽  
Simon F. De Meyer ◽  
Parnpen Viriyavejakul ◽  
...  

Abstract Background Malaria-associated acute respiratory distress syndrome (MA-ARDS) is an understudied complication of malaria and is characterized by pulmonary inflammation and disruption of the alveolar-capillary membrane. Its pathogenesis remains poorly understood. Since endothelial activation plays an important role in other malarial complications, the expression of two endothelial activation markers, von Willebrand factor (VWF) and angiopoietin-2 (ANG-2), was investigated in the lungs of patients with MA-ARDS. Methods Post-mortem lung sections of Plasmodium falciparum-infected patients without alveolar oedema (NA), P. falciparum-infected patients with alveolar oedema (MA-ARDS), and uninfected people who died accidentally with no pathological changes to the lungs (CON) were immunohistochemically stained for VWF and ANG-2, and were evaluated with semi-quantitative analysis. Results Alveolar oedematous VWF and ANG-2 and intravascular VWF staining were significantly increased in patients with MA-ARDS versus infected and uninfected control groups. The levels of VWF in the alveolar septa and endothelial lining of large blood vessels of patients with MA-ARDS was significantly decreased compared to controls. ANG-2 expression was increased in the alveolar septa of malaria patients without alveolar oedema versus control patients, while ANG-2+ leukocytes were increased in the alveoli in both infected patient groups. Conclusions This study documents a high level of VWF and ANG-2, two endothelial activation markers in the oedematous alveoli of post-mortem lung sections of Thai patients with MA-ARDS. Decreased detection of VWF in the endothelial lining of blood vessels, in parallel with an increased presence of intravascular VWF staining suggests marked endothelial activation and Weibel–Palade body release in the lungs of patients with MA-ARDS.

Author(s):  
Guillaume Hékimian ◽  
Paul Masi ◽  
Manon Lejeune ◽  
Guillaume Lebreton ◽  
Juliette Chommeloux ◽  
...  

Hemostatic changes induced by extracorporeal membrane oxygenation (ECMO) support have been yet poorly documented in COVID-19 patients who have a baseline complex hypercoagulable state. In this prospective monocentric study of patients with severe acute respiratory distress syndrome (ARDS) rescued by ECMO, we performed longitudinal measurements of coagulation and fibrinolysis markers throughout the course of ECMO support in 20 COVID-19 and 10 non-COVID-19 patients. Blood was sampled before and then 24 hours, 7 and 14 days after ECMO implantation. Clinical outcomes were prospectively assessed until discharge from the intensive care unit or death. The median age of participants was 47 (35-56) years, with a median body mass index of 30 (27-35) kg/m², and a SOFA score of 12 (8-16). Baseline levels of von Willebrand factor, fibrinogen, factor VIII, prothrombin F1+2, thrombin-antithrombin, D-Dimers and PAI-1 were elevated in both COVID-19 and non-COVID-19 ARDS patients, indicating that endothelial activation, endogenous thrombin generation and fibrinolysis shut-down occur in all ARDS patients before ECMO implantation. From baseline to day 7, thrombin generation (prothrombin F1+2, p<0.01) and fibrin formation markers (fibrin monomers, p<0.001) significantly increased, further resulting in significant decreases in platelet count (p<0.0001) and fibrinogen level (p<0.001). PAI-1 levels significantly decreased from baseline to day 7 (p<0.0001) in all ARDS patients. These changes were more marked in COVID-19 patients, resulting in 14 non-fatal and 3 fatal bleeding. Additional studies are warranted to determine whether monitoring of thrombin generation and fibrinolysis markers might help to early predict bleeding complications in COVID-19 patients supported by ECMO.


2020 ◽  
Author(s):  
Ankit Bharat ◽  
Melissa Querrey ◽  
Nikolay S. Markov ◽  
Samuel Kim ◽  
Chitaru Kurihara ◽  
...  

ABSTRACTLung transplantation can potentially be a life-saving treatment for patients with non-resolving COVID-19 acute respiratory distress syndrome. 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-induced pneumonia in the native lung. Additionally, the native lung might recover, resulting in long-term outcomes preferable to transplant. Here, we report the results of the first two successful lung transplantation procedures in patients with non-resolving COVID-19 associated acute respiratory distress syndrome in the United States. We performed smFISH 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. Single cell RNA-Seq of the explanted native lungs from transplant and paired warm post-mortem autopsies showed similarities between late SARS-CoV-2 acute respiratory distress syndrome and irreversible end-stage pulmonary fibrosis requiring lung transplantation. There was no recurrence of SARS-CoV-2 or pathogens associated with pre-transplant ventilator associated pneumonias following transplantation in either patient. Our findings suggest that some patients with severe COVID-19 develop fibrotic lung disease for which lung transplantation is the only option for survival.Single sentence summarySome patients with severe COVID-19 develop end-stage pulmonary fibrosis for which lung transplantation may be the only treatment.


2020 ◽  
Vol 49 (10) ◽  
pp. 418-421
Author(s):  
Christopher Werlein ◽  
Peter Braubach ◽  
Vincent Schmidt ◽  
Nicolas J. Dickgreber ◽  
Bruno Märkl ◽  
...  

ZUSAMMENFASSUNGDie aktuelle COVID-19-Pandemie verzeichnet mittlerweile über 18 Millionen Erkrankte und 680 000 Todesfälle weltweit. Für die hohe Variabilität sowohl der Schweregrade des klinischen Verlaufs als auch der Organmanifestationen fanden sich zunächst keine pathophysiologisch zufriedenstellenden Erklärungen. Bei schweren Krankheitsverläufen steht in der Regel eine pulmonale Symptomatik im Vordergrund, meist unter dem Bild eines „acute respiratory distress syndrome“ (ARDS). Darüber hinaus zeigen sich jedoch in unterschiedlicher Häufigkeit Organmanifestationen in Haut, Herz, Nieren, Gehirn und anderen viszeralen Organen, die v. a. durch eine Perfusionsstörung durch direkte oder indirekte Gefäßwandschädigung zu erklären sind. Daher wird COVID-19 als vaskuläre Multisystemerkrankung aufgefasst. Vor dem Hintergrund der multiplen Organmanifestationen sind klinisch-pathologische Obduktionen eine wichtige Grundlage der Entschlüsselung der Pathomechanismen von COVID-19 und auch ein Instrument zur Generierung und Hinterfragung innovativer Therapieansätze.


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