The many faces of coronavirus disease 2019: COVID-19 and the liver

Modeling mechanisms underlying differential inflammatory responses to COVID-19 in type 2 diabetes using a patient-derived microphysiological organ-on-a-chip system

Background: COVID-19 pandemic has caused more than 6 million deaths worldwide. Co-morbid conditions such as Type 2 Diabetes (T2D) have increased mortality in COVID-19. With limited translatability of in vitro and small animal models to human disease, human organ-on-a-chip models are an attractive platform to model in vivo disease conditions and test potential therapeutics. Methods: T2D or non-diabetic patient-derived macrophages and human liver sinusoidal endothelial cells were seeded, along with normal hepatocytes and stellate cells in the liver-on-a-chip (LAMPS - liver acinus micro physiological system), perfused with media mimicking non-diabetic fasting or T2D (high levels of glucose, fatty acids, insulin, glucagon) states. The macrophages and endothelial cells were transduced to overexpress the SARS-CoV2-S (spike) protein with appropriate controls before their incorporation into LAMPS. Cytokine concentrations in the efflux served as a read-out of the effects of S-protein expression in the different experimental conditions (non-diabetic-LAMPS, T2D-LAMPS), including incubation with tocilizumab, an FDA-approved drug for severe COVID-19. Findings: S-protein expression in the non-diabetic LAMPS led to increased cytokines, but in the T2D-LAMPS, this was significantly amplified both in the number and magnitude of key pro-inflammatory cytokines (IL6, CCL3, IL1β, IL2, TNFα, etc.) involved in cytokine storm syndrome (CSS), mimicking severe COVID-19 infection in T2D patients. Compared to vehicle control, tocilizumab (IL6-receptor antagonist) decreased the pro-inflammatory cytokine secretion in T2D-COVID-19-LAMPS but not in non-diabetic-COVID-19-LAMPS. Interpretation: macrophages and endothelial cells play a synergistic role in the pathophysiology of the hyper-inflammatory response seen with COVID-19 and T2D. The effect of Tocilizumab was consistent with large clinical trials that demonstrated Tocilizumab's efficacy only in critically ill patients with severe disease, providing confirmatory evidence that the T2D-COVID-19-LAMPS is a robust platform to model human in vivo pathophysiology of COVID-19 in T2D and for screening potential therapeutics.

Endovascular management of massive hemoptysis due to covid-19 related pulmonary artery pseudoaneurysm: A rare entity

Pulmonary artery pseudoaneurysms are rare causes of massive hemoptysis, even less common in setting of COVID-19 pneumonia. We describe and discuss an index case of cavitating COVID-19 pneumonia complicated by a pulmonary artery pseudoaneurysm without concomitant pulmonary thromboembolism. The patient presented with severe hemoptysis and was managed by endovascular coil embolization. Good technical and clinical success was achieved with complete resolution of hemoptysis.

Coronavirus disease 2019 (COVID-19): Multisystem review of pathophysiology

Coronavirus disease-19 (COVID-19) pandemic is associated with high morbidity and mortality. COVID-19, which is caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2), affects multiple organ systems through a myriad of mechanisms. Afflicted patients present with a vast constellation of symptoms, from asymptomatic disease to life-threatening complications. The most common manifestations pertain to mild pulmonary symptoms, which can progress to respiratory distress syndrome and venous thromboembolism. However, in patients with renal failure, life-threatening cardiac abnormalities can ensue. Various mechanisms such as viral entry through Angiotensin receptor (ACE) affecting multiple organs and thus releasing pro-inflammatory markers have been postulated. Nevertheless, the predictors of various presentations in the affected population remain elusive. An ameliorated understanding of the pathology and pathogenesis of the viral infection has led to the development of variable treatment options, with many more that are presently under trial. This review article discusses the pathogenesis of multiple organ involvement secondary to COVID-19 infection in infected patients.

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This review sheds light on the pathogenesis of multi-organ involvement secondary to COVID-19 infection.

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The predictors of various presentations in the affected population are not clear at present. A better understanding of the pathology and pathogenesis of the viral infection will be pivotal in the development of variable treatment options.

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Various proposed mechanisms such as viral entry through Angiotensin receptor (ACE) affecting multiple organs, releasing pro-inflammatory markers and cytokines inducing hypercoagulable state and cytokine storm syndrome have been postulated.

COVID-19 and mucormycosis superinfection: Exploring the missing pathophysiological links

The coronavirus disease 2019 continues to unearth new facets that portend grave clinical implications. In recent times, there has been mounting fervor regarding coronavirus disease 2019 and mucormycosis superinfection. While the correlation between the two is conspicuous, the underlying pathophysiological mechanisms that render a patient with coronavirus disease 2019 susceptible to mucormycosis, or vice versa, are still elusive.

Elevations in Liver Transaminases in COVID-19: (How) Are They Related?

Liver involvement in COVID-19 is not yet well-understood, but elevations in liver transaminases have been described to occur in 14–53% of the cases and are more frequently seen in severe disease. This cross-sectional study explored the relationship between the elevations in liver transaminases and inflammatory parameters in 209 adults with COVID-19. Demographic and clinical data, serum levels of inflammatory cytokines and liver aminotransferases were analyzed. Three groups were formed according to the liver transaminase abnormalities: (I) Normal transaminases, (II) Borderline transaminases elevation, and (III) Mild to severe transaminases elevation. Altered liver transaminases were directly related to disease severity, showing association with the NEWS2 score at admission and greater need for ICU or death. Moreover, higher levels of IL-2 and CRP were associated with borderline transaminases elevations, whereas higher levels of IL-10 and Neutrophil to Lymphocyte ratio were associated with mild to severe transaminases elevation. These results reinforce the importance of liver transaminases in patients with COVID-19 as a complementary marker for disease severity and also point to them as a parameter reflecting the continuous dynamics between viral infection and the immune response.