Histopathological features in fatal COVID-19 acute respiratory distress syndrome

Abstract

Background: COVID-19 acute respiratory distress syndrome (ARDS) shares the common histological hallmarks with other forms of ARDS. However, the chronology of the histological lesions has not been well established. Objective: To describe the chronological histopathological alterations in the lungs of patients with COVID-19 related ARDS. Design: A prospective cohort study was carried out. Setting: Intensive Care Unit of a tertiary hospital. Patients: The first 22 consecutive COVID-19 deaths. Measurements: Lung biopsies and histopathological analyses were performed in deceased patients with COVID-19 related ARDS. Clinical data and patient course were evaluated. Results: The median patient age was 66 [63 - 74] years; 73% were males. The median duration of mechanical ventilation was 17 [8 - 24] days. COVID-19 induced pulmonary injury was characterized by an exudative phase in the first week of the disease, followed by a proliferative/organizing phase in the second and third weeks, and finally an end-stage fibrosis phase after the third week. Viral RNA and proteins were detected in pneumocytes and macrophages in a very early stage of the disease, and were no longer detected after the second week. Limitation: Limited sample size. Conclusions: The chronological evolution of COVID-19 lung histopathological lesions seems to be similar to that seen in other forms of ARDS. In particular, lung lesions consistent with potentially corticosteroid-sensitive lesions are seen.

Increased Serum Thromboxane A2 and Prostacyclin but Lower Complement C3 and C4 Levels in COVID-19: Associations with Chest CT Scan Anomalies and Lowered Peripheral Oxygen Saturation

“…The COVID-19 virus enters the lung cells after binding viral Spike proteins-S with the ACE2 receptors [5] and, consequently, the virus may cause histopathological lesions in the lungs, which appear to be similar to those observed in other forms of ARDS [6].…”

Time-Dependent Molecular Motifs of Pulmonary Fibrogenesis in COVID-19

“…In patients with ongoing respiratory symptoms three months after infection, the presence of ground-glass opacities and bands was reported in 48% and 37%, respectively, as well as signs indicative of established fibrosis, such as volume loss and traction bronchiectasis in 12% [7]. In addition, pulmonary alterations that can be found on a histological level in patients who succumbed to COVID-19, include diffuse alveolar damage and acute fibrinous and organizing pneumonia [8,9]; two alterations that are known to potentially induce pulmonary parenchymal fibrosis.…”

Risk factors for mortality in patients with COVID-19 needing extracorporeal respiratory support

“…Adequate management of the extracorporeal support, together with the pathological condition itself, also have a direct impact on outcome. Lung parenchyma of COVID-19 patients needing ECMO is severely affected, with notably high lung elastance and very low residual function [ 12 , 13 ]. High ECMO flows are needed in this situation in order to ensure adequate oxygen delivery and allow ultraprotective MV.…”