Analyzes by scientists to investigate lung pathology in patients who died from SARS-CoV-2 infection could help identify important determinants of disease severity and recovery. What did the group of researchers find out?

18 people who died as a result of COVID-19 had a lung dissection between March and July 2022, and some of them also had plasma samples taken before they died. The mean age of the deceased was 67.7 years, most of them were men. The time interval from the onset of symptoms to death ranged from 3 to 47 days.

Each case study had respiratory failure, and 12 people required mechanical assisted ventilation. All patients had at least one comorbid condition. According to the data available in the hospital, these patients showed increased levels of C-reactive protein, ferritin and D-dimers in the plasma.

The results analyzed show how SARS-CoV-2 spreads in the lungs, damages them, and how it affects the immune system's response. It found that, unlike the flu, COVID-19 infects the respiratory epithelial cells responsible for generating and repairing lung tissue.

Observations have shown that both direct virus-induced effects as well as immune and inflammatory responses in the patient's body led to early damage to the lung epithelium and endothelium, dysfunction of the alveolar-capillary barrier, impaired pulmonary tissue repair processes, and extensive vascular thrombosis.

In addition, where disease lasts longer, disease progression has led to excessive pulmonary fibrosis, alveolar loss, and vascular remodeling. The study also found aging of epithelial and endothelial cells in the COVID-19 pathophysiology, consistent with increased disease susceptibility and severity in the elderly and comorbid risk populations.

RNA sequence analysis revealed evidence of possible secondary bacterial infectionMoraxella(7 out of 13 cases),Pseudomonas(6 out of 13 cases) ,Acinetobacter(5 of 13 cases) andStreptococcusspecies (2 of 13) in a subgroup of 13 patient lung samples.

The authors of the analysis say that COVID-19, unlike the flu, causes damagelung disease and associated immune responses so severe that it does not require co-infection to be fatal. After conducting the research, scientists were able to determine that people who died at least 20 days after the onset of the initial symptoms showed high levels of pulmonary fibrosis.

The group of researchers believe their findings could help predict severity and recovery in elderly or comorbid patients when they become infected with SARS-CoV-2. Moreover, the results of the analyzes carried out may contribute to the adaptation of existing drugs for COVID-19 depending on the stage of the disease.

Category: