[COVID-19: effects on the lungs and heart]

Area of Science:

• Pulmonary Medicine
• Pathology
• Virology

Background:

• Viral respiratory diseases are leading causes of hospitalization globally.
• Diffuse alveolar damage (DAD) causes respiratory failure and death in COVID-19.
• COVID-19 pneumonia shares histopathological traits with influenza-related acute respiratory distress syndrome (ARDS).

Purpose of the Study:

• To compare the histopathological features of COVID-19 pneumonia with influenza-related ARDS.
• To investigate the vascular and inflammatory aspects of COVID-19 lung pathology.
• To propose a new understanding of COVID-19 as a systemic vascular disease.

Main Methods:

• Histopathological examination of lung tissue from COVID-19 pneumonia patients.
• Comparative analysis of lung pathology in COVID-19 and influenza (H1N1)-related ARDS.
• Microscopic evaluation for inflammation, endothelial injury, microangiopathy, and angiogenesis.

Main Results:

• COVID-19 pneumonia exhibits diffuse alveolar damage (DAD), edema, hemorrhage, and fibrin deposition, similar to influenza-related ARDS.
• Unique findings in COVID-19 lungs include perivascular inflammation, endothelial injury, microangiopathy, and intussusceptive angiogenesis.
• These vascular and inflammatory changes suggest a broader systemic involvement.

Conclusions:

• COVID-19 pneumonia shares key features with influenza-induced ARDS but presents distinct vascular pathology.
• The observed angiocentric inflammation and microvascular changes support the hypothesis of COVID-19 as a systemic vascular disease.
• Further research is warranted to explore the systemic implications of COVID-19's vascular effects on other organs.