Intestinal Abnormalities in Patients With SARS-CoV-2 Infection: Histopathologic Changes Reflect Mechanisms of Disease

Area of Science:

• Gastroenterology and Virology
• Pathology of infectious diseases

Background:

• Gastrointestinal symptoms like bleeding and diarrhea affect ~20% of symptomatic SARS-CoV-2 patients.
• Limited data exists on direct SARS-CoV-2 gastrointestinal effects due to risks of endoscopy and reliance on autopsy/surgical cases.
• Understanding the spectrum of gastrointestinal manifestations in COVID-19 is crucial given global mortality.

Observation:

• A case series investigated intestinal findings in SARS-CoV-2 infection.
• Methods included immunohistochemistry, in situ hybridization, and electron microscopy to detect the virus.
• Observed were direct viral cytopathic effects and secondary injury.

Findings:

• SARS-CoV-2 can induce direct epithelial cell injury, characterized by cytoplasmic blebs and tufted cells, without inflammation.
• Viral infection can lead to reversible mucosal ischemia, microvascular injury, hemorrhage, and thrombosis.
• Post-viral gastrointestinal symptoms may result from systemic cytokine and complement activation, not direct viral presence.

Implications:

• These findings clarify mechanisms of SARS-CoV-2-induced gastrointestinal pathology.
• Distinguishes direct viral injury from immune-mediated effects in COVID-19 gastrointestinal disease.
• Contributes to understanding the diverse clinical presentations of COVID-19.