Gastrointestinal involvement attenuates COVID-19 severity and mortality

Area of Science:

• Gastroenterology
• Virology
• Immunology

Background:

• Gastrointestinal (GI) symptoms are common in COVID-19.
• The role of intestinal infection in COVID-19 pathogenesis is not fully understood.

Approach:

• SARS-CoV-2 presence in small intestinal enterocytes was confirmed using immunofluorescence and electron microscopy in a cohort of patients.
• High-dimensional analyses of GI tissues were performed to assess inflammatory markers and cell subsets.
• Clinical significance was evaluated by examining two large, independent cohorts of hospitalized patients in the US and Europe.

Key Points:

• SARS-CoV-2 was detected in the small intestine of most patients studied.
• GI tissues exhibited low inflammation levels, with active downregulation of key inflammatory genes and reduced proinflammatory dendritic cell subsets.
• Hospitalized COVID-19 patients with GI symptoms showed significantly reduced disease severity and mortality, independent of demographic factors and comorbidities.

Conclusions:

• Intestinal infection with SARS-CoV-2 is associated with a mild inflammatory response.
• The GI tract plays a role in attenuating SARS-CoV-2-associated inflammation.
• GI involvement in COVID-19 confers a mortality benefit.