The case of complement activation in COVID-19 multiorgan impact

Area of Science:

• Immunology
• Pathology
• Virology

Background:

• COVID-19, caused by SARS-CoV-2, primarily affects the lungs but can lead to multiorgan damage, including cardiac and kidney injury.
• Kidney injury in severe COVID-19 correlates with a higher risk of mortality.
• Tissue damage in COVID-19 is mainly driven by the host's inflammatory response, not direct viral infection.

Purpose of the Study:

• To review the role of complement activation products in COVID-19 pathogenesis.
• To explore the contribution of complement to inflammation, endotheliitis, and thrombosis in COVID-19.
• To propose terminal complement pathway blockade as a potential therapeutic intervention.

Main Methods:

• Literature review focusing on the immune response to SARS-CoV-2.
• Analysis of the role of complement system activation in COVID-19.
• Discussion of complement activation products and their pathogenic mechanisms.

Main Results:

• Unrestrained complement activation contributes significantly to hypercytokinemia, inflammation, and endothelial dysfunction in COVID-19.
• Complement-mediated effects promote endotheliitis, thrombotic events, and intravascular coagulation.
• These processes ultimately lead to multiorgan failure and increased mortality.

Conclusions:

• The complement system plays a critical role in the severe manifestations of COVID-19, including multiorgan damage and thrombosis.
• Targeting the terminal complement pathway may offer a novel therapeutic approach for managing COVID-19-associated organ injury and improving patient outcomes.