Endothelial cell-activating antibodies in COVID-19

Area of Science:

• Immunology
• Vascular Biology
• Infectious Diseases

Background:

• Endothelial dysfunction is a key feature of severe COVID-19, contributing to thrombo-inflammatory complications.
• The specific factors driving this endotheliopathy in COVID-19 remain largely unknown.

Approach:

• Human endothelial cells were exposed to serum/plasma from COVID-19 and sepsis patients.
• Expression of cell adhesion molecules (E-selectin, VCAM-1, ICAM-1) was measured.
• The role of antiphospholipid antibodies and IgG was investigated.

Key Points:

• COVID-19 serum significantly increased endothelial cell adhesion molecule expression.
• Elevated soluble ICAM-1 and E-selectin correlated with disease severity.
• Antiphospholipid antibodies in COVID-19 serum were strongly associated with endothelial activation.
• IgG from COVID-19 patients induced endothelial activation in control serum.

Conclusions:

• This study identifies specific antibodies in some COVID-19 patients that drive endotheliopathy.
• These autoantibodies contribute to the thrombo-inflammatory state observed in severe COVID-19.
• Understanding these antibody-mediated effects provides crucial context for COVID-19 pathogenesis.