NET Formation in Systemic Lupus Erythematosus: Changes during the COVID-19 Pandemic

Area of Science:

• Immunology
• Rheumatology
• Infectious Diseases

Background:

• COVID-19 severity is linked to immune dysregulation, raising concerns for autoimmune patients on immunosuppressants.
• Thromboembolism is a complication of COVID-19 and systemic lupus erythematosus (SLE), potentially involving neutrophil extracellular traps (NETs).
• Imbalances in NET formation and clearance may worsen autoimmune conditions like SLE.

Purpose of the Study:

• To assess NET formation markers in SLE patients before and during the COVID-19 pandemic.
• To correlate NET formation with clinical parameters in SLE patients.
• To determine if SARS-CoV-2 exposure influences NET formation in SLE.

Main Methods:

• Assessed neutrophil elastase (NE) activity, cell-free DNA, MPO-DNA, and NE-DNA complexes in pre-pandemic and pandemic serum samples from SLE patients.
• Correlated NET markers with clinical parameters including blood cell counts and complement levels.
• Analyzed serologic evidence of SARS-CoV-2 exposure.

Main Results:

• Significant differences in NE-DNA complexes and NE activity were observed between pre-pandemic and pandemic serum samples.
• NE activity correlated with hemoglobin, blood cell counts, and complement levels (C3, C4) pre-pandemic.
• During the pandemic, NE activity correlated only with leukocyte and neutrophil counts.
• These changes in NE activity occurred independently of SARS-CoV-2 exposure.

Conclusions:

• NET formation, specifically NE activity, appears to change in SLE patients during the pandemic.
• These alterations in NET activity are not solely driven by SARS-CoV-2 infection or exposure.
• Findings suggest a potential link between pandemic-related factors and NET dysregulation in SLE, impacting disease activity.