Serum AXL is a potential molecular marker for predicting COVID-19 progression

Area of Science:

• Virology
• Immunology
• Biomarker Discovery

Background:

• COVID-19 severity is linked to viral entry into host cells, involving ACE2 and AXL receptors.
• Limited research exists on circulating ACE2 and AXL levels and their role in COVID-19 outcomes.

Purpose of the Study:

• To investigate the correlation between serum ACE2 and AXL levels and COVID-19 severity.
• To evaluate the diagnostic and predictive value of ACE2 and AXL in COVID-19 patients.

Main Methods:

• Enzyme-linked immunosorbent assay (ELISA) was used to measure serum ACE2/AXL levels in 358 COVID-19 patients and 71 controls.
• SARS-CoV-2 IgG/IgM antibody levels were assessed using an iFlash 3000 analyzer.
• Receiver operating characteristic (ROC) curves analyzed diagnostic value, and associations with illness progression were explored.

Main Results:

• COVID-19 patients showed decreased ACE2 and AXL levels, and increased SARS-CoV-2 IgG compared to controls.
• AXL demonstrated a stronger predictive ability (AUC = 0.774) for COVID-19 than ACE2.
• In severe cases, ACE2, AXL, and IgM peaked around days 8-15, while IgG peaked later (days 31-180).

Conclusions:

• Serum ACE2 and AXL levels correlate with COVID-19 severity.
• AXL provides an early warning for clinical deterioration within the first week post-infection.
• AXL is a promising molecular marker for predicting COVID-19 progression.