Mannose-Binding Lectin is Associated with Thrombosis and Coagulopathy in Critically Ill COVID-19 Patients

Area of Science:

• Immunology
• Hematology
• Critical Care Medicine

Background:

• COVID-19 is associated with severe morbidity, mortality, and a high risk of thromboembolic (TE) complications.
• The precise mechanisms driving COVID-19-associated coagulopathy, even with thromboprophylaxis, remain incompletely understood.
• Mannose-binding lectin (MBL), a key initiator of the lectin complement pathway, is implicated in amplifying coagulation during thromboinflammation.

Purpose of the Study:

• To investigate the role of MBL in the coagulopathy of critically ill COVID-19 patients.
• To determine if MBL levels correlate with the development of symptomatic thromboembolic events.
• To explore MBL as a potential biomarker and therapeutic target for COVID-19-related thrombosis.

Main Methods:

• Analysis of a cohort of 65 critically ill COVID-19 patients admitted to an intensive care unit (ICU).
• Measurement of plasma MBL levels and activity upon ICU admission.
• Correlation analysis of MBL levels with clinical outcomes, including symptomatic TE, D-dimer levels, inflammation markers, and organ dysfunction.

Main Results:

• A subset of patients exhibited significantly elevated MBL plasma levels and activity.
• Patients who developed symptomatic TE (14%) had markedly higher MBL levels compared to those without TE.
• MBL levels showed a strong correlation with D-dimer, a marker of coagulopathy, but not with inflammation or organ dysfunction.

Conclusions:

• Complement activation via the MBL pathway represents a novel mechanism amplifying pathological thrombosis in critically ill COVID-19 patients.
• Targeting the MBL pathway presents a potential therapeutic strategy for managing thrombosis in COVID-19.
• Assessing MBL levels may aid in identifying COVID-19 patients at elevated risk for TE events.