The pattern recognition molecule collectin-L1 in critically ill children

Area of Science:

• Immunology
• Pediatric Critical Care
• Complement System

Background:

• Critically ill children face high risks of nosocomial infections.
• Low mannan-binding lectin-associated serine protease (MASP)-3 concentrations are linked to infection risk and prolonged PICU stays.
• Collectin-L1 (CL-L1) is a novel protein in the lectin pathway.

Purpose of the Study:

• To investigate the association between serum collectin-L1 (CL-L1) concentrations and adverse outcomes in critically ill children.
• To determine if CL-L1 independently predicts infection risk and PICU length of stay.

Main Methods:

• Serum CL-L1 concentrations were measured in 700 critically ill children and 81 healthy children.
• Statistical analyses were performed, adjusting for baseline characteristics, risk factors, and other lectin pathway proteins.

Main Results:

• Critically ill children had significantly lower CL-L1 concentrations than healthy children.
• Higher CL-L1 concentrations were independently associated with increased risk of new infections and prolonged PICU discharge time.
• Low MASP-3 concentrations remained independently associated with adverse outcomes.

Conclusions:

• Elevated serum CL-L1 upon PICU admission is paradoxically linked to increased infection risk and longer intensive care duration.
• High CL-L1 may counteract the protective effects of high MASP-3 concentrations.
• These findings highlight a complex role for CL-L1 in pediatric critical illness.