[Complement activation during extracorporeal circulation. A model for understanding lesional pulmonary edema]

Area of Science:

• Cardiovascular Surgery
• Immunology
• Complement System Biology

Context:

• Extra-corporeal circulation (ECC) is a critical component of cardiac surgery.
• The impact of ECC on the immune system, particularly the complement system, is not fully understood.
• Ischemic heart disease patients undergoing ECC represent a relevant population for this investigation.

Purpose:

• To investigate the dynamic changes in complement system components (CH50, C3, C4, C3 PA) during ECC in patients with ischemic heart disease.
• To explore the potential correlation between complement activation and early post-operative complications like neutropenia, hypoxemia, and pulmonary edema.

Summary:

• Mean concentrations of CH50, C3, C4, and C3 PA significantly decreased within 5 minutes of ECC initiation and remained low throughout surgery in 10 ischemic heart disease patients.
• Transient neutropenia was observed early in the procedure, while significant hypoxemia appeared 24 hours post-surgery.
• The study hypothesizes that complement-mediated leukostasis and subsequent endothelial damage contribute to the "post-pump syndrome," characterized by pulmonary edema.

Impact:

• Findings suggest a direct link between ECC, complement activation, and potential inflammatory responses.
• Highlights the role of the complement system in ECC-induced complications, offering insights into the "post-pump syndrome".
• Provides a basis for exploring therapeutic strategies targeting complement activation to mitigate ECC-related adverse effects.