Terminal complement complexes and anaphylatoxins in septic and ischemic patients

Area of Science:

• Immunology
• Critical Care Medicine
• Vascular Surgery

Background:

• Sepsis and acute limb ischemia are critical conditions associated with systemic inflammation.
• The terminal complement complex (TCC) and anaphylatoxins (C3a, C5a) are key mediators of the complement system.
• Their role in the pathogenesis of sepsis and acute limb ischemia requires further elucidation.

Purpose of the Study:

• To investigate the levels of terminal complement complex (TCC) and anaphylatoxins in patients with sepsis and acute limb ischemia.
• To assess the changes in these complement components following treatment.
• To explore the in vitro formation of TCC induced by Escherichia coli.

Main Methods:

• Plasma levels of TCC and anaphylatoxins were measured in 18 sepsis patients and 20 acute limb ischemia patients before and after treatment.
• In vitro experiments involved incubating Escherichia coli in human serum to study TCC formation.
• Statistical analysis was performed to compare pre- and post-treatment levels.

Main Results:

• Patients with sepsis or acute limb ischemia exhibited elevated plasma TCC and anaphylatoxin levels prior to treatment.
• Successful treatment led to normalization of these elevated levels within seven days.
• Escherichia coli stimulated TCC formation in human serum in a dose-dependent manner in vitro.

Conclusions:

• Elevated TCC and anaphylatoxin levels are indicative of complement system activation in sepsis and acute limb ischemia.
• Successful treatment correlates with the resolution of complement activation.
• These findings suggest that complement-mediated pathways contribute to the pathophysiology of sepsis and acute limb ischemia.