Circulating Complement C3-Alpha Chain Levels Predict Survival of Septic Shock Patients

Area of Science:

• Immunology
• Critical Care Medicine
• Biochemistry

Background:

• Septic shock can lead to severe complications like hypotension and disseminated intravascular coagulation.
• Complement C3 fragments may play a role, but its exact function is unclear due to limitations in detecting different C3 forms.
• Western blotting offers a method to differentiate C3 forms and assess their clinical relevance.

Purpose of the Study:

• To investigate the relationship between specific circulating complement C3 forms and clinical outcomes in septic shock patients.
• To determine if C3 forms, differentiated by Western blotting, can serve as prognostic markers for survival.

Main Methods:

• Secondary analysis of two prospective septic shock cohorts (discovery n=24, validation n=181).
• Measurement of C3 levels using Western blotting at the time of enrollment.
• Comparison of C3 forms between survivors and non-survivors, assessing independent prognostic value.

Main Results:

• Non-survivors consistently showed significantly lower levels of the C3-alpha chain compared to survivors in both cohorts.
• The C3-alpha chain level remained a significant predictor of survival even after adjusting for the Sequential Organ Failure Assessment score.
• Kaplan-Meier analysis revealed that lower C3-alpha chain levels were associated with significantly reduced survival rates (P < 0.001).

Conclusions:

• Circulating C3-alpha chain levels are a significant and independent predictor of survival in patients with septic shock.
• This finding highlights the potential of C3-alpha chain as a valuable prognostic biomarker in managing septic shock.