Complement (C3, C4) and C-reactive protein responses to cardiopulmonary bypass and protamine administration
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Published on: March 23, 2018
M Tulunay1, S Demiralp, S Tastan
1Department of Anaesthesiology, Ibn-i Sina Hospital, University of Ankara, Turkey.
Insights
Cardiopulmonary bypass (CPB) activates the complement system, primarily via the classic pathway, without significantly altering C-reactive protein (CRP) levels during the procedure. Protamine administration did not further activate complement.
Area of Science:
- Immunology
- Cardiovascular Surgery
Background:
- Complement activation is implicated in cardiopulmonary bypass (CPB)-associated damage during open heart surgery.
- The study investigates complement system components C3, C4, and C-reactive protein (CRP) in patients undergoing CPB.
Purpose of the Study:
- To assess the impact of CPB and protamine administration on complement activation.
- To evaluate changes in C3, C4, and CRP levels during and after CPB.
Main Methods:
- Studied 22 patients undergoing CPB, divided into two groups based on protamine administration route (intravenous vs. aortic root).
- Measured serum levels of C3, C4, and CRP at various time points.
Main Results:
- Significant decreases in C3 and C4 observed during CPB, indicating classic pathway activation.
- Protamine did not induce further complement activation.
- C3 levels normalized within 24 hours post-CPB, while C4 remained lower.
- CRP levels showed no significant change during CPB but increased 24 hours post-operation.
Conclusions:
- CPB activates the complement system, but the duration may not be sufficient to trigger an acute phase response indicated by CRP increase.
- Protamine administration does not exacerbate complement activation in this context.
Abstract:
Complement activation has been deemed responsible for the damaging effects of cardiopulmonary bypass (CPB) in patients undergoing open heart surgery. We studied C3, C4 and C-reactive protein (CRP) in 22 patients undergoing CPB. In Group 1 (11 patients), protamine was given intravenously and in Group 2 (11 patients), via the aortic root after CPB. Significant decreases were observed in C3 and C4 during CPB in both groups indicating complement activation primarily by the classic pathway. Protamine did not lead to further activation of the complement system. In both groups, C3 levels gradually returned toward baseline within 24 hours but C4 levels were still lower than baseline 24 hours postoperatively. CPB and protamine administration did not cause any significant changes in CRP levels, but CRP increased abruptly 24 hours after operation. Although activation of complement system during CPB is expected to invoke an acute phase response, we conclude that this period is not long enough to induce an increased production of CRP in response to tissue injury or inflammation.
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