Predictive value of IL-18 and SC5b-9 for neurocognitive dysfunction after cardiopulmonary bypass.
BACKGROUND
Neurological injury after cardiopulmonary bypass (CPB) continues to be a major problem after cardiac surgery. The aim of this study was to investigate the predictive value of Interleukin-18 (IL-18) and SC5b-9 as biochemical markers of neurocognitive dysfunction after cardiac surgery.


METHODS
A total of 30 patients undergoing elective cardiac surgery using CPB were recruited. Blood samples were obtained for IL-18 and SC5b-9 concentrations before induction, 24, 48, 72, 96 and 120 h post-CPB and 6 weeks after operation. In addition, patients underwent a standard battery of neuropsychometric tests before operation and at day 5 and 6 weeks after operation.


RESULTS
Serum concentration of IL-18, but not SC5b-9, was significantly different between patients with and without neurocognitive dysfunction; serum IL-18 concentration significantly increased in patients with neurocognitive dysfunction (P = 0.018). Neurological outcome was significantly dependent on peak difference in IL-18 concentration at day 5 (P = 0.033), but not on peak difference in SC5b-9 concentration (P = 0.16). Eight patients had neurocognitive dysfunction at day 5 and three had neurocognitive dysfunction at 6 weeks. In a very small number of patients, no significant association was demonstrated between IL-18 or SC5b-9 concentrations and neurocognitive dysfunction at 6 weeks.


CONCLUSIONS
IL-18 has the potential as a useful marker of neurological dysfunction, requiring further investigation.
Kumar
R A
RA
Department of Anaesthetics and Intensive Care Medicine, Wales College of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK. arunkumar@btinternet.com
Cann
C
C
Hall
J E
JE
Sudheer
P S
PS
Wilkes
A R
AR
D000368:Aged; D015415:Biomarkers / Q000097:blood; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D003072:Cognition Disorders / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D015938:Complement Membrane Attack Complex; D003165:Complement System Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D020382:Interleukin-18 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011184:Postoperative Period; D011237:Predictive Value of Tests
D015415:Biomarkers; D015938:Complement Membrane Attack Complex; D020382:Interleukin-18; C047610:SC5b-9 protein complex; D003165:Complement System Proteins