Impact of cardiopulmonary bypass surgery on cytokines in epicardial adipose tissue: comparison with subcutaneous fat.
BACKGROUND
Cardiac surgery and cardiopulmonary bypass (CPB) have been shown to stimulate a systemic inflammatory response which has been associated with adverse postoperative outcomes. Adipose tissue, both epicardial (EAT) and subcutaneous (SAT), is a known source of inflammatory cytokines, but its role in the pathophysiology of surgery- and CPB-induced systemic inflammatory response has not been fully elucidated. Therefore, we conducted a study to establish levels of selected cytokines in EAT and SAT prior to and after surgery with CPB.


METHODS
Adipose tissue samples were obtained from patients undergoing planned cardiac surgery on CPB. Samples from EAT and SAT were collected before and immediately after CPB. Levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), adipocyte fatty acid-binding protein (AFABP), leptin and adiponectin were determined by ELISA, which were adjusted for a total concentration of proteins in the individual samples.


RESULTS
Samples from 77 patients (mean age 67.68 ± 11.5 years) were obtained and analysed. Leptin, adiponectin, TNF-α and AFABP were shown to decrease their concentrations statistically significantly in the EAT after CPB while no statistically significant drop was observed in the SAT. On the contrary, IL-6 showed only a slight and statistically insignificant decrease in the EAT after CPB and it was in the SAT where a statistically significant drop was observed.


CONCLUSIONS
One of the most relevant findings of this study was the marked decrease in EAT levels of TNF-α, AFABP, leptin and adiponectin after the CPB termination. Our results suggest that EAT might serve as a pool of cytokines which are released into the circulation in reaction to surgery with CPB. Should these novel findings be confirmed, new strategies to assess and possibly reduce EAT contribution on adverse outcomes of cardiac surgery may be developed.
1 University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.|2 International Clinical Research Centre, St. Anne's University Hospital Brno, Brno, Czech Republic.
Lukas
L
Mach
3 Centre of Cardiovascular Surgery and Organ Transplantation Brno, Brno, Czech Republic.
Helena
H
Bedanova
2 International Clinical Research Centre, St. Anne's University Hospital Brno, Brno, Czech Republic.
Miroslav
M
Soucek
4 Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic.
Michal
M
Karpisek
5 Keck Medical Centre of the University of Southern California, Los Angeles, CA, USA.
Tomas
T
Konecny
2 International Clinical Research Centre, St. Anne's University Hospital Brno, Brno, Czech Republic.|3 Centre of Cardiovascular Surgery and Organ Transplantation Brno, Brno, Czech Republic.
Petr
P
Nemec
3 Centre of Cardiovascular Surgery and Organ Transplantation Brno, Brno, Czech Republic.|4 Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic.
Marek
M
Orban
D000273:Adipose Tissue / Q000378:metabolism*; D000368:Aged; D002315:Cardiopulmonary Bypass / Q000379:methods*; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D010496:Pericardium / Q000378:metabolism*; D050151:Subcutaneous Fat / Q000378:metabolism*
D016207:Cytokines
cardiopulmonary bypass; cytokines; epicardial adipose tissue; inflammation; subcutaneous adipose tissue; systemic inflammatory response