The Relationship Between Serum Concentration of Interleukin-35 and FoxP3 Polymorphism in Patients Undergoing Coronary Artery Bypass Graft Surgery

Objective: To investigate the association between interleukin-35 (IL-35) levels and single nucleotide polymorphisms (rs3761548, rs3761547) of the FoxP3 gene in coronary artery bypass grafting (CABG) patients. Methods: We conducted a prospective study including 140 patients, who were scheduled for elective isolated on-pump CABG with cardiopulmonary bypass (CPB) from January 2017 to September 2018 in the Jorjani heart center. Blood samples were collected before and 12 hours after the operation. Serum levels of IL-35 were measured by enzyme-linked immunosorbent assay and the pattern of genetic variations was assessed using single specific primer-polymerase chain reaction. Results: The serum concentrations of IL-35 after surgery were significantly higher than pre-surgery levels (18.4 +/- 8.3 vs. 9.89 +/- 3.2, respectively, P=0.002). There was no significant association between genotype frequencies of rs3761548 and rs3761547 and elevated IL-35 levels (P>0.05). There were significant associations between IL-35 levels and preoperative variables, including age (r=-0.34, P=0.047) and body mass index (r=-0.41, P=0.045), and intraoperative variables, including CPB time (r=0.4, P=0.02) and mean arterial pressure (r=0.38, P=0.046), in carriers of the rs3761548 AA genotype. Conclusion: Serum IL-35 concentrations were significantly increased in CPB patients, which may contribute to the post-CPB compensatory anti-inflammatory response syndrome. IL-35 increased levels were not influenced by FoxP3 promoter polymorphisms (rs3761548, rs3761547).