The −251A>T polymorphism of interleukin-8 is associated with longer mechanical ventilation and hospital staying after coronary surgery

Background: Cardiac surgery is associated with inflammatory responses that are known to affect its outcome. The present study was designed to define whether post-operative release of interleukin (IL)-6, 8 and tumor necrosis factor-alpha (TNF-α) is related to the presence of a certain allele in functional polymorphism and its relationship to clinical outcome after off-pump coronary artery bypass (OPCAB). Methods: One hundred and forty-five patients undergoing first time elective OPCAB were genotyped for IL-6(−174G>C), IL-8(−251A>T) and TNF-α(−308G>A) polymorphisms using polymerase chain reaction (PCR) and gene sequencing. Cytokine levels were measured in plasma samples taken before the operation and 4, 24 and 72 h postoperatively by suspension array system. Results: Levels of IL-6 and IL-8 increased significantly after OPCAB. Patients with IL-6−174GG and IL-8−251AA genotypes had higher post-operative circulating levels of IL-6 and IL-8, respectively. Logistic regression showed that IL-8−251AA genotype was an independent risk factor of ventilation time more than 1 day (OR = 11.80, 95% CI: 1.87-74.48) and hospital staying more than 14 days (OR = 38.00, 95% CI: 4.15-347.87) after surgery. Conclusions: OPCAB results in post-operative inflammatory responses. Genetic backgrounds alter the extent of inflammatory response and might relate to clinical outcome of OPCAB.