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-alpha) 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-alpha(-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 72h 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 1day (OR=11.80, 95% CI: 1.87-74.48) and hospital staying more than 14days (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.