A variant of the gene for the inflammatory modulator interleukin (IL)-18 has been found to be associated with a prolonged ICU stay after cardiopulmonary bypass (CPB) surgery. New research links the TT genotype of the IL-18 9545 T/G polymorphism with a larger pro-inflammatory response.
Professor Keith Walley worked with a team of researchers from the University of British Columbia, Canada, to investigate associations between the IL-18 haplotype and post-surgery inflammatory phenotype in 658 patients undergoing CPB. He said, "Inflammatory gene polymorphisms have been linked to the intensity of the post-operative inflammatory response and to clinical outcomes after CPB surgery. Here, we've found an IL-18 variant that is associated with increased IL-18 levels and adverse outcomes."
IL-18 is known to increase levels of the pro-inflammatory cytokine TNF-α, while reducing levels of the anti-inflammatory IL-10. The TT genotype of the IL-18 9545 T/G polymorphism is believed by the authors to cause an increase in expression of IL-18. Their research confirmed this mechanism and, according to Walley, "The resulting inflammatory response may account for the adverse clinical outcomes associated with the TT genotype post-surgery".
In the cohort studied, the TT genotype was carried by 58% of the subjects, 34% were GT and 8% were GG. Apart from a small difference in body mass index, there were no significant differences in baseline characteristics between the groups.
This research was funded by The Canadian Institutes of Health Research (CIHR).
Cite This Page: