Association of Interleukin 6 Promoter Polymorphism (-174G/C) with IL-6 Level and Outcome in Severe Sepsis

Interleukin (IL-6) is a key cytokine in the pathogenesis of severe sepsis. The importance of a regulatory polymorphism within the IL-6 promoter remains unclear in these patients. The aim of the study was to determine if IL-6 (-174 G/C) promoter polymorphism has an effect on IL-6 plasma level and outcome of severe sepsis. The study was conducted in general ICU of Stradiñš Clinical University Hospital. A total of 103 critically ill patients with confirmed severe sepsis were prospectively included. Association analysis of the IL-6 (-174C) allele with serum level and clinical outcome was performed. We found no differences in genotype distribution between survivors and nonsurvivors. The serum IL-6 level was significantly higher in nonsurvivors compared with survivors. We found an association of genotype with the IL-6 level in nonsurvivors, but not in survivors. Our findings show a functional significance of IL-6 promoter polymorphisms in nonsurviving severe sepsis patients.