IL-6 gene polymorphisms and sepsis in ICU adult Romanian patients: A prospective study

Abstract

Objectives: The goal of the study was to investigate the correlations between the interleukin-6 IL-6 -174 G/C and IL-6 -572 G/C gene polymorphisms and sepsis risk and severity in adult ICU patients. Materials and Methods: We prospectively assessed 107 septic patients and divided them into two subgroups: organ dysfunction-free sepsis subgroup S (n=60) and septic shock subgroup SS (n=47). A control group of 96 healthy individuals was included. Both patients and controls underwent IL-6 -174 G/C and -572 G/C genotyping and circulating IL-6 in the study group which were measured from samples taken in the first day of sepsis diagnosis. Results: No differences in the genotype frequencies of the two polymorphisms between study and control groups were identified. The GC genotype and C allele of IL-6 -572 G/C gene polymorphism was statistically significant more frequent in the organ dysfunction-free subgroup (p=0.01, p=0.004 respectively). No statistically significant differences for the IL-6 -174 G/C gene polymorphism were found between the two sepsis subgroups. Circulating IL-6 levels were significantly higher in the septic shock subgroup and among patients with GG genotypes of both studied polymorphisms. Conclusion: We underline the possible role of IL-6 -572 G/C as a marker of severe evolution. There is no evidence of a direct role of IL-6 -174 G/C gene polymorphism in sepsis risk and outcome. Il-6 levels are correlated with sepsis severity but not with variant genotype of investigated IL-6 gene polymorphisms.