Association of IL-10 promoter polymorphism -1082 G/A with adverse outcome in severe sepsis and septic shock

Introduction

IL-10 is an anti-inflammatory cytokine with pleiotropic effect in immunoregulation and inflammation. Several recent papers reported association of the IL-10 -1082G allele with adverse outcome in sepsis [1, 2]. The study objective was to investigate whether IL-10 promoter polymorphism -1082 G/A is associated with adverse outcome in severe sepsis and septic shock patients.

Methods

The study was conducted in the mixed medical–surgical adult ICU of P. Stradinš Clinical University Hospital in Riga in 2007 and 2008. A total of 103 critically ill patients who met the proposed severe sepsis and septic shock criteria were included. The IL-10 -1082 polymorphism was genotyped by sequencing. All patients were followed up throughout their stay in the ICU to clinical outcome. The frequency distributions of the genotypes in the subgroups were compared using the Pearson chi-square test. P < 0.05 was considered to indicate statistical significance.

Results

Of the 103 patients observed, 44 (43%) had an adverse outcome in the ICU. In the survival group 11 (19%) had G/G at position -1082 of the IL-10 gene, 25 (42%) were heterozygous G/A, and 23 (39%) were homozygous A/A. In the nonsurvival group five (11%) had G/G, 30 (68%) had A/G, and nine (21%) had the A/A genotype. The polymorphism frequencies between survival and nonsurvival differed significantly (P = 0.034, χ² = 6.8). The relative risk for adverse outcome in IL-10 -1082 alternative G allele carriers (G/G and G/A genotypes) was 1.6 (95% CI = 0.91 to 2.83).

Conclusion

We found association of the IL-10 promoter polymorphism -1082 G/A with clinical outcome in severe sepsis and septic shock patients; alternative -1082 G allele carriage seems to be associated with greater risk for adverse outcome in the studied patient population.