Interleukin-6 single gene polymorphism in patients with inflammatory bowel diseases.

OBJECTIVE

Our study aimed to evaluate the association between single nucleotide polymorphism of IL-6-174G/C and the disease course in patients with ulcerative colitis (UC) and Crohn's disease (CD).

METHODS

105 patients (aged 18-75 years) with diagnosed inflammatory bowel disease (IBD), 50 with CD, and 55 with UC, were involved in the study. The controls consisted of 124 healthy individuals. In all patients, the following parameters were evaluated: disease duration, location, presence of complications, and past surgical procedures. Morphology, biochemical parameters, fibrinogen, interleukin 6 (IL-6) level, and IL-6 single nucleotide (174 G/C) polymorphism were assessed in all subjects. Associations of those markers with disease activity, location, complications, and inflammatory markers were evaluated.

RESULTS

No statistically significant differences in IL-6 single nucleotide (174 G/C) polymorphism were observed between patients with UC, CD, and controls. In IBD patients with the GG genotype, a higher mean IL-6 level was noticed than in patients with other genotypes (4.685 ± 5.9 vs. 2.715 ± 5.1 in GC and 3.186 ± 3.6 in CC). A positive correlation was found between IL-6 and fibrinogen levels and CRP in UC and CD patients with GG and GC genotypes. In IBD patients with CC genotype, no correlation between IL-6 and fibrinogen was found (p = 0.48).

CONCLUSIONS

The risk of developing IBD appears not connected with IL-6 polymorphism. However, IL-6 variation might influence the course of the disease in UC patients.