Clinical parameters of inflammatory bowel disease in children do not correlate with four common polymorphisms of the transforming growth factor β1 gene.

Transforming growth factor β1 (TGF-β1) is a cytokine affecting cell proliferation and development, which also has an immunomodulatory activity. Correlations between polymorphisms of the TGF-β1 gene and clinical parameters of inflammatory bowel disease (IBD) were reported previously in adults. Here, we tested whether such correlations occur in pediatric patients suffering from IBD. One hundred and four pediatric IBD patients were involved in this study. Among them, 36 were diagnosed with Crohn's Disease (CD) and 68 were diagnosed with ulcerative colitis (UC). The control group consisted of 103 children, in which IBD was excluded. TGF-β1 levels were determined in plasma and intestinal mucosa samples. The presence of the TGF β1 protein and the amount of TGF β1 mRNA were estimated in intestinal mucosa by immunohistochemistry and reverse transcription Real-Time PCR, respectively. Four common polymorphisms of the TGF-β1 gene were investigated: -800G/A, -509C/T, 869T/C and 915G/C. No significant correlation between TGF-β1 genotypes and (i) TGF-β1 levels in plasma and tissue samples, (ii) TGF-β1 gene expression efficiency in intestinal mucosa, (iii) IBD clinical parameters and (iv) inflammatory activity could be detected in children suffering from IBD. We conclude that, contrary to previous suggestions, the four common polymorphisms of the TGF-β1 gene do not influence the susceptibility to or clinical parameters of IBD in the tested population of children.