Interleukin 10 promoter region polymorphisms in inflammatory bowel disease in Tunisian population.

OBJECTIVE: To test whether IL-10 promoter region polymorphisms are associated with susceptibility to inflammatory bowel disease, we examined the contribution of interleukin- 10 (IL-10) gene polymorphisms to Crohn's disease (CD) and Ulcerative colitis disease (UC) occurrence and also to CD phenotype. MATERIELS AND METHODS: SNPs at positions -627 (C > A) and -1117 (G > A) in the IL-10 promoter were determined in a sample of 105 Tunisian patients with IBD (75 CD and 30 UC) and 90 matched healthy controls. RESULTS: The 627 CA genotype is associated with ileal location (p = 0.015) and with stricturing (p = 510-3) and penetrating (p = 310-3) presentation of CD. An additive effect between IL10 variants and CARD15 3020 insC mutation (p = 0,006) on severe forms of CD was shown. CONCLUSIONS: In Tunisian population, the 3020insC insertion in NOD2/CARD15 gene is a marker of susceptibility to CD, while the A allele at position -627 in the IL-10 promoter increases the risk of CD ileal location and severe disease presentation. A genetic epistasis between IL-10 gene polymorphisms and CARD15/NOD2 gene mutation was suggested.

3020insC insertion in NOD2/CARD15 gene, a prevalent variant associated with anti-Saccharomyces cerevisiae antibodies and ileal location of Crohn's disease in Tunisian population.

OBJECTIVE: Our aim is to investigate the relation between CARD15 3020insC mutation, anti-Saccharomyces cerevisiae antibodies (ASCA) and disease phenotype, in Tunisian inflammatory bowel disease (IBD) patients. MATERIALS: A hundred Tunisian patients with IBD (75 Crohn's disease CD and 25 ulcerative colitis UC) and 60 matched healthy controls were studied. METHODS: CARD15 mutation was analysed by using an allele-specific polymerase chain reaction and sequencing. Assessment of ASCA in serum was performed by ELISA. RESULTS: The frequency of the mutation was significantly higher in Crohn's disease than in control (p = 0,0005; OR = 20.45; CI 95% = 2.86-413.85) and did not differ statistically in UC group (p = 0, 05) from control. ASCAs were present in 60% of CD and 20, 8% of UC. CONCLUSION: This study suggests that in northern Tunisian population, 3020insC mutation in NOD2/CARD15 gene is a prevalent mutation leading to the typical Crohn's disease including ileal location, stricturing and penetrating clinical types and ASCA expression.